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Report Number: MIS 8908001

t rF, j REMOTELY OPERATED VEHICLE ROV/AUV

AD-A240 672 RELIABILITY STUDY

1 1111 I' HI PHASE II FINAL REPORT

Kurt L. Smrcina / John Perry Fish

Marine Imaging Systems, Inc.8 Otis Park DriveBourne, MA 02532

September, 1989

FINAL REPORTN00014-87-C-0728

Prepared for:

Office of Naval Research (Code 122)Department of the Navy800 N. Quincy StreetArlington, VA 22217 91-11147

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REMOTELY OPERATED VEHICLE (ROV) RELIABILITY STUDY; SEPTEMBER 1989SFINAL REPORT

KURT L. SMRCINA; JOHN PERRY FISH MIS 89

MARINE IMAGING SYSTEMS, INC.8 OTIS PARK DRIVE 'c u Qrmng "

BOURNE, MA 02532 ' N00014-87-C-0728

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OFFICE OF NAVAL RESEARCH (CODE 122)

DEPARTMENT OF THE NAVY FINAL REPORT800 NORTH QUINCY STREETARLINGTON. VA 22217

ONR COTR CAPT. D. KOCZUR (202) 696-4713KURT L. SMRCINA (508) 759-1311

A REMOTELY OPERATED VEHICLE (ROV) RELIABILITY STUDY WAS INITIATED IN TWO

PHASES TO DETERMINE HOW ROVs CAN BE DESIGNED AND BUILT TO ACHIEVE ENHANCED

OPERATIONAL RELIABILITY WHEN OPERATED DURING EXTENDED UNDERWATER DEPTOYMFN7.THE CONTRACTOR WAS TO EXAMINE THE TEGHNOLOGY USED IN THE DESIGN AND

CONSTRUCTION OF REPRESENTATIVE ROVs IWHICH ARE CURRENTLY STATE-OF-THE-ARTAND DOCUMENT PROPOSED DESIGN OR CONSTRUCTION METHODOLOGY TO EFFECT HIGHRELIABILITY. THIS REPORT IS THE CONTRACT FINAL REPORT OF THE PHASE I

STUDY EFFORTS AND PHASE II STATEMENT OF WORK (SOW) DEVELOPMENT.

THE RESULTS OF THE PHASE I STUDY WERE COMPILED AND DETAILED IN THE STUDY

REFORT (DELIVERED SEPARATELY). IT WAS RECOMMENDED THAT EFFORTS SHOULD BE

INITIATED UP FRONT TO DEVELOP TECHNOLOGICAL APPROACHES AND DESIGN ANDMANUFACTURING CRITERIA TO ADDRESS THE LONG TERM RELIABILITY PROBLEMSIDENTIFIED IN THE STUDY. A PRIORITIZED LISTING OF RECOMMENDED THEORECTICAl

AND EXPERIMENTAL WORK WAS DEVELOPED FROM THE STUDY RESULTS AND FORWARDEDIN THE FORM OF A PROPOSAL FOR PHASE II TASKING APPROVAL.

REMOTELY OPERATED VEHICLES (ROV)

AUTONOMOUS UNDERWATER VEHICLES (AUV)UNMANNED UNTETHERED VEHICLES (UUV)

TETHERED VEHICLES, UNTETHERED VEHICLES, RELIABILITY

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UNLIMITED UNCLASSIFIED

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Report Docamnw- :-3t

REPORT DOCU MENTATION

PAGE 2

THE PHASE II TASKING WAS APPROVED BY THE SPONSOR AND SOWs WERE DEVELOPED FOR THETECHNICAL AREAS OF INTEREST.

THE RESULTS OF THE PHASE I1 SOW DEVELOPMENT ARE PROVIDED AS APPENDICES TO THISREPORT. IT WAS INTENDED THAT THE SOWs DEVELOPED IN PHASE Ii WOULD BE USED 1O

GENERATE SOLUTIONS IN THE FORM OF RELIABILITY DESIGN SPECIFICATIONS, VIDELT_-ES

AND DOCUMENTATION FOR THE PROBLEMS.

IN A FOLLOW-ON EFFORT, THE CONTRACTOR WILL PROVIDE EXPERT TECHNICAL PERSO >'vL,

MATERIALS, AND FACILITIES NECESSARY TO SUPPORT EXECUTION OF THE INDIVIDUALCONTRACTS FOR THE SOWs.

TABLE OF CONTENTS

I. Executive Summary ................................. 1

II. Acknowledgements .................................. 3

III. Introduction ...................................... 4

IV. Statement of Work (SOW) Development Methodology... 3

v. Manufacturer List Development Methodology ......... 15

VI. Conclusions/Recommendations ........................... 13

Appendix A. Statements of Work (SOW)

Appendix B. Expert Data Base

Appendix C. Technical Review Board

Appendix D. Bibliography

Appendix E. Distribution

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I. EXECUTIVE SUMMARY

A Remotely Operated Vehicle (ROV) reliability study wasinitiated in two phases to determine how ROVs can bedesigned and built to achieve enhanced operationalreliability when operated during extended underwaterdeployment. The contractor was to examine the technologyused in the design and construction of representative ROVswhich are currently state-of-the-art (Phase I) and documentproposed design or construction methodology to effect highreliability (Phase II). This report is the final report ofthe contract, focusing on the Phase II Statement of Work(SOW) development. The Phase I study report was deliveredpreviously.

The Phase I study results revealed that the process ofdevelopment and procurement of ROVs for Navy use presentlyinvolves modification of off-the-shelf commercial vehicles.Long term reliability is not a design criterion forcommercial vehicles and is certainly lost in the developmentprocess due to cost competition. As a result, commercial-grade vehicles with broad applications are modified forspecific requirements. These vehicles have reliability andother problems as described in detail in the Phase I studyreport.

Present state-of-the-art ROVs cannot be modified to meet thereliability requirements of extended deployment vehicles.Develcpment of a highly reliable long term deploymentvehicle requires the rigorous use of a thorough developmentprocess. Experts in the field recommend that simultaneouslywith vehicle development, efforts should be initiated upfront to develop technological approaches and design andmanufacturing criteria to address the long term reliabilityproblems identified in the study.

The results of the Phase I study were compiled and detailedin the Phase I study report. A prioritized listing ofrecommended theoretical and experimental work to improvevehicle reliability was developed from the study results andforwarded in the form of a proposal for Phase II taskingapproval.

The approved Phase II tasking resulted in the development ofSOWs for each of the technical areas of interest. The SOWsare provided herein as Appendix A. Two lists were alsogenerated, one of manufacturers known to produce qualityunderwater connectors and another of manufacturers known toproduce quality syntactic foam. These lists were providedto the Government under separate cover.

This final report, specifically Sections IV and V, describeshow the SOWs and lists were derived, and details theinteraction with the experts during list development. Theresultant SOWs are included as appendices to this report.(The Contract Data Requirements List (CDRL), form DD1423,and Figure (1) to the SOWs, Acoustic Noise Levels, will beprovided by the Government). It was intended that the SOWsdeveloped in Phase II would be executed vid contracts togenerate solutions in the form of reliability design andspecification guidelines for each of the problems.

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II. ACKNOWLEDGEMENTS

The contractor would like to acknowledge the assistance ofthe following people in identifying experts in varioustechnical fields:

Mr. Theodore AustinNUWES, Keyport, WA

Mr. Dennis HurstHoneywell Inc.

Dr. Colin SandwithApplied Physics LabUniversity of Washington

Dr. Robert SpindelDirector, Applied Physics LabUniversity of Washington

Dr. Robert WernliNOSC, San Diego, CA

Mr. Jeffrey Wilson,Naval Civil Engineering Laboratory

A list of the many technical personnel contacted and whoparticipated during the course of this contract are listedin Appendix B.

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III. INTRODUCTION

1. Summary

A Remotely Operated Vehicle (ROV) reliability study wasinitiated in two phases to determine how ROVs can bedesigned and built to achieve enhanced operationalreliability when operated following extended underwaterdeployment. The contractor was to examine the technologyused in the design and construction of representativestate-of-the-art ROVs and document proposed design orconstruction methodology to effect high reliability. Theresults of the contractor's Phase I study effort isdocumented in reference (a).

The result of the Phase I study was a prioritized listing ofrecommended theoretical and experimental work for Phase IItasking approval.

The Phase II approved tasking included the preparation ofStatements of Work (SOWs) for each technology area ofinterest to the government. The purpose was to address eachof these technology areas thoroughly and to define theproblems for generation of SOWs. The SOWs would be used todevelop design guidelines, specifications and documentationfor the ROV design engineers. The technology areasrequiring the generation of SOWs were:

1. Hydraulics2. Seals3. Suspect Manufacturing Processes4. Variable Ballast5. Buoyancy Materials6. Tether Assemblies7. Dry Connectors8. Magnetically Coupled Thrusters

In addition to the generation of SOWs, two lists, one toidentify Reliable Connector Manufacturers and the other toidentify reliable Syntactic Foam Manufacturers was requestedby the government. These lists were provided under separatecover.

The SOW development methodology is described in Section IV.The methodology used to generate the manufacturers list isdescribed in Section V.

2. Program Overview

2.1 Description of Work

The program was a two-phased study contract to determinehow Remotely Operated Vehicles (ROVs) can be desianed orbuilt to achieve reliability of 0.98 or better when

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operated during extended underwater deployment. Thecontractor was to examine the technology used in thedesign and construction of representative ROVs which arecurrently state-of-the-art (e.g. the Perry OffshoreSystems' TRITON or AMETEK's SCORPIO) and documentproposed design or construction methodology to effecthigh system reliability. The ROV system includes thelaunch, recovery and storage system, power and controlcables and the tether storage and management subsystemthat would be required to support the ROV when installedon platforms from which the ROV would be deployed.

2.2 Program Description

The contract for the study consisted of two phases: thefirst to review the design, manufacturing processes,maCerials used, sensors, lights, cables, connectors,handling systems and electronic component reliability ofROV systems; and the second, to develop, recommend anddocument specific design and manufacturing methodologiesto use, or to change current practice as necessary toachieve the desired reliability. To satisfactorilycomplete this work, the contractor used consultants whoare experts in the various ROV components and subsystems.The deliverable from the contract was to be acomprehensive technical report detailing technologicalapproaches and design and manufacturing criteria todesign, construct, and operate an ROV system having thedesired reliability.

2.3 Program Modification

During the conduct of the Phase I study it becameapparent that development of detailed technologicalapproaches and design and manufacturing criteria todesign, constcuct, and operate an ROV system havinq tnedesired reliability was an inappropriate next step ana anadditional step was required in the development process.The additional effort required definition of the problemsin sufficient detail so SOWs could be generated. TheSOWs could then be awarded as contracts to have thedetailed technical approaches developed, and design andmanufacturing criteria generated. This additional stepwas approved and has required a follow-on Phase III toexecute the SOWs generated in Phase II.

2.4 Deliverables

The contractor provided a written report at the end ofPhase I which was accepted and approved by the governmentprior to proceeding to Phase II. This document serves asthe final report required at the conclusion of Phase IIefforts. A program plan was developed for each -rogr~nph&se (delivered separately). Oral and written progress

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reports were made as necessary during the conduct of thiscontract. A detailed description of the methodology forconduct of Phase I was included in the Study Report,reference (a). The methodology for the conduct of PhaseII and the deliverable SOWs are included in this, theFinal Report.

3. Reliability Study Discussion

3.1 The state-of-the-art and maturity of the ROV marketwith regard to the US Navy, has led to the U.S. Navy'suse of commercial grade broad application vehicles thathave been modified for specific requirements. Long termreliability is not a design criterion and is certainlylost in cost competition. Vehicles are reqaired tooperate for hours, not weeks; these ROV can be easilyretrieved and repaired, if necessary. Extensivemaintenance is performed between the short operationalperiods. Present state-of-the-art ROVs cannot bemodified to meet the requirements for reliability :fextended deployment vehicles. Instead, a vehicle willhave to be developed to meet the stringent requirementsfor extended deployments.

3.2 To develop a highly reliable, long-term deploymentvehicle requires the rigorous use of a thoroughdevelopment process. This process should includerequirements definition, prototype design and developm.entthough full scale engineering development, and theassociated test programs to ensure that the prouct beingdeveloped will meet the system design requirements.

3.3 The Phase I study identified several reliabilityproblem areas Lhat needed to be addressed. A thoroughassessment of those problems along with identification ofsolutions would ensure that the reliability problemswould be ddequately addressed in any vehicle develop-t-.

3.4 A synopsis of the reliability problems consideredsignificant for a future long-tetin exposure system showsthat solutions would affect both the design and themanufacturing processes.

All of these problems must be addressed in order to bringan ROV system to a state of high reliability. In amajority of cases, however, this design for increasedreliability will be at the ex:pense of ease ofmaintenance. In most design changes tc increasereliability, Mean Time Between Failures (MTBF) figuresand those for the Mean Time To Repair (MTTR) are relatedin that an increase in the time between failures willincrease the time required to repair the system.

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Both simplicity of design and operational requirementsare closely related to reliability. The more complex thesystem becomes and the more varied its requirements, themore unreliable it will become.

In conclusion, of the reliability problems identified inthe Phase I study, the government chose to pursue thedetailed investigation and development of Statements ofWork for seven of them. The purpose of this report is todetail how the problems were addressed and how theStatements of Work were developed (Section IV). Themethodology for development of the two lists is alsoincluded (Section V). This report provides the vehiclefor forwarding the approved Statements of Work. TheManufacturers lists were provided to the Government underseparate cover.

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IV. STATEMENT OF WORK (SOW) DEVELOPMENT METHODOLOGY

1. Approach

The following is a description of the process by which theStatements of Work were generated:

1.1 The individual task problems were defined ascompletely as possible using inputs from expertsidentified during the Phase I study. The expert database list was expanded during Phase II after discussionsAnH meetings with persons identified to us as the expertor experts in the technological area of interest. Usin-gthese experts, the individual task problems were furtherconfirmed as problems for the high reliability Ro'designer. This confirmation process resulted in on!y oneof the original problems being reclassified as a non-problem (dry connector failure from vibration) by theexperts. The decisions were Lupported by the technicalreview board.

Through a variety of meetings, telephone contacts and on-site visits, the contractor developed specific problemdefinitions as well as specific potential solutions tothe problems. Visits to experts located across thenation were necessary to discuss the problems andpotential solutions for development of the Statements ofWork. Included were meetings with NOSC fr discussionson all eight problem areas, Gianinni Institute fordiscussions on magnetically coupled thruster assemblies,Harbor Branch Foundation for discussions on connectorsand variable ballast systems, University of WashingtonAPL for discussions on all eight problem areas, NCEL fordiscussions on tethers and connectors, Woods HoleOceanographic Institution for discussions on all eightproblem areas, NUWES for discussions on all eight problemareas, Brantner Sea Con, Impulse, D.G. O'Brien,Envirocon, Burton, for discussions on connectorreliability, Rochester Corporation concerning tethers andconnectors, Coors Ceramics for discussions onalternatives to the use of syntactic foam, CumingCorporation, W. R. Grace, and Flotation Technologies fordiscussions on limitations of syntactic foam.

1.2 The detailed task nroblem3 generated in Section 1.1were used by the contractor in developing the individualSOWs. After internal review, each draft SOW was reviewedby the respective Technology Review Board (TRB)member(s). The TRB consisted of expert(s) considered themost knowledgeable in their field and available. Theirexpertise was used to guide the development of the finalSOWs. It should be noted that significant effort wasmade to ensure that both the experts and the TRB

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member(s) were thoroughly indoctrinated with regard tothe requirements and objectives of the contract. As aresult, we found our experts and TRB member(s) verysupportive of the SOW development and the Navy's effortto address technology reliability problems up front,prior to vehicle design. We feel this enthusiasm isreflected in the quality of the efforts put forth by theexpe:ts and TRB member(s). The ROV technical experts andTRB members are identified in Appendices B and C,respectively.

1.3 The developed SOWs were forwarded to the governmentfor internal review and comment. On receipt of thecomments, the necessary changes were incorporated intothe SOWs. The final SOWs are forwarded as Appendix A tothis Final Report. The Contract Data Requirements List(CDRL) form DD1423, and Figure (1) to the SOWs will beprovided by the Government.

Major comments from government reviewers included theirdesire to include AUVs in the effort and to modify thedesign depth guidelines to include 3,000 feet and 20,000feet.

1.4 During development of the SOWs, pertinent comments,technical inputs and general information were acquiredfrom the experts which had direct bearing and inputs onhow the SOWs were structured. These comments, technicalinputs and information are considered important and areprovided here as insight into the development of theSOWs.

1.4.1 Hydraulics Statement of Work

In developing the Statement of Work to solve chronichydraulic system problems, the approach was reasonablystraightforward. Although the problems are classic andgeneric to many hydraulic systems existing today, theexperts developing the problem definitions focused onhighly specialized aspects of hydraulic systems. Forthis SOW, the technical review board had considerableinput.

1.4.2 Seals Statement of Work

As in hydraulics, the seals SOW was reasonablystraightforward; however, the seal problem is verybroad and includes static, rotary, and sliding seals,each of which requires a separate definition/solution.The broad nature of this SOW required a variety ofexpert input in order to accomplish precise problemdefinition.

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1.4.3 Suspect Manufacturing Processes Statement ofWork

The structuring of this SOW was difficult and it soonbecame apparent that the contracting approach beingutilized for execution of the other SOWs wasinappropriate in this effort. The developer of thesuspect manufacturing processes list had to be anuninterested third party able to interface with themanufacturers providing inputs. To accommodate thisapproach, an SOW was generated for implementation byMarine Imaging Systems. The planned approach is asfollows:

Marine Imaging Systems would contact those majormanufacturers who have provided work vehicles to thegovernment, who have production facilities and who haveexperience with production runs of medium and largesized remotely operated vehicle systems. Thesecontractors would be requested to compile a list of ROVreliability problems they or their users haveexperienced that have resulted from past or presentmanufacturing errors or faulty production design.Participation in the error identification effort wouldbe encouraged by offering manufacturers the results ofthe effort.

Marine Imaging Systems would compile those lists ofreal and potential errors as supplied by themanufacturers and form a matrix of errors, causes andrecommendations/solutions. The deliverable from MarineImaging Systems would be an outline of manufacturingerrors and production design faults that have causedreliability problems for ROV systems in the past.

The list would be cross-referenced so that the designerand/or manufacturer of high reliability vehicle systemswill be able to draw from it to help in preventingsimilar problems in future manufacturing processes. Inorder to protect the participating manufacturers whoare providing the information, MIS would organize theinformation not by manufacturer but rather by the majorvehicle categories. The list would also be sanitizedfor the protection of the individual manufacturers.Emphasis would be placed on identifying errors ratherthan those who experience them.

1.4.4 Variable Ballast Statement of Work

During Phase I of the study, emphasis had been placedon 1500 psi ROVs for variable ballast systems. DuringPhase II when 3,000 and 20,000 foot systems were to beconsidered it was realized that each of these depthswould require its own unique approach. It was

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discovered during Phase II that most of the VariableBallast systems in use today for the deeperapplications were designed in the early 1970's and manyof the parts are obsolete and no longer manufactured.This new problem was also taken into consideration indeveloping the Variable Ballast SOW.

1.4.5 Buoyancy Materials Statement of Work

During early phases of research on the BuoyancyMaterials SOW there were indications that the problemdescribed in Phase I may have become obsolete, howeverfurther investigations showed that there was really nousable specification for quality syntactic foam forgovernment applications. Further, the specificationsin existence were outdated and, today, higherperforming foams are in use. It was realized thatthere is a need for both design recommendations as wellas specifications for high reliability foams.

1.4.5.1. Additional Tasking (Functional Alternativesto Syntactic Foam)

The Syntactic Foam task, to develop a Statement ofWork, requested that MIS present alternative effortsthat are ongoing to design pressure hulls frommaterials that would not require the use of syntactic.Our investigations were only into the unclassifiedactivities of R&D efforts. Although some aspects ofwork underway at Coors Ceramics in Golden, CO werecorporately classified, we were able to judge the stateof the technology from a conceptual standpoint.

Historically, syntactic foam used for flotation onunderwater structures has exhibited reliabilityproblems over the long term. In an effort to find amore suitable solution to underwater systems buoyancy,a number of avenues have been explored. The mostpromising to date has been the elimination of anyrequirement for buoyancy by designing the structuralcomponents of the underwater system from lightweightmaterials. Classically, materials with a low weight todisplacement ratio (light weight) have had lowstrength, even when designed into structures in such away as to maximize strength (interior or exterior ribstiffening, lamination, etc.). New materials,specifically ceramics and Filament Wound Epoxy (FWE)composites have undergone extensive R&D and testing inan effort to produce workable configurations for largediameter cyl nders strong enough to survive highcompression forces.

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1.4.5.1.1 Composites

Although FWE technology is not immature, most pastapplications for it have been in the aerospace industrywhere high compressive forces on cylinders are nottypically found. One of the first major steps inutilizing reinforced resins in a pressure hull on acommercial submarine was made by a British firm,Slingsby Engineering Ltd., by the construction ofseveral manned submersibles including a 21 ton lockoutboat (LR5), from glass filament wound cylinders. Sincethe main cylinder in manned submersibles is typicallylarge diameter, and the interior is only partiallyfilled with equipment, these systems requiresubstantial ballast loads. The same is not expected tobe true for unmanned vehicles where functionaldiameters will be far less with smaller electronics andequipment densities.

The major limitation to composite hulls appears to betheir low resistance to abrasion and shock.Delamination of the materials, resulting in significantstructural weakening, has been the major effect ofshock.

More recent experiments in Filament Wound Epoxy (FWE)cylinders under hydrostatic pressure have shown wallfailure beginning with delamination due to the exposureof cylinder wall ends to hydrostatic pressure as well.Although this problem may be solved with wall-endtreatment or sophisticated "outside-seal" endcapdesigns, the manufacturing process is not asstraightforward as with some other materials.

Of the two materials now being used for the highstrength component in composite structures (graphiteand glass), FWE using glass fibers appears to bestronger, albeit heavier, in formulation whereapproximately 70% fiber content is used. Althoughgraphite fibers result in more costly manufacturingprocesses and are lighter, they may be preferable overglass in applications where maximum buoyancy isrequired.

Recent experimentation with hybrid compositesconstructed from both glass and graphite FWE appear tohave very attractive weight to displacement ratios.However, further testing is required to determine thesuitability of these hybrid composites in environmentswhere abrasion and shock loading will be found.

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1.4.5.1.2 Ceramics

For decades, ceramics cylinders constructed fromPyroceramtm, alumina, zirconia and silicon carbide havehistorically been viewed with potential for use aspressure hulls, yielding high strength and a low weightto displacement ratio. However, even more thancomposites, these materials are susceptible to damagefrom shock. There are man, different formulae forceramic materials and ong. ing experimentation mayprovide more shock resistant materials. Although theJapanese have been applying ceramics to underwaterbuoyancy spheres for over 15 years, the actalapplication of these materials as cylinders in themarine environment is relatively immature. Some of thetechnological limitations in ceramics involve controlof tolerances when manufacturing large diametercylinders, although ongoing R&D may provide solutionsto this.

The major limitation to the ceramic designs forpressure hulls still appears to be shock. In purecompression, ceramic cylinders posses extremely highstrength and even more so in a spherical configuration.However, the materials used to date have a limitedcapacity to withstand shock, failing most often byspalling, chipping or cracking.

1.4.5.1.3 Overview

There appears to be, at the present time, an industrycapacity limit to both FWE and ceramic cylinders foruse in large diameters applications. Further thereappears to be technology limitations to both conceptsbut significant funding is urging further technologicaldevelopments at a rapid pace.

These developments may provide hull structures thatwould eliminate the requirement for syntactic foammodules. Although the American oceanographic industrycommonly uses cylindrical pressure hulls constructedfrom FWE materials, for the near term, it appears thatpressure hulls of the diameter required for medium andlarge size unmanned vehicles will be constructed frommetals such as titanium and aluminum. The weight todisplacement of these materials will require theattachment of low density modules such as syntacticfoam to increase the overall system buoyancy.

1.4.6 Tether Assemblies 3tatement of Work

A major factor in developing the SOW to solve chronicproblems in ROV powered tether systems was the apparentdichotomy between the design performance of tethers

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(and underwater cables) and the actual manufacturedproduct performance in real-world applications. Thisrequired careful examination of historical performanceof a variety of cable types under a variety ofconditions in order to predict problem areas that mayoccur in future high reliability tethers.

1.4.7 Dry Connectors Statement of Work

Research into the problem of dry connector failureproved that there is not a problem and those companiesthat had reported these failures described in Ohase I,had simply been using improper components and .gnoredavailable design guidelines. It was recommended thatthis effort be dropped and a SOW was not developed.

1.4.8 Magnetically Coupled Thrusters Statement ofWork

In closely defining the problem of limited powerapplicability to magnetically coupled thrusterassemblies, two related and important problems becamevery apparent. These are: (1) the high levelacoustic signature of bearings in water contact and,(2) corrosion problems from exposing sensitivethruster components to the environment. These newproblems may also be solved through the use ofmagnetics and, as a result, were included in the SOWfor magnetically coupled thrusters.

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V. LIST DEVELOPMENT METHODOLOGY

1.1 Overview

In developing the lists of ROV system componentmanufacturers (Underwater Connectors and Syntactic Foam)the approach for each differed greatly due to the natureof the product application. Because there is anextremely limited application for syntactic foam andthere are a limited number of companies that produce theproduct, generating the list of recommended syntacticmanufacturers was a comparatively straightforwardprocess. In contrast, the sheer number of underwaterconnector types available to the design engineer andrelatively large number of connector manufacturers madethe generation of the reliable connector manufacturer amuch more complex process. Also, since far more peoplehave had considerable historical experience withunderwater connectors many more experts had to beconsulted. The analysis of connector manuficturersrequired a lengthy process of assuring that the properpeople were contacted in order to properly analyze theconnectors available.

1.2 Connector List

There are approximately ten major American underwaterconnector manufacturers who supply the major portion of a20 million dollar worldwide annual market. Of thesemanufacturers most have a good knowledge of their productperformance in the field under working conditions overtime as a result of feedback from their customers. Inorder to determine what companies provide reliableproducts in service it was necessary to interview manyexperienced users of many different kinds and types ofconnectors. Even the most experienced program managersde-emphasize electrical connector problems, because theconnector component is physically small, relative!1simple in design, and often low cost in comparison to theequipment or vehicle on which it is used. Therefore, itis usually expected to perform well. When it does not,it often jeopardizes entire programs and can result invery expensive losses. As a result, users find it intheir own interest to provide failure data to themanufacturer.

The Phase II work included interviewing numerous expertsin the field of underwater connectors. These peopleincluded major underwater systems manufacturers,commercial and Government underwater equipment users andGovernment program managers. Each had extensiveexperience with underwater connectors of a variety oftypes and styles.

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The interviewees were virtually unanimous in theiropinions of the companies who manufactured qualityconnectors. Some experts agreed that there is nofoolproof connector and of the two companies favored forreliability, many experts had qualifying statementsrelative to each.

In selecting the reliable components produced by the twomanufacturers, we chose to go to the manufacturersthemselves. It was determined that, although they may bebiased, the manufacturer has the most complete knowledgeand data on individual design reliability. Consequently,it was in the governments best interest for themanufacturer to supply this data.

During interviews and discussions with the twomanufacturers, individual connector and/or connectortypes were identified as being the most reliable. Thelist of reliable connectors was generated specificallywith the assistance of the two manufacturers.

A description of connector types and typical applicationsaccompanies the reliable connector list which wasdelivered separately.

1.3 Syntactic Foam Manufacturers List

There are less than ten manufacturers who haveconsistently produced syntactic foam for the Americancommercial and government market. This market isconsiderably smaller than the connector market and somemanufacturers produce foam from very small facilities, onand off, as demand for small amounts of the productarise.

In analyzing the producers of this product, we chose toconcentrate on the manufacturers that consistentlyproduced the product and have had a history of doing so.

Although there are manufactures of quality foam in theU.S. and England, as a result of our Phase II interviews,it appears that there is no manufacturer of syntacticfoam that produces a high performance foam that does notexhibit water pickup, eventual degradation from stressesencountered in deployment, and that is also notformulated from potentially harmful constituents. Thedevelopment of the SOW on syntactic foam was directed atthe definition/design of such a high performance foam(Appendix (A)).

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10 25 91 09:00 %50 759 1595 MAROUEST GROUP 002

One of the difficuLtie t~nr:vered in defining individualreliability problems with syntactic foam is that many ofthe experts in this field work in the foam manufacturingindustry. It was necessary, therefore, to look toindividual manufacturers for some of the expertiserequired in defining individual problem areas.

A list of major syntactic foam manufacturers was preparedand provided to the Government under separate cover.

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VI. CONCLUSIONS/RECOMMENDATIONS

1. Conclusion

To provide credibility to the development of the Statementsof Work (SOWs) in Phase II, extensive effort was expended toidentify the experts in each of the technological areas.Their expertise was subsequently applied to define theproblems, define the approaches for solving the problems andto develop the SOWs. The result was the generation of sevendetailed SOWs which are available for execution to addresshigh reliability technological problems prior to thedesign/development of high reliability Remotely OperatedVehicles by the government. The experts identified duringPhase II are available for the next phase of the program tosupport execution of the SOWs. Their participation willincrease the chances of the government receiving a qualityproduct.

2. Recommendations

It is proposed that the SOWs developed in Phase II beexecuted to generate solutions in the form of reliabilitydesign specifications, guidelines and documentation to theproblems.

It is recommended that the experts be utilized to provideknowledgeable personnel to support execution of the SOWcontracts. A detailed proposal describing the recommendedapproach for the use of experts in the execution of the SOWshas been prepared and provided under separate cover.

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APPENDIX A

STATEMENTS OF WORK (SOW)

1. Hydraulic Systems

2. Magnetically Coupled Thrusters

3. Suspect Manufacturing Processes

4. Buoyancy Materials

5. Sealing Systems

6. Tether Assemblies

7. Variable Ballast Systems

STATEMENT OF WORK

FOR

High Reliability Remotely Operated Vehicle (ROV)

and Autonomous Underwater Vehicle (AUV)

Hydraulic Systems

Prepared By:


Prepared For:

Office of Naval Research (ONR)Warfare Technologies Division

(ONR Code 122)

TABLE OF CONTENTS

Section/Paragraph

1 BACKGROUND AND INTRODUCTION........................ 1

2 APPLICABLE DOCUMENTS................................ 22. 1 Other Government Documents......................... 2

3 SCOPE.................................................2

4 REQUIREMENTS......................................... 34.1 Critical Design Areas............................. 34.1.1 Hydraulic System Leaking and Flooding Problems .44.1.2 Hydraulic Line Failure Problems.................. 74 .2 Manufacturing...................................... 84.2.1 Components......................................... 94.2.2 Fabrication and Assembly.......................... 94 .3 Reference Documentation........................... 9

5 DELIVERABLES....................................... 105.1 Program Plan (A002)............................... 105.2 Project Status (AO0l)............................. 115. 3 Final Report (A005)............................... 115.3.1 Problem Documentation (A005)................ ..... 115.3.2 Reference Documentation (A003).................... 135. 3 .3 Manufacturing Errors (A004)....................... 13

STATEMENT OF WORK

1. BACKGROUND AND INTRODUCTION

Future Navy requirements will involve protracted deploymentsof underwater Remotely Operated Vehicles (ROVs) andAutonomous Untethered Vehicles (AUVs) . To date, theperformance of such vehicles has been heavily dependent onthe quality and quantity of the maintenance and supportavailable during relatively limited deployments. An ROVdesign that is appropriate for industrial (e.g., petroleumindustry) operations, with limited exposure and theexpectation of much maintenance, as a tradeoff againsthigher initial cost, is inappropriate for military missionswith little or no opportunity for upkeep. As a result, thecommon practice of modifying existing ROVs and ROVsubsystems for long term, at-sea storage and/or operationwithout maintenance is not considered to be a long termsolution for extended mission Navy operations.

The following operational capabilities and reliability goalsneed to be achieved for the Navy to meet its long termdeployment ROV/AUV requirements. The vehicles must bedesigned and built to achieve an operational reliability of98% or better when operating from submarines duringprotracted deployments (3-6 months wet or in a powered-downconfiguration for one to two months followed by severalweeks of subsequent operations) . The ROV/AUV systemoperational capabilities to be considered are as follows:

1. The operational depth design consideration is a maximumof 3,000 feet. Consideration shall also be given tosystems that have a maximum depth capability of 6,000feet.

2. TETHERS:

A. The ROV system shall have a 4,000 ft powered tetherworking from a station keeping platform with a maximumdistance from the platfform of 3,000 feet in anydirection. Station keeping is defined as zero relativevelocity between platform and geodetic or geographicsurroundings.

B. The AUV shall have no tether.

3. The ROV or AUV system shall have low self-radiated noise,according to the goals shown in Figure I, and itsauxiliary acoustic components shall not interfere withthe platform sensors. The entire system should minimizeacoustic radiation.

4. The ROV or AUV system's magnetics shall not interferewith the platform or its sensors and vice versa.

5. The ROV's capacity for a variety of work tasks, includingheavy duty work and high power manipulators, shall alsobe considered.

6. The ROV's or AUV's maximum nominal speed shall be 5knots.

All aspects of the system life cycle that may offsetreliability were considered in an initial investigation,including; design, procurement practices, fabrication,inspection, in-service use and maintenance. The reliabilityproblems identified in the investigation report covered theentire development phases of design, manufacturing and in-service life. The in-service life phase, concerned withtraining, maintenance and documentation are not to beconsidered under the tasking of this SOW, but later on aspart of a specific system design. The focus of this SOW ison the application of technology to improve reliability.

Specifically, this statement of work addresses ROV/AUVhydraulic systems reliability problems and how their designmight be improved to help obtain the long range Navyobjective of achieving a substantial increase in theextended mission reliability of ROVs/AUVs.

2. APPLICABLE DOCUMENTS

2.1 Other Government Documents

The following Government document forms a part of thisspecification to the extent specified herein.

David Taylor Research Center, Annapolis - Ocean EngineeringHandbooks

3. SCOPE

The objective of this SOW is to provide recommendations forspecific solutions to chronic failures in hydraulic systems.This will be presented in the form of deliverables so thatdesigners can use this information in the creation of newvehicles and systems, or in ti-oubleshooting/retro-fittingexisting systems.

The work will be focused on ways to improve the reliabilityof hydraulic systems, including associated controls,plumbing and fittings. The trend toward quieter vehicles,and therefore quieter and lower power hydraulics, isrecognized as a major future design goal. Quieting a systemworks against reliability in a volume constrained system,and can, with a high reliability ROV/AUV, drive up the size

and complexity of the vehicle. Consequently, the contractorshall conduct design trade-offs to select the optimumhydraulics design affording the desired reliability levelwith the least noise.

Hydraulic failures (unrelated accidents excepted) can comeabout for a wide variety of reasons, but they may be groupedinto two major areas of proximal cause:

* Those traceable to faulty design* Those resulting from faulty materials or manufacturing

processes.Those resulting from improper building, assembly ormanufacturing workmanship.

The SOW is organized around the two areas of design andfabrication with "faulty materials or manufacturingprocesses" included under the latter area. Further, the SOWis structured so as to treat each thoroughly, with thefailure modes as documented to date and described in detailin Section 4. The Design (4.1) and Manufacturing (4.2)subheadings deal with the breakdown of the two majorcategories into areas of specific interest.

4. REQUIREMEVITS

The contractors proposal shall identify from an overview howto approach each problem technically, alternativeapproaches, costs and schedules. The approach shall addressthe two major reasons for hydraulic failures as delineatedabove in Section 3 and as follows.

The contractor shall examine common failure modes ofvehicle hydraulics and recommend design and/or proceduralsolutions to these problems so that they can be implementedat a later date for testing and/or evaluation purposes.These solutions will be in the form of deliverablesdescribed later in this section of the SOW. Thedeliverables shall reflect the current state-of-the-arttechnology, and assume implementation in the next fiveyears.

4.1 Critical Design Areas

The overall objective is reliable longer-term deployment ofROVs/AUVs than is possible with current commercial vehicledesigns modified to meet Navy requirements. Severalspecific critical areas have been identified which must beaddressed in order to improve reliability to an acceptablelevel. In dealing witi- specific design recommendations formaximizing system reliability, the contractor must keep inmind that these must be based on the realization thatcompromise is an inevitable part of every design effort.Consequently, the importance of each recommendation,

3

relative to other recommendations, must be indicated.Further, the contractor shall provide reasonable comparisoninformation on the application of less than optimumalternatives and their possible consequences.

The contractor shall give consideration to the effect ofnoise reduction criteria on system design (see Figure IGoals) and resulting reliability to provide the designerwith adequate information to properly evaluate theconsequences of the tradeoffs involved. As an example;(a) the relative merits of low pressure/high volume vs.high pressure/low volume systems, (b) output power vs.quieting, (c) volume occupied vs. quieting, and (c) outputpower to input power ratio vs. quieting shall be carefullydocumented.

4.1.1 Hydraulic System Leaking and Flooding Problems

The contractor's critical design review must considerleaking and flooding involving the loss of hydraulicfluid overboard and the ingress of water. The loss offluid overboard is a problem because of the relativelylong time between service/maintenance opportunities.The ingress of water presents corrosion, lubrication,and particle contamination problems.

Hydraulic fluid loss and water ingress in underwaterhydraulic systems can come about through faulty orimproperly installed line termination, fittings onmotors/pumps/compensators, faulty hydraulic lines orcorroded mechanical components. Another potential leaksite is rotary seals on moving shafts in the hydraulicpropulsion system. These seals commonly experienceexcessive friction and wear which can lead to failureof the seal integrity over a period of time. Mostexisting hydraulic systems can tolerate a limitedamount of fluid loss or contamination because of theuse of sufficient fluid quantities and filters in thesystem. This scenario is not acceptable for a systemundergoing long deployments and this problem requiressolutions to prevent both a loss of fluid and ingressof water into the system.

4. 1. 1.1 Manifolds

The use of manifolds machined from solid stock tomount and interconnect control valves and even somepower devices such as linear actuators shall beexamined. The objective is to minimize the quantityof potential leakage sites. This approach canreduce the quantity of potential leak sites (aswell as the space required for lines and fittings)by a significant factor. It is realized that whenmanifolds vice smaller and more convenient

4

connections are employed there may be a serioustrade off between the Mean Time To Repair (MTTR)figures and the Mean Time Between Failure (MTBF)figures. In designing systems to secure highreliability, it may make the vehicle harder torepair at a forward deployment site and require itsreturn to the manufacturer for repair. This processis time consuming, very costly, and adverselyaffects the availability of the vehicle. It isdesirable for these hydraulic systems to beconfigured in a manner that considers the trade-offsbetween repair in the field or at the factory. Thecontractor shall provide recommendations for the useand design of manifolds in the final report. Thecontractor shall also analyze the tradeoffs expectedbetween MTBF and MTTR figures using manifold vicesingle connection interconnects and include thesetradeoffs in the final report (CDRL item #A005).

4.1.1.2 Welded Lines

The contractor shall examine the use of weldedpiping assemblies and subassemblies to decrease thenumber of leak sites. Consideration shall be givento the weldability of the specific materialssuitable for use in a high pressure, vibrational,long term salt water immersed application. It isacknowledged that the use of welded lines toincrease system reliability carries the sameadvantage and disadvantage in terms of MTBF versusMTTR figures as the use of manifolds (section4.1.1.1.). Considering that maintenance and repairis desirable at a forward deployment site in orderto increase the systems' availability, the trade-offs between the use of welded lines and the use ofother line fittings shall be evaluated. Thecontractor shall provide recommendations for and/oragainst the use of welded lines and suitablematerials in the final report. The contractor shallalso provide the analysis and tradeoffs in MTBF andMTTR figures when using welded lines vice linefittings in the final report (CDRL item #A005).

4. 1. 1. 3 Threaded Connections

The need for some threaded connectors is recognizedand the relative merits of the various typesavailable shall be investigated. Since many systemcomponents are available with a limited number ofinterconnection fitting choices, evaluation of thesechoices shall be made to provide analysis of theirsuitability. For example, it may be shown that asingle pipe fitting decreases system reliability byan amount equivalent to using 10 "0" seal fittings

5

but that seal welding the pipe fitting results in ajoint equivalent to socket welding. The contractorshall compare and report on the suitability of theseconnections in the final report (CDRL item #A005).

Methods for correcting the deficiencies in existingthreaded joint designs shall be considered in thehope that the specific low maintenance applicationwill allow improvements. As an example, it mayprove practical to utilize tack welding to overcomethe tendency of a threaded connection to loosen in ahigh vibration environment. The contractor shallprovide recommendations for improved design ofthreaded connections in the final report (CDRL item#A005).

The choice of acceptable materials for threadedconnections shall be carefully evaluated.Particular attention shall be paid to problems ofcrevice corrosion and stress corrosion cracking in asalt water environment. Again, the low maintenanceapplication may allow use of novel solutions such asjoint encapsulization in a suitable conformalcoating. The contractor shall evaluate andrecommend acceptable materials for threadedconnections in the final report (CRDL 4tem #A005).

4.1.1.4 Pressure Loaded Compensator Connection Seals

Typically a hydraulic system that is designed forunderwater operation is equipped with a pressurecompensator that maintains hydraulic system pressureat or slightly above the ambient water pressure.When the hydraulic fluid pressure is slightly abovewater pressure, if a leak does occur, oil will leakout. This is usually the preferred situation tominimize the possibility of system degradation dueto corrosion. Examination shall be made of optimumcompensator connection points and pressures. Bothactive and passive methods for providingcompensation pressure shall be evaluated. Theexamination results and recommendations shall bepresented in the final report (CDRL item #A005)

4.1.1.5 High Friction Seals

At rotary and sliding seals special seal methodssuch as advanced lip or O-ring seal, redundant seal,or hermetic boundary seals shall be examined. Thecontractor shall examine the long term effect ofboth oil and water on these seals. Further, thecontractor shall specify or design and qualify thesehigh reliability sealing methods as a potentialsolution to leaking and flooding. The contractor

6

shall provide these specifications, designs and/orqualifications in the final report (CDRL item#A005). The contractor shall quantify seal leakagerates to expect after 1000 operational hours andassociated passive exposure to saltwater and/or oil.

4.1.1.6 Other Potential Leak/Flood Problems

There are many different hydraulic component designsnow in use on Remotely Operated Vehicles. Each ofthese systems may have unique problems with respectto the loss of fluid or ingress of water. Thecontractor shall detail any other problems ofconcern to a design engineer of which he may beaware and provide potential solutions for theseproblems in the final report (CDRL item #A005).

4.1.2 Hydraulic Line Failure Problems

Line failure can be caused by several system-design oroperational problems. The major causes of line failurefollowing acceptance testing are; corrosion, abuse, andfatigue resulting from pressure and large spikes orpulsations. Failure modes are normally bursting orleakage but other, less common, failure modes exist.

Any hydraulic line that carries fluid at or nearambient pressure is susceptible to possible collapse.The line will collapse if the internal pressure issufficiently lower than the external pressure and linewalls are of inadequate strength. Such a line is inunstable equilibrium. If constant flow is maintained,once collapse starts it will tend to quickly proceed tocomplete collapse. Lower internal pressure is due totwo factors; low hydrostatic pressure at the exit endof the line, and fluid flow velocity (which reduceshydrostatic pressure at the line wall) within the line.Bends, external loads or rapid pressure changes due topulsations can aggravate the situation. Collapse in apump suction line can also occur if the systemcompensator bottoms (due to a leak somewhere in thesystem) and the pump continues to deliver fluid. Sincehose generally is weaker than tubing or pipe, it is themore likely system element to fail by collapsing.

4.1.2.1 Contamination

Despite a competent manufacturing process,maximizing reliability will involve both particleand water removal. The contractor shall considerthe various methods for accomplishing this and makerecommendations; specifically the type, fineness,location, quantity, size, leakage potential and failsafe aspects of available filtering components shall

7

be addressed. The contractor shall also providerecommendations on cleanliness levels and associatedprocedures. The contractor shall provide theserecommendations in the final report (CDRL item#A005).

4.1.2.2 Hydraulic Line Noise

The contractor shall review those areas of existinghydraulic system design practices, Navy andcommercial sound silencing techniques, and the useof noise reduction components (i.e. flex hoses andsound dampeners) with the goal of achieving thedesired reliability level and reduced acousticsradiation. The impact of these designs/componentson reliability shall be examined and specificrecommendations made. The contractor shall providethese recommendations in the final report (CDRL item#A005).

4.1.2.3 Working Fluids

Trar-e-offs between various working fluids in thesystem shall be considered for ROV/AUV deploymentswith particular attention to long term wet storageof the system and extended power down periods.Consideration shall also be given to whetherperiodic start-up/exercise of hydraulic systems isnecessary or desirable. The contractor shallprovide these trade-offs and make recommendations inthe final report (CDRL item #A005).

4.1.2.4 Other Potential Line Failure Problems

Depending on the type and design of the hydrauliclines in any given system, there may be uniqueproblems with line failure not covered in thissection. The contractor shall detail any otherproblems of concern to a design engineer andpotential solutions of which he may be aware. Thecontractor shall provide a description anddiscussion of these problems and potentialsolutions in the final report (CDRL item #A005).

4.2 Manufacturing

Even with reliable, quality designs for all parts of avehicle, system errors in manufacturing involving theincoming materials or components from vendors, fabricationof materials in house and the assembly of these can cause areduction in the overall system reliability. These errorscan be product-wide and effect virtually all units in aproduction run and result in multiple in-service failuresbefore detection.

8

4.2.1 Components

Incoming components for the production of vehiclesystems are most often either tested by themanufacturer or certified as tested by the vendor.Even if the components are certified by the vendor theycan still be faulty and cause unpredictable failures inservice. In some vehicle systems, manufacturers willutilize marginally reliable components due to eithercost competition or component availability.

4.2.1.1 Component Failure

The contractor shall review the available componentsused in the manufacturing of ROV/AUV systems withregard to their reliability history. The contractorshall consider whether the formulation of a QualityParts List (QPL) for ROV/AUV systems will improvetheir reliability and make his recommendation in thefinal report (CDRL item #A005).

4.2.2 Fabrication and Assembly

Errors in fabrication and assembly which may be missedby even a good quality assurance program, may weakenthe product and create later in- service failures.Identification and documentation of these known errorscan contribute to their elimination.

4. 2. 2. 1 Manufacturing Errors

During the contract it is expected that thecontractor shall develop a list of commonmanufacturing errors found to cause various types ofhydraulic failures. This list will be valuable inwarning the vehicle designer or manufacturer oftheir existence. The contractor shall make thislist available as an attachment to the final report.The list of errors shall include explanations,desirable alternative solutions, and recommendations(CDRL item #A004).

4.3 Reference Documentation

DTRC (Annapolis) has published a series of Ocean EngineeringHandbooks on tcpics ranging from electric underwater motorsto hydraulic systems. These handbooks provide the designerwith examples, design data, standards and other informationof great practical value during the design process. Thecontractor shall draw on these and other sources ofinfuimaLion (z- described elsewhere in this SOW), and on hisown extensive experience in the design and implementation ofunderwater hydraulic systems of all types, and produce a

9

compendium of specific guidelines on how to design toprevent problems (historical and expected) which plague ROVhydraulics reliability. This compendium shall be presentedas an attachment (CDRL item #A003) to the final report.

The contractor shall make a thorough survey of applicablemilitary standards, specifications and handbooks. Thecontractor shall compile all such documents, cross-referenced and explained so that the designer will have asingle, concise source for selection of applicablecontrolling documents to reference during the preparation ofmaterial, process, or product specificaticns. Thecontractor shall provide this compilation as an attachment(CDRL item #A003) to the final report.

5. DELIVERABLES

Designer Guidelines for the technical aspects of thehydraulic system which contribute to failures shall be aprime product (CDRL item #AO05). The contractor shallproduce a compendium of specific design guidelines forpreventing problems which plague ROV hydraulics systems(CDRL item #A003). The contractor shall also provide a listof common manufacturing errors found to cause hydraulicfailures (CDRL item A004). Other deliverables required area program plan (CDRL item #AO02), status reports (CDRL item#AO01) and a final report (CDRL item #AO05).

The deliverables on this project shall be in contractorformat and in accordance with the attached Contract DataRequirements List (CDRL), Form DD1423. The details of therequired deliverables are as follows:

5.1 Program Plan (A002)

The contractor shall develop a program plan in accordancewith CDRL #A002 identifying: how to approach each problemtechnically (including breakpoints), alternative approaches,and a schedule for each required deliverable in section 4 ofthe SOW. The plan shall elaborate on the contractorsproposed technical approach to the SOW and detail how thecontractor will perform each required item within theallocated time and cost. A draft program plan shall bedelivered 30 days after contract award, and is subject toGovernment approval. A final version of the program plan,with Government comments incorporated, shall be required 15days after the contractors receipt of the Governmentscomments.

10

5.2 Project Status (AO01)

The contractor shall provide project status in accordancewith CDRL #AO01 by the fifteenth of each month for theprevious calendar month.

5.3 Final Report (A005)

A draft final report prepared in accordance with CDRL #A005,describing all research results and conclusions, shall besubmitted 60 days prior to completion of the contract forreview and comment.

A final report updating the draft report, as required by thereview comments, shall be submitted 30 days after thecontractors receipt of the Governments comments on the draftreport.

Specific deliverables to be included in the final report arethe following:

5.3.1 Problem Documentation (A005)

Section 4 requires the contractor to provideevaluations, designs, specifications, comparisons,trade-offs, descriptions, discussions and/orrecommendations for each specific problem and toinclude the results as separate, identifiable items inthe final report. The results shall be prepared inaccordance with CDRL #A005 for the ROV/AUV hydraulicscomponents, subsystems, supporting/auxiliary equipmentor processes as directed in items 4.1 through 4.2inclusive, less item 4.2.2.1 Manufacturing Errors.The specific items to be reported are:

(4.1.1.1) Manifolds

Recommendations for the use and design of manifolds.Provide an analysis of trade offs between MTBF andMTTR figures using manifolds vice singularinterconnections.

(4.1.1.2) Welded Lines

Recommendations for the use of welded lines andsuitable materials. Provide an analysis and thetradeoffs in MTBF and MTTR figures when using weldedlines vice line fittings.

11

(4.1.1.3) Threaded Connections

Provide comparisons and applicability of threadedconnections, and recommendations for improveddesign of threaded connections. Provide anevaluation and recommendations of acceptablematerials for threaded connections.

(4.1.1.4) Pressure Loaded Compensator Connection Seals

Provide recommendations of optimum compensatorconnection points and pressures (active and passive)for seals.

(4.1.1.5) High Friction Seals

Provide specifications, designs and/orqualifications for sealing methods. Provide aquantification of seal leakage rates expected after1,000 hours of operation with high friction seals.

(4.1.1.6) Other Potential Leak/Flood Problems

Provide a description, discussion and potentialsolution for each problem identified.

(4.1.2.1) Contamination

Recommendations for removal of particle and watercontamination during the manufacturing process andrecommendations on cleanliness levels and associatedprocedures.

(4.1.2.2) Hydraulic Line Noise

Recommendations for the use of designs/components onnoise reduction and reliability.

(4.1.2.3) Working Fluids

Provide trade-offs between various working fluidsand make recommendations. Include recommendationson the desirability/necessity of periodic start-up/exercise of hydraulic systems.

(4.1.2.4) Other Potential Line Failure Problems

Provide a description, discussion and potentialsolution for each problem identified.

12

(4.2.1.1) Components

Provide an assessment and recommendations of aQuality Parts List (QPL, program for ROV/AUVsystems.

5.3.2 Reference Documentation (A003)

The contractor shall provide a compendium of specificguidelines on how to design to prevent problems whichplague ROV/AUV hydraulics reliability.

The contractor shall make a thorough survey ofapplicable military standards, specifications andhandbooks. He shall compile all such documents,cross-referenced and explained so that the designerwill have a single, concise source for selection ofapplicable controlling documents to reference duringthe preparation of material, process, or productspecifications. (Item 4.3 Reference Documentation.)

5.3.3 Manufacturing Errors (A004)

The contractor shall provide a list of common ROV/AUVhydraulics manufacturing errors including desirablealternative solutions and explanations. (Item 4.2.2.1Manufacturing Errors).

13

STATEMENT OF WORK

FOR



Magnetically Coupled Thrusters

Prepared By:

Marine Imaging Systems, Inc.8 Otis Park DriveBourne,MA 02 5

Prepared For:


(ONR Code 122)

TABLE OF CONTENTS

Section/Parag~raph


2 APPLICABLE DOCUMENTS................................ 32.1 Other Government Documents........................ 3

3 SCOPE................................................. 3

4 REQUIREMENTS....................................... 34.1 Critical Design Areas............................

5 DELIVERABLE........................5.1 Program Plan (AOO1)............................... 65.2 Status Report (A002).............................. 65.3 Final Report (A003)............................... 65.4 Prototyping Plan (A004)........................... 8

STATEMENT OF WORK


Future Navy requirements will involve protracted deploymentsof underwater Remotely Operated Vehicles (ROVs) andAutonomous Underwater Vehicles (AUVs )the performance ofsuch vehicles has been heavily dependent on the quality andquantity of the maintenance and support available duringrelatively limited deployments. An ROV design that isappropriate for industrial (e.g., petroleum industry)op-rations, with limited exposure and the expectation ofmuch maintenance, as a tradeoff against higher initialcost, is inappropriate for military missions with little orno opportunity for upkeep. As a result, the common practiceof modifying existing ROVs and ROV subsystems for use inmilitary service is undesirable and is not considered to bea long term solution for extended mission Navy operations.

The following operational capabilities and reliability goalsneed to be achieved for the Navy to meet its long termdeployment ROV/AUV requirements. The vehicles must bedesigned and built to achieve an operational reliability of98% or better when operating during protracted deployments(3-6 months wet or in a powered-down configuration for oneor two months followed by several weeks of subsequentoperations). The ROV system operational capabilities to beconsidered are as follows:

1. The operational design depth consideration are maximums

of 6,000 feet and 20,000 feet.

2. TETHERS:

A. The ROV system shall have a 4,000 ft powered tetherworking from a station keeping platform with amaximum distance from the platform of 3,000 feet inany direction. Station keeping is defined as zerorelative velocity between platform ana geodetic orgeographic surroundings.


3. The ROV or AUV system's shall have low self-radiatednoise, according to the goals shown in Figure I, andits auxiliary acoustic components shall not interferewith the platform sensors. The entire system shouldminimize acoustic radiation.

4. The ROV or AUV system's magnetics shall not interferewith the platform or its sensors and vice versa.

5. The ROY's capacity for a variety of work tasks,including heavy duty work and high power manipulators,shall also be considered.



-pecifically, this statement of work addresses ROV/AUVmagnetically coupled thruster assemblies and how to improvetheir power and reliability without undue increase in sizeor complexity. The objective is to improve the design ofmagnetically coupled thrusters to help achieve a substantialincrease in the extended mission reliability of NavyROVs/AUVs.

In current state-of-the-art ROV systems there are a numberof different propulsion system designs. One of the morereliable designs utilizes an air backed electric motor.Although the average life of this type of thruster design iscomparatively long, one of the components of this assemblywith the shortest life cycle, is a rotating shaft seal wherethe propeller shaft penetrates the pressure housingcontaining the motor. In many designs this seal, althoughreliable in the short term, demonstrates extremely high wearrates and requires frequent maintenance.

One type of thruster design implemented on a number of ROVseliminates these shaft seals altogether through the use ofmagnetic field- which transfer rotational power without theuse of sealed, pressure-housing-penetrating shafts. Byeliminating shaft sEals altogether the reliability of theelectric thruster has been greatly improved allowing longterm deployments with little or no maintenance to thethruster assemblies.



The following Government document forms a part of thisspecification to the extent specified herein.

David Taylor Research Center, Annapolis - Ocean EngineeringHandbooks

3. SCOPE

The objective of this SOW is to assess the feasibility ofincreasing power levels that can be applied to small,magnetically coupled thruster assemblies and to providerecommendations for specific solutions to increasing theperformance of magnetically coupled thruster assemblies.These will be presented in the form of deliverables so thatdesigners can use this information in the creation ofprototypes for testing and evaluation of the designsolutions.

The work will be focused on ways to improve the design ofthruster assemblies utilizing magnetic fields to transferpower from an electric motor to a rotating propulsion shaft.The work will also focus on improving the design ofassociated bearings and other parts that may be exposed tothe underwater environment. The trend toward quietervehicles, and therefore quieter propulsion shaft bearings,is recognized as a major future design goal.

Several problems exist with current designs of magneticallycoupled thrusters. The limitations of these thrusterassemblies fall into 3 categories:

" Torque limitations within size restrictions.

" Rotational Speed limitations

" Abbreviated life of propeller shaft support bearings

This statement of work is designed around these limitations

and shall address these problem areas.

4. REQUIREMENTS

The contractor's proposal shall identify from an overviewhow to approach each problem technically, alternativeapproaches, additional problems, costs and schedules, andrecommendations for prototyping.

The contractor shall examine existing designs ofmagnetically coupled thruster assemblies and recommenddesign and/or procedural solutions to these problems so that

3

they can be implemented at a later date for testing and/orevaluation purposes. These solutions will be in the formof deliverables described later in this section of the SOW.The deliverables shall reflect the current state-of-the-arttechnology, and assume implementation within the next fiveto seven years.

4.1 Critical DesiQn Areas

The overall objective is reliable longer-term deployment ofROVs/AUVs than is possible with current vehicle designs.Several specific critical areas have been identified whichmust be addressed in order to improve performance to anacceptable level. In dealing with specific designrecommendations for maximizing system performance, thecontractor must keep in mind that these must be based on therealization that compromise is an inevitable part of everydesign effort. Therefore, an indication of the relativeimportance of the recommendations must be provided as wellas reasonable information on the application (and possibleconsequences) of less than optimum alternatives.

Consideration shall be given to the effect of noisereduction criteria on system design and resultingreliability to provide the designer with adequateinformation to properly evaluate the consequences of thetrade-offs involved.

4.1.1 Torque vs Size, Weight and Fragility

The magnetically coupled thruster assemblies in usetoday are fairly large, particularly where higher thannormal torque forces are required. In particular, thematerials used in the past, require inordinately longcoupling housings in order to deliver high levels oftorque to the shaft. New materials may be available atpresent that will allow the use of shorter, morecompact coupling assemblies. These potentialimprovements may allow shorter thrusters overall whiledelivering greater torque than has been possible in thepast.

It is known that there are further limitations to thematerials used in the past for magnetically coupledthrusters. Sumarium cobalt is a fragile material;Gaudolinium is somewhat stronger magnetically; somerare earth materials are not resistant to hightemperatures.

The contractor shall investigate and recommend in thefinal report (CDRL item #A003), reliable materials thatwill increase the torque performance of existingmagnetically coupled thruster designs.

4

4.1.2 Speed

There are further limitations to the performance ofmagnetically coupled thruster assemblies in terms ofrotational shaft speed. Historically, in order tomake housings for magnetically coupled thrusters usedin deep water (greater than 1000 feet) strong andpressure proof, the materials for these housing aretypically metallic and have been chosen for their highresistivity.

In using metals (or other conducting materials),designers have found that magnetic inductance from therotating couplings induces eddy currents in the housingmaterials resulting in heat buildup. Most designs ofthis type also have a tangential speed limitation ofapproximately 5 feet per second even when usingrelatively high resistivity metallic materials such ashastelloy.

The contractor shall evaluate and recommend in thefinal report (CDRL item #A003), new housing materialsthat will substantially improve, or eliminate,rotational speed limitations and inductance heatbuildup in magnetically coupled thruster assemblies.

4.1.3 BearinQs in Sea Water

Another drawback to the use of magnetically coupledthruster assemblies is the exposure of bearingassemblies to the environment. This creates anundesirable corrosion problem in the bearing assemblieswhich necessitates undesirable frequencies ofmaintenance. An added performance problem for manyapplications is the added acoustic output of thesebearing assemblies immersed directly in seawater.

A design that utilizes magnetic bearings may eliminatethe requirements for bearings exposed to sea water andstill allow the shaft to be exposed to seawaterwithout corrosion or acoustic problems.

The contractor shall provide design recommendations inthe final report (CDRL #A003), for magnetic bearingsfor use on the secondary coupling component inmagnetically coupled thruster assemblies.

4.1.4 Other Potential Design Problems

There may be other potential problems encountered inhigh performance magnetically coupled thruster design.The contractor shall detail any other problems ofconcern and provide potential solutions for theseproblems in the final report (CDRL item #A003).

4.1.5 Prototypinq Plan

If the results of the solutions to the problemsidentified above (and by the contractor) are favorable,and an overall assessment of the feasibility ofincreasing power levels that can be applied to small,magnetically coupled thruster assemblies is promising,prototyping of the design efforts will likely bepursued. The contractor shall provide a plan forprototyping of the designs developed under this phase(including cost and schedule). This effort may beperformed in the second phase of this SOW as an option.The prototyping plan shall be submitted separately fromthe final report as (CDRL item #A004).

5.0 DELIVERABLES


5.1 Program Plan (AO01)

The contractor shall develop a program plan in accordancewith CDRL #A001 identifying how to approach each problemtechnically (including breakpoints), alternative approaches,and a schedule for each required deliverable in Section 4 ofthis SOW. The plan shall elaborate on the contractor'sproposed technical approach to the SOW and detail how thecontractor will perform each required item within theallocated time and cost. A draft program plan shall bedelivered 30 days after contract award, and is subject toGovernment approval. A final version of the program plan,with Government comments incorporated, shall be required 15days after the contractor's receipt of the Government'scomments.

5.2 Status Reports (A002)

The contractor shall provide project status in accordancewith CDRL item #A002 by the fifteenth of each month for theprevious calendar month.


A draft final report prepared in accordance with CDRL item#A003, describing all research results and conclusions,shall be submitted 60 days prior to completion of thecontract for review and comment.

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A final report updating the draft report, as required by thereview comments, shall be submitted 30 days after thecontractor's receipt of the Government's comments on thedraft report.

Specific deliverables to be included in the final report are

the following:

5.3.1 Problem Documentation

Section 4 requires the contractor to provideevaluations, specifications, design guidelines,comparisons, descriptions and/or recommendations foreach specific problem and to include the results asseparate, identifiable items in the final report. Theresults shall be prepared in accordance with CDRL item#A003 for the ROV/AUV Magnetic Coupled Thruster taskingas directed in items 4.1.1 through 4.1.4 inclusive.The specific items to be reported are:

(4.1.1) Torque vs. Size, Weight and Fragility

The contractor shall investigate and recommendreliable materials that will increase the torqueperformance of existing magnetically coupledthruster designs.

(4.1.2) Speed and Temperature

The contractor shall evaluate and recommend newhousing materials that will improve on, or eliminaterotational speed limitations and heat buildup in thehousings of magnetically coupled thrusterassemblies.

(4.1.3) Bearings in Sea Water

The contractor shall provide design recommendationsfor magnetic bearings for use on the secondarycoupling component in magnetically coupled thrusterassemblies.

(4.1.4) Other Design Problems

The contractor shall detail and provide detailedpotential solutions for these problems in the finalreport.

5.4 Prototyping Plan (A004)

The contractor shall provide a draft plan for prototypingthe designs developed in this phase of the SOW. The planqhall be ,-irt to government approval. A final versionwill be required 15 days after receipt of governmentcomments.

8

STATEMENT OF WORK

FOR


Suspect Manufacturing Processes

Prepared By:


Prepared For:


(ONR Code 122)

TABLE OF CONTENTS

Sect ion/Paragraph


2 SCOPE ............................................. 1

3 REQUIREMENTS...............................23.1 Critical Manufacturing Problem A reas.........23.1.1 Problems with Working Systems..................... 23.1.2 Vehicles of Recent Manufacture................... 23.1.3 Vehicles Presently in Production................. 2

4 DELIVERABLES......................34.1 Final Report (AOl)............................... 34.1.1 Problems with Working Systems..................... 44.1.2 Vehicles of Recent Mai~.facture................... 44.1.3 Vehicles Presently in Production................. 4

STATEMENT OF WORK


In the future the U.S. Navy shall require the use of ROVsystems for prolonged deployments. Toward this goal thegovernment would like to compile a comprehensive list ofmanufacturing errors encountered in past ROV manufacturingoperations which may have affected the reliability of theproduct. This comprehensive list shall be provided to ROVmanufacturers to aid in production of more reliable ROVsystems.

Every manufacturer of ROV systems and ancillary equipmenthas experienced manufacturing errors and production designproblems which have adversely affected the reliability ofthe final product. These errors range over a wide spectrumof manufacturing processes from failure to reinspectcertified incoming subassemblies and components toinadvertently exposing certain materials to a solvent thathad detxiaiental effect on the material months later.Knowledge of all of these errors can assist a manufacturerin providing a more reliable product in the future.

The most knowledgeable and capable contractors to dssemblecomprehensive list of these problems are the manufacturers.It is anticipated that manufacturers have records a. iknowledge of a variety of manufacturing problems andproduction design errors that have been eliminated forimprovement of product reliability.

2. SCOPE

The objective of this contract is to identify problems thathave caused errors in the manufacturing of ROV systems.These problems shall be identified, categorized andpresented in the form of non-attributable deliverables forthe use in the creation of new vehicles and systems, or introubleshooting/retrofitting existing systems. The effortshall be focused on identifying the manufacturing errorsthat have occurred in ROV systems even with adequate QA-QCprocesses.

3. REQUIREMENTS

The contractor shall examine and identify from an overviewall ROV manufacturing problems that have been observed bythe manufacturers and their subcontractors. Included inthis examination shall be alternative approaches, andexpected solutions devised to correct the problems. Thecontractor shall categorize the manufacturing errors andrecommend procedural solutions to these problems so thatthey can be avoided in the manufacturing of future high

I

reliability ROV systems. These recommendations shall be inthe form of deliverables to this contract. The deliverablesshall reflect the current state-of-the-art technology, andassume implementation in the next five years.

i.± Critical Manufacturing Problem Areas

In dealing with specific manufacturing recommendations formaximizing system reliability, the contractor must keep inmind that these must be based on the understanding thateliminating the large majority of these problems does notnecessarily require major restructuring of the manufacturingprocess. It is expected that recognition of many of theproblems shall be sufficient for the manufacturer to avoidthem.

3.1.1 Problems with Workinq Systems

ROV systems produced in the past have experiencedreliability problems resulting from production designand manufacturing problems. Many of these problemswere identified by the users and in many cases the usercontacted the manufacturer with full descriptions ofthe problem. The contractor shall outline theseproblems, their cause as it relates to manufacturingand production design and their solutions. Thecontractor shall identify and categorize any suchproblems and provide recommendations/solutions for themin the final report.

3.1.2 Vehicles of Recent Manufacture

There are a variety of ROV systems that have beenrecently (within three years) produced which have alimited time in the field. These would include systemsthat, although not yet accepted by the customer, arestill undergoing trials in the field at the presenttime. Many of the major ROV manufacturers haveproducts in this stage of production. Many of thesesystems have experienced faults that may be a result ofproduction design problems and/or manufacturing errors.As in item 3.1.1 above, these failures may be detailedin reports on operations and/or communications witheither the manufacturer or technical support group forthe system. The contractor shall identify andcategorize those reliability problems and providerecommendations/solutions in the final report.

3.1.3 Vehicles Presently in Production

ROV systems that are in production at the present timealso demonstrate reliability problems that are a resultof faulty production design or other manufacturingproblems. Most of the manufacturing errors that occur

with vehicles currently in production become knownthrough quality testing procedures for the finalsystem. Testing procedures that include vibration andshock tests, environmental tests, and pressure testsoften bring manufacturing errors to light before thesystem experiences field trials. The contractor shallidentify and categorize any manufacturing errors thathave been identified for ROV systems still in theproduction process. Further, the contractor shallprovide these categorizations and recommendationsand/or potential solutions in the final report.

4. DELIVERABLES

The deliverable for this project shall be in the contractorformat and in accordance with the attached Contract DataRequirements List (CDRL), form DD 1423. Details for therequired deliverable follow:

The deliverable for this contract shall include lists of allthe ROV reliability problems, of which the contractor isaware, arising from problems in the manufacturing and/orproduction design process. Recommendations/solutions tothese problems shall also be detailed for each problem area.These lists should be categorized bymanufacturing/production processes within the three majorgroupings of vehicle field history.

The deliverable for this contract shall be in the form of afinal report, CDRL Item # A001, including the above listsand categories. This report will be compiled with the finalreports from the other manufacturing contractors for thegovernment by Marine Imaging Systems. During thiscompilation the identification of contractors contributingto the report and the identification of specific ROV systemsshall be eliminated thus making the individual problemsoutlined generic and anonymous in the final compilation.

This compilation shall be made available to themanufacturing contributors to this effort. This willprovide to the contributors listings of major manufacturingerrors, production design problems andrecommendations/solutions to these problems, so that theymay avoid these problems in future manufacturing efforts.

4.1 Final Report (AO01)

The final report, CDRL Item # A001, shall outline ROVreliability problems which stem from manufacturing errors.These errors/problems shall be categorized by vehicle fieldhistory as described in Sections 3.1.1 through 3.1.3 of thisStatement of Work. The problems shall be further sub-categorized by production processes within each majorcategory. For each problem area (or each individual problem

3

if appropriate) recommendations/solutions to the problem asthey relate to manufacturing or production design shall beoutlined.

A draft final report prepared in contractor format,describing all results and conclusions, shall be submitted60 days prior to completion of the contract for review andcomment. A final report updating the draft report, asrequired by the review comments, shall be submitted 30 daysafter the contractors receipt of the review comments on thedraft report.Specific deliverables to be included in the final report

are:

4.1.1(3.1.1) rroblems with Working Systems

The contractor shall identify and categorize anymanufacturing related failures to ROV systems whichhave a significant field history and providerecommendations/solutions for them in the final report.

4.1.2(3.1.2) Vehicles of Recent Manufacture

The contractor shall identify and categorize thosereliability problems attributable to production designsand/or manufacturing errors which have occurred withvehicles of recent manufacture and providerecommendations/solutions in the final report.

4.1.3(3.1.3) Vehicles Presently in Production

The contractor shall identify and categorize anymanufacturing errors that have been identified for ROVsystems still in the production process. Further, thecontractor shall provide these categorizations andrecommendations and/or potential solutions in the finalreport.

4

STATEMENT OF WORK

FOR



Buoyancy Materials

Prepared By:


Prepared For:


(ONR Code 122)

TABLE OF CONTENTS

Section/Paragraph

1 BACKGROUND AND INTRODUCTION .....................

2 APPLICABLE DOCUMENTS ........................... 2

2.1 Other Government Documents ........................ 2

3 SCOPE .......................................... 2

4 REQUIREMENTS ................................... 34.1 Syntactic Foam Performance ........................ 34.2 Design ......................................... 44.3 Manufacturing .................................. 74.4 Testing ........................................ 84.5 Other Potential Problems .......................... 94.6 High Reliability Syntactic Foam Specification .. 94.7 New Materials .................................. 94.8 Design Testing ................................. 10

5 DELIVERABLES. 0...................................05.1 Program Plan (AO01) ............................ 105.2 Status Reports (A002) .......................... 105.3 Final Report (A003) ............................ 105.4 High Reliability Syntactic Foam

Specification (A004) ........................... 13

STATEMENT OF WORK


Future Navy requirements will involve protracted deploymentsof underwater Remotely Operated Vehicles (ROVs) andAutonomous Untethered Vehicles (AUVs) . To date, theperformance of such vehicles has been heavily dependent onthe quality and quantity of the maintenance and supportavailable during relatively limited deployments. An ROVdesign that is appropriate for industrial (e.g., petroleumindustry) operations, with limited exposure and theexpectation of much maintenance, as a tradeoff againsthigher initial cost, is inappropriate for military missionswith little or no opportunity for upkeep. As a result, thecommon practice of modifying existing ROVs and ROVsubsystems for use in military service is undesirable and isnot considered to be a long term solution for extendedmission Navy operations.

The following operational capabilities and reliability goalsneed to be achieved for the Navy to meet its long termdeployment ROV/AUV requirements. The vehicles must bedesigned and built to achieve an operational reliability of98% or better when operating during protracted deployments(3-6 months wet or in a powered-down configuration for oneto two months followed by weeks of subsequent operations).The ROV/AUV system operational capabilities to be consideredare as follows:

1. The operational depth design considerations aremaximums of 3,000 feet, 6,000 feet and 20,000 feet.

2. Tethers:

A.The ROV system shall have a 4,000 foot poweredtether working from a station keeping platform witha maximum distance from the platform of 3,000 feetin any direction. Station keeping is defined aszero relative velocity between platform and thesurrounding water.


3. The ROV or AUV system shall have low self-radiatednoise according to the goals shown in Figure 1, and itsauxiliary acoustic components shall not interfere withthe platform sensors. The entire system shall minimizeacoustic radiation.

4. The ROV or AUV system's magnetics shall not interferewith the platform or its sensors.

5.The ROV's capacity for a variety of work tasks,including heavy duty work and high power manipulators,shall also be considered.



Specifically, this statement of work addresses ROV/AUVsyntactic foam buoyancy modules design and reliabilityproblems and how their design and manufacture might beimproved to help obtain the long range Navy objective ofachieving a substantial increase in the extended missionreliability of ROVs/AUVs.

2.0 APPLICABLE DOCUMENTS


The following government document forms a part of thisspecification to the extent specified herein:

SynLactic Buoyancy Material for High HydrostaticPressures, MIL-S-24154A (SHIPS)

3. SCOPE

The objective of this Statement of Work is to providerecommendations for specific solutions to long term failuresexhibited by standard formulations of syntactic foambuoyancy modules. This will be provided in the form ofdeliverables which will allow the designer of ROV/AUVsystems with a basis for selecting reliable syntactic foammodules when designing new vehicles or in retrofittingexisting systems.

The work shall be focused on ways to improve the reliabilityof syntactic foams. Although the use of commerciallyavailable syntactic appears to be the best choice forbuoyancy materials at present, better performing materialsshall be required for high reliability underwater systems inthe near future. Many of the foams currently available todayexhibit long term unreliability due to failures in the

structural makeup of the foam matrix. Failures that havebeen noted frequently in the past include physical breakdownof the individual modules. This most often occurs when thematerial has been subject to shock or impact.

4. REQUIREMENTS

The contractor's proposal shall identify from an overviewhow to approach each problem of syntactic foam unreliabilitytechnically, alternative approaches, costs and schedules.The approach shall address the major failure modes ofsyntactic foam modules, those being structural failureexperienced by cracking and chipping and water absorption asa result of microsphere failure and improper formulation ofthe foam itself. These major failure modes can be caused byproblems occurring in the three areas of design,manufacturing and testing.

The genesis of the results of the work in this Statement ofWork shall generate a new specification for design,manufacture and testing of high reliability, long-termdeployment syntactic foam capable of three depth regimes of3,000, 6,000 and 20,000 feet.

The contractor shall examine these common failure modes andrecommend design and/or procedural solutions to theseproblems so that they can be implemented at a later date fortesting and/or examination purposes. These solutions shallbe in the form of deliverables described later in thissection of the SOW. The deliverables shall reflect thecurrent state-of-the-art technology, and assumeimplementation in the next five years.

4.1 Syntactic Foam Perfo ,ance

Microspheres within a resin matrix are commonly used forbuoyancy in the underwater environment for use on manned andunmanned submersibles. The small spheres do not exhibithigh energy release upon failure because, individually, theydo not have any appreciable kinetic energy at depth and theydo not often fail simultaneously. Also, because of theirsmall size, they have very small interstitial spaces. Binaryblends of the microspheres with a mixture of two sizes (lxdia and 7x dia) create a nearly perfect fill and minimizethe interstitial spaces as well.

Syntactic foam is produced in varying densities, with thedenser foams (which generally have smaller gas-filledspheres) being rated for deeper depths. These "deeper"foams inherently have less buoyancy per volume than the lessdense, shallower rated foams.

3

Unfortunately, many designs of syntactic foam in productiontoday exhibit undesirable characteristics such as crackingand chipping under physical abuse and water pickup afterprolonged exposure to high hydrostatic pressure. Crackingand chipping results from low strength in the bindingagents. Water pickup is most often caused by the wallfailure of microspheres located tangential or very close tothe outside of the syntactic foam unit as well as waterpenetration into "voids" in the binding agents. When foamblocks chip or crack more of the materials surface area isexposed to the underwater environment and as a result, someamount of buoyancy is lost. Another failure exhibited byexisting formulations of syntactic foam is the failure ofthe structure of "microspheres" which are the main buoyancycomponent of the modules. Under pressure and over longperiods of time, wall failure of these small buoyancycomponents result in a loss of buoyancy of the system.Further loss of buoyancy over the long term results from asimilar "water pickup" due to "macro voids" in the bindingagents used in the formulation of the modules

It has been known that even the higher quality syntacticfoam formulations demonstrate water absorption to a minimumof .10" to all exposed surfaces of the modules. This occursbecause the microspheres at the surface are not fullyencapsulated and collapse under pressure. This actionresults in a permanent loss of buoyancy for the overallmodule. This penetration occurs very rapidly under pressureand most foams will exhibit at least 50% of its totallifetime water absorption within 48 hours at pressure. Thislevel of water absorption is acceptable in most buoyancyapplications but further water pickup is unacceptable andcontributes to the lack of reliability of the product.

The expected solution for high reliability buoyancycomponents would be to develop and use a very highperformance foam that has special features (binary blendedmicrospheres, pre-pressurized microspheres, high strength,low density binding compounds, etc). This approach has thepotential to keep the size and weight of syntactic buoyancysystems under control. To insure the final product ismaintained with the design guidelines, further steps ofimplementing a rigorous Quality Assurance procedure at everystep of manufacturing and testing are required.

4.2 DesiQn

A reliably performing foam should be designed that does notexhibit the common failure modes of existing foams. Thedesign process shall address all the major components ofbuoyancy modules for use in the underwater environment.

4

4.2.1. Glass Microspheres

Sources for glass microspheres have been limited in thepast to one or two suppliers. This can severely limitthe availability of production of acceptable productsfor the government. The contractor shall investigateboth additional sources of glass microsphere and thepossibility of other, more readily available materialsfor use in syntactic foam.

4.2.2. Resin Binders

The resin binder component in syntactic foam is acrucial part of the modular unit and has the greatestpotential for design improvements. With a strong, lowdensity binder structural failure of the final productcan be minimized. The contractor shall recommenddesign improvements to existing formulations of bindingmaterials for use in a high performance syntactic foam.

4.2.2.1 Bulk Modulus

The binder is often the component that dictates, toa large part, the three directional compressibilityor bulk modulus of the final product. In order tominimize the requirements for large ballastingsystems on underwater vehicles, the ideal buoyancycomponent of the system would have a modulus similarto that of seawater. This would allow the buoyancymodules to maintain the same buoyancy throughout therated working depth of the system. The contractorshall recommend syntactic foam formulations thathave suitable bulk modulus for use at 3,000, 6,000and 20,000 foot depths. Recommendations shall bepi-ovided in the final report (CDRL item #A003).

4.2.2.2 Fillers

Low density fibers and other fillers in the resinbody of syntactic foam can degrade its performanceand strength over long periods of time. Thecontractor shall design resin binders that do notcontain fillers to lower its density. The designshall be provided in the final report (CDRL item#A003).

4.2.2.3 Hazardous Materials

Some formulations of binders contain potentialhazardous materials. The removal of these compoundsfrom the manufacturing process may affect theavailability of the final product until a substitutecan be found. The contractor shall investigateformulations that do not require potentially

5

hazardous materials and he shall further identifypotential replacements for any materials in questionin the final report (CDRL item #A003).

4.2.2.4 Exothermic Properties

Most resin binders used in the production ofsyntactic foams possess exothermic properties which,unless carefully controlled, can result in a non-homogenous product. Also, exothermic reactions canprevent small test runs of a product from accuratelyrepresenting the final product run in largervolumes. The contractor shall investigate thepossibility of using binders that do not possessexothermic properties during the manufacturingprocess. If less exothermic material is found, thecontractor shall recommend control of productionprocess during manufacture. Recommendations shallbe provided in the final report (CDRL item #A003).

4.2.3. Coatin s

On many formulations of syntactic foam, protectivecoatings have been applied to the modules outersurface. These coatings, when used on a water blockingmaterial, can fail and significantly degrade theperformance of the foam. Although protective coatingscan be valuable to enhance the shock absorbingqualities of the final product, these coatings shouldnot block water from contacting the outer surface ofthe foam proper, since water blocking coatings are ashort term, stop gap measure to prevent water pick upin buoyancy modules. Further these coatings should beof low density, but elastic enough and strong enough toprotect the modules from shock. The contractor shallrecommend protective coatings for high performancesyntactic foam that provide effective shock absorbingqualities without waterproofing the surface of the foammodules. The recommendation shall be provided in thefinal report (CDRL item #A003).

4 .2.4. Macrospheres

In lower density, shallower rated foams larger spherescalled "macrospheres" are often used. The materials,construction and size of these macrospheres can have animportant impact on the performance of the finalproduct. The contractor shall recommend high performingmaterials, design and size of macrospheres for optimumperformance in the final syntactic foam product andprovide the reccmmendations in the final report (CDRLitem #A003).

6

4.2.5. Fasteners

In assembling final production modules of syntacticfoam to an underwater vehicle system, very often avariety of adhesives and fasteners must be used. Thesefasteners must be reliable and perform over long termdeployments. The contractor shall recommend types anddesigns of fasteners and adhesives to be used in thefinal assembly of the buoyancy components to thefinished system. Recommendations shall be provided inthe final report (CDRL item #A003).

4.3. Manufacturing

In the manufacturing process there are a number of processesthat can improve the reliability of syntactic foam.Syntactic foam has been manufactured in a number ofdifferent ways including mixing a viscous formulation andvacuum injection. It is desirable during manufacture tocreate a homogeneous, consistent product which exhibits theoptimum characteristics of low density and high strength.The contractor shall provide the recommendations on theoptimum processes in the final report (CDRL item #A003).

4.3.1. Microspheres

In the prrd,,ction of microspheres, a great variety ofproduct is typically found. Selecting the appropriatesize and strength product has an important impact onthe performance of the syntactic with which they aremade. The contractor shall investigate and recommendmethods by which the final microspheres used in themanufacture of the syntactic foam are selected.Recommendations shall be provided in the final report(CDRL item #A003).

4.3.2. Packing Factor

The distribution of microspheres within a manufacturedblock of final product can affect the quality andperformance of the final product. In some manufacturingmethods, the microspheres will shift while the formulais still in a slightly viscous state. This does notprovide an even distribution of the microspheres andprevents the product from having a uniform density. Thecontractor shall recommend methods of packing thespheres within the mold for the final product toinclude the maximum quantity of microspheres.Additionally, he shall recommend methods to prevent themicrospheres from shifting within the formula before ithas hardened. The reconamendations shall be providAd inthe final report (CDRL item #A003).

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4.3.3. Adherence

Many formulations of binding agents do not lendthemselves to adhering to the microspheres within theproduct. This can lead to a lower than desired strengthfoam as well as voids within the foam module. Thecontractor shall recommend methods to aid adherence ofthe resin to the microspheres to maximize the strengthof the final product. Recommendations shall beprovided in the final report (CDRL item #A003).

4 .3.4. Macrospheres

The placement of macrospheres in foams t1it requirethem is important to the performance of the product.The contractor shall recommend manufacturing methods toassure that the packing and positioning of themacrospheres is optimum and shifting does not occurduring the manufacturing process. Recommendationsshall be provided in the final report (CDRL item#A003).

4.4. Testing

In the manufacture of syntactic foams, a variety of tests isrequired to ensure a reliable product. These tests must bedesigned to evaluate the product properly or the results canbe misleading. If the buoyancy test of the product is basedon weight alone, a loss of buoyancy due to permanentcompression during pressure test may be overlooked.

4.4.1. Test Samples

Common methods of sampling production units ofsyntactic foam do not adequately represent the finalmanufactured product. The contractor shall recommendsampling methods that provide samples that arerepresentative of the final product. Recommendationsshall be provided in the final report (CDRL item#A003).

4.4.2. Displacement Testing Under Pressure

Experience has shown that representative samples shouldbe tested to show long-term buoyancy performance in onetest rather than in two separate tests which evidenceweight gain and changes in size. The contractor shallrecommend short-term, long-term and accelerated highpressure testing methods, which provide accurate,continual data during the production, on displacementand buoyancy of syntactic foam test samples.Recommendations shall be provided in the final report(CDRL item #A003).

4.4.3. Fasteners

Failure modes in many syntactic foam blocks haveoccurred due to unreliable nonmetallic adhesives andfasteners used in joining or attaching syntactic foammodules to other components. The contractor shallrecommend test procedures to test adhesives andfasteners used in conjunction with the syntacticmodules during final assembly to a submersible vehicle.Recommendations shall be provided in the final report(CDRL item #A003).

4.5 Other Potential Problems

The contractor shall provide recommendations for otherproblems that may be encountered by the syntactic foam userother than the problems listed above. There are manydifferent syntactic foams now in use on Remotely OperatedVehicles (ROVs) and Autonomous Underwater Vehicles (AUVs).Each of these foams has unique problems with respect tomeeting the design specification and operationalrequirements other than those listed above. The contractorshall detail any other identified problems which may be ofz nen Lo uesl.i engineers. Potential solutions for theseproblems shall be provided in the final report (CDRL item#A003).

4.6 High Reliability Syntactic Foam Specification

The contractor shall develop a specification forconstruction of a high reliability, long term deploymentsyntactic foam for use on ROV/AUV systems. Thespecification shall address the problems listed above andthose generated by the contractor, that are associated withsyntactic foams used at deep ocean depths with emphasis onthe depths of 3,000 feet, 6,000 feet and 20,000 feet. Thecontractor shall provide this specification separate fromthe final report (CDRL item #A004).

4.7 New Materials

The contractor shall assess new materials that are availableto substitute for syntactic foam, including theadvantages/disadvantages, status of the associatedtechnology and degree of promise. The potential newmaterials assessment shall be included in the final report(CDRL item #AO03).

9

4.8 Design TestinM

The contractor shall identify and recommend in this SOW anyconcept definiticn design testing that should be undertakenand the associated advantages of that testing in validatingthe High Reliability Syntactic Foam Specification. Theconcept definition design testing description shall includethe cost and schedule impact. The recommendation shall beincluded in the final report (CDRL item #A003).

5.0 DELIVERABLES

Evaluations, specifications, design guidelines, comparisons,descriptions and/or recommendations for the specifictechnical problems of buoyancy materials shall be a primeproduct (CDRL item #A003). The contractor shall provide aspecification for high reliability syntactic foam as adeliverable on this contract (CDRL item #A004) . Thecontractor shall provide a final report (CDRL item #A003).Other deliverables required are a program plan (CDRL item#AO01), and status reports (CDRL item #A002).


5.1 Program Plan (A001)

The contractor shall develop a program plan in accordancewith CDRL item #AO01, identifying how to approach eachproblem technically (including breakpoints), alternativeapproaches, and a schedule for each required deliverable inSection 4 of the SOW. The plan shall elaborate on thecontractor's proposed technical approach to the SOW anddetail how the contractor will perform each required itemwithin the allocated time and cost. A draft program planshall be delivered 30 days after contract award, and issubject to Government approval. A final version of theprogram plan, with Government comments incorporated, shallbe required 15 days after the contractor's receipt of theGovernment's comments.




A draft final report prepared in accordance with CDRL item#A003, describing all research results and conclusions,shall be submitted 60 days prior to completion of the

10

contract for review and comment.




Section 4 requires the contractor to provideevaluations, specifications, design guidelines,comparisons, descriptions and/or recommendations foreach specific problem and to include the results asseparate, identifiable items in the final report. Theresults shall be prepared in accordance with CDRL item#A003 for the ROV Buoyancy Materials tasking asdirected in items 4.2.1 through 4.4.3 inclusive anditems 4.5, 4.7, and 4.8. The specific items to bereported are:

(4.2.1) Glass Microspheres

The contractor shall investigate both additionalsources of glass microspheres and the possibility ofother, more readily available materials for use insyntactic foam.

(4.2.2) Resin Binders

The contractor shall recommend design improvementsLo existing formulations of binding materials foruse in a high performance syntactic foam.

(4.2.2.1) Bulk Modulus

The contractor shall recommend syntactic foamformulations that have suitable bulk modulus foi useat 3,000, 6,000 and 20,000 foot depths.

(4.2.2.2) Fillers

The contractor shall recommend resin binder formulaetnat do not contain fillers to lower its density.

(4.2.2.3) Hazardous Materials

The contractor shall investigate formulations thatdo not require potentially hazardous materials andhe shall further identify potential replacements for

11

any materials in question.

(4.2.2.4) Exothermic Properties

The contractor shall investigate the possibility ofusing binders that do not possess exothermicproperties during the manufacturing process. Ifless exothermic materials are found, the contractorshall recommend controls for the production process.

(4.2.3) Coatings

The contractor shall recommend protective coatingsfor high performance syntactic foam that provideeffective shock absorbing qual'ties withoutwaterproofing the surface of the foam modules.

(4.2.4) Macrospheres

The contractor shall recommend high performingmaterials, design and size for macrospheres t!-twill provide optimum performance in the finalsyntactic foam product.

(4.2.5) Fasteners

The contractor shall recommend types and designs offasteners and adhesives to be used in the finalassembly of the buoyancy components to the finishedsystem.

(4.3.1) Microspheres

The contractor shall investigate and recommendmethods by which the final microspheres used in themanufacture of the syntactic foam are selected.

(4.3.2) Packing Factor

The contractor shall recommend methods of packingthe spheres within the mold for the final product toinclude the maximum quantity of microspheres.Additionally, he shall recommend methods to preventthe microsphere from shifting within the fornulabefore it has hardened.

(4.2.3) Adherence

The contractor shall recommend methods to aid in theadherence of the resin to the microspheres tomaximize the strength of the final product.

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(4. 1.4) Macropheres

The contractor shall recommend manufacturing method!;to assure that the packing and positioning of themacrospheres is optimum and shift does not occurduring the manufacturing process.

(4.4.1) Test Samples

The contractor shall recommend sampling method:; thitprovide samples that are representative of the f i n lproduct.

(4.4.2) Displacement TestingUnder Pressure

The contractor shall recommend short term, long termand accelerated high pressure testing methods whichprovide accurate, continual data during thfproduction run on displacement and buoyance ofsyntactic loam test samples.

(4.4.3) Fasteners

The contractor shal l recommend test procedu res t.)test adhesives and fasteners used in conjunct ionwith the syntactic modules during final as:embly toa submersible vehicle.

( 4.) O1ther Potential Problems

The contractor shal 1 detai I and prov ide det, i I , Ipotential solutions for these problems in the t in.ilreport (CDRL item #AO03).

(4.7) New Mater ia ls

The contractor sha I I assess new materials that iareavailable to substitute for syntactic foam.

(4.8) Design Testing

The contractor ;ha ll identify any concept del initiondesign testing that should be conducted inaccordance of this !;OW.

. 4 !High Rol iabil ity !;yntoctic _ Foam _j;pec it icat on (AO).I)

The cont.ractor shal 1 develop a speci fication per- p,iraqr,iph(4. ,) for construction of a high reliability, long term(ployment .-;yntactic foam for use on ROV/AUV systems. Th,(Iepths; of i ntere.t are 3,00 feet, 6,000 fe tarlnl 20,000 feet.

IH

STATEMENT OF WORK

FOR



Sealing Systems

Prepared By:


Prepared For:


(ONR Code 122)

TABLE OF CONTENTS

Section/Paragraph

1 BACKGROUND AND INTRODUCTION....................... 1

2 SCOPE.............................................. 2

3 REQUIREMENTS....................................... 33.1 Critical Design Areas............................. 33.2 High Friction Seal Design......................... 43.3 Static Seals....................................... 73.4 Reference Documentation........................... 83.5 Manufacturing Errors.............................. 9

4. DELIVERABLES ........................ 94.1 Program Plan (AO0l)............................... 94.2 Project Status (A002)............................. 94.3 Final Report (A003)............................... 9

STATEMENT OF WORK


Future Navy requirements shall involve protracteddeployments of underwater Remotely Operated Vehicles (ROVs)and Autonomous Untethered Vehicles (AUVs). To date, theperformance of such vehicles has been heavily dependent onthe quality and quantity of the maintenance and supportavailable during relatively limited deployments. An ROVdesign that is appropriate for industrial (e.g., petroleumindustry) operations, with limited exposure and theexpectation of much maintenance, as a tradeoff againsthigher initial cost, is inappropriate for military missionswith little or no opportunity for upkeep. As a result, thecommon practice of modifying existing ROVs and ROVsubsystems for long term, at-sea storage and/or operationwithout maintenance is undesirable and is not considered tobe a long-term solution for extended mission Navyoperations.

The following operational capabilities and reliability goalsneed to be achieved for the Navy to meet its long termdeployment ROV/AUV requirements. The vehicles must bedesigned and built to achieve an operational reliability of98% or better when operating during protracted deployments(3-6 months wet or in a powered-down configuration for oneto two months followed by several weeks of subsequentoperations). The ROV/AUV system operational capabilities tobe considered are as follows:

1. The operational depth design considerations are maximums

of 3,000 feet, 6,000 feet amd 20,000 feet.

2. Tethers:

A. The ROV system shall have a 4,000 foot powered tetherworking from a station keeping platform with a maximumdistance from the platform of 3,000 feet in anydirection. Station keeping is defined as zero relativevelocity between platform and geodetic and geographicsurroundings.


3. The ROV or AUV system shall have low self-radiated noise,according to the goals shown in Figure I, and itsauxiliary acoustic components shall not interfere withthe platform sensors. The entire system should minimizeacoustic radiation.

4. The ROV or AUV system's magnetics shall not interferewith the platform or its sensors.

5. The ROV's capacity for a variety of work tasks, includingheavy duty work and high power manipulators, shall alsobe considered.



Specifically, this statement of work addresses reliabilityproblems with high pressure differential shaft seals used onvehicles and how their design might be improved to helpobtain the long range Navy objective of achieving asubstantial increase in the extended mission reliability ofROVs/AUV's.

2. SCOPE

The objective of this SOW is to provide recommendations foreliminating the chronic failures in sliding, rotating,hydraulic and static seals on ROV/AUV systems in the marineenvironment. This shall be presented in the form ofdeliverables so that designers can use this information inthe creation of new vehicles and systems, or introubleshooting/retrofitting existing systems.

The work shall be focused on ways to improve the reliabilityof seals, including the static and moving components ofthese sealing assemblies. The design of elaborate,compensated seal assemblies can, with a high reliabilityROV/AUV, drive up the size and complexity of the vehiclesubcomponents. Consequently, the contractor shall conductdesign tradeoffs to select the optimum seal designcharacteristics affording the desired reliability level in asmall size.

For electronics housing endcaps, mechanical hull penetrationcomponents (rotating or sliding) and cable terminations onROV/AUV systems, effective mechanics for seal barriers arevery important for overall system reliability. Areas wherethese seals are used include thruster assemblies andactuator rod seals. It has been the experience of vehiclesystem designers and users that although all of these areas

are potential failure points, some are more reliable thanothers.

Many seals are largely static and experience very littlefriction. An example of this is the standard "0" or "X" ringseal used on electronic housing endcaps. Often the onlymovement these seals experience other than when removing orreplacing the seals themselves, is caused by the pumpingaction resulting from cycling through high pressureenvironments.. However, these components do breakdown overtime and require consideration during system design. Dualseals of different types such as face seals for highpressure environments and radial seals for low pressureenvironments are often designed into systems to increasetheir overall reliability.

However, seals that experience high levels of friction, suchas moving shatt seals, more significantly contribute toreliability problems primarily due to the increased wearwhich they experience. Seals across which there is a highpressure differential are found on a number of parts ofunderwater vehicles and are of particular concern, in thatwith time, their reliability drops dramatically.Specifically, the seal reliability must be increased forhydraulic and air-backed thruster assenblies and any othercomponents on the ROV/AUV system which utilizes highfriction seals.

3. REQUIREMENTS

The contractors proposal shall identify from an overview howto approach each problem technically, alternativeapproaches, costs and schedules.

The contractor shall examine and develop solutions tocommon failure modes of seals in the marine environment andrecommend design and/or procedural solutions to theseproblems so that they can be implemented at a later date fortesting and/or evaluation purposes. These solutions shallbe in the form of deliverables described later in thissection of the SOW. The deliverables shall reflect thecurrent state-of-the-art technology, and assumeimplementation in the next five years.

3.1 Critical Design Areas

The overall objective is reliable longer-term deployment ofROVs/AUVs than is possible with current commercial vehicledesigns modified to meet Navy requirements. Severalspecific critical areas have been identified which must beaddressed in order to improve reliability to an acceptablelevel. In dealing with specific design recommendations formaximizing system reliability, the contractor must keep in

3

mind that these must be based on the realization thatcompromise is an inevitable part of every design effort.Consequently, the importance of each recommendation,relative to other recommendations, must be indicated.Further, the contractor shall provide reasonable comparisoninformation on the application of less than optimumalternatives and their possible consequences.

Specific consideration shall be given to the environment inwhich this ROV/AUV shall be performing. The pressures arenot expected to exceed 1500 psia but there may besignificant pressure cycling during active and inactiveperiods. There may also be long periods (up to 90 days) ofinactivity after which the system is expected to function atany pressure within the rated range. Consideration shallalso be given to seals operating in the 3000 psia and 10,000psia pressure ranges.

The design of most long life, noncompensated seals requiresome form of lubrication for both cooling and frictionreduction. Since the reliability of an ROV/AUV may beadversely affected by even small amounts of water intrusion,a compensated seal design is likely to be more desirablethan a non compensated seal design in high friction, highdifferential pressure conditions. However, tradeoffs existbetween the use of compensated or non compensated sealdesigns particularly in the areas of failure andmaintenance. The contractor shall examine the tradeoffs inthe application of these two designs in terms of MTTR andMTBF figures.

3.2. High Friction Seal Design

Due to the complexity of the construction, a variety of sealdesigns for rotating and sliding compensated seals arepossible. The contractor shall compare the different methodsand recommend the most reliable method of compensating andintegrating the seal within the housing which the shaftpenetrates. It is expected that there shall be no allowancefor water intrusion into the housing being sealed. If thefinal design of the seal absolutely requires leakage forseal lubrication and increased reliability, the contractormust realize that it is preferable in this situation to have

small amount of lubricant leak out into the environmentrather than water leak into the sealed component.

3.2.1. High Friction Seal Carrier Assembly Materials

Corrosion adversely affects the reliability of anyunderwater system. The design and construction of aseal system for use on a long-term deployable ROV/AUVsystem must take the problems of various types ofcorrosion into account. The contractor shall design aseal that may be constructed from stainless steel,

4

Inconel, titanium or other alloy resistant to corrosionand provide the design in the final report (CDRL item#A003). If the material of choice for the seal systemhas distinct advantages over other materials, it isunderstood that its use may drive the choice ofmaterial for the sealed housing.

3.2.2. High Friction Sealing Face Materials

For seal systems, the materials used most often are acomposite material that shall pe;form reliably underhigh rpm rotation conditions. The contractor shallexamine all possible materials for the seal faceincluding graphites and ceramics such as tungsten orsilicon carbide as well as any other material which mayperform reliably. The contractor shall recommend thematerial in the final report (CDRL item #A003) thatwill provide the highest reliability.

3.2.3. Acoustic Output

The ROV/AUV systems employing high reliability sealsfor high friction applications shall be designed tohave minimal acoustic output during operation. Bearingassemblies contained within some sealing systems maycontribute significantly to overall acoustic output.The contractor shall recommend bearing designs thathave a low noise signature while maintaining positivebearing qualities for wear, strength and corrosionresistance and provide these recommendations in thefinal report (CDRL item #A003).

3.2.4. Operating Ranges

Seal systems are typically comprised of a number ofmachined parts with close tolerances. The reliabilityof the seal system relies, in part, on the precisionwith which these parts fit together. Some of theseparts are susceptible to physical changes with varyingtemperature which could adversely affect thereliability of the sealing system. The contractor shallprovide the tradeoffs involved, if any, of choosingmaterials that shall not be adversely affected boperating in underwater environments ranging from -2to 400 C, and provide the results in the final report(CDRL item #A003).

3.2.5. Toraue Requirements

An increase in pressure across any shaft seal facetypically increases the torque required to bothinitiate movement and in the case of extension androtary shafts, maintain movement of the shaft. Sincethe new seal design may be applied to torque sensitive

5

electric motors, the contractor shall provide a sealdesign that does not significantly contribute to thenormal torque required to initiate movement andcontinue movement. The contractor shall provide theresults in the final report (CDRL item #A003).

3.2.6. Test Plan

Since these high friction seals may experiencecontinual changes in ambient pressures, a test plan isrequired. The following test plan shall be developedto determine the performance of the seal for long-termdeployment as well as for 1000 cycles from oneatmosphere absolute to rated working pressure andreturn, with particular attention to long-term wetstorage of the ROV/AUV system and extended power-downperiods.

3.2.6.1. Leak Rates

The contractor shall draft a test plan for theprototype to determine that the seal designdemonstrates minimal or no leakage through cyclingand over the long term. The leak rates shall bequantifiable during this period. The contractorshall provide the results in the final report (CDRLitem #A003).

3.2.6.2. Torque

The contractor shall draft a plan for testing theprototype unit's torque required over the full rangeof rated working pressure for both startup andcontinuance of shaft movement, and provide theresults in the final report (CDRL item #A003).

3.2.6.3. Lonq-term Static TestinQ

The contractor shall draft a test plan for theprototype where the seal is inactive (no rotationalor sliding motion) for up to 90 days after which theseal should function under working conditions, andprovide the results in the final report (CDRL item#A003).

3.2.6.4. Acoustic Output

The contractor shall draft a test plan to determinethe acoustic output of the seal assembly underrealistic duration (active or inactive period (i.e.after a 90 day inactive period)) and throughout therated working pressures of the seal assembly, andprovide the results in the final report (CDRL item#AO03).

6

3.2.6.5. Bearing Wear

The contractor shall draft a test plan to determinethe bearing wear that shall be experienced by theseal assembly during the operation of the finalsystem at various working pressures over thedeployment duration (active or inactive period) andprovide the results in the final report (CDRL item#A003).

3.2.6.6. Seal Face Wear

Since the heart if any sealing assembly is the highfriction face area, the contractor shall draft aplan to test and quantify the seal face wear of theunit throughout the depth and duration of expecteddeployment (active or inactive period), and providethe plan in the final report (CDRL item #A003).

3.2.7. Prototype

A new high friction seal design for high reliabilitymay require prototyping in order to test the variousrequired qualities in the design. The contractor shalldraft a proposal for building a prototype design inorder to test the seal's performance for long-termdeployment, and provide the plan in the final report(CDRL item #A003). This proposal may be executed as anoption to this contract at the discretion of theGovernment.

3.3 Static Seals

High friction shaft seals frequently have secondary sealswithin the main seal carrying assembly and at the seal-housing joint which are referred to as "static" seals .These indirect seals , although not usually subject to highfriction conditions, can be as crucial to the whole sealintegrity as the main seal itself. The contractor shallminimize these indirect seals, in addition to trying andmaximize their reliability and performance, during thedesign process. These static seals also are applied tohousing endcaps, hydraulic joints, connector assemblies,cable terminations and other sealed assemblies.

3.3.1. Static Seal Materials

Given the pressures and cycling for which the ROV/AUVsystem shall be designed, the static seals shall berequired to maintain their seal integrity over a fairlywide pressure range for more than 1000 cycles. Thecontractor shall investigate and recommend any newmaterials for these seal components that may be bettersuited to the application than those in common use, andprovide the results in the final report (CDRL item#A003).

3.3.2. Static Seal Configuration

For static O-seals, face and radial configurations havetradeoffs and are often used together to increasereliability. Further, there may be other static sealdesigns and/or configurations, such as Quad-sealsTM orthe use of back-up rings, that may have morereliability than conventional O-seal installations. Thecontractor shall examine and recommend any of thesesealing configurations that would be expected toincrease the reliability of the overall seal system,and provide the results in the final report (CDRL item#A003).

3.3.3. Static Seal Compression Setting

The contractor shall consider the detrimental effectsof seal and gasket compression setting caused by longterm exposures to high pressure environments. Thecontractor shall recommend materials and configurationsof the static seal components that do not demonstratestatic seal compression setting, and provide theresults in the final report (CDRL item #A003).

3.3.4 Cable Terminations

Effective cable terminations, particularly thoseintegrated with cable strength members, can be acritical link in any underwater system. Regardless ofthe strength member integration, the seal for the ROVcable termination and high reliability system iscommonly the weakest link in the cable assembly. Thecontractor shall evaluate all termination typescurrently in use and provide recommendations for highreliability terminating methods and designs in thefinal report (CDRL item #A003).


The contractor shall make a thorough survey of applicablemilitary standards, specifications and handbooks. Thecontractor shall compile all such documents, cross-

referenced and explained so that the designer shall have asingle, concise source for selection of applicablecontrolling documents to reference during the preparation ofmaterial, process, or product specifications. Thecontractor shall draw on these and other sources ofinformation, and on his own experience in the design andimplementation of underwater sealing systems of all types,and produce a compendium of specific guidelines on how todesign to prevent problems (historical and expected) whichplague ROV/AUV seals reliability. This compendium shall bepresented as an attachment (CDRL item #A003) to the finalreport.

3.5 ManufacturinQ Errors

During the contract it is expected that the contractor shalldevelop a list of common manufacturing errors found to causevarious types of sealing system failures. This iist will bevaluable in warning the ROV/AUV designer or manufacturer oftheir existence. The contractor shall make this listavailable as an attachment to the final report, The list oferrors shall include explanations, desirable alternativesolutions, and recommendations (CDRL item #A003).

4. DELIVERABLES

Design recommendations for the technical aspects of sealassemblies which contribute to failures shall be a primeproduct. The contractor shall provide a prototype sealdesign as part of the deliverable on this contract alongwith the test plan as outlined in section 3.2.6. (CDRL item#A003.) The contractor shall produce a compendium ofspecific design guidelines for preventing problems whichplague ROV/AUV seals (CDRL item #A003). The contractorshall also provide a list of common manufacturing errorsfound to cause seal failures, and a final report (CDRL item#A003) . Other deliverables required are a program plan(CDRL item #AO01), and status reports (CDRL item #A002).


4.1 ProQram Plan (AO01)

The contractor shall develop a program plan in accordancewith CDRL #A001 identifying: how to approach each problemtechnically (including breakpoints), alternative approaches,and a schedule for each required deliverable in section 4 ofthe SOW. The plan shall elaborate on the contractorsproposed technical approach to the SOW and detail how thecontractor shall pertorm each required item within theallocated time and cost. A draft program plan shall bedelivered 30 days after contract award, and is subject to

9

Government approval. A final version of the program plan,with Government comments incorporated, shall be required 15days after the contractors receipt of the Governmentscomments.

4.2 Project Status (A002)

The contractor shall provide project status in accordancewith CDRL #A002 by the fifteenth of each month for theprevious calendar month.


A draft final report prepared in accordance with CDRL #A003,describing all research results and conclusions, shall besubmitted 60 days prior to completion of the contract forreview and comment.



4.3.1 Problem Documentation (CDRL item #A003)

Section 3 requires the contractor to provideevaluations, designs, tradeoffs, and/or recommendationsfor each specific problem and to include the results asseparate, identifiable items in the final report. Theresults shall be prepared in accordance with CDRL#A003 for the ROV/AUV shaft seal components,subsystems, supporting/auxiliary equipment or processesas directed in items 3.2.1 through 3.2.7. inclusive.The specific items to be reported are:

(3.2.1.) Seal Carrier Assembly Materials

The contractor shall provide designs for sealcarriers that can be constructed of a variety ofcorrosion resistant materials. The contractor shallalso recommend the best material from amanufacturing and reliability standpoint.

(3.2.2.) Seal Face Materials

The contractor shall provide the trade off andanalyses for using a variety of materials in theseal face. The contractor shall also recommend thebest material to be used in this part of the seal.

10

(3.2.3.) Acoustic Output

The contractor shall provide seal designrecommendations for bearings assemblies that shallminimize the expected seal wear while maintaining alow noise signature.

(3.2.4.) Operating Ranges

The contractor shall provide seal designrecommendations that shall perform well within thetemperature and pressure ranges outlined.

(3.2.5.) Torque Requirements

The contractor shall provide seal designrecommendations that shall require minimal torquefor initial and continuing shaft movement in theoperating environment.

(3.2.6.1) Leak Rates

The contractor shall provide a test plan for theprototype seal design to determine that itdemonstrates minimal or no leakage. The leak rateshall be quantified with respect to pressure cyclingand long-term deployment.

(3.2.6.2.) Torque

The contractor shall provide a test plan to measurethe prototype seal design torque requirementsthroughout the rated working pressures of the seal.

(3.2.6.3.) Long-term Static Testing

The contractor shall provide a test plan for theprototype seal design to determine the effects ofextended power-down periods on the effectiveness ofthe seal integrity.

(3.2.6.4.) Acoustic Output

The contractor shall provide a test plan todetermine the seal assembly's contribution toradiated noise throughout rated working pressuresand life cycle (active/inactive) of the sealassembly.

(3.2.6.5.) Bearing Wear

The contractor shall draft a test plan to determinethe rate of wear which will be experienced by anybearing subassemblies in the seal design over itsworking life (active/inactive).

11

(3.2.6.6.) Seal Face Wear

The contractor shall provide a test plan to quantifythe sealing face wear in a prototype designthroughout the duration (active/inactive) andworking depths of the system.

(3.2.7.) Prototype

The contractor shall provide a proposal forconstructing prototype seal assemblies to testperformance of the design. This proposal may beexecuted as an option to this contract at thediscretion of the Government.

(3.3.1.) Static Seal Materials

The contractor shall provide recommendations andevaluations of any new materials that can be appliedto static seals for use at the rated workingpressures and deployment duration for a highreliability vehicle.

(3.3.2.) Static Seal Configuration

The contractor shall evaluate and recommend any newconceptual designs in radial, face or other staticseal configuration that may be expected to increasethe reliability of sub-components of a long-termdeployed ROV/AUV system.

(3.3.3.) Static Seal Compression Setting

The contractor shall provide evaluations ofmaterials and configurations of static seals thatdemonstrate minimal compression setting.

(3.3.4.) Cable Terminations

The contractor shall provide recommendations andevaluations of cable termination methods and designsfor use on a high reliability ROV/AJV system.

4.3.2. Reference Documentation (A003)

The contractor shali provide a compendium of applicableliterature and specific guidelines on how to design toprevent problems which plague ROV/AUV shaft sealreliability. The contractor shall make a thoroughsurvey of applicable military standards, specificationsand handbooks. He shall compile all such documents,cross-referenced and explained so that the designerwill have a single, concise source for selection ofopplicabie controllinq documents to reference durin-

the preparation of material, process, or product

specifications. (Item 3.4 Reference Documentation.)

4.3.3 ManufacturinQ Errors (A003)

The contractor shall provide a list of common sealassembly manufacturing errors including desirablealternative solutions and explanations. (Item 3.5Manufacturing Errors.)

STATEMENT OF WORK

FOR


Tether Assemblies

Prepared By:


Prepared For:


(ONR Code 122)

TABLE OF CONTENTS

Section/Paragraph

1 BACKGROUND AND INTRODUCTION.........................1

2 APPLICABLE DOCUMENTS................................ 2

3 SCOPE.................................................2

4 REQUIREMENTS......................................... 24.1 Tether Assembly Performance....................... 34.2 Design............................................. 44.3 Manufacturing...................................... 74.4 Testing............................................ 8

5 DELIVERABLES....................... ....'*'**105.1 Program Plan (AO0l)............................... 105.2 Status Reports (A002)............................. 105.3 Final Report (A003)............................... 10

STATEMENT OF WORK


Future Navy requirements will involve deployments ofunderwater Remotely Operated Vehicles (ROVs) for deploymentperiods of between three to six months with little or noopportunity for maintenance. The ROV and its associatedcomponents must be built to achieve an operationalreliability of 98% or better. The vehicle will be designedto operate from a platform with a range of 3,000 feet in anysingle direction. The tether will be powered, use fiberoptics data transmission and must obtain the samereliability as the ROV and its subsystems.

The following operational capabilities and reliability goalsfor the ROV tether must be achieved for the Navy in order tomeet its long-term ROV deployment goals.

A. Depth design consideration is a maximum of 6,000 feetoperational depth. Consideration should also be givento a tether design which is operable to depths of20,000 feet.

B. The tether length will be 4,000 feet in order to allowthe operation of the ROV to a distance of 3,000 feet inany direction from the platform.

C. The tether must remain flexible under conditions of lowtemperature and long periods of inactivity in storagewithin the platform. The cable and jacket materialwill be required to retain their integrity duringtemperature fluctuations ranging from +110 F to +280 Fand must be resistant to the effects of UV radiation,hydraulic fluids, acids, alkalies and detergents.

D. Tether construction shall include both power and fiberoptic data channels for the ROV and tether design shallacheive a low self-radiated magnetic signature.

E. The tether shall be terminated at both ends via Mil-Spec connectors which will withstand long periods ofimmersion without delamination or loss of integrity.

F. The tether shall be designed for low drag when operatedin a 5 knot current and shall have excellent abrasionresistant capabilities. Additionally, the tether shallbe neutrally buoyant at its maximum deployment length.

G. The tether shall be fully water blocked to preventwicking of water up the tether or through the connectorwhile under pressure.


Operational Guidelines for Remotely Operated Vehicles,Marine Technology Society, ROV Sub-Committee, 1984.

Gibson, Philip T.; Walther, James A. PerformanceCharacteristics of Tether Cables, pg. 37, Marine TechnologySociety ROV-83 Proceedings, San Diego, CA, March 1983.

3. SCOPE

The objective of this Statement of Work is to providerecommendations for the solution of long-term failuremechanisms exhibited by conventional ROV tether cables.This will be provided in the form of deliverables which willallow the ROV designer a means of selecting the mostreliable means of incorporating a vehicle tether system.

The work shall focus on the development of a highreliability and highly survivable tether cable which issuperior to commercially available cables. Development ofthe high reliability tether must address those failureswhich most frequently occur in commercially availablecables. They involve the intrusion of water into theinterstices of the cable at depth, delamination of cableconnectors, abrasion and increased cable drag, degradationof the cable jacketing material and failure of internalconductors due to uneven strain distribution over the cableunder high load conditions.

4. REQUIREMENTS

The contractor shall identify, from an overview, how toapproach each problem identified in the Scope of thisStatement of Work aihd in the following Design section of theStatement of Work. The major problems involving a tetherassembly can be found in three major areas, tether design,manufacture and testing.

The contractor shall examine all identified designparameters and recommend - solution to these parameterswhich most closely matches the requirements of the tetherassembly. These solutions shall be in the form of materialsidentification, design practices and procedures for theareas described later in this SOW. The deliverables, underthis SOW, shall be in the form of a tether assembly designfor a low profile, abrasion resistant tether including powercable, data cables and strength member plus connectors thatis applicable for use with an ROV system. The design shallreflect the current state-of-the-art technology and assumesimplementation in the next five years.

It is anticipated that the design specifications andguidelines provided as a result of this Statement of Work

shall be used to design a high performance tether assembly.

The contractor shall also provide recommendations forprototyping, but it is anticipated that prototyping will beperformed by Navy engineers under their specific projects.

4.1 Tether Assembly Performance

The tether assembly described in the SOW is considered to bea lightweight component which utilizes a high strength fiberto achieve the required strength and which is neutrallybuoyant when deployed. The design is complicated by thefact that it is required to be deployed in a manner thatdoes not allow access for repair during a deploymentmission, thus requiring a 98% reliability. The requirementfor the cable to be low drag and to operate in currents andvehicle speeds up to 5 knots is a factor.

The management of the tether assembly by a mechanical tethermanagement system will mean that the tether assembly will bemanipulated at the platform during the deployment as aresult, the tether jacketing, internal conductors andstrength members will be subjected to repeated bending andstress above a level that is experienced by conventionallight tether assemblies. Additionally, the tether could besubjected to the constrictive stress imposed by a physicalseal required to provide for below waterline deployment.These manipulations and the forces will place a degree ofstress on the overall cable assembly, which will containfiber optic members, and the effects of both constructionalstretch and elastic stretch in the strength member may havean effect upon the performance of the power and data lineswithin the cable.

The potential for long-term in-water or dry storage of thetether assembly (three to six months), and its exposure toboth high pressure and a wide temperature range must beconsidered when designing the jacketing material. Thememory that is present in some synthetic jacket materials atdifferent temperature ranges can have an adverse effect uponthe deployment of the tether from the management system.

The manufacture cf jacketed cables has shown that withoutadequate machinery and manufacturing processes there existsa potential for an uneven distribution of the jacketingmaterial over the core of the tether. This inconsistencycan result in a jacket which has numerous "thin spots"which can be interpreted as potential failure points thatwhen breached will accelerate the effects of abrasion andultimate failure of the tether. Such jacket failures canresult in water entering the interstices of the cable,uneven surface conditions which can effect the tethermanagement and an exposure of the strength member, therebyreducing its effectiveness. A potential for these types of

, | ,H n m3

failures is considered to be unacceptable.

The expected solution to the tether assembly, includingconnectors, will be the design of a high performance,neutrally buoyant cable of precise and repeatabledimensions. To insure that the manufacturing processremains within the guidelines, a rigorous Quality Assuranceprocedure will be implemented at all key points in themanufacture of the tether assembly to insure consistent andreliable performance of the tether assembly. Within thescope of the manufacturing process, new techniques mayrequire development in order to meet the requirements of thetether assembly.

4.2 DesiQn

A reliably performing tether assembly shall be designedwhich does not exhibit any of the failure modes that havebeen experienced in previously manufactured tethers. Thedesign process shall address all the tether components, bothindividually and as an assembled unit, and shall produce adesign which meets the overall ROV system reliabilityrequired.

4.2.1 MaQnetic Signature

The use of platform supplied power to the ROV willproduce a magnetic signature commensurate with thepower levels involved. This potential signature shallbe reduced or eliminated through the use of a balancedtwisted power cable and shielding of all puwer and datawires. Tne balancing of all wires carrying power anddata will also succeed in acting as a filter formagnetic signals originating outside of the ROV system.The contractor shall provide design guidelines in thefinal report (CDRL item #A003) , that eliminate orreduce the magnetic signature of the ROV tether.

4.2.2 Tether Dimensions

Requirements for low drag, high relative strength andneutrally buoyant tethers represents a compromise inconflicting requirements. In the design of the tetherassembly a cable of minimum diameter and highflexibility is required. The contractor shall providedesign guidelines in the final report (CDRL item#A003), for a tether meeting these dimensionalrequirements.

4

4.2.3 Tether StrenQth Member

The material selected for the strength member of thetether should be of a light weight, high strength pervolume synthetic. Elongation and elasticity of thematerial selected as well as the technique used toincorporate it into the tether shall be such that itsconstructional stretch and elastic stretch underloading do not exceed the limits of the least elasticpower or data line. The contractor shall providedesign guidelines in the final report (CDRL item#A003), that balance these factors to achieve the bestcompromise.

4.2.4 Power and Data Lines

The requirements for the conductors, which will be theROV power and data transmission lines (as yetundefined), will dictate the gauge and type of wire tobe used. In the design of the tether the requirementsof the ROV will serve as the guide for the sizing ofall conductors. Size of conductor to achievereliability of operation, tether strength, elasticityand drag will be a major design factor that must beaddressed. The contractor shall recommendspecifications in the final report (CDRL item #A003),for conductors contained within the tether.

4.2.5 Tether JacketinQ

The material used to jacket the tether is of primeconcern as it will be required to remain flexiblewithout cracking or degradation in extremes oftemperature and in the presence of corrosive substancesand UV radiation. The jacket material must possess anabsolute minimum of memory after long-term storagewithin the tether management system and shall not placeadditional strain on either the ROV or the tethermanagement system during deployment, i.e. it mustremain flexible under all environmental conditions.The contractor shall recommend in the final report(CDRL item #A003) , jacketing materials that areresistant to degradation, demonstrate little or nomemory when spooled and maintain flexibility.

4.2.6 Tether Creep and Cold Flow

The jacket material shall be designed in order toretain its circular cross section while in storage.Cold flow of the jacket material or creep of thematerial beyond 5% concentricity will be unacceptable.Any condition which adversely affects the calculateddrag of the cable or prevents the tether from being

5

deployed in other than a linear configuration maycompromise the performance of the ROV. The contractorshall recommend design guidelines in the final report(CDRL item #A003), for jacketing material that isresistant to creep and/or cold flow.

4.2.7 Temperature Range

The tether shall be designed to operate in a wide rangeof temperatures from +280 F to 1100 F. Under alltemperature conditions expected to be encounteredduring deployment, the tether must remain flexible andfully operable. The tether assembly shall not degradein static modes over a temperature range of -400 F to+1400 F. The contractor shall provide tether designguidelines in the final report (CDRL item #A003), thatprovide for operations over the above-mentionedtemperature ranges.

4.2.8 Water Blocking

The construction of the cable shall be such that thetether is fully water blocked. This is defined to meanthat water is not allowed to "wick" up the inside ofthe tether under pressure. The use of appropriate voidfillers and a high packing density can be balanced inorder to achieve this condition without sacrificingflexibility. The contractor shall provide designguidelines in the final report (CDRL item #A003), forwater blocking of the tether assembly.

4.2.9 Neutral Buoyancy

The tether shall be designed to be neutrally buoyantout to its maximum extension. An error, if present,shall be one of positive buoyancy not to exceed 1.0pound per 1,000 feet. A negatively buoyant conditionwill be unacceptable. The contractor shall providedesign guidelines in the final report (CDRL item #A003)which meet these buoyancy requirements.

4.2.10 Tether Drag

The tether should be designed to achieve minimum dragor a drag coefficient between .001 and .004. Theprojected ROV speed of 5 knots maximum limits thecurrent that the vehicle can operate in, but succeedsin defining the drag forces which must be met by thetether design. Tether strum may not be a problem andthe use of a fairing on the cable is unlikely due tothe increase in the drag coefficient that will be seenthrough its use. The contractor shall providespecifications for a tether design meeting these dragrequirements. The contractor shall further provide in

6

the final report (CDRL item #A003), predictions ofcable performance in terms of drag and strummingbehavior.

4.2.11 Tether Management System

A tether management system (undefined at present), willbe required to control the deployment and recovery ofthe ROV. For some applications the tether may passthrough a seal for below waterline deployments. Thiswill involve the mechanical manipulation of the tetherat all times and can result, in the extreme, of thesystem being required to recover a "dead vehicle". Inthe design of the tether, a consideration will be the"dead vehicle" condition and its effect upon the tetherrelative to stretch and bending over the managementsystems sheaves. Tether integrity must be maintainedfor forces two times that of the anticipated "deadvehicle" load. The contractor shall provide designguidelines, in the final report (CDRL item #A003), forthe tether to maintain integrity under dead vehicleload conditions.

4.2.12 Connectors

A series of two connectors per assembly will berequired. These connectors must also be capable ofsurviving long-term submersion without delamination orloss of integrity. The mechanical strength of theconnectors shall be such that they are capable ofsupporting a load four times that of the highestanticipated system load without failure. Failure isdefined as both mechanical failure of the connector orfailure of the power and data lines. The contractorshall provide design guidelines in the final report(CDRL item #A003) for the tether to support suchterminations.

4.3 Manufacturing

During the manufacturing process there exists a number oftechniques which can improve the reliability of the tetherassembly. The potential for techniques to exist which havenot been previously applied to the manufacture of a tethercable make it desirable to explore alternatives. Non-standard options and materials should be explored andevaluated during the design and prototyping in order tocreate a reliable and repeatable tether assembly.

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4.3.1 Jacketing Material and Technique

Cable jacketing materials such as HytrelTM and PVC havebeen used frequently in the manufacture of deep oceancables. These should act as a point of departure inthe search for a material that meets the requirementsof this SOW. The contractor shall investigateapplicable materials, procedures and processes forassuring a well bonded, abrasion resistant and flexiblejacket material and recommend, in the final report(CDRL item #A003), procedures to be used.

4.3.2 StrenQth Members

A variety of synthetic materials such as KevlarTM,HytrelTM, and Teknor are available on the market andcan be used as strength members in a low profileneutrally buoyant tether. The contractor shallinvestigate all available materials suitable asstrength members and recommend, in the final report(CDRL item #A003), a material for incorporation in thetether design. The contractor shall insure that thematerial selected is of U.S. manufacture and that ithas a long-term availability.

4.3.3 Manufacturing Processes

It is well known that most manufacturers of cable inthe United States often assemble components provided byother manufacturers. Frequently, the "cablemanufacturers" will be provided copper conductors fromone source, fiber optic materials from another sourceand strength members from yet another. This practicecomplicates the process of quality assurance. Thecontractor shall identify, in the final report (CDRLitem #A003), all sources of process production andrecommend adequate quality control procedures in orderto meet the reliability required of the tetherassembly.

4.4 Testing

Although testing of a prototype tether may not become theresponsibility of the contractor it is, nonetheless,important that the contractor develop a testing plan toassure the reliable performance of the tether assembly.Such testing should include the evaluation of componentsthat will be used in the manufacture of the tether anddefine procedures for the testing of the prototype.

HytrelTM and KevlarTM are trade marks of Dupont Chemical

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4.4.1 Test Samples

A testing procedure shall be recommended by thecontractor to insure that all component units andassemblies can be shown to perform in accordance withthe requirements of the tether assembly. Such testsshould demonstrate both material suitability as well asprocess reliability and can be included in theproduction of a full assembly. The contractor shallprovide, in the final report (CDRL item #A003),testing procedures for component assembly and fullassembly production.

4.4.2 Representative Test Samples

The contractor shall provide recommendations for makingtest samples of the tether after production in thefinal report (CDRL item #A003). Such samples shall berepresentative of the overall product.

4.4.3 Testing Under Pressure and Temperature

A critical component of the tether design will be itsperformance under extremes of temperature and pressure.It can be anticipated that low temperature/highpressure conditions will exist in the field. Thecontractor should recommend testing procedures, bothshort and long term, which will prove the neutralbuoyancy, watertight integrity and overall flexibilityof the tether assembly. Additionally, tests todemonstrate the integrity of the tether under allloading conditions should be recommended. Thecontractor shall recommend, in the final report (CDRLitem #A003), testing procedures that adequatelydemonstrate tether performance under all conditionsexpected to be encountered.

4.4.4 Other Potential Design Problems

There may be potential problems encountered in highperformance tether design other than the problemslisted above. The contractor shall detail any otherproblems of concern to a design engineer and providepotential solutions for these problems in the finalreport (CDRL item #A003)

4.4.5 Prototyping

In order to demonstrate the suitability of a tethrassembly design, it is desirable to prototype thedesign and test its performance. The contractor shallprovide recommendations, in the final report (CDRL item#A003), for prototyping tether assembly designs.

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5. DELIVERABLES


5.1 Program Plan (AO01)

The contractor shall develop a program plan in accordancewith CDRL #AO01 identifying how to approach each problemtechnically (including breakpoints), alternative approaches,and a schedule for each required deliverable in Section 4 ofthe SOW. The plan shall elaborate on the contractor'sproposed technical approach to the SOW and detail how thecontractor will perform each required item within theallocated time and cost. A draft program plan shall bedelivered 30 days after contract award, and is subject toGovernment approval. A final version of the program plan,with Government comments incorporated, shall be required 15days after the contractor's receipt of the Government'scomments.




A draft final report prepared in accordance with CDRL item:A003, describing all research results and conclusions,shall be submitted 60 days prior to completion of thecontract for review and comment.




Section 4 requires the contractor to provideevaluations, specifications, design guidelines,comparisons, descriptions and/or recommendations foreach specific problem and to include the results asseparate, identifiable items in the final report. The

I()

results shall be prepared in accordance with CDRL item#A003 for the ROV tether assemblies tasking as directedin items 4.2.1 through 4.4.4 inclusive. The specificitems to be reported are:

(4.2.1) Magnetic Signature

The contractor shall provide design guidelines thateliminate or reduce the magnetic signature of theROV tether.

(4.2.2) Tether Dimensions

The contractor shall provide design guidelines for atether meetiing the dimensions required to achievehigh reliability in the parameters identified.

(4.2.3) Tether Strength Member

The contractor shall provide design guidelines thatbalance these characteristics to achieve the optimumdesign.

(4.2.4) Power and Data Lines

The contractor shall recommend specifications forconductors contained within the tether.

(4.2.5) Tether Jacketing

The contractor shall recommend jacketing materialsthat are resistant to degradation, demonstratelittle or no memory when spooled and maintainflexibility.

(4.2.6) Tether Creep and Cold Flow

The contractor shall recommend design guidelinesfor jacketing materials that are resistant to creepand/or cold flow.

(4.2.7) Temperature Range

The contractor shall provide tether designguidelines that provide for operations over theabove-mentioned temperature ranges.

(4.2.8) Water Blocking

The contractor shall provide design guidelines forwater blocking of the tether assembly.

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(4.2.9) Neutral Buoyancy

The contractor shall provide design guidelines whichmeet the buoyancy requirements os Section 4.2.9.

(4.2.10) Tether Drag

The contractor shall provide specifications fortether design meeting the drag requirements ofSection 4.2.10. The contractor shall furtherprovide predictions of cable performance in terms ofdrag and strumming behavior.

(4.2.11) Tether Management System

The contractor shall provide desiqn guidelines forthe tether to maintain integrity under dead vehicleload conditions.

(4.2.12) Connectors

The contractor shall provide design guidelines forthe tether to support the terminations identified inSection 4.2.12.

(4.3.1) Jacketing Material and Technique

The contractor shall investigate applicablematerials, procedures and processes for assuring awell bonded, abrasion resistant and flexible jacketmaterial and recommend manufacturing procedures tobe used.

(4.3.2) Strength Members

The contractor shall insure that the materialselected is of U.S. manufacture and that it has along-term availability.

(4.3.3) Manufacturing Processes

The contractor shall identify and evaluate allsources of process production and recommend adequatequality control procedures in order to meet thereliability required of the tether assembly.

(4.4.1) Test Samples

The contractor shall recommend testing proceduresthat adequately demonstrate tether performance underall conditions expected to be encountered.

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(4.4.2) Representative Test Samples

The contractor shall provide recommendations formaking test samples of the tether after production.

(4.4.3) Testing Under Pressure and Temperature

The contractor shall recommend testing proceduresthat adequately demonstrate tether performance underall conditions expected to be encountered.

(4.4.4) Other Potential Design Problems

The contractor shall detail and provide detailedpotential solutions for these problems in the finalreport.

(4.4.5) Prototyping

The contractor shall provide recommendations forprototyping tether assembly designs.

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STATEMENT OF WORK

FOR

High Reliability Autonomous Underwater Vehicle (AUV)

Variable Ballast Systems

Prepared By:


Prepared For:


(ONR Code 122)

TABLE OF CONTENTS

Section/Paragraph

1 BACKGROUND AND INTRODUCTION ........................ 1

2 SCOPE .......................................... 2

3 REQUIREMENTS ................................... 43.1 Variable Ballast Design Evaluation ................ 43.2 Critical Design Area ............................... 43.2.1 Variable Ballast Pumps ......................... 53.2.2 System Plumbing ................................ 53.2.3 Control Valving ................................ 63.2.4 Corrosion ...................................... 63.2.5 Fluid Pumped ................................... 63.2.6 Displacement Receptacle ........................ 73.2.7 Pressurized Ballast Tanks ......................... 73.2.8 Efficiency ..................................... 73.2.9 Sensors ........................................ 73.2.10 Radiated Noise Levels ............................. 83.3 Manufacturing Errors ............................... 83.4 Reference Documentation ........................ 8

4 DELIVERABLES. ................................... 84.1 Program Plan (AO01) ............................ 94.2 Project Status (A002) .......................... 94.3 Final Report (A003) ............................ 94.3.1 Variable Ballast Design Evaluation ................ 94.3.2 Problem Documentation ............................. 104.3.3 Manufacturing Errors ............................... 114.3.4 Reference Documentation ........................... 11

STATEMENT OF WORK


Future Navy requirements will involve protracted deploymentsof underwater Remotely Operated Vehicles (ROVs) andAutonomous Untethered Vehicles (AUVs) . To date, theperformance of ROVs has been heavily dependent on thequality and quantity of the maintenance and supportavailable during relatively limited deployments. An ROVdesign that is appropriate for industrial (e.g., petroleumindustry) operations, with limited exposure and theexpectation of much maintenance, as a tradeoff againsthigher initial cost, is inappropriate for military missionswith little or no opportunity for upkeep. As a result, thecommon practice of modifying existing ROVs and ROVsubsystems for long term, at-sea storage and/or operationwithout maintenance is undesirable and is not considered tobe a long-term solution for extended mission Navyoperations.

The Statement of Work (SOW) for a high reliability VariableBallast System will be limited to Autonomous UnderwaterVehicles (AUVs) in order that the impact of limited power onthe performance of the variable ballast system may be fullyexplored.

The following operational capabilities and reliability goalsneed to be achieved for the Navy to meet its long termdeployment AUV requirements. The AUV's must be designed andbuilt to achieve an operational reliability of 98% or betterwhen operating from submarines during protracted deployments(3-6 months wet or in a powered-down configuration for oneto two months followed by several weeks of subsequentoperations). The AUV system's operational capabilities tobe considered are as follows:

1. The operational depth design consideration is a maximumof 3,000 ft. Consideration shall also be given tosystems that have a maximum depth capability of 20,000ft.

2. The system shall not have a tether.

3. The AUV system shall have low self-radiated noise,according to the goals shown in Figure I, and itsauxiliary acoustic components shall not interfere withthe platform sensors. The entire system shall minimizeacoustic radiation. Noise limitation shall receive thesame priority as reliability in design.

4. The AUV system's magnetic field shall not interferewith the platform or its sensors and vice versa.

5. The AUV's capacity for a variety of work tasks,including moderate duty work and moderate powermanipulators, shall also be considered.

6. The AUV's maximum nominal speed shall be 5 knots.

All aspects of the system life cycle that may offsetreliability were considered in an initial investigation,including design, procurement practices, fabrication,inspection, in-service use and maintenance. The reliabilityproblems identified in the investigation report covered theentire development phases of design, manufacturing and in-service life. The in-service life phase, concerned withtraining, maintenance and documentation are not to beconsidered under the tasking of this SOW, but later on aspart of a specific system design. The focus of this SOW ison the application of technology to improve reliability.

Specifically, this statement of work addresses AUV variableballast system reliability problems and how their designmight be improved to help obtain the long range Navyobjective of achieving a substantial increase in theextended mission reliability of AUVs.

2. SCOPE

The objective of this SOW is to provide recommendations forspecific design solutions to the problem of remotelyballasting AUV systems. This will be presented in the formof deliverables so that designers can use this informationin the creation of new vehicles and systems, or introubleshooting/retrofitting existing systems.

A high reliability, long term deployment AUV is expected toencounter two scenarios that will require d variable ballastsystem.

1. One would require a modest degree of ballastflexibility (0-450 lbs. for trimming) for a vehicleoperating over a range of depths, temperatures, andsalinity conditions. Included within this categorywill be compensation for small amounts of air trappedin ROV/AUV components (i.e. pressure compensated oilfilled connectors (PCOF) and cable assemblies, and oilcompensated electric windings) as that air compressesor dissolves with depth.

2. The second involves payload compensation which dealswith larger volumes and higher flow rates. Payloadcompensation could include deposit/recover of objectsweighing approximately 2500 lbs. Two time periods forpayload compensation shall be considered: compensationwithin 1/2 hour and compensation within 24 hours,respectively.

There are two common methods of changing a underwatervehicle's buoyancy during deployment. Both require pumpingsystems. The first involves the system pumping an amount ofwater inboard or outboard with the use of fixed size ballasttanks. In this manner the system varies its weight whilemaintaining a constant displacement. The second involves thesystem displacing less or more by pumping a stored supply ofa low density fluid into a variable size bladder orcylinder/piston assembly thereby varying its displacementwhile maintaining a constant weight. For both methods theamount of buoyancy changed per unit volume of fluid pumpedis similar. In fact, the two methods are nearly identical,differing only in what is considered to be the boundary ofthe vehicle and fluid pumped.

However, to meet AUV system noise signature goals, aVariable Boyancy (VB) system may have to consider quieteralternatives (i.e. change of ballast over a longer periodof time, or taking on/expelling sea water via seepagethrough a porous plug.

An important part of this SOW is to provide an analysis ofexisting VB systems, outlining the tradeoffs between thedifferent types and indicating which type would allow thegreatest potential for future modification while supplyinghigh reliability on long term deployments. These VB systemsshall have weight displacement capabilities of 450 lbs. and2,500 lbs. each for the two depth regimes at 3,000 and20,000 ft. Should a VB system of the weight displacementcapabilities not be available for these two regimes, thecontractor shall conduct a cursory design effort tofacilitate the component comparison/reliabilityrecommendations. This cursory design effort should notexceed two man weeks of effort for any of the fourweight/depth combinations not covered in the analysis ofexisting VB systems. Any cursory design effort shallprovide a forward and aft ballast tank and provision fortransfer of fluid between the two.

The work will be focused on ways to improve the reliabilityof VB systems and associated hardware, including pumps,tanks and plumbing while meeting the AUV noise signaturegoals of Figure I. Trade off studies conducted to satisfythe twin priorities of reliability and quietness shouldinclude analysis of the relationships between noise and flowrates/velocities through pipes, flow limiters, valves,pumps, etc. For schemes using an intermediate fluid toavoid running high pressure pumps, more volume is required;consequently, the study should address volumetricefficiency. Also, the deliverables for this SOW shouldinclude design recommendations that would allow for theballasting system to be upgraded at a later date to beeither oil or salt water based.

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3. REQUIREMENTS

The contractor's proposal shall identify how to approacheach problem technically, alternative approaches, costs andschedules. The approach shall address all the problems asdelineated above in Section 2 and as follows.

The contractor shall examine all the reasonable methods fordesigning a VB system for an AUV and recommend design and/orprocedural solutions to foreseen problems so they can beimplemented at a later date for testing and/or evaluationpurposes. These solutions will be in the form ofdeliverables described later in this section of the SOW.The deliverables shall reflect the current state-of-the-arttechnology, and assume implementation in the next fiveyears.

3.1. Variable Ballast Design Evaluation

There are a number of VB systems currently in operation onmanned submersibles and others in design phases by majorNavy contractors for ROVs/AUVs. The contractor shall reviewthese designs and group them in a list via design/capabilitybreakpoints (i.e. weight displaced, depth capability, etc.).This list will be used to identify those designs which offerthe greatest promise for, and the least modifications for,meeting high reliability requirements. From this list, thecontractor will select the most promising designs thatrepresent 450 lbs. and 2,500 lbs. weight displacementcapabilities each for two depth regimes, 3,000 ft and 20,000ft. The contractor shall identify any components other thanthose listed in section 3.2 that are categorized as thosehaving low reliability. The contractor shall then performtradeoffs and generate design specifications for thesecomponents, and provide the lists and results as anattachment to the final report (CDRL item #A003). Shouldvariable ballast systems not be available for any of thesefour combinations, the contractor shall conduct a cursorydesign effort, not to exceed two man weeks each, tofacilitate the component comparison/reliabilityrecommendations. The results of this design effort shall beprovided in the final report (CDRL item #A003).

3.2. Critical DesiQn Areas

The overall objective is to develop a reliable longer-termdeployment of AUVs than is possible with current commercialvehicle designs modified to meet Navy requirements. Severalspecific critical areas have been identified which must beaddressed in order to improve reliability to an acceptablelevel. In dealing with specific design recommendations formaximizing system reliability, the contractor must keep inmind that these must be based on the realization thatcompromise is an inevitable part of every design effort.

4

Consequently, the importance of each recommendation,relative to other reccmmendations, must be indicated.Further, the contractor shall provide reasonable comparisoninformation on the application of less than optimumalternatives and their possible consequences.

The designs for the VB systems shall include capabilitiesfor displacing up to a maximum of the two weights required,450 lbs. and 2,500 lbs. Two system designs shall beconsidered, each capable of operating at the twodepthratings specified, 3,000 ft. and 20,000 ft.

Specific considerations that should be kept in mind includethe fact that the AUV to use the VB system is designed tohave a low noise signature and the variable ballast systemdesign should not significantly contribute to the overallacoustic signature of the ROY. Acoustic signature goals forthe AUV system are presented in Figure I.

3.2.1 Variable Ballast Pumps

The heart of VB systems is usually a pump whichtransfers fluid in and out of "hard" ballast tanks ordisplacement receptacles. These pumps are required topump against high pressures. For a number of existingVB systems, exotic special purpose pumps have beendesigned. It is felt that there may be a number ofstandard pumps in existence that would require onlyminor modifications in order to be applied to highreliability VB systems for use at the intended depths.The designed system may be powered by hydraulics or anelectrical system. The pump does not have to be arotary type and may be of a staged type. For thiscomponent, simplicity and reliability need to beemphasized. The contractor shall provide descriptionsof VB pumps in use today indicating tradeoffs. Also,the contractor shall provide r esign and recommendationsfor a variable ballast pump system which provides thegreatest opportunity for updating in the future, andprovide the results in the final report (CDRL item#A003).

3.2.2 System Plumbing

Considerations shall be given to the physical size andconfiguration of the line runs and fixtures in the VBsystem. ROV/AUV designs are typically compact. Thisrestriction requires that subsystems shall not beoverly bulky and consume more space than is necessarywhile maintaining high reliability. The contractorshall provide recommendations and/or designs foroptimal physical layout for variable ballast plumbingsystems assuming forward and aft ballast tanks andprovision for transfer of fluid (i.e. water or other)

5

between the two. Results shall be provided in the

final report (CDRL item #A003).

3.2.3 Control Valving

As indicated in section 3.2.1, the pumps involved inthe VB system are often required to pump against highpressures. Initial startup can cause stalling inhydraulic systems and excessive currents in electricalsystems. The system design shall consider the startupforces and include, if appropriate, a method otunloading the pump prior to startup if necessary. Thecontractor shall provide recommendations for the use ofcontrol valving to eliminate undo startup forces. Inany variable ballast syste, control valves, reliefvalves and flow directicn control valves play a crucialpart in the reliability of the system. In some designsthe system is allowed to free flow in one direction.This valving is als- important in controlling freeflow. The contractor shall evaluate and recommenddesign and placement of all valving in order tomaintain high reliability and quietness, and providethe results in the final report (CDRL item #A003).

3.2.4 Corrosion

Certain components of any variable ballast system canbecome exposed to a corrosive environment. This isparticularly true where sea water comes into contactwith high partial pressures of oxygen insidepressurized "hard" ballast tanks. Further, in someundersea environments such as deep sea vents, highlycorrosive compounds can be encountered that may bedetrimental to system components. Considerations shouldbe given to the selection of suitable materials in thesystem for components that would contain pressurizedair and seawater. The contractor shall providerecommendations and tradeoffs for suitable materialsfor hard ballast tank systems and other VB systemcomponents to po.event or resist corrosion, and providethe results in the final report (CDRL item #A003).

3.2.5 Fluid Pumped

In a displacement VB system, a fluid such as oil istypically pumped in and out of an expanding receptacleto alter the vehicles displacement. The fluid that ispumped shall be selected carefully to be the rightviscosity and lack corrosive components that may damageinternal system parts. Also, it shall be a fluid thatis resistant to changes in viscosity with changes intemperature and pressure. In order to maintain highreliability, the fluid may also be required to act as alubricant tc other components of the VB system. The

contractor shall evaluate and recommend appropriatefluids to be used in any recommended systems which pumpfluids other than seawater. The contractor shallprovide the results in the final report (CDRL item#A003).

3.2.6 Displacement Receptacle

A variable displacement system often utilizes anexpanding module such as a beliows to pump fluid to andfrom, thereby changing the overall displacement of thesystem. A high reliability AUV may require a VB systemhaving reliable displacement receptacles. Thecontractor shall provide recommendations and/or designsthat include those for a recepta2le such as a metalpiston and cylinder or other ruggedized design. Thecortractor shall provide the ro-ilts in the finalreport (CDRL item #A003).

3.2.7 Pressurized Ballast Tanks

In VB systems, pa":ticularly those used in deep water,it may be advantageous and increase reliability to usegas pressurized hard ballast tanks. The contractorshall evaluate the impact on the reliability of the VBsystem using pressurized gas systems having forward andaft tanks and provision for transfer of fluid betweenthe two. Results shall be provided in the final report(CDRL item #A003).

3.2.8 Efficiency

Efficiency, capacity and speed are crucial performancespecifications for VB systems. This system shall beexpected to displace totals of 450 lbs. and 2,500 lbs.in time periods ranging from 1/2 hour to 24 hours. Thecontractor shall provide evaluations/tradeoffs andrecommendations for these and other rates of achievingthis ballast change. The contractor shall also provideevaluations of different methods of achieving thesespecifications while maintaining high reliability, andprovide the results in the final report (CDRL item#A003).

3.2.9 Sensors

In order to achieve overall system reliability andquietness, variable ballast designs shall includesensors to provide information on trim, buoyancy, fluidlevels and pump performance. The contractor shallevaluate high reliability sensors to provide thisinformation and provide the results in the final report(CDRL item #A003).

7

3.2.10 Radiated Noise Levels

Since the AUV shall have low self-radiated noise, inaccordance with the goals of Figure I, the VB systemshall be designed to provide high reliability andperform without radiating excessive noise. Thecontractor shall provide recommendations and/or designswhich minimize radiated noise, and provide the resultsin the final report (CDRL item #A003).

3.3 Manufacturing Errors

During the contract the contractor shall develop a list ofcommon manufacturing errors found that may causeunreliability in subsea VB systems. This list will bevaluable in warning the AUV designer or manufacturer oftheir existence. The contractor shall make this listavailable as an attachment to the final report (CDRL item:A003). The list of errors shall include explanations,desirable alternative solutions, and recommendations.


The contractor shall make a thorough survey of applicablemilitary standards, specifications and handbooks. Thecontractor shall compile all such documents, cross-referenced and explained so that the designer will have asingle, concise source for selection of applicablecontrolling documents to reference during the preparation ofmaterial, process, or product specifications. Thecontractor shall draw on these and other sources ofinformation, and on his own experience in the design andimplementation of underwater VB systems of all types, andproduce a compendium of specific guidelines on how to designto prevent problems (historical and expected) which plagueVB systems reliability. This compendium shall be presentedas an attachment (CDRL item #A003) to the final report.

4. DELIVERABLES

Design evaluations for the technical aspects of the VBsystem which contribute to failures shall be a prime product(CDRL item #A003). The contractor shall provide a list ofcommon manufacturing errors found to cause variable ballastfailures. Other deliverables required are a program plan(CDRL item #AO01) , status reports (CDRL item #A002) and afinal report (CDRL item #A003).


8

4.1 Proqram Plan (AO01)

The contractor shall develop a program plan in accordancewith CDRL #AO01 identifying: how to approach each problemtechnically (including breakpoints), alternative approaches,and a schedule for each required deliverable in Section 3 ofthe SOW. The plan shall elaborate on the contractor'sproposed technical approach to the SOW and detail how thecontractor will perform each required item within theallocated time and cost. A draft program plan shall bedelivered 30 days after contract award, and is subject toGovernment approval. A final version of the program plan,with Government comments incorporated, shall be required 15days after the contractor's receipt of the Government'scomments.

4.2 Project Status (A002)



A draft final report prepared in accordance with CDRL item#A003, describing all research results and conclusions,shall be submitted 60 days prior to completion of thecontract for review and comment.


Specific deliverables to be included in the final report are

the following:

4.3.1 Variable Ballast Design Evaluation

The contractor shall provide full descriptions ofexisting designs of VB systems, indicating tradeoffsand recommendations. The contractor shall providelists and evaluations of existing variable ballastsystems and identify components other than those listedin section 3.2 having low reliability. The contractorshall also generate design specifications for thesecomponents. If VB systems are not available for thesedepth regimes, the contractor shall provide a cursorydesign effort to support the componentcomparison/reliability recommendations for the fourweight/depth combinations previously cited. (Item 3.1Variable Ballast Design Evaluation.)

9


Section 3 requires the contractor to provideevaluations, specifications, comparisons, tradeoffs,descriptions, and/or recommendations for each specificproblem and to include the results as separate,identifiable items in the final report. The results

shall be prepared in accordance with CDRL item #A003for the AUV VB system components, subsystems,supporting/auxiliary equipment or processes as directedin items 3.2.1 through 3.2.10 inclusive. The specificitems to be reported are:

(3.2.1) Variable Ballast Pumps

The contractor shall provide recommendations forpump designs and/or pumps available that can beexpected to perform quietly in a high reliabilitysystem.

(3.2.2) System PlumbinQ

The contractor shall provide recommendations and/ordesigns for a VB system physical layout that can bereadily modified at a later date. The contractorshall indicate tradeoffs in various physicalconfigurations of VB systems.

(3.2.3) Control Valving

The contractor shall provide recommendations and/ordesigns for the use of valves or other methods toprevent pressures from stalling or otherwise causingdetriment to the system during initial startup.

'3.2.4) Corrosion

The contractor shall provide recommendations and/ordesigns that will prevent excessive corrosion to theVB system components that may be exposed to severecorrosion environments.

(3.2.5) Fluid Pumped

For designs that use a variable displacement methodfor changing buoyancy, the contractor shall evaluatevarious fluids appropriate for a high reliability,low noise AUV system.

(3.2.6) Displacement Receptacle

As in 3.2.5 (above) for designs that use a variabledisplacement method, the contractor shall providerecommendaticns and/or designs for a fluid

10

receptacle that will perform adequately on a high

reliability system.

(3.2.7) Pressurized Ballast Tanks

The contractor shall provide evaluations andrecommendations for the use of pressurized ballasttanks in variable ballast systems for each of theworking depths described.

(3.2.8) Efficiency

The contractor shall provide design recommendationsand tradeoffs based on size vice efficiency in VBsystems. The contractor shall also providetradeoffs and recommendations for various rates ofachieving 0-450 lbs. and 0-2,500 lbs. changes inballast.

(3.2.9) Sensors

A number of sensors may be required in a VB systemin order to maintain high reliability. Thecontractor shall provide evaluations of highreliability performance indicating sensors that canbe integrated into a VB system for AUVs.

(3.2.10) Radiated Noise Levels

The contractor shall provide design recommendationsand tradeoffs to minimize acoustic output of the VBsystems for AUVs to the specifications outlined inFigure I.

4.3.3 Manufacturing Errors

The contractor shall provide a list of common ROV/AUVsubsea VB system manufacturing errors includingdesirable alternative solutions and explanations.(Item 3.3 Manufacturing Errors.)

4.3.4 Reference Documentation

The contractor shall provide a compendium of specificguidelines on how to design to prevent problems whichmay be encountered in AUV VB system's reliability.

11

The contractor shall make a thorough survey ofapplicable military standards, specifications andhandbooks. He shall compile all such documents,cross-referenced and explained so that the designerwill have a single, concise source for selection ofapplicable controlling documents to reference duringthe preparation of material, process, o. productspecifications. (Item 3.4 Reference Documentation.)

12

APPENDIX B

EXPERT DATABASE

APPENDIX B

EXPERT DATABASE

Sandi L.M. Agen Honeywell San Diego CA

Carl S. Albro Battelle BDD Duxbury MA

C.M. Ulexander UCSD, SIO La Jolla CA

Larry Armbrewster Honeywell Seattle WA

Russell Arnold NCEL Port Hueneme CATheodore Austin NUWES Keyport WAJames Bailey Crouse Hinds Elec. La Grange NC

Richard Berey Nat'l Undersea Research St. Croix VAlan Berian Rochester Corporation Culpeper VAHenri Berteaux W.H.O.I. Woods Hole MAAl Bertoldo Advanced Cable Laguna Hills CA

Richard Bloomquist. NSRDC Annapolis MDPaul Boehm Battelle BDD Duxbury MABruce Boston Honeywell San Diego CAAlan V. Bray Texas Research Institute, Inc.Austin TXGary Brown Consolidated Cable Idylwild CAWayne J. Bywater Nortech Troy NYRobert Chome NSRDC Annapolis MDAndrew Clark Harbor Branch Foundation Fort Pierce FLPeter Clay Bouy Group Woods Hole MA

Duane Clayton Rochester Cable Culpeper VAKenneth Collins Applied Remote Tech Scripps Ranch CA

David Cook Flotation Technology Biddeford MEMike Cook NOSC San Diego CARoger Cook Harbor Branch Foundation Fort Pierce FL

Thomas Coughlin Vector Cable Sugarland TXJoseph Craven SUBDEVGRU-I, DSV-4 San Diego CA

James Cummings Honeywell San Diego CA

Roy Dody NOSC San Diego CAJames Dombrowski NOSC San Diego CA

Philip Doringer D.G. O'Brien Seabrook NHAlan Driscoll URI Narragansett RIDave Dunfey D.G. O'Brien Seabrook NH

Norman Estabrook NOSC San Diego CAMarshall Flake Harbor Branch Foundation Fort Pierce FLHugh L. Frisbie Honeywell San Diego CADavid Fuller Spears Associates Norwood MAThomas Garriety SUBDEVGRU-I ,UVD San Diego CARobert A. Gatherer SUBDEVGRU-I ,UVD San Diego CAPhilip Gibson Tension Mmbr. Tech Westminster CA

Jack Graham Maloney Houston TX

Bruce Griffin NAVSEA Washington DCThomas Gurnry Martin Marietta Orlando FLRobert Gwalchmai Naval EODTC Indian Head MD

Kevin Hardy UCSD, SIO La Jolla CAJohn Hart APL Univ of Wash. Seattle WA

Bruce Harting Kintec St. Peterburg FLRobert Hawkins Naval EODTC Indian Head MDWilliam Hayes Martin Marietta Oakwood TN

Page 1 of 3

James Held NOSC San Diego CAPatrick Hickey DSL, W.H.O.I. Woods Hole MAHarry Hilberg D.G. O'Brien Seabrook NHTerry Hoffman NUSC HIBruce Hood NSRDC Annapolis MDDennis Hurst Honeywell San Diego CAPamela J. Hurst Honeywell San Diego CAJack Jaeger Saches Engineering San Diego CADaniel Johnson Ketema A & E El Cajon CAVicky Johnson NCEL Port Hueneme CAChristopher Kennedy SUBDEVGRU-I, DSV-3 San Diego CARoy Knapp Univ. of Hawaii Honolulu HITed Kretchner NCEL Port Hueneme CAPat Larkin ISE Vancouver BCRichard Longabaugh Impulse CTRS San Diego CARichard Laudermilk Seacon El Cajon CADana Lynn NSRDC Annapolis MDRichard Marone NOSC San Diego CALan Martini NOSC San Diego CASteve R. McCorkle Vector Cable Sugar Land TXMichael McDonald ISE Vancouver BCWilliam McElroy MAST W. Falmouth MAJames McFarland ISE Vancouver BCDaniel McLeocd Perry Offshore Riviera Beach FLJames Meisler Syntech Materials Springfield VACharles Mitchell Ketema A & E El Cajon CADaniel Murray Sanders Nashua NHDaniel Nicsky Applied Remote Tech Scripps Ranch CADonald G. O'Brien D.G. O'Brien Seabrook NHMack O'Brien Draper Labs Cambridge MAPatrick O'Conner Subsee Inc Fort Pierce FLPatrick O'Malley W.H.O.I. Woods Hole MALee Olsen APL Univ. of Wash Seattle WAMark Olsen Deep Sea Power & Light San Diego CALen Onderdonk Rochester Cable Culpeper VAJohn Owen Honeywell Seattle WAWilliam Oxford Rochester Cable Culpeper VAPeter Parker NUWES Keyport WADwayne Peacock NUWES Keyport WAAndrew Pederson Naval EODTC Indian Head MDMark Perival Sandia Labs Albequerque NMCarl Peters Consolidated Cable Idylwild CAHarold Peterson Battelle BDD Duxbury MARichard Pilkington EG & G SEALOL Providence RIBill Pope Battelle BDD Columbus OHSteve Porier SUBDEVGRU-l DSV-4 San Diego CAFred Potter NCEL Port Hueneme CAJohn Rackliffe Bendix Los Angeles CACharles Reader NOSC San Diego CARonald Reich NOSC San Diego CADonald Rosencrantz NOSC San Diego CABrock Rosenthal Deep Sea Power & Light San Diego CARichard Rounds Nat'l Undersea Research St. Croix VI

Page 2 of 3

Jack Runtoca Rochester Cable Culpeper VAColin J. Sandwith APL Univ. of Wash Seattle WA

John Sasse NSRDC Annapolis MD

Pat Scanlon SUBDEVGRU-l, DSV-4 San Diego CAPaul W. Schrader EM Blues Houston TXDenton S. Seilhan Seacon El Cajon CAMichael Serifin SUBDEVGRUI, UVD San Diego CA

Thomas Sheridan MIT Cambridge MAPreston Shultz Burton Electrical Eng. El Segundo CALarry Shumaker General Offshore St. Croix VIPatrick Simar Brantner Sea Con El Cajon CAAlden Simmons Coors Ceramics Golden CORobert Smith NOSC San Diego CARobert Spindel APL Univ of Wash Seattle WARobert Starr NOSC San Diego CAJulius Stegman NOSC San Diego CAGerald Stenovec Ametek, Straza Div. El Cajon CA

Anthony Sussi NUSC New London CTRichard Tackaberry Honeywell San Diego CA

Archibald Tannock ISE Vancouver BCJames Teague Grace Syntactics Canton MA

William Tell Consolidated Cable Idylwild CA

Christopher Tietze Harbour Branch Foundation Fort Pierce FLRoy Truman Eastport International Upper Marlboro MDLee Tucker Weztern Instrument Ventura CA

John Vnth Coors Ceramics Golden COBarric Walden W.H.O.I. Woods Hole MARonald Walrod Applied Remote Tech Scripps Ranch CAAlan Waltz NOSC San Diego CADavid Warford Ketema A & E El Cajon CA

Louis Watkins Cuming Corporation Easton MARobert Weiner Blake Wire & Cable Torrance CARobert Wernli NOSC San Diego CAH.C. Wheeler NOSC San Diego CAFred White NUSC Newport RIWillem Wijmberg Vector Cable Sugarland TX

Jeff Wilson NCEL Port Hueneme CAGary Winkleman SUBDEVGRU-l San Diego CAGregory Winslow SUBDEVGRUI San Diego CA

Page 3 of 3

APPENDIX C

TECHNICAL REVIEW BOARD (TRB) PERSONNEL

APPENDIX C

TECHNICAL REVIEW BOARD (TRB)

The contractor would like to acknowledge the assistance ofthe following Technical Review Board (TRB) Personnel whoparticipated in finalizing the seven technical Statements ofWork included in this report.

Mr. Barrie WaldenDeep Sumergence OperationsWoods Hole Oceanographic Institution

Ms. Pamela HurstHoneywell, Inc.

Dr. Alan DriscollDirector of the School of OceanographyUniversity of Rhode Island

Mr. Louis WatkinsCuming Corporation

Mr. Marshall FlakeHarbor Branch Foundation

Mr. Christopher NicholsonDeep Sea Systems, Inc.

Mr. Philip GivsonTension Member Technology, Inc.

Dr. Gabriel GianinniGianinni Institute

Mr. David CookFlotation Technologies Corporation

Mr. Wayne BywaterNortheastern Underwater Services, Inc

Mr. Richard PilkingtonEG&G Sealol

Mr. William McElroyMarine Systems Technology, Inc.

Mr. Bill PopeBattelle BDD

Mr. Carl AlbroBattelle BDD

APPENDIX D

BIBLIOGRAPHY

APPENDIX D

BIBLIOGRAPHY

Gibson, P.T. Operational Characteristics ofElectrom-chanical Cables. New Orleans, LA: ThirdInternational Offshore Mechanics and Arctic EngineeringSymposium [February 12-17, 1984].

Hobaica, E.C. and Cook, S.D., "The Characteristics ofSyntactic Foams Used for Buoyancy". Journal of CellularPlastics [April 1968].

Jackson, Doug and Clay, Peter. "Syntactic Foam SphereImproves Oceanographic Mooring Performance". SeaTechnology Magazine [September 1983].

Jenkins, J.F. Inspection of Objects Retrieved from the D-epOcean - AUTEC Acoustic Array. Port Hueneme, CA: CivilEngineering Laboratory, Technical Report N-1424 [1976].

McCartney, J.F. and Wilson, J.V. High-PowerElectromechanical Cable Connectors for Deep OceanApplications. Port Hueneme, CA: Civil EngineeringLab., Naval Construction Battalion Center, TechnicalReport R806 [April 1974].

O'Brien, Donald G. An Update on Recommended Techniques forTerminating Underwater Electrical Connectors to Cables.Marine Technology Society Tenth Annual ConferenceProceedings [1967].

O'Brien, Donald G. Application of Glass-Hermetic-SealedWatertight Electrical Connectors. San Diego, CA:Marine Technology Society [June 1967].

Product Engineering. "Designer Profile - Working withmaterials, this engineering looks to the sea",[September 22, 1969].

Reinhard, Donald L., and Smith, Stewart W. MacrosphereDevelopment Provides Cost Effective Buoyancy Packagesfor ROV'S, Agawam, MA: Albany InternationalCorporation.

Sandwith, C.J. "0-Ring Installation for UnderwaterComponents and Applications". Naval ResearchLaboratory Memorandum Report 4809 [April 15, 1982].

Page 1 of 2

Shutov, F.A. Syntactic Polymer Foams. Moscow 125820, USSR:Mendeleev Institute of Chemistry and Technology, Dept.of Polymer Processing [1985].

"Specification for Sea Cliff Modification Syntactic Foam,"N00024-80-B-7102 [October 1979].

Stachiw, J.D. Graphite Fiber-Reinforced Plastic PressureHull Mod 1 for the Advanced Unmanned Search System(AUSS). San Diego, CA: Naval Ocean Systems Center,Technical Report No. 1182 [December 1986].

Stachiw, J.D. Pressure Resistant Ceramic Housings for DeepSubmergence Systems. San Diego, CA: Naval OceanSystems Center, Technical Document 1294 [June 1988].

Stachiw, J.D. Deep Submergence AUSS Pressure Hull Project,San Diego, CA: Naval Ocean Systems Center, TechnicalDocumen- "Thick Composites in Compression" [July1988].

Stachiw, J.D. and Frame, B. Graphite-Fiber-ReinforcedPlastic Pressure Hull Mod 2 for the Advanced UnmannedSearch System Vehicle. San Diego, CA: Naval OceanSystems Center, Technical Report 1245 [August 1988].

Stachiw, J.D. and Held, J.L. Exploratory Evdluation ofAlumina Ceramic Cylindrical iousings for Dee-Submergence Service: The Second Generation NOSC CeramicHousings. San Diego, CA: Naval Ocean Systems Center,Technical Report 1176 [September 1987].

"Syntactic Buoyancy Material for High HydrostaticPressures", Military Specification MIL-S-24154A (SHIPS)[March 28, 1967].

Watkins, L.W. Predicting the Long-Term Performance ofSyntactic Foam Buoyancy in Production Riser Systems.Canton, MA: Grace Emerson & Cuming [May 1986].

Wilson, J.V. Coaxial Underwater Mateable Connectors - A NewTechnology for Seafloor Structure App-ications. PortHuenemo, CA: Technical Report R875, Civil EngineeringLaboratory, Naval Construction Battalion Center[September 1979].

Page 2 of 2

APPENDIX E

DISTRIBUTION

APPENDIX E

DISTRIBUTION

ENCLOSTRE NUMBER 1CONTRACT DATA REQU:REMENTS L:ST:NSTRUCT:ONS FOR D:STRIBUTTON

D:STR:BUT:ON OF TECHNICAL REPORTS AND F:NAL REPORT

The mininum distribution of technica reports and the final reportsubmitted in connection with this contract is as foilows:

NUMBER OF COP:ESADDRESSEE DODAAD UNCLASSZFIED UNCLASSZF:ED/L:M:TED

CODE 1W.:IMITED AND CLASS-F-ED

Scientific Officer N00014 iAdminstrative Contracting S2206A

OfficerDirector, Nava: Research N00173 6

Laborato--y, ATTN: Code 26:7Washinaton, D. C. 20275

Defense Technical Information S47031 12CenterBidc. 5, Cameron StationAlexandria, Vlrgln.a 22M4

:f the Scientific Officer directs, the Contractor shall make additionaldistribution of technica: reports in accordance with a supp'ementa'distribution -is. provided by the Scientific Officer.

Distribution of Remorts which are NOT Technical Revorts

The mlnimur. d stribution for reports which are no: technical reportsis as follows:

NUMBER OF COPIES

AD DRE DODAAD UNCLASS:F:ED UNCLASS:F?:E,-D':M-TDCODE UNL:! :TED AN CLASSIFIE

Scien:lfic Officer NOOC:4Adm.nlstra::ve Contractinc 52206A .

Off.cer

CONTRACT NUMBER: N000i4-87-C-0728

Download - t rF, j REMOTELY OPERATED VEHICLE ROV/AUV AD … · ... (ROV) RELIABILITY STUDY WAS INITIATED IN TWO ... which are currently state-of-the-art (Phase I) ... forwarded in the form of

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