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Investigation of the Cost of Future Naval Amphibious Capability

Andrew J Jones

1 (MRINA), Rob W Armstrong

2 (AMRINA)

1. Principal Naval Architect, BMT Defence Services Ltd, Future Platforms Team.

2. Naval Architect, BMT Defence Services Ltd, Future Platforms Team.

Through the creation of a large number of concept designs, the cost and vessel impact of

deploying and supporting amphibious operations has been investigated. The investigation has

looked at capabilities such as the transportation and delivery of vehicles, landing craft, aviation

and embarked troops in a number of platform types such as LPDs, LHDs and Ro-Ros. A series of

trends describing the costs of the capability have been investigated to estimate the cost of

individual capabilities within a design. Over the timeframe of the study, vessel manning is

predicted to change and a method of predicting the crew requirement has been developed to

investigate the impact of reduced manning on amphibious platform designs. This is the first of two

stages of work; in the second stage the requirements for a task group will be investigated to

determine the best way to deploy capability at a fleet level. .

KEY WORDS: Ship design; naval vessel design; sealift; human factors and

manning; computer supported design; cost modelling.

NOMENCLATURE CCSS – Command and Combat Support Ship

CGT – Compensated Gross Tonnage

LPH – Landing Platform Helicopter

LPD – Landing Platform Dock

LHD – Landing Helicopter Dock

LitM – Littoral Maneuver

LSD(A) – Landing Ship Dock (Auxiliary)

LwL – Length on Waterline

RFA – Royal Fleet Auxiliary

RN – Royal Navy

ROM – Rough Oder of Magnitude

RoRo – Roll on Roll off

UPC – Unit Purchase Cost

TLC- Through Life Cost

INTRODUCTION The out of service dates of a number of UK amphibious classes

are predicted to occur around the mid 2030’s. This coincidence

of out of service dates provides an opportunity for the

distribution of amphibious capability across the different classes

to be reassessed. BMT conducted a study to investigate a large

number of possible concept designs to inform planning

decisions. This paper analyses the designs created to investigate

how amphibious capability can most cost effectively be

deployed and the appropriate distribution of capability between

naval, naval auxiliary and commercial shipping. This

exploration of the design space could assist with setting

requirements for a number of classes from where further

exploration of the design space and analysis of alternatives can

be considered as described by Singer (2009) and Mebane

(2011).

Whilst looking to the mid 2030’s, the concept designs created

represent an evolution of current amphibious vessel designs and

Jones, Andrew J Investigating the Cost of Future Naval Amphibious Capability

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continue the doctrine and thinking of today’s approach to littoral

maneuver. They represent realistic and feasible combinations of

capability and provide a sensible basis the development of

platform design trends.

As there is significant pressure on navies around the world to

reduce crew size, a statistical model of possible technologies

and changes to naval doctrine was created allowing the

reduction in crew size in the timeframe of the study to be

estimated and the impact on the platform and costs identified.

UNDERSTANDING AMPHIBIOUS PLATFORMS

Amphibious Platform Capability The primary role of the platforms investigated is to support the

landing and sustainment of a military force in the littoral

environment. This requires a significant range of capabilities to

be deployed by the platforms including but not limited to:

command and control, transportation and offload of heavy

equipment and personnel, aviation facilities, medical facilities

and stores. These capabilities, and the requirement to operate as

part of a task group, also drive a number of platform

characteristics such as speed, range and maneuverability.

Hullform Design Drivers These capabilities and requirements have a significant impact on

the hullform of the platform. As shown by Watson (1962

&1976), commercial vessels can typically be described by one

of three categories;

1. Volume driven, such as passenger ferries;

2. Linear driven, such as container ships;

3. Deadweight driven, such as bulk carriers and tankers.

For existing vessels, these categories can be seen by comparing

the deadweight to vessel length as shown in Fig.1. When

existing amphibious vessels (LPD, LPH, LSDA) are also plotted

by estimating their equivalent deadweight, they can be seen to

form a region between the linear and volume driven design

regions.

Fig.1 Commercial and Amphibious Hullform Design Drivers.

Amphibious vessel hullforms are typically developed

specifically for the role due to the need to dock down and have

slow speed maneuverability but, as can be seen, there is some

overlap with commercial hullforms at lower deadweight, and

commercial shipping is used by several navies to support

amphibious operations.

This study has used a number of existing amphibious and

commercial hullforms as the basis of the study, but has not

looked at redistributing capability across other naval vessels

such as frigates and destroyers as the relatively high payload

and volume demands are not compatible with these vessel types

without significantly compromising their primary role.

Breadth of Study To deliver and sustain littoral maneuvers at a task group level, a

large amount of equipment, vehicles, stores and troops are

required. The total capability to be delivered into a theatre of

operations by a future task group can be met by varying the

number, capacity and/or role(s) of the individual platforms.

Within each capability area a large number of variations of

requirement are possible. A range was defined for each

capability area to ensure that the designs studied covered the

breadth of possible UK requirements in the mid-2030s

timeframe. Due to the large number of possible combinations of

capabilities a reduced subset of the combinations were selected.

This approach was selected rather than investigating the impact

of individual changes to a capability around a baseline design, in

order to ensure that the interactions between the capabilities and

their impact on the different designs was captured. The range of

the capabilities investigated are shown in Table 1 below, where

the lower bound shown excludes “None” capability.

Table 1. Range of Capability by Capability Area

Capability

Area

Lower Bound

(Low)

Upper Bound

(Excellent)

Command

and Control

Ships own

operations

LitM operations room and

planning spaces

Logistics Ships own

operations

Ammunitions, Stores,

Fuel and Containerized

stores in support of LitM,

RAS

Surface

Maneuver

Landing craft

personnel

Landing craft utility,

personnel and Mexeflote

Aviation Landing and

refuel for single

medium

helicopter

Control, support,

maintenance and refueling

of up to 12 medium

helicopters

Embarked

Force

Force protection Commando group

Vehicles Limited, light

vehicles only

Full heavy and light

vehicle load

Medical Sick Bay

(NATO Role 1)

Casualty Receiving and

Treatment (NATO Role 3)

35 capability combinations were defined as a baseline design set

to cover the full range of possibilities from traditional role

specific platforms to more multi-role platforms. Quantitatively


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scoring each design against the range defined the distribution of

capability scores within each capability area as shown in Table

2.

Table 2. Heat Map Showing the Distribution of Capability

Scoring the Bay Class (LSD(A)) and Albion and Bulwark Class

(LPD) against the same criteria, a range of scores typical for

these ship classes can be seen in Table 3, and demonstrate the

distribution and level of total capability.

Table 3. Distribution of Capability for Existing Ship Classes

Whilst naval vessels will always be required to lead the way and

act as a first wave, operations can be sustained by a mixture of

naval auxiliary and commercial shipping. Where capability can

be deployed across the other types of shipping, the relative costs

have also been explored to understand any cost reduction

possible.

PLATFORM CONCEPT DESIGN

Description of Modelling For each design, the combination of capability requirements

formed the starting point of the design process. From these

requirements an initial high level arrangement was created and a

basis hullform and build standards were selected to understand

the implications of the capabilities on the design.

A suite of parametric design tools covering weight, space,

resistance & powering, electrical load, crewing and hullform,

were then used to size the concept refining the initial

dimensions and arrangement, balancing weight and space

provision and demand. The initial outline design was then

developed with a high level arrangement and Rough Order of

Magnitude (ROM), Through Life Cost (TLC) and Unit Purchase

costs (UPC) estimated. This process was iterative with feedback

between each stage as shown in Fig.2.

Fig.2. Overview of Concept Modelling Approach.

Design Process Inputs The relative locations and arrangement of vehicles, aviation,

accommodation and landing craft were used to initially

determine the high level platform architecture decisions such as

the number of decks and superstructure location. This high level

initial analysis allowed minimum hull length, breadth and depth

drivers to be identified and the internal subdivision to be

initially placed.

The basis for the design (naval, naval auxiliary or commercial)

was used to identify the appropriate standards such as

accommodation, watertight subdivision, stability and

survivability features to be included within the design.

For each design, a ships company was defined based on its

capability, using expert knowledge and data from suitable

existing ships. Understanding the fundamental role(s) of each

concept, and the expected threat environment, allowed an

appropriate manning level to be generated. For example, a

single role vessel operating between established (and secure)

ports only requires a minimal ship’s company, more akin to a

commercial level of manning. In the more complex concepts,

that are expected to operate in a higher threat environment, a

number of additional considerations have to be taken into

account:

1. The tempo of operations in a 24 hour cycle. A platform

that is expected to operate at full capability around the

clock will require sufficient operations personnel to

maintain full operational capability for the duration.

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Excellent 2 1 3 4 4 4 1

High-Excellent 3 5 6 0 11 3 0

High 5 12 8 2 8 0 21

Medium-High 4 5 5 2 2 15 4

Medium 14 4 4 11 2 6 0

Low-Medium 2 4 6 13 1 5 5

Low 2 1 3 2 6 2 0

None 3 3 0 1 1 0 4

Ship Class Co

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Example LSD(A) 2 5 3 2 4 4 3 23

Example LPD 6 5 5 2 5 4 5 32


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2. The threat environment the ship is expected to operate

in. In addition to maintaining navigational safety and

maintenance, a vessel operating in a high threat

environment has to have sufficient crew to be able to

fight both the external battle (engaging the enemy,

landing troops and operating air and surface

connectors) and the internal battle (damage control,

and repair functions post damage control).

3. The length of time the ship is expected to remain on

operations and its distance from a secure port. A small

Ship’s Company can support 24 hour operations for a

limited time (of the order of days), before rotating crew

is required limiting its distance from a secure port. For

a vessel that can be deployed globally, a larger Ship’s

Company is required to sustain 24 hour operation over

a lengthy deployment (of the order of months).

4. The level of automation of the systems, machinery and

role required. Propulsion machinery and command

systems can be manpower intensive and, as capability

increases, the manpower required typically also

increases.

To generate the manning required for each concept, the most

appropriate ‘real world’ vessel was selected based on the

requirements to act as a starting point. This set of reference

vessels included the RN Albion Class LPD, RFA Bay Class

LSD(A), Point Class Strategic RoRo, Danish Absalon Class

CCSS, USN Wasp Class LHD and French Mistral Class LHD. It

is recognized that different Navies have varied manning

philosophies, with Danish and French ships relatively lean

manned and USN ships comparatively heavily manned. For the

study, the current UK complementing philosophy was

maintained with options to reduce manning investigated as

described later.

The Ship’s Company generated for each concept defined the

branch and rank structure proposed to allow key skills and ranks

to be identified.

Balanced Design BMT’s suite of parametric concept design tools were used to

quickly achieve a balanced design for each concept design.

These tools were validated and then tailored for the study using

existing amphibious platforms and allow the space, weight,

stability and power and propulsion architecture to be iteratively

balanced.

Hullform resistance was predicted using the methodology

described by Holtrop (1978, 1982 & 1984), with indicative

equipment selected based on a wide range of manufacturers

data. This covered mechanical, hybrid, partial and full electrical

propulsion architectures with fixed pitched propellers,

controllable pitched propellers or podded propulsors. The

electrical load was parametrically scaled from basis vessels and,

where appropriate, individual equipment items were included as

required. Generic operational profiles based on the primary

capability of the ship (supporting surface maneuver, air

maneuver or a mix of the two), the operating profile, including

maximum and cruise speeds required and vessel range, were

used to generate total fuel loads. The most efficient power and

propulsion architecture capable of meeting the maneuvering

requirements for each concept was selected.

The intact stability of the concept was checked by numerical

integration of the proposed hullform and comparison of the ratio

of the transverse metacenter (GM) to the waterline beam, to

existing amphibious ships.

Outputs of Modellings A 'high level' general arrangement, indicating the location of

key spaces and demonstrating the relative positioning of certain

features in the ship was created for each design. A centerline

section view of a high level general arrangement is shown in

Fig.3.

Fig.3. High Level General Arrangement

A weight based cost model was used to generate a Rough Order

of Magnitude (ROM) Unit Purchase Cost (UPC) for each

concept design. The model estimates the labor, material and

equipment costs and uses a factor based on Compensated Gross

Tonnage (CGT) as developed by OECD (2007) to adjust the

labor rates for each concept design based on its complexity and

size. This has previously been described by Craggs (2003 &

2004) and Lamb (2002 & 2003) for naval ship types, and a trend

for amphibious auxiliary platforms has been used within the

study.

Shipyard build efficiency has been modelled as shown by Lamb

(1998 & 1999) and using BMT’s own derived data from a

number of projects to reflect the equivalent of a modern UK

shipyard. The costs represent the build cost for a first of class

allowing for a shipyard having to amend build practice for a

new ship class but excluding design costs and assessment costs.

The build cost compensating factors used reflect recent UK

large amphibious ship practice and represent vessels that lies

between that of commercial designs and front line

frigates/destroyers. The cost of weapons systems are not

included in the estimates as it is assumed that they would be


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provided to the ship as government supplied equipment, or be

developed under another project.

A Through Life Cost (TLC) model was also created to capture

the range of costs that will be associated to the ship during an

assumed 30 year life including:

1. Manpower;

2. Fuels and lubricants;

3. Consumables (i.e. commissaries, engineering spares,

etc);

4. Maintenance periods and refits/mid-life

updates/docking periods.

All costs assumed a generic annual inflation rate of 2.5%,

except manpower which was assumed to be 4.5% in line with

current UK inflation.

Manpower costs for the crew have been based on capitation

rates including pensions and taxes but excluding other

allowances. The costs do not include a shore margin or

specialist crew such as aviators or medical staff who are

provided at a fleet level, or recruitment and retention

allowances.

Fuel and lubricant costs have been estimated for each design by

assuming a proportion of time spent in harbor and at cruise and

full speed based on existing vessels. This assumes 66% of time

spent at sea of which 94% of the time is spent at an economical

cruise speed and 6% of time spent at maximum speed. The

commercial cost of fuel has been assumed and does not include

the fully burdened cost of energy.

The maintenance cost of each design has been estimated based

on the complexity of the vessel. Each capability area was

subjectively weighed for its contribution to the TLC based on

BMT’s engineering judgement. The range of requirements for

each capability area was then also assessed for their impact on

TLC allowing each design to be scored and given a relative

complexity score.

The complexity scores were then used to rank the designs.

Based on analysis of equivalent existing ships, the range of costs

were found to be between 5 and 9% UPC/annum. Where 5%

represents the more commercial vessel types and 9% represents

the most complex vessels within the design set.

The complexity weighting was also used to estimate a midlife

upgrade cost for each platform as a % of UPC. With an

equivalent range of between 5 and 20% of the UPC found.

Modelling of Lean Manning Given current pressure to reduce crew size to minimize both

acquisition and through life costs, significant change to the crew

size is possible between now and the delivery of the vessels.

This required a methodology to be derived to assess how the

crew size might reduce compared to current manning practice

and structures.

A significant number of potential lean manning technologies

and changes to naval doctrine could be applicable to the designs

and both military and public domain information were reviewed

including Johnson (2005), Malone (2013) and Post (2013). The

applicable themes under which manpower savings could be

achieved were identified as a number of drivers and these are

summarized in Table 4.

Table 4. Lean Manning Drivers.

D1 Operations Room Manning Structure

D2 Bridge Manning Structure

D3 Automation of Weapons Systems

D4 Reduced/ Unmanned Ship Control Centre

D5 Automation of Logistics/ Stores Accounting

D6

Combining Combat System Operation and

Maintenance

D7 Removal of Steward Branch

D8 Automation of Damage Control Monitoring

D9

Direct Entry into Naval Service from Other

Industries

D10 Combat Management Systems Improvements

D11 Use of Unmanned Aviation Vehicles

D12 Improvements in Food Preparation and Delivery

D13 Remote Monitoring of Systems from Shore

For a crew saving to be achieved, individual roles must be

removed within the same branch for all the vessel operating

states as individuals within the crew fulfil different roles at

different states. A typical UK Watch and Station Bill for an

amphibious platform was used to identify the driving states and

roles for the analysis:

1. State 1 – Action

2. State 2 – Defence Watches

3. State 3 – Cruising

Enabling technologies are required in conjunction with the

drivers identified in order to remove the roles across the vessel

states. The enabling changes to technology and doctrine

identified are shown in Table 5.


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Table 5. Lean Manning Enablers.

E1 Reduced Seamanship Burden - Improved Mooring

and Berthing

E2 Reduced Seamanship Burden - Reduced Requirement

to RAS

E3 Reduced Seamanship Burden - Automated RAS

equipment

E4 Reduced Ship's Husbandry Burden - Improved

Cleaning and Upper Deck Maintenance

E5 Improved Damage Control - Fixed Eductors in all

sections/ Automated Drain Down Valves/ 'Self

Healing'/ Re-routing Ring Main (and Other

Pipework)

As each of the drivers and enablers identified has a subjective

probability of reaching maturity, and none are certain of

reaching maturity, a model was constructed to allow a reduction

in crew to be estimated for a chosen confidence level.

The individual probability of each driver and enabler reaching

maturity in the timeframe of the study was subjectively

assessed. This was based on the state of the art for the

technology, if it had been achieved in a commercial or naval

application with another navy and the navy's perceived appetite

for the change. The associated impacts for each driver and

enabler were also estimated, to capture the changes that would

be required to maintain the equivalent level of capability:

1. Manpower saving - saving achieved for each branch in

each state, used as a new input to the concept model;

2. Weight impact - additional weight of systems and

equipment to replace personnel;

3. Space impact –additional space required for equipment

and systems to replace personnel;

4. Electrical impact – additional power demand for

equipment and systems required to replace personnel;

5. Equipment cost - change to UPC equipment costs

required to replace personnel.

As several enablers could be combined to achieve the full

benefit of one driver, probability trees were constructed to allow

the probability of each outcome to be predicted. The outcomes

for all the drivers were then sorted to discount combined

options, and to stop double accounting by manpower savings

released by an enabler being taken across multiple drivers.

In order to account for the probabilistic nature of the drivers and

enablers, a simulation was performed. This looked at the

outcomes of all of the possible combinations of enablers and

drivers that were captured in the analysis and acknowledges that

the enablers and drivers may or may not reach maturity. Whilst

there may be additional enablers and drivers not captured, a

sufficient number and range of options were considered to allow

the simulation to provide a realistic assessment.

The simulation also helped to mitigate any error in the

subjective probability of an enabler or driver occurring. By

averaging over a large number of outcomes, the sensitivity of

the model to any uncertainty in the individual manpower saving

or ship impacts is also reduced. The simulation allowed for a

statistical distribution to be derived and the data to be applied as

an input to the design process. The cumulative distribution

derived from this simulation is illustrated in Fig.4, which shows

the likelihood of reducing the crew number by a given

percentage.

Fig. 4. Cumulative Probability vs % Reduction in Naval Crew

The other inputs to the modelling were determined by creating

similar distributions for space, weight, power and UPC. A

cumulative probability of 50% was chosen for the study (as

likely as not to save at least that proportion of the crew)

resulting in a 30% reduction being selected for the study.

Not all drivers and enablers are appropriate for each design. For

less complex vessels with small starting crew numbers, a

number of the combat management system technologies are not

appropriate. Removing these from the analysis resulted in only a

small change in crew reduction, and ship impacts, but had a

large impact on equipment costs.

The outputs from the lean manning model are shown in Table 6;

these are additional requirements necessary to support a

manning reduction and are in addition to any effect of changing

the crew number.

Table 6. Lean Manning Model Inputs to Design Process.

Model Item Output

Reduction in Crew 30%

Weight Impact 45te

Space Impact 86m2

Electrical Impact 45 kW

UPC impact (Complex vessels) £9.5M

UPC impact (Simple Vessels) £6.2M


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RESULTS

Design Drivers The design set created covers a wide range of capabilities and requirements. By inspecting the models and arrangements created for each concept it is apparent that the designs are either driven by achieving a suitable payload, the arrangement of the capability or by internal volume requirements. These three groups can be seen when plotting the displacement against length (similar to the hullform regions described in Fig.1) and have been shown as high, medium and low displacement per unit length respectively in Fig.5.

Fig.5 Concept design LWL(m) vs Disp (t)

As shown, there can be significant variation in the displacement for the same length vessel and the frontiers have been found at which payload and internal volume are driving the vessel principal dimensions. For comparison a number of existing amphibious platforms are also shown, and whilst this study has not explored every possible combination of capability or all possible variations to the requirements or hullform, these limits represent a practical frontier at which payload or volume appear to drive the vessels principal characteristics. For the designs with a high displacement to length ratio (Disp/L), it can be seen that across all the capability areas they typically have a medium level of capability but with a low to medium level of Aviation and Command and Control as shown in Table 7.

Table 7. Distribution of Capability (High Disp/L)

The designs with the lowest Disp/L conversely typically have either a high or low level of capability for each capability area. These can be split into two groups, commercial designs with a low overall capability and naval platforms with a higher level of capability for Command and Control, Aviation, Embarked Force and Vehicle Lift as shown in Table 8. Table 8. Distribution of Capability (Low Disp/L)

The tables above show that certain levels of individual capabilities can contribute significantly to one of the design drivers. As the capability requirement is increased, more of the capability areas tend to drive the volume demand. Whilst all the capabilities affect the volume, payload and arrangement of a concept it is the combination of all the capabilities for a concept that determines where the concept sits, either on or between the frontiers described in Fig.5. By looking at how the capability is distributed within each design it is possible to look at the focus of the design

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Excellent 1 1 1 0 1 0 0


High 0 7 4 0 5 0 10

Medium-High 3 1 4 1 1 7 1

Medium 9 1 4 6 2 4 0

Low-Medium 2 4 2 9 1 2 5

Low 1 1 1 0 3 2 0

None 0 0 0 0 0 0 0

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Excellent 1 0 1 4 2 4 0


High 4 1 1 2 0 0 4

Medium-High 0 1 1 0 0 2 3

Medium 0 3 0 1 0 1 0

Low-Medium 0 0 4 1 0 3 0

Low 1 0 2 2 3 0 0

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between achieving a single capability/role or multiple capabilities/roles. Each capability was scored between 0 (none) and 7 (excellent) giving a maximum total capability score of 49. Looking at designs with a common maximum speed, the designs with a low Disp/L typically have the highest overall capability score and comparatively high variance as shown in Fig.6, indicating that they are more focused on providing a limited number of capabilities.

Fig.6 Variance of Capability for Common Maximum Speed

The concepts with a lower level of capability then sit in either

high or medium Disp/L groups and can be seen to vary by the

overall level of capability they provide.

All of the remaining low Disp/L concepts have high or excellent

Aviation capability. A significantly lower level of capability for

Aviation is included in the medium and high Disp/L concepts

indicating that Aviation capability is a significant volume

demand. When comparing the vessel size, a greater level of

capability can be achieved for the same ship size for high and

medium Disp/L concepts with a lower Aviation capability as

shown in Fig.7, indicating that the volume required drives the

ship size.

Fig.7. Concept Design LWL Vs Total Capability for Common

Maximum Speed.

Cost of Capability As the UPC is not just a result of the size of the vessel but also

dependent on a number of other characteristics and the

capabilities within the concept design, the same trend as shown

for length is not apparent when looking at the UPC. Assuming

no weighting between the capability areas, the medium Disp/L

concepts are typically more expensive for the same level of total

capability as shown in Fig.8.

Fig.8. UPC Vs Total Capability.

The same trend can be seen for TLC as shown in Fig.9.

Fig.9. TLC Vs Total Capability

As the Medium disp/L concepts have a high to excellent level of

Surface Maneuver capability, this would indicate that this is a

significant cost driver. The data set has been further investigated

to look at the effect of individual capabilities, the basis of the

crewing, how focused the design is on a single role and the total

level of capability.

Looking at Individual capability areas, it is not possible to

draw any trends from the whole data set. This is due to the

interactions between the capabilities and as those concepts with

a higher level of capability in an individual capability area also

tend to be more multi-role (as shown by Fig.6), with a higher

level of capability in other areas.


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Only a few of the data points represent a change in only one of

the capability areas, with no points suitable for analysis of the

Command and Control, Vehicle Lift and Embarked Force

capability areas. The suitable data points are shown in Fig.10.

Fig.10. UPC Comparison of Individual Capability Changes

These points show an increase in cost for increasing capability,

except for Logistics where no significant increase can be seen.

For Surface Maneuver, little increase in cost is seen between a

low to medium capability level, but a significant increase in cost

is seen from medium to high/excellent. For Aviation and

Medical, a significant increase in cost is seen between a high to

excellent level of capability.

Looking at the TLC for the same data points, the same trends

can be seen, except that there is a larger increase in the cost of

providing a high Logistics capability that can be seen in Fig.11.

Fig.11. TLC Comparison of Individual Capability Changes

The basis of the crewing is a contributing factor to the UPC

modelling, with commercial or naval auxiliary crewing used

where possible to reduce the cost of a concept. The concepts by

crew are shown in Fig.12.

Fig.12. UPC Vs Capability for Different Crewing Basis

For the concepts investigated, commercial crewing has only

been used for very low capability concepts and naval auxiliary

crewing only used for low to medium capability concepts. This

is due to the operating environment defined for each concept.

Commercial crewing is only applicable for those concepts

operating between secure ports. Naval auxiliary crewing has

been used for those concepts that would typically operate in a

relatively benign threat environment or under the protection of a

task group. The most capable concepts with naval auxiliary

crewing would be required to operate in an equivalent role to the

naval vessels to exploit their capability; this appears to remove

any reduction in UPC achieved by using a naval auxiliary crew.

The effect of just changing the crew from Naval to naval

auxiliary is shown in Fig.12 as Crew Type 1, where no real

difference has been observed.

At the higher capability level, no cost benefit can be seen. This

is also demonstrated by the number of crew required as shown

in Fig.13, where the higher capability concepts with naval

auxiliary crews have equivalent manpower to naval vessels of a

similar capability.

Fig.13. Crew Complement Vs Total Capability

As crewing costs are a significant element of the TLC, the effect

of commercial and naval auxiliary manning on costs can be seen

in Fig.14.


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Fig.14 Through Life Cost Vs Capability

Whilst the crew types can be seen to occupy different regions of

Fig.14, there are also some specific differences in the types of

capability being deployed. The naval crewed concepts have

greater Aviation, Command and Control and Surface Maneuver

capability, with the naval auxiliary vessels more focused on

delivery of Logistics, Vehicles and the transportation of an

Embarked Force.

How focused a design is on a single or multiple roles can be

seen by the level of variance as previously described in Fig.6.

Looking at the cost of deploying capability against the variance,

even though there is some scatter within the data, different

trends can be seen for high, med and low Disp/L concepts as

shown in Fig.15.

Fig.15. Average Cost of Capability Vs Variance

The high Disp/l concepts can be seen to have a lower cost per

capability point as variance increases, the opposite of the trend

seen for medium and low Disp/L. The trends are not directly

comparable as the groups also include the effect of platform

size, increasing total capability and changing focus on specific

capability areas.

The high Disp/L platforms represent smaller, lower overall

capability and low to medium aviation capability. It can be seen

for a low to medium aviation capability that specializing the role

of the platform (increasing the variance) reduces the average

cost of the capability. The designs studied were focused on

delivering Command and Control and Surface Maneuver, or

Embarked Force and Vehicle Lift capability at an excellent

level.

For the low and medium Disp/L platforms it can be seen that as

the variance increases, the average cost of the capability

increases. The designs with the lowest average cost of capability

are those with a medium to high aviation capability where

significant other capability is included. This indicates that

aviation capability is a significant driver for the cost of the

platforms, and that as the aviation capability is increased, other

capability can also be increased cost effectively.

The overall size of a platform, could also be expected to have

an impact on the average cost of capability. As shown in Fig.16,

as the vessel size increases, the average cost of the capability

decreases.

Fig.16. Average Cost of Capability Vs Waterline Length

However due to the other factors already investigated there is

significant scatter within the data and no meaningful trend can

be drawn. When the Through Life Cost (TLC) is also

investigated the opposite trend can be seen as shown in Fig.17.

Fig.17 Average TLC of Capability Vs Waterline Length.

As for the UPC trend, there is significant scatter within the data

and no clear trend can be drawn.


11

Effect of Moving to Lean Manning As the lean manning model predicted that the naval crew could

be reduced by 30% (at a 50% level of confidence), but

additional space weight and power would have to be

incorporated into the design, a relatively small reduction in the

design size and impact on the hullform arrangement was

anticipated. As the Aviation capability has a significant effect

on the topside layout of the vessel and crew accommodation

location, four designs were down selected to look at both the

effect of Aviation capability and crew number.

For designs with a high Aviation capability, the crew

accommodation is typically located within the hull as the

superstructure size is limited. Conversely, the designs with a

low aviation capability typically have crew accommodation

located within the superstructure. Little impact on ship length,

or difference between the levels of Aviation capability or

different accommodation locations was found as shown in

Fig.18, or for the TLC as shown in Fig.19.

Fig. 18. Reduction in LWL Due to Reduction in Crew

Fig.19. Reduction in TLC for Reduction in Naval Crew.

However, a significant difference was found in the reduction of

UPC based on accommodation location as shown in Fig 20.

Fig. 20. Reduction in UPC for Reduction in Naval Crew

Whilst the reduction in ship size is relatively small, a significant

reduction in the UPC and TLC can be achieved.

CONCLUSIONS

For typical amphibious platform hullforms, realistic frontiers at

which the displacement and volume are driving the size of a

design can be found. Whilst all the capabilities contribute to the

volume, payload and arrangement of a concept, it is the

combination of all the capabilities that determines where the

concept sits relative to the frontiers described. The individual

capability areas can be seen to influence the demands for

volume and payload, with Command and Control, Aviation,

Embarked Forces and Vehicle Lift having significant volume

demands.

Providing a high or excellent level of Aviation capability can be

seen to drive the platform size, achieving a lower total level of

capability compared to lower Aviation capability concepts for

the same ship length. However as Aviation is a key capability

how this can best be achieved within a task group needs to be

considered further.

Some of the capabilities have been found to have a significant

effect on the cost (UPC and TLC) of a concept, with increases in

Aviation, Surface Maneuver and Medical capability found to

individually significantly increase costs. Whilst a small increase

was found in UPC, increasing Logistics led to a significant

increase in TLC.

Due to required operational environment capability, regions can

be seen where commercial crewing can be used and where it is

beneficial for through life cost for naval auxiliary crewing to be

used.

Interactions between the capabilities can be seen to influence the

overall cost of capabilities. For concepts with a low Aviation

capability, focusing the role of the platform is cost effective,

conversely, as Aviation capability increases to a high level, the

other capabilities can also be increased cost effectively. For the

design points studied, whilst high Surface Maneuver and

Medical are expensive capabilities to include in a design, they

can be deployed as a role focused vessel with low Aviation


12

capability or added to a high to excellent Aviation capability

platform cost effectively.

Looking at the average cost of capability, no clear benefit can be

seen of moving to a large platform over a smaller platform

although this would need to be looked at further at a fleet level

to include the respective numbers of the platforms required.

A method for predicting the future crewing requirement has

been demonstrated. The impact of moving to lean manning for

naval crewed platforms has been estimated and the platform

impacts of lean manning were found to be relatively small, with

a small overall change to the platform size but a significant

reduction in the UPC and TLC.

ACKNOWLEDGEMENTS The Authors wish to thank David Lander (DSTL) for his

support throughout the study, Tom Smith (BMT) for support

in the statistical analysis conducted and BMT for the kind

permission and resources granted to complete the

investigation. All findings, ideas, opinions and errors herein

are those of the authors and are not those of BMT Defence

Services Limited.

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