towed undulating oceanographic vehicles from chelsea technologies group

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www.chelsea.co.uk Towed Undulating Vehicles Chelsea Technologies Group

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www.chelsea.co.uk

Towed Undulating Vehicles

Chelsea Technologies Group

www.chelsea.co.uk

Introduction

Application of sensor technology

Process control & monitoring

Medical diagnostics

Algal biofuel production

Fresh water & coastal monitoring

Offshore pipeline leak detection

Hydrocarbon pollution monitoring

NAD

Tactical Oceanography

Acoustic Target Simulation

Oceanographic research

Sensors & systems

Acoustic transducers

Fisheries

Exhaust gas monitoring

Ballast water monitoring

FerryBox

Security

Water Quality/Treatment

Bio/chem Security

Storage Tank Security Environmental

www.chelsea.co.uk

Introduction• Overview of CTG Towed Vehicle Systems• Description and Deployment of vehicles

– SeaSoar– Nν-Shuttle– AquaShuttle III

www.chelsea.co.uk

Why tow vehicles?

•Traditionally a profile of the upper ocean is taken by using profiling CTDs

– Requires vessels to stop at set stations

– Number of achievable casts are limited per mission

– Disturbs other operations required from vessel

– Multiple deployments per mission = multiple risks

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Advantages

• Provides profiles to significant depths with towing vessel underway

• Just deploy and recover at start and end of transect or journey

• No cable reeling on deck once deployed

• Provision of real time data can provide immediate points of interest to further investigate

• CTG platforms offer a large and flexible cargo area for instruments

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And the end product ….

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Towed Vehicle Selection•Criteria

• Depth requirement

• Parameters required (Payload implications)

• Tow speeds available from host vessel

• Size of host vessel

• Budget

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Towed Vehicle Comparison

AQUAshuttle III

Nν-Shuttle SeaSoar

Tow Speed Range (knots)

8 to 25

5 to 15

6.5 to 12

Undulation range unfaired cable

0 to 65m

0 to 80m

0 to 100m

Undulation range faired cable

0 to >125m

0 to >160m

0 to >500m

Payload 20 litres 60 litres 85 litres

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Winch Selection•Is there a winch already available?

•Depth and Speed requirement – Defines Light or Heavy Duty Winch

•Hydraulic or Electric?

•Size of host vessel

•SeaSoar requires winch for faired cable

•See CTG website for winch specifications

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Cable Requirements

•Cable type used for towed vehicle dominates performance achieved

•Large diameter = Large drag = shallow depth performance

•SeaSoar demands conductive cable for operation

•Nν-Shuttle and AquaShuttle benefit from use of conductive cable

•CTG has identified the Rochester 7-314-AXX as the ‘ideal’ commercially available cable

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Cable Specification•Type

•Diameter

•Conductors

•Breaking Strain

•Working Load

•Bend Diameter (min)

•Weight in Air

•Weight in Fresh Water

Rochester 7-H-314AXX

8.2mm

7 + Armour

51.6kN

20.0kN

43cm

268 kg/km

220 kg/km

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Cable Fairing•Reduces drag on the cable as it passes through the water

•Advantages

• SeaSoar Depth Range increases from surface to 120m to surface to 500m

• Nν-Shuttle Depth Range increases from surface to 80 metres to surface to 150m

•Disadvantages

• Additional Cost

• Requires purpose built winch of large drum diameter

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Fairing Specification•Type

•Weight in Air

•Thickness

•Chord

•Length

•Nose Hole

•Minimum Bend Diameter

•Max Cable Diameter

Indal Flexnose Style FA-478-350-1

0.28 lb/ft

0.48”

1.92”

4”

0.35” dia

36”

0.333”

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Towing Sheaves

•2 towing sheave designs available from CTG

• Towing Sheave for Faired Cable

• Towing Sheave for Non-faired Cable

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MiniPack CTD-F Features•Mechanical

•Size

•Weight in Air

•Pressure Rating

•Communications

•Input

•Tx

•Scan Rate

•Integral Sensors

114mm dia x 200mm

6kg

600m (Titanium / Acetal)

16 analog external channels

RS232 or RS422

1 Hz all channels

CTD Fluorescence

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MiniPack II Specification

Type Range Accuracy Resolution

Conductivity Inductive Cell 0 to 70 mmhos/cm

0.005 mmhos/cm

0.001 mmhos/cm

Temperature Pt Resistance -2 to +35 C 0.003 C 0.0005 C

Pressure Strain Gauge with temp compensation

0 to 600 dbar 0.2 dbar 0.01 dbar

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MiniPack Fluorometer SpecificationFluorimeter Excitation

(nm)Emission(nm)

Concentration(ug/l)

Resolution(ug/l)

Chlorophyll-a 470/30430/30

685/30685/30

0.03 to 1000.03 to 100

0.01

Rhodamine 470/30 590/45 0.03 to 100 0.01

Amido Rhodamine

425/30 550/30 0.04 to 200 0.025

Fluoroscein 480/80 530/30 0.03 to 100 0.01

Nephelometer 470/30 470/30 0.04 to 100 0.01 FTU

Phycoerythrin 530/30 580/30 0.03 to 100 0.01

Phycocyanin 590/35 645/35 0.03 to 100 0.01

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SeaSoar Specification

•Length (excluding Bridle)

•Height (rudder bar down)

•Width (over wing hooks)

•Weight in air

•Max Depth

•Max tow speed

•Min tow speed

•Cable Requirements

1.5m

0.98m

1.6m

150kg

500m (with fairing)

10 knots (with fairing)

5 knots (with fairing)

1000m, 750 m faired

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SeaSoar Deck System

•Combination of SeaSoar Controller and CTD station

•CTD Station either MiniPack CTD-F or Seabird 911

•SeaSoar Controller runs CFlightWin

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SeaSoar Alternative ConfigurationsDATA

ACQUISITIONPC

DECK UNIT

FLIGHTCONTROL

PC

SEASOARDECK UNIT

SERVO VALVE

HYDRAULICRAM

WINGS

PRESSURESENSOR

C.T.D. SENSOR

IMPELLER

FEEDBACK SIGNAL

CONTROL SIGNAL

DECK UNIT

UNDERWATER UNIT

DATAACQUISITION

PC

DECK UNIT

FLIGHTCONTROL

PC

SEASOARDECK UNIT

SERVO VALVE

HYDRAULICRAM

WINGS

C.T.D. SENSOR

IMPELLER

DEPTH SIGNAL

CONTROL SIGNAL

DECK UNIT

UNDERWATER UNIT

FEEDBACK LOOP

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SeaSoar Deployment•If deploying new cable, ensure this is de-torqued prior to deployment

•Conduct pre-launch checks using Wing Control Box

•Set SeaSoar to a level tow depth of 20 – 30 metres

•Check water depth

•Operators: 2 at winch, 2 at vehicle, 1 at A frame, 1 at control

•SeaSoar centred at A frame, nose towards stern

•Always maintain tension on cable

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SeaSoar Deployment (Continued)

•Vessel speed to be 4 knots during deployment

•Once in water veer cable at 0.5 metre / second

•At 50 metres, increase vessel speed to 6 knots

•Increase veer speed to 1 metre / second (no faster) beyond 100 metres

•Increase speed to 7 knots once fully deployed

•To obtain maximum performance, 750 metres cable out, 8.0 – 8.5 knots

www.chelsea.co.uk

CFlightWin

www.chelsea.co.uk

CFlightWin Features•Logging of SeaSoar flight data to PC

•Control of the SeaSoar within CONFIG menu

•Selection and Set-up of Pressure Data input

•Control Parameters

•gain0 – shallow region Gain value

•gain1 – deep region Gain value

•pres0 – transition region centre

•deltaP – depth interval of transition

•Setup of Sawtooth; min depth, max. depth, period & period up

•Plot Variables

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NuShuttle Specification•Length (excluding Bridle)

•Height (rudder bar down)

•Width (excluding sponsons)

•Weight in air

•Max Depth (with fairing)

•Max Depth (without fairing)

•Max tow speed (without fairing)

•Min tow speed

•Cable Requirements (faired)

•Cable requirements (non-faired)

1.3m

0.57m

0.5m

72kg

150m

80m

15 knots

5 knots

350m, 150 m faired

500 metres

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NuShuttle Deck System•Single Rack Mounted PC Station

•Marine Interface Unit

•Runs MiniPack GUI

•Option for GPS input

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NuShuttle Configuration

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NuShuttle Deployment•Conduct pre-launch checks checking communications with the MiniPack and the Servo Unit

•Set to 3 metres level flight

•Check water depth

•Operators: 1 at winch, 1 at vehicle, 1 at A frame

•Always maintain tension on cable

•Vessel speed to be 4 knots during deployment

•Once in water veer cable at 0.5 metre / second

•Start tow vessel acceleration to 8 knots

•If operating without slip rings, check communications at 50 metre cable out point

•To obtain maximum performance, 275 metres cable out, 9 knots

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NuShuttle Performance

0

200

400

600

800

1000

1200

1400

14:0

0:00

14:0

0:56

14:0

1:52

14:0

2:48

14:0

3:44

14:0

4:40

14:0

5:36

14:0

6:32

14:0

7:28

14:0

8:24

14:0

9:20

14:1

0:16

14:1

1:12

14:1

2:08

14:1

3:04

14:1

4:00

14:1

4:56

14:1

5:52

14:1

6:50

14:1

7:50

14:1

8:49

14:1

9:45

14:2

0:41

-40

-20

0

20

40

60

80

100

SPEED rpm

CABLE OUT Metres (in w ater)

ACTUAL DEPTH Metres

CMND DEPTH Metres

WING ANGLE Degrees

SHIPS SPEED knots

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TPlot8 Software

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TPlot8 Features

•Display of real time Data in tabular form

•Display of Data in Graphical form

•Playback of Data or Log File

•Setup of Nν-Shuttle Min & Max Depth, Climb Rate

www.chelsea.co.uk

Servo Parameters•Main Parameters set from MiniPack GUI

•Maximum Depth (metres)

•Minimum Depth (metres)

•Climb Rate (metres / minute)

•Bottom Avoidance Setting (metres above bottom)

•PID Settings - Set within Shuttle Terminal View

•Change Proportional (P) and Integral (I) terms only when tuning required

•$ command to view settings

•KI then P or I to change variable followed by value <CR>

www.chelsea.co.uk

Servo Settings TableSystem

Description Required

PerformanceSettings

Upper Depth

Lower Depth m

Upper Depthm

Lower Depthm

Climb Ratem / min

Cable Scopem

Tow Speedknots

P I D

Shallow Tow Near surface

5 -1 6 5 13 8 0.3 0.009 0

Shallow Tow Near surface

10 -2 13 10 16 8 0.3 0.009 0

Shallow Tow Near Surface

20 -6 24 10 28 8 0.3 0.009 0

Deep Tow Near Surface

80 -10 80 55 180-270

9 0.3 0.03 0

Deep Tow – Faired Cable

Near surface

150 -15 165 57 315 10-11 0.1 0.01 0

www.chelsea.co.uk

Mariner NuShuttleStandardised Instrumentation Package

for Large Marine Ecosystem (LME)

programme.

Instrumentation Package includes:

•MiniPack CTD-F

•Autonomous Plankton Sampler

•Fastracka II

•Optical Plankton Sampler

•Dissolved Oxygen

•Nutrients

www.chelsea.co.uk

Thank You!Any Questions?

Chelsea Technologies Group