OJ900 Technical Specification - Oceanteam

PROJECT
OCEANJET 900 TRENCHING SYSTEM
DOCUMENT TITLE
DOCUMENT REF. NR.
CLIENT REF NUMBER
OJ900-001
Oceanjet 900 Technical Specification
OJ900-001-TS-001
OCEANTEAM PROJECT REF NR.
This is a Project Controlled Document and should be retained only by an authorised person. If this document was not specifically
issued to its user, then the user must obtain a controlled copy from the Project manager.
A2 In
progress
Second Draft To Incorp New Snubber PHW
A1 26/09/07 First Draft AKT
Rev Date Description Prep QA PM
Document Revision History

Contents
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
1 Introduction ............................................................................................................................... 3
1.1.1 Purpose ................................................................................................................................3
1.2 Overview ..............................................................................................................................3
1.3 References ...........................................................................................................................4
1.4 List of Abbreviations.............................................................................................................4
2 Specification ............................................................................................................................. 5
2.1 General ................................................................................................................................5
2.2 Dimensions ..........................................................................................................................6
2.3 Technical Data .....................................................................................................................6
2.4 Water Pumps and Compensators ........................................................................................7
2.5 Jetting Sword System ..........................................................................................................8
2.5.1 Functional Description .........................................................................................................8
2.5.2 Technical Data .................................................................................................................. 10
2.6 Thrusters ........................................................................................................................... 11
2.7 Hydraulic System .............................................................................................................. 12
2.7.1 Hydraulic Power Unit ........................................................................................................ 12
2.7.2 Oil Reservoir ..................................................................................................................... 13
2.7.3 Valve Packages ................................................................................................................ 14
2.7.4 Filter System ..................................................................................................................... 15
2.7.5 Tubing and Fittings ........................................................................................................... 15
2.8 Buoyancy System ............................................................................................................. 16
2.9 Umbilical Termination / Launch and Recovery Tool ......................................................... 17
2.10 Frame Structure ................................................................................................................ 19
OJ900 Technical Specification
Page 2 of 19

1 Introduction
1.1.1 Purpose
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The purpose of this document is to give an overview of the Oceanjet 900 trencher. It is not
intended to be a set of operating instructions, nor a detailed breakdown of all the systems
components.
1.2 Overview
The Oceanjet 900 trenching system (formally ROTS II), in its original specification, offered a
reliable and proven high trenching performance using its 900 kW output power, and has
performed trenching operations on a variety of products; including power cable, umbilical’s, and
pipelines of 10" diameter in varying soil conditions.
During 1st & 2nd quarter 2007, Oceanteam have made significant improvements to the original
specification to further enhance trenching performance; in line with present and predicted Client
requirements, particularly of larger diameter products. Improvements include complete redesign
of jetting swords, modification to vary flow and pressure, control system upgrade and the addition
of a modified skid arrangement to allow operation on pipelines. Oceanjet 900 has a
burial/deburial capacity of nominal 0.5 - 2.0 metres depth, with variable trenching width of
nominal 0.10 - 0.75 metres utilising 2m swords. Oceanjet 900 has successfully completed post
lay trenching of some 45km of export and infield power cables on a Dutch Wind farm Project.
Additionally the Oceanjet 900 has successfully trenched 12” and 14” pipelines with 2” piggyback
lines attached.
The OJ900 Jetting system has the ability to control the flow of water to the forward, undercut and
backflush jets. This allows variable jetting performance of the tool on the seabed without having
to recover as the seabed conditions change.
The Oceanjet 900 system consists of the Trenching ROV, a self-contained Control Cabin,
Transformer Van, Umbilical Winch, Snubber Assembly and 20t A-Frame, along with its own
Electrical and Mechanical workshops and Environmental container
The versatile design allows the complete system to be road transportable and easily
mobilised/demobilised on suitable vessels of opportunity.
OJ900 Technical Specification
Page 3 of 19

1.3 References
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
This document should be read and referenced in conjunction with the following relevant
documents:
Framo Users Manual ROTS 2 vehicle (doc. nr. 1563-496-4)
1.4 List of Abbreviations
Abbreviation Description Abbreviation Description
CRP Common Reference Point MBL Minimum Breaking Load
DGPS Differential Global Positioning System MBR Minimum Bending Radius
DOC Depth of Cover NAV Navigation
DOL Depth of Lowering OP&U Oceanteam Power & Umbilical
DP Dynamic Positioning POB Personnel On Board
DPO Directional Positioning Officer PPE Personal Protective Equipment
ETA Estimated Time of Arrival PTW Permit to Work System
HP High Pressure QC Quality Control
HPR Hydro Acoustic Positioning Reference M&R Maintenance and Repair
HSE Health Safety and Environment ROV Remotely Operated Vehicle
HSEQ Health Safety Environment and Quality RPL Route Position List
JSA Job Safety Analysis SIT Silicone Intensified Target
KP Kilometre Point SWL Safe Working Load
LARS Launch and Recovery System TSD Temperature Severity Depth
LAT
Lowest Astronomical Tide TSS
Manufacturer’s market name of
specific survey equipment
LP Low Pressure TSV Trenching Support Vessel
LWM Low Water Mark USBL Ultra Short Base Line
OJ900 Technical Specification
Page 4 of 19

2 Specification
2.1 General
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The OceanJet 900 vehicle is a totally remotely operated, submergible system for trenching cables
and pipelines into the seabed. The vehicle is built on standard ROV principle and components.
The OceanJet 900 vehicle consists of the following main systems:
Water pumps
Water Distribution System
Swords
Hydraulic Power Unit
Valve Packages
Hydraulic Reservoir
Hydraulic Distribution System filters
Thrusters
Buoyancy Blocks
Frame and Lifting Structure
Umbilical Termination Head
Control System
Electrical Power-distribution
Cameras
Lights
OJ900 Technical Specification
Page 5 of 19

2.2 Dimensions
Length 5000mm
Width 4190mm
Height 2970mm
Weight 13.0 Te in Air
2.3 Technical Data
Operating depth 1000 msw
Min calculated continuous operating time
submerged
Max power consumption
10 days
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
440 VAC, 3ph, 60Hz, 1047kw, max start current
2775A
Trenching depth Nominal 500 - 2000 mm (adjustable)
Gap between swords Nominal 100 - 750 mm (adjustable)
Length frame 5000mm
Width frame 2710mm
Height frame with buoyancy 2770mm
Weight dry (ex. payload) 13,000 kg
Net buoyancy 5,900kg
Max hydraulic flow/pressure 380 1/min - 270 bar
HPU motor 1 x 190 Kw - 3000V - 60Hz
Water pump motor 2 x 225 Kw - 3000V - 60Hz
Water pump performance
Variable 250-600 m3/h @ 6 - 13 bar (230 kW shaft
power) (accuracy under review)
Max forward thrust see 1500 pump Kg curve
Max vertical thrust 1500 Kg
Hydraulic applications
8 x Thrusters
2 x Swords – Height, Width & Tilt functions
1 x Cable pickup arm - 3 functions (Not Fitted)
2 x Water Dump valves
1 x Manipulator (Not Fitted)
2 x Sonar & SIT Camera Tilt platforms
6 x Sword Sectional Valves (3 per sword)
1 x TSS Frame Raise/Lower function
OJ900 Technical Specification
Page 6 of 19

Hydraulic Fluid
Hydraulic filtration
Analogue sensors
Digital sensors
Camera
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
Petro Canada
Environ MV46
Non-Toxic/Biodegradable
1 x pressure filter 10 micron
1 x return filter 10 micron
1 x drain filter 10 micron
Lights 2 x gas light
12 x halogen light
Navigation
2.4 Water Pumps and Compensators
Refer to User’s Manual No. 2010-1224-4.
Sword angle (2 of)
Sword depth (2 of)
Sword width (2 of)
Oil reservoir level (1 of)
Compensator Umb. J. Box (1 of)
Compensators water pump motor/cofferdam (4 of)
Oil pressure pump motors (2 of)
Oil pressure cofferdam (2 of)
Hydraulic pressure (1 of)
Water pump pressure (2 of)
Depth sensor (1 of)
Oil pressure tilt cylinder sword (2 of)
Water ingress sensor PSP (1 of)
Compensator HPU - Low level (l of)
Compensator Valve Box - Low level (1 of)
Compensator Light Termination/fuse Box - Low
level (l of)
Compensator instrument transformer box – Low
level (l of)
1 x SIT camera
2 x Colour Camera (pan & tilt & zoom)
5 x B/W fixed camera
1 x sonar SIMRAD Mesotech MS 1000
2 x transponder/responder
1 x fluxgate compass
1 x altimeter
1 x depth sensor
OJ900 Technical Specification
Page 7 of 19

2.5 Jetting Sword System
2.5.1 Functional Description
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The purpose of the swords is to flush the water down each side of the cable, or pipeline, in order to
create a ditch. The sword system is built into the frame, and consists of 2 sets of individual operated
sword arrangements built into a common horizontal guide rail.
Each sword arrangement can individually be tilted 45° from the horizontal parking position down to
the operating position. In addition it can be lifted 650 mm straight vertically in order to vary the burial
dept, and also move sideways in order to increase the trenching width from approximately 100 mm
to 750 mm.
Restrictions: When sword length is more then 3300 mm vertical lift max. 350 mm.
OJ900 Technical Specification
Page 8 of 19

Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
A set of linear sensors together with software mathematics gives the trencher pilot continuously
updating information about the sword depth and sword positions.
The water is pumped from the pump through an 8" pipe into a water chamber.
This has the capability of shutting off the flow of water to the forward, undercut and backflush jets.
This allows variable jetting performance of the tool on the seabed without having to recover as the
seabed conditions change.
The 2m swords bolted to the water manifold can be replaced with 1m swords.
In case of communication failure or other system breakdown, a system for retracting the sword is
built into the hydraulic system. By connecting two hydraulic hoses strapped on the outside of the
vehicle to an external power unit, it is possible to tilt the swords up to help facilitate recovery.
The hoses can also be connected together before the vehicle is lowered down on the parking frame.
OJ900 Technical Specification
Page 9 of 19

Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
In this case the oil will bypass the hydraulic circuit and the swords will easily tilt up due to the weight
of the vehicle.
Female connector = Pressure in
Male Connector = Return out
2.5.2 Technical Data
The two metre trenching tool is used for operations in non-cohesive sea beds of sands & silts.
Specification for 2m Swords
No of Swords 2
No of vertical nozzles 21 each sword
Dim vertical nozzles Ø12
No of horizontal nozzles 11 each sword
Hoses for emergency
retract
Dim horizontal nozzles Ø14
No of backflush nozzle(s) 1 each sword
Dim backflush nozzles Ø40 to 50
Material Sword Aluminium 5083-O
Max opening 750 mm (between swords)
Min opening 100 mm
Max trench depth 2000 mm
Max weight 125 kg (each sword)
OJ900 Technical Specification
Page 10 of 19

2.6 Thrusters
Hydraulic Power (KW)
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The OceanJet 900 vehicle is provided with 8 Sub-Atlantic thrusters, 4 horizontal pointing 45°
forwards and 4 pointing 85° upwards.
SA-420-FF Hydraulic Power Vs Thrust
Tests witnessed by DNV
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
340
360
380
400
420
440
460
480
500
520
540
560
580
600
Bollard Thrust (Kg)
SA-420-FF Reverse
SA-420-FF Forward
OJ900 Technical Specification
Page 11 of 19

2.7 Hydraulic System
2.7.1 Hydraulic Power Unit
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The HPU (Hydraulic Power Unit) consists an oil filled electrical motor and a hydraulic pump.
The motor is driving the pump through a flexible coupling.
The pump is a variable piston pump type Rexroth A4VSO and has a capacity of 380 l/min @ 250
bar.
The rear end of the motor shaft is machined to fit an auxiliary pump
Temperature element and a water ingress sensor are fitted inside the motor housing.
A pilot line from the pressure regulator is routed to a remotely operated pilot valve (in A12) in order to
steplessly adjust the system pressure from the control system.
All other pump adjustments are pre-set from supplier.
The pilot pressure is limited by means of a manual adjustable pressure control valve located under
the pilot valve.
Power 195 kW
Current 3000VAC
Frequency 60 Hz
Poles 4
Speed 1750 rpm
Weight - Motor 400 kg
Weight - Pump 180 kg
Max Pressure 260 bar
Max Flow 380 l/min
OJ900 Technical Specification
Page 12 of 19

2.7.2 Oil Reservoir
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The purpose of the reservoir is to contain the hydraulic oil, filtrate it and keep the oil pressure
above the ambient seawater pressure.
The two diaphragms make a 100% tight barrier between the hydraulic oil and the ambient
seawater.
Two spring-loaded pistons acting on the diaphragms provides an overpressure in the
reservoir of approximately 0,5 bar.
The oil from all the hydraulic consumers flows through the 10-micron return filter into the
reservoir.
A 10-micron drain filter cleans the drain oil from the hydraulic pump. The filters are easy
accessible for service and maintenance.
A transparent cover in the end of the reservoir enables service personnel to visually inspect
the condition of the oil.
Removing the cover gives also easily access to the inside of the reservoir.
The level of the reservoir and the hydraulic temperature is monitored on the control system
by means of a temperature element mounted inside the reservoir and a level sensor
mounted on the outside of the reservoir.
Weight 121 kg
Capacity 80 L
Variable volume 31L
No of diaphragms 2
Material Anodized seawater resistant
Aluminium
OJ900 Technical Specification
Page 13 of 19

2.7.3 Valve Packages
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The OceanJet 900 is equipped with five oil filled hydraulic valve packages:
2 off - Valve Package with proportional valves for thruster control.
3 off - Valve Package with solenoid valves for control of sword functions, cable grip arm
functions, pump pressure control etc.
The valve package consists of several combinations of Wandfluh pressure and flow control
valves.
Each valve box contains an I/O card providing power to the solenoids and communication
from/to the topside control system.
The I/O card also provides communication between sensors and control system.
External cables are connected to connectors on the valve box.
Each solenoid connector is provided with a Light Emitting Diode (LED) visible through the
transparent cover.
The LED’s light up once the solenoids are activated.
The valve box housing is pressurized by means of a compensator.
Bleed plugs / drains plug are fitted in the top/bottom of the valve box.
All adjustment screws are accessible by removing the front cover.
Details regarding each valve package setup ref drawing no 1563-094-1
Valve Box with solenoid valves
OJ900 Technical Specification
Page 14 of 19

2.7.4 Filter System
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The cleanliness of the hydraulic oil is provided by an extensive filter system.
The oil is pumped through a 10-micron high-pressure filter via valves and consumers
through a 10-micron low-pressure filter and into the reservoir.
The drain oil from the hydraulic pump will always contain wearing particles.
A separate 10-micron filter cleans the particles from the drain oil before it flows into the
reservoir.
Note: The filters are not provided with pop up indicators.
2.7.5 Tubing and Fittings
All tubing is made from stainless steel tube, and the Parker EO system is used as fittings.
The Parker EO fitting system is based on a "functional nut" assembly consisting of a nut, a
soft sealing and a retainer ring.
For further details see separate product book enclosed in the component manual.
OJ900 Technical Specification
Page 15 of 19

2.8 Buoyancy System
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
Each buoyancy module is designed for 1000 MSW.
The modules are bolted on the top of the frame.
The total net buoyancy capacity of 5908 kg makes that the OceanJet 900 neutral floating in
seawater.
The modules are provided with M16 thread inserts at the top plane for handling
Fwd module
Weight: 1475.5 kg.
Buoyancy: 2062.8 kg.
Stbd module
Weight: 1266 kg.
Buoyancy: 1789.7 kg.
Centre module
Weight: 250 kg.
Buoyancy: 275 kg.
Port module
Weight: 1273 kg.
Buoyancy: 1780.5 kg.
OJ900 Technical Specification
Page 16 of 19

2.9 Linksyn& Snubber
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
This section is being reviewed and updated
The Launch and Recovery Tool hanging in the crane hook will be guided down along the Umbilical.
Once it is in the proper position it will automatically lock into the Umbilical Termination system.
A remotely operated hydraulic lock/unlock device enables the OceanJet 900 pilot to release the
Launch and Recovery Tool from the Termination after launching OceanJet 900 vehicle into the sea.
The Umbilical outer wire layers are moulded to the Umbilical Termination head by means of Wire
Lock.
The Umbilical moulded to the hardened Wire Lock is secured against rotation by means of a small
lug bolted to the inside the Termination hollow.
A bend restrictor prevents the Umbilical from damage due to over-bending.
The Umbilical Termination together with the Launch and Recovery Tool is load tested with 31.5 tons.
The "Launch and Recovery Tool" is designed to lift the weight of OceanJet 900 from a submerged
condition through the splash-zone and up to the parking frame on deck. (Or vice versa)
OJ900 Technical Specification
Page 17 of 19

Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The tool itself is a mechanically device designed to fit the OceanJet 900 Umbilical Termination head
and must be used together with this in order to activate the lock/unlock mechanism.
The latch mechanism actuated by a rod connected to the latch weight remains the latch either in
open or locked position depending on the position of the hydraulic docking plate.
If the hydraulic docking plate is retracted in the lower position, the latch will open, and the Launch
and Recovery Tool is released from the Umbilical Termination head.
If the hydraulic docking plate is not activated, the two springs will keep the latch mechanism in locked
position.
By removing the parts shown as blue items (see figure), the Umbilical can be entered into the slot.
A lifting gear is connected to the two attachment lugs at both side of the tool.
The lifting gear shall be hanged up in the ship's crane hook.
After reassembling the parts, the tool can be guided down along the Umbilical and locked to
Umbilical Termination.
Once the tool is locked to the Termination, the lifting operation can start.
OJ900 Technical Specification
Page 18 of 19

2.10 Frame Structure
Client: Oceanteam
Project: OJ900 Trenching System
Ref.: OJ900 - 001
Rev.: A2
The frame is basically welded together from aluminium U-profiles.
The lifting structure made from stainless steel (duplex) and bolted to the frame picks up the weight of
the vehicle from the corners and into the lifting point.
A light platform in the front of the frame gives place for equipment like cameras, lights, sonar etc.
The thrusters are attached to the thruster brackets.
A number of small brackets are welded to the frame beams in order to fit the buoyancy modules to
the top of the frame.
OJ900 Technical Specification
Page 19 of 19