Fallpipe Vessels

7/25/2019 Fallpipe Vessels

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CAPABILITYSHEETDYNAMICALLY POSITIONED FALLPIPE VESSEL (DPFV)A SEAGOING SELFPROPELLED VESSEL WITH A FALLPIPE

INTRODUCTIONA Dynamically Positioned Fallpipe Vessel (DPFV)is a seagoing selfpropelled vessel with a fallpipe,designed to be lowered underneath the vessel. Atthe lower end of the fallpipe a ROV is installed.By a so-called dynamically positioning system,the vessel can stay in exact position or be guidedalong a predefined track.

MAIN PARTS DPFVIn principle the main parts of the DPFV are:

The hull, containing the engines, propulsion,the crew quarters, the bridge with naviga-tional and dumping control etc.

The hold(s), in which the rock is loaded andthe excavators for discharging are placed.

The fallpipe, consisting of polyethylene orsteel pipe sections.

Moonpool and pipe tower, a hole in the vesselwith a tower construction on top in which thefallpipe can be built up and lowered to therequired depth.

The fallpipe ROV, a manoeuvrable at the

lower end of the fallpipe. Transportation unit, containing hoppers, con-

veyor belts and a chute above the fallpipe. (Free-flying) ROV, a Remotely Operated

Vehicle which is equipped with several surveyequipment, cameras, sonar and pipe tracker.

Dynamic Positioning (DP) system, utilising tun-nel- and/or retractable thrusters.

A DPFV Sandpiper

B DPFV Seahorse

C DPFV Seahorse

WORK METHODAfter loading the vessel with rock material at a quarry, the vessel will sail tothe location where the rock has to be installed. Once at location the vesselswitches over to Dynamic Positioning (DP). The actual dumping is performedas follows: The fallpipe ROV is positioned above the start point, 4-8 metres above

the seabed depending on the prevailing conditions. The vessel is moved along the track aided by the instruments on the fall-

pipe ROV, like scanning sonars and cameras. During this phase the fallpipe ROV is positioned by its thruster- and

heading package, whilst the vessel may assist in this process for largermovements by making a parallel shift of the track.

Rock material is discharged from the cargo holds by excavators mountedon a pedestal, into a hopper installed on deck adjacent to the hold.Wheel loaders, if applicable, are used to bring the material into reach ofthe excavators.

The rock is fed from the hoppers onto the relevant conveyor belts, whichtransport the rock to the central hopper. From here the rock is fed ontothe central conveyor belt which transports the rock via a chute into thefallpipe. Start and stop of the feeders and feeding rate are remotelycontrolled from the bridge, whilst a closed circuit TV system allows thecontinuous control of the discharging process.

When reaching the end point of the track, rock feeding is stopped andthe vessel may shift to a survey position or set up for a new track. It is

also possible to dump close to a rig or other structure by bow and/orside dumping instead of using a fallpipe. In this case an extra conveyorbelt is mounted up to a few metres outside the vessel.

SUITABILITYA DPFV can be used for a wide range of applications in the field ofunderwater pipelines and other subsea structures, like: - reducing and/oreliminating free spans - stabilising pipelines on the seabed - preventingupheaval buckling - thermally insulating oil and gas lines to assure flow -providing structure foundation - preparing pipeline crossings and - providingfinal protection - providing protection against anchors and fishingoperations- providing erosion protection - ballasting gravity base structures

A

B

C

1. Holds 4. Fallpipe ROV

2. Fallpipe 5. Thrusters

3. Pipe tower


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Royal Boskalis Westminster N.V.

PO Box 433350 AA Papendrecht

The Netherlands

T +31 78 69 69 000

F +31 78 69 69 555

[email protected]

www.boskalis.com

DYNAMICALLY POSITIONED FALLPIPE VESSEL (DPFV)A SEAGOING SELFPROPELLED VESSEL WITH A FALLPIPE

E

D Conveyor belt

E Fallpipe handling

F Combined survey and rock installation

ROV for newly built DPFV

G DPFV working close to platform

H Discharging rock into hopper

F

H

G

DYNAMICALLY POSITIONED FALLPIPE VESSEL

Boskalis' fleet contains 3 DPFV's

Name Max. CargoCapacity (tons)

Max. operationaldepth (m)

Sandpiper 18,000 1,500

Seahorse 18,000 1,500

Rockpiper 24,000 1,500

DUMPING CONTROL AND TOLERANCEDumping through the fallpipe system makes itpossible to place the rock in a controlledmanner independent of the water depth orcurrents, with a horizontal accuracy of 1 metre

from a defined point/position. The verticaltolerance when dumping rock material isdependent to some extent on the size of the rockmaterial, but for a typical rock berm verticaltolerance will be 20cm.

FLEET OF BOSKALISThe fleet of Boskalis includes two DPFVs,namely Sandpiper and Seahorse. Find thecomplete list of the Boskalis fleet onwww.boskalis.com

D


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MAIN DATA

Dynamic positioning system DP-2

Subsea positioning system HIPAPLength overall 158.60 m

Breadth 36.00 m

Moulded depth 13.50 m

Design draught 9.40 m

Cargo carrying capacity 24,000 t

Cargo hold capacity 15,500 m

Sailing speed loaded 13.5 kn

Total installed power 15,192 kW (3x4,500kW +

1x1,200kW + 1x492kW)

Main engines 3 x 4,500 kW

(3x main generator sets)

Main propellers 2 x 4,500 kW

(2x azimuth thrusters)

Azimuth thrusters 2 x 1,500 kW

(2x retractable thrusters)

Bow thruster 1 x 1,000 kW

7,000 kW

2 x 1,250 kW + 2 x 1,000 kW

EQUIPMENTSHEETROCKPIPER

ROCK DUMPING FALLPIPE VESSEL

CONSTRUCTION/CLASSIFICATION

Built by Keppel Singmarine Pte Ltd

Year of construction 2011Classification Bureau Veritas

FEATURES

Completely new ship design, fallpipe system and rock dumping

system.

Rock dumping capacity abt. 2,000 t/h.

Dumping depth 1,500 m through fallpipe with inner diameter of

abt. 700 mm.

Diesel electric propulsion system comprising three main dieselgenerator sets and one auxiliary diesel generator set.

Accommodation on fore ship, complement 60 persons.

Engine room in aft ship.

Rock dumping system and moonpool in mid ship.

Innovative fall pipe ROV with integrated survey ROV.


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The Netherlands

T +31 78 69 69 000

F +31 78 69 69 555

[email protected]

www.boskalis.com

SIDE VIEW

TOP VIEW DECK LEVEL

ROCKPIPER

ROCK DUMPING FALLPIPE VESSEL


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MAIN DATA

Dynamic positioning system Kongsberg Simrad SDP21

Subsea positioning system HiPAPLength overall 160.80 m

Breadth 22.90 m

Depth 13.10 m

Draught 9.75 m

Cargo capacity 18,000 t

Operational depth 1,500 m maximum

Displacement 26,600 t

Sailing speed 13.5 kn

Total installed power 16,405 kW

Main engines 2 x 4,474 kW

Main propellers 4 blades controllable pitch

Azimuth thrusters 4 x 1,490 kW controllable pitch

Generators for azimuth thrusters 4 x 2,138 kVA

Auxiliary generators 2 x 625 kVA diesel generators

EQUIPMENTSHEETSANDPIPER



Built by Upper Clyde Shipbuilders Ltd., Clyde-

bank Division

Converted by Rosenberg Mekaniske Verksted A/S

Year of construction 1971

Year of conversion 1978

Registration Panama

Classification Det Norske Veritas

+1A1 HC DYNPOS AUTR EO

NMD DP Consequence Class II

FEATURES

Separate free-flying ROV for verification of results


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The Netherlands

T +31 78 69 69 000

F +31 78 69 69 555

[email protected]

www.boskalis.com

SIDE VIEW

TOP VIEW DECK LEVEL

SANDPIPER



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MAIN DATA

Dynamic positioning system Kongsberg Simrad SDP21

Subsea positioning system HiPAPLength overall 162.00 m

Breadth 38.00 m

Depth 9.00 m

Draught 6.34 m

Cargo capacity 18,000 t

Operational depth 1,500 m maximum

Displacement 28,734 t

Sailing speed 13.0 kn

Total installed power 14,474 kW

Main engines 6,524 kW

Main propellers 2 x 3,220 kW

Azimuth thrusters 4 x 1,000 kW

Bow thruster 1 x 600 kW

Generators for azimuth thrusters 2 x 1,860 + 1 x 2,790 kVA

Auxiliary generators 3 x 480 kVA diesel generators

EQUIPMENTSHEETSEAHORSE



Built by Mitsubishi Nagasaki Shipyard and

Engine Works

Converted by Schelde Shipyard, Vlissingen,

The Netherlands

Year of construction 1983

Year of conversion 1998/1999

Registration Vlissingen, The Netherlands

Classification Lloyds Register of Schipping

DP Class 2

FEATURES

Optional: DP grab installation (16 m3) up to 1,000 m water depth


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The Netherlands

T +31 78 69 69 000

F +31 78 69 69 555

[email protected]

www.boskalis.com

SIDE VIEW

TOP VIEW DECK LEVEL

SEAHORSE


Vessel owned by Deeprock C.V.

Documents

Fallpipe Vessels