-   Bourbon Orca

Bourbon is a large French shipping company with the headquarters in Paris. The company employs approx. 3,600 people and owns about 230 vessels. It is divided in three divisions: Towage & Salvage Division (Les Abeille), the Bulk Division (Setat Saget) and, by far the largest, the Offshore Division (Bourbon Offshore) with a number of subsidiaries. Bourbon Offshore has implemented ambitous new building programs in 2003 and 2006. Currently it owns approx. 130 vessels and has 100+ vessels on order. One of the subsidiaries, Bourbon Offshore Norway, commissioned an Anchor Handling Tug Supply vessel (AHTS) built by Ulstein Verft from this program in summer 2006. This vessel is remarkable for a number of reasons: The Ulstein X-Bow®, the new Odim Safe Anchor Handling System (SAHS), and the diesel-electric propulsion system. The name of the vessel is :

Bourbon Orca

-   Construction phase

The Ulstein Group is a company with more than 80 year longs experience in shipbuilding. The "old" Ulstein Group was sold to Vickers, later to become Rolls Royce, including the rights to the UT-designs in 1999. The shipbuilding branch was not included in the sale. This shipbuilding branch was the starting point of the "new" Ulstein Group. The design subsidiary Ulstein Design AS started the design of the inverted bow, which was named Ulstein X-Bow®, in 2001. First results were published in the customer magazine Ulstein Today No.1 / 2004. Bourbon Offshore Norway got interested in this design very early. A year before Statoil had challenged the offshore players to make anchor handling safer, so Bourbon Offshore Norway, Ulstein Desein AS, and Odim, a well-known supplier of hydraulik solutions, teamed up in a Research & Development (R&D) partnership to design an AHTS with safe anchor handling capacities. The model tank tests were executed at Marintek in Trondheim in February 2005 with promising results.The Odim SAHS was presented for the first time on 4. April 2005. Around this time Bourbon Offshore Norway and Ulstein Verft signed a contract to build the first AHTS type AX104 with Ulstein X-Bow® and Odim SAHS to be named BOURBON ORCA. The hull was built in Poland and towed to Ulsteinvik / Norway, the home of the shipyard, just in time for Christmas 2005. The vessel left the building dock on 7. April 2006 and was christened on 24. June 2006. Shortly after she got commissioned and entered a charter with Norsk Hydro.

-   Description


The AX104 BOURBON ORCA is a unique vessel in a number of ways:

    Ulstein X-Bow®: This bow is also called an inverted bow. Compared to a conventional bulbous bow it has no bulb and slopes backwards above the waterline. The tank tests showed lower resistance levels in comparison to the standard design allowing for higher speeds or less fuel consumption respectively. The Ulstein X-Bow® has approx. 900 m3 more buoyancy in the bow area than a conventional bulbous bow when all other parameters are the same. For this reason buoyancy builds immediately when the ship begins to enter a wave, giving it a smooth lift. For a ship with a bulbous bow and flare the equivalent buoyancy build-up starts later. This leads to increased accelleration, and rates and amplitudes of pitching. The Ulstein X-Bow® reduces bow impact and slamming and provides better crew comfort. The tank test showed that spray water on the bridge deck is largely reduced, minimizing the danger of broken bridge windows, one of the most common accidents on offshore vessels in high waves.

    "Diesel-electric propulsion: The BOURBON ORCA is one of the first AHTS's to be equipped with this kind of propulsion. The power plant consists of four Wartsilä diesel engines type 6L32 with 2,880kW ( 3,916bhp) at 720rpm and two Wartsilä 9L20 diesel engines providing 1,665kW (2,264bhp) at 900rpm. All are equipped with appropriate Siemens generators. For emergency /harbour use a Cummins gen-set with 315kVA is provided. The electronics allow any combinationof these gen-sets while keeping the working engines in the most fuel-efficient range of speeds allowing substantial fuel savings. The electrical power is distributed to the stern rudder propellers, the retractable bow rudder propeller, bow tunnel thruster, and hotel accomodation. The stern rudder propellers were supplied by Wartsilä-Lips and are type CS3500/3500WN with 3.60m dia. controllable pitch propellers (cpp) in HR-nozzles. They are capable of 5,000kW (6,800bhp). Each of these rudder propellers is driven by two electric motors on one shaft. One motor is delivering 0-3,000kW (4,080bhp) at 0-720rpm, the second one 2,000kW (2,720bhp) at 720rpm. Up to an electrical power of 3,000kW the rotational speed of the motors can be controlled between zero and 720rpm, above 3,000kW the motor speed is 720rpm. The maximum propeller speed is 180rpm. The retractable Wartsilä-Lips bow rudder propeller type CS250/MNR has a 2.40m dia. cpp propeller in 19A-nozzle. It is driven by a frequency-controlled electric motor of 1,800kW (2,448bhp) and is used for additional bollard pull, manoeuvering, and dynamic positioning. It replaces a second bow thruster usually necessary as redundancy for DP2 dynamic positioning systems. The bow tunnel thruster is a Wartsilä-Lips CT250M-D with 2.50m dia. cpp propeller driven by a frequency-controlled electric motor of 1,200kW (1,632bhp).

    Odim SAHS: It will be described with the main deck.

BOURBON ORCA reached a maximum speed of 17.1kts and a maximum continous bollard pull of 183 metric tons (t) on trials. The bunker capacities are 1,486m3 fuel (diesel) oil, 503m3 freshwater, and 2,422m3 ballast / drilling water. Cargo tanks are provided for 447m3 base oil, 530m3 liquid mud (4 tanks), 558m3 brine, 167m3 slop, and 254m3 dry bulk in four tanks. The vessel is equipped with two passive roll reduction tanks.

Deck descriptions:

The decks are presented from bottom to top.

Tank top:

From bow to stern it is used as follows: Bow tunnel thruster, retractable rudder propeller, generator set compartment (power plant), bunker and cargo tanks.

Platform deck:

Again from bow to stern the deck is used as follows: Frequency converters and electric motors for tunnel and retractable thruster, power plant, main switchboard, bunker and cargo tanks, and stern rudder propellers with electrical motors, switchboards, and frequency converters.

Main deck:

The foreward third of the deck is the "deck house" part. It is occupied by lobby, laundry, conference room, office, gym, and hospital. Directly behind this area the Rauma Brattvag (Rolls Royce) waterfall towing and anchorhandling winch with three drums is mounted. The lower anchor handling drum has a capacity of 5,000m of 77mm dia. wire. The drum has a pulling power 400t at up to 18.7m/min. The dynamic braking power (working against the resistance of the hydraulic or electric motors) is 90-470t at 0-88m/min. The second and third drums are for towing and mounted at a higher level on the same shaft. They have a capacity of 2,500m of 77mm dia. wire and a static brake holding power of 500t. Pulling and dynamic brake power are the same as on the lower drum. Directly behind the winch a massive towing fairlead, the so-called crucifix, is fitted. Two tugger winches with a pulling power of 20t are located at starboard and port cargo rails, in this case more wall than rails . Further aft are two capstans with 15t pulling power behind the cargo rails. The working deck has a cargo area of 540m2 allowing a deck load of 1,200t at up to 10t/m2.

Odim SAHS:

the typical stern roller was replaced by the Odim Safe Anchor Handling System. It consists of a hydraulically operated ramp which can be tilted and deployed vertically and horizontally, two tugger cranes on top of the bulwarks and cargo rails, and a number of hydraulic measures to fix chains and wires. The ramp is equipped with two rollers each at the foreward and aft edges and has a static safe working load (swl) of 500t. The system addresses the most hazardous operations on deck during anchor handling and claims to eleminate them as most of the operations can be done remote-controlled without crew on deck. The following operations are illustrated in accompanying pictures:

  1. For catching the pennant wire the ramp is tilted into a vertical position. The wire is winched down from the rig and placed behind a hydraulically steered T-type catcher. This catcher fixes the pennant wire against the ramp. The ramp is tilted back and the pennant wire can be connected to the AHTS's anchor handling wire manually.

  2. Now the rig's anchor is winched up. To eliminate the huge amount of power needed to drag the anchor over the conventional stern roller, the ramp is rotated again in a vertical position. When the anchor reaches the top of the ramp, the ramp is tilted back to horizontal and the anchor lies on deck.

  3. With the help of a hydraulically operated positioning tool in front of the ramp the anchor chain is moved sideways in a position, where the forks can fix it.

  4. When the anchor is on deck, anchor chain and anchor handling cable may be twisted and under immense tension. Uncoupling the anchor from the cable this twisting can cause the cable to move on deck violently. The spin tool is used to hold the cable in place and lock it down. Raising the tool a bit the grooves on the underside of the tool allow the cable to unwind under controlled conditions.

  5. To catch the anchor buoys the tugger cranes, running the full working deck length on bulwarks and cargo rails, are used. These cranes were provided by ABAS Crane AS and have swl of 3 t at a reach of 10 m. The cranes are run into the far aft position with remote-controlled hooks holding a lasso to catch the buoy.

  6. The tugger cranes are mounted on a box which houses the crane winch and a tugger winch with a pulling power of 15t. The tugger winches are used to minimize wire length while moving equippment around on deck so that a breaking wire causes less damage because of its shorter length. The cables from the tugger winch can be used directly or guided through openings between the rails and in the cargo rail using casters. This way heavy equippment can be dragged right to the side of the cargo rail.

Directly in front of the SAHS-ramp four hydraulically operated pins with plates on top and two Karmoy forks are mounted.
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Bourbon Orca Bourbon Orca
A: Catching the pennant B: Taking anchor on board
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C + D: Positioning and spin tools E: Catching the anchor bouys
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Galley, mess/ cafeteria, and a day-room are located here. Dry provisions, cooler, and freezer rooms are arranged adjacent to the galley.


An enclosed forecastle is located at the bow. It is equipped with a combinated anchor/ mooring winch with two warping heads supplied by Rauma Brattvag. Behind this part of the deck the fully air-conditioned accommodation is arranged. Behind the accomodation two secondary winches are mounted. Each has a capacity of 5,000m of 77mm dia.wire or 1,600m of 203mm dia. synthetic fibre rope. They have a pulling power of 138t at 0-44m/min and a dynamic braking power of up to 170t at 0-70m/min. A Dreggen Crane AS knuckle boom crane with 10t swl at 16m reach is fitted at the aft end at starboard. Directly behind a craddle with three inflatable life rafts for 20 persons each is placed. A second identical craddle is located directly opposite at port. In front of port craddle a fast rescue boat by Maritime Partners is mounted using a TTS Marine davit. Two wide rollers are fitted between crane and davit to prevent the wires from the secondary winches from running over a sharp edge of the deck.


Accomodation and a day-room with view of the cargo deck are located here. The complete accomodation on all decks consist of two one-berth en-suite cabins with day-room and bedroom, three one-berth en-suite cabins, nine one-berth cabins, and ten two-berth cabins, alltogether accommodation for 34 persons.

Bridge deck:

The wheelhouse is set back a few meters from the deck's foreward bulwark. Two consoles with complete controls are located foreward and aft near the bulkheads. Navigation and communication equippment is state-of-the-art and complies with GMDSS A3 standard. Among others it contains: Two ARPA-radars*, one ECDIS by TCDIS, log*, echo sounder*, GPS*, VDR (Voyage Data Recording)-system*, Navtex* , AIS*, three Anschütz gyro compasses, VHF and VHF-DSC (digital selective calling)-system**, MF/HF radio**, Inmersat C**, and SSAS (ship security alert system)**. The DP2 dynamic positioning system is from Kongsberg AS.
The *-marked equippment was provided by Furuno, the **-marked equippment by Sailor.

Top deck:

It carries the mast with radars and navigational lights, magnetic compass, searchlights, and antennas. The exhaust pipes are brought up through the wheelhouse and exit on the port side from a hood.


BOURBON ORCA has a crew of twelve.


BOURBON ORCA is in a one year charter with Hydro Norsk.

-   Particulars

Length o.a.: 86,20m
Length between perpendiculars: 77,00m
Breadth, moulded: 18,50m
Design draught: 06,00m
Max. draught: 07,00m
Depth to main deck: 08,50m
Power plant: 4x Wartsilä diesel engines 6L32 with Siemens generators + 2x Wartsilä diesel engines 9L20 with Siemens generators. Details see text.
Stern rudder propellers: 2 x Wartsilä-Lips CS3500/3500WN, details see text
Retractable bow rudder propeller: Wartsilä-Lips CS250/MNR, details see text
Bow tunnel thruster: Wartsilä-Lips CT250M-D, details see text
Bollard pull: 183t
Max. speed: 17,1kts
Volumes: 4,089 grt, 1,226 nrt
Deadweight at max. draught: 3500t

Bourbon Offshore Norway,
Ulstein Group,
Maritimt Magasin,
Wärtsilä: Thrusters for the offshore market

For photos in higher resolution please click the thumbnails!
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Tank test General arrangement drawing
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Diesel-electric propulsion Starboard view
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Bow view Port view
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Stern view Aerial view
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Bow view Bow area
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B-deck and wheelhouse Wheelhouse with mast
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Stern view of superstructure Dreggen main crane
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Port stern with tugger crane Odim SAHS stern ramp
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Positioning the chain Spin tool, fork and pins
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Working with tugger cranes -
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