Vessels adapted for long-distance shipments of subsea structures

Nov. 1, 2004
Amsterdam-based BigLift Shipping operates a fleet of 14 multi-purpose, heavy lift vessels, all suited for off-shore operations.

Amsterdam-based BigLift Shipping operates a fleet of 14 multi-purpose, heavy lift vessels, all suited for off-shore operations. Recent assignments have included long-distance shipments of various subsea and topsides structures ranging from reels and turrets to living quarter modules.

Since 2002, Saipem, Stolt Offshore, and Technip have regularly contracted the company's four Happy-R type vessels for subsea and FPSO projects offshore West Africa and Eastern Canada. Each of these vessels has two cranes, offering a combined lifting capacity of 800 tonnes. The cranes can also be fitted with a fly-jib, providing a 7.5-m extension to their nominal reach of 26.8 m. The lifting capacity at that range is 37.5 tonnes, which is useful for handling lighter, sensitive cargo, such as buoyancy elements, jumpers, and winches, BigLift's Marketing Manager Martijn Coopman explains.

"Every shipment that we make is unique and demands adaptation of our vessels for special transport," Coopman says.

This can include deck extensions to increase the deck area, special grillages for load-spreading, and tonnage planning to ensure the loads imposed by a full carousel are distributed evenly over, for instance, the hatches. One project the company recently undertook involved enhancing a vessel's deck strength so that it could carry the full weight of a carousel.

For some of BigLift's charters, the vessel is contracted on a daily working and standby basis. In other cases, the company receives a lump sum for the total voyage. "This depends on the client's preference. It varies every time," Coopman explains. "Rates also vary widely, depending on factors such as location and risk."

From the client's point of view, the logistics of each offshore project present a varying degree of complexity, with a spread that can include pipelay vessels, offshore cranes, installation vessels, tugs, and supply vessels. The client is looking for optimum use and planning of all this equipment, and often in these cases, a multi-purpose heavy lift ship can be a better solution, Coopman says.

West Africa line-up

BigLift's reference list of deliveries to West African projects in recent years includes the Abo, Bonga, Ekonga Notch, Etame-Djambala, Jade, Xikomba, and Zafiro field developments. BigLift engineers have worked closely with Technip to ensure delivery of numerous 380-tonne hose reels and 1,200-tonne umbilical carousels for these projects from Le Trait in northern France to Lagos. After delivery, BigLift returned the empty reels to the original fabrication yard.

Last November, the Happy Ranger brought a consignment comprising a 540-tonne utility module, a subsea pump, and suction anchors from Radoy and Halden in Norway to Angola for the upgrade of Amerada Hess' Ceiba field complex. Stolt Offshore's construction vessel Seaway Polaris transferred the utility module onto the FPSO's deck under a delicate discharge operation.

BigLift's Happy R-type vessels are used frequently for long distance transport of subsea hose/umbilical reels.
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"To keep the module under control during the transfers, special bumpers were welded onto our ship to protect both it and the cranes. Tugger lines were also deployed from the Polaris to reduce swinging motions," Coopman explains.

Last December, under contract from Saipem, the MV Tracer picked up reels carrying flexible hoses and umbilicals from, respectively, Dunkirk and Newcastle-Upon-Tyne, UK. The vessel sailed fully laden directly to an offshore site in Soyo, Angola, where the equipment was transferred to the subsea installation vessel, the Saibos FDS, for subsequent deployment on Kizomba A. BigLift's MV Enchanter had also transported the three locally-built flare boom sections, two laydown platforms, and a helideck for the same project a year earlier.

Atlantic crossings

Early this year, the Happy Buccaneer delivered the fourth and final section of SBM Imodco's turret system for the White Rose FPSO to Marystown, Canada. This was a 1,000-tonne steel buoy, collected from fabricator GPC in Abu Dhabi. The same vessel had delivered the other three sections the previous July from GPC to Samsung in Koje, South Korea, the sections comprising an 809-tonne lower turret, and 830-tonne upper turret and a 973-tonne gantry. These have since been integrated into the FPSO's hull. On arrival in February at the location in Bay Bulls, the buoy was offloaded into the water with its anchor chains already attached, ready for towing to its final destination offshore Newfoundland.

Earlier during the same voyage, the Happy Buccaneer had also collected the 1,220-tonne living quarters module for the Mad Dog platform from fabricator Pharmadule Emtunga in Gothenburg, Sweden. The vessel's stern ramp was opened so that trailers could roll the 50-m long structure onto the vessel's tweendeck. The module's width allowed for just over 1 m of free space on either side, with the helideck sticking out over the port side.

Afterward, the vessel crossed the Atlantic with both consignments. On arrival at New Orleans, a reverse RO-RO operation was mounted, with the living quarters transferred to another barge for subsequent installation on the Mad Dog deck.

According to Coopman, BigLift has other offshore jobs lined up for Technip off eastern Canada and West Africa in the first half of 2005, and is hopeful of clinching new deliveries to other offshore clients.

"We are continually working on new designs to meet the market's changing requirements. Any new vessels would also be multi-purpose, allowing for maximum flexibility."