VESSEL REVIEW | JSD6000 – Versatile derrick lay vessel to enhance Saipem’s subsea installation capability

Chinese shipbuilder Shanghai Zhenhua Heavy Industries (ZPMC) has completed construction of a large derrick lay vessel capable of heavy lift, S-lay, and J-lay operations. The custom-built JSD6000 will be operated under a five-year bareboat charter plus two one-year extensions by Italian offshore engineering specialist Saipem while remaining under the ownership of ZPMC. Design work on the vessel was provided by Norway's Ulstein Design and Solutions in compliance with Lloyd’s Register class rules.

The vessel was originally ordered by another customer. Ownership of the vessel transferred to ZPMC while it was still under construction in 2018, as the original customer had decided to exit the subsea installation market.

Capable of both J-lay and S-lay installation

JSD6000 has an LOA of 215.9 metres (708.3 feet), a moulded beam of 49 metres (160 feet), a draught of 10.9 metres (35.8 feet), a depth of 22.4 metres (73.5 feet), and accommodations for up to 399 personnel including crewmembers. The propulsion, which includes six 9,312kW diesel generators and azimuthing and tunnel thrusters from Kongsberg Maritime, complies with safe return to port (SRTP) requirements and can deliver a maximum speed of 11.8 knots. A 1,550kW emergency generator is also installed.

Key features of the vessel include an NOV revolving main deck crane with a lifting capacity of 5,200 tonnes, two smaller NOV 50-tonne knuckle boom cranes, a large off-centre moonpool, an eight-point mooring system, and a DP3 system supplied by Kongsberg Maritime. The vessel can lay pipelines up to 36 inches (0.9 metre) in diameter in J-lay mode and up to 60 inches (1.5 metres) in S-lay mode, at water depths up to 3,000 metres (10,000 feet), allowing for safe installation of oil and gas pipelines across a broad range of ocean environments. This is made possible by a combination of a 600-tonne Remacut S-lay system via a centre-firing line below the main deck and a 2,000-tonne Royal IHC EB J-lay system via the moonpool.

Ulstein said that the double-deck configuration and the positioning of the moonpool allow for a large, unobstructed deck area of 2,100 square metres (23,000 square feet) as well as below-deck pipe fabrication. The vessel is therefore capable of undertaking deepwater and SURF projects as well as shallow-water construction, cable-laying, and heavy lifting words. Secondary duties include wind turbine installation, platform decommissioning, and even underwater salvage.

Because some parts of the vessel's J-lay and S-lay production lines are integrated, the systems have a common prefabrication line as well as a common disposal and recovery system. This allows the vessel to undertake either pipeline laying method without any significant increase in the quantity of the requisite onboard equipment, hence reducing costs.

Deck layout that can be adapted to suit various roles

The deck has a starboard side overboarding platform with two sheaves to allow deep-water lowering works. The deck itself can accommodate chain laying equipment and can be configured to allow installation of a removable carousel, a large reel handling system, stern facilities for handling two work-class remotely operated vehicles (ROVs), or umbilical and flexible laying equipment.

The charter of JSD6000 is in line with Saipem's capital-light strategy defined in the company's strategic plan, and allows the company to expand its offer with an additional vessel that meets the highest standards of safety and environmental protection. It also consolidates Saipem's positioning in the deepwater subsea installation services market.