The offshore yard of Hyundai Heavy Industries in Korea will start cutting steel for Dockwise's new marine transportation super vessel in September. David Morgan reports.
Previously referred to as ‘Type 0' but officially named as Dockwise Vanguard on 19 August, the giant $240 million semisubmersible heavy transportation vessel – easily the world's largest – is expected to open up new offshore design horizons in the way Heerema's giant heavy lifting semis did back in the 1970s.
Targeting offshore structures in the 50,000-110,000t† range, the vessel features an innovative bowless design to facilitate optimal use of its 275m x 70m deck area and maximize cargo flexibility. By way of comparison, the load-carrying ceiling for today's heavy lift semis is generally deemed to be around 50,000t, although current Dockwise flagship Blue Marlin is capable in specific cases and depending on stability compliance, of transporting structures up to 73,000t.
Dockwise expects the super-sizing of its latest vessel to accommodate floating production units of just about any shape or size, including a new and much larger generation of deepwater spars, semis and TLPs. On the Dockwise Vanguard radar too are shallow water gravity base structures, plus FPSOs, semisubmersible crane vessels and other items that traditionally require towing to location. For example, its unobstructed deck will allow cargoes to protrude fore and aft, putting it in the frame for a 325m FPSO. The vessel will also be marketed for top end structures in the 25,000-50,000t category as, with a large maximum submersible draft of 16m, it will be better equipped to transport the latest fifth and sixth generation semisubmersible drilling rigs.
Crucially, the arrival of this new vessel will present first-time ‘opportunities for clients to build their structures completely integrated', says Dockwise engineering manager Michel Seij. ‘This is not only interesting from a cost perspective, but it's also interesting for platforms in remote areas, where there is basically no integration infrastructure, which means we can focus on challenging projects in harsher climates in remote areas such as the Arctic, West Africa and Western Australia. This will afford us new opportunities in the LNG market as well.'
Dockwise Vanguard will boast two diesel electric main propulsion trains plus two azimuthing thrusters, prompting Dockwise CEO André Goedée to declare: ‘There is no self-propelled vessel of this size in the market and we are keen to provide a solution that will meet the needs of our clients in the oil & gas industry all over the world for decades to come.'
Chevron had given its intent to use the new vessel as a base carrier for the transport of its Jack/St Malo hull provided certain conditions could be met -– since followed up with a confirmed order on 25 July this year – giving Dockwise shareholders and bankers sufficient incentive to fund its construction. The job in question calls for the transport from Korea to the US of the 50,000t hull for Chevron's Jack/St Malo semisubmersible hub production facility, to be located in 7000ft of water in the Walker Ridge area of the Gulf of Mexico.
With that giant hull also being built in Korea by Samsung, the race is now on to get the super vessel completed in time for the hull's anticipated end-2012 loadout.
Dockwise is confident that this fasttrack schedule will be met. It has also declared itself more than happy with the outcome of the tank tests that began a year ago at Marin in the Netherlands using a 6000kg model and, at Chevron's behest, continued in Canada at the Oceanic Consulting wave basin facility in St John's, Newfoundland. ‘They turned out fine, even better than we had assumed,' confirms Seij.
Clearly hoping that Chevron's choice will encourage other operators to explore Dockwise Vanguard options, Dockwise suggests this could for example trigger a resurgence of spar platform interest in the deepwater Gulf of Mexico. The company transported the hulls of all but two of the US Gulf's 18 spars from Technip's Pori facility in Finland for topping out in local yards, including the biggest of them all, Shell Perdido. Its new flagship vessel will be capable of handling spars that are at least 25% bigger. OE
With the bowless design of the Dockwise Vanguard super vessel, the accommodation block and navigation bridge are located on the extreme starboard side. Its casings can be moved to various positions to accommodate different cargo shapes.