Building has commenced on the first example of Damen Shipyards Group’s new Fast Crew Supplier (FCS) 7011 concept – a CTV designed to provide “business-class” levels of comfort to the offshore oil and gas sector. The 73.6m x 11.2m vessel is being constructed at Damen’s Antalya yard in Turkey as an on-spec design, with launch scheduled for Q3 2020 and entry into service anticipated in 2021.
The FCS 7011 will transfer personnel to and from platforms, drill ships and FPSO units. “The number of people it can carry depends on the layout selected,” says David Stibbe, Damen director for business development and market intelligence. “The one we are building, for example, will be able to carry 122 personnel in full business-class seating. With full economy class, this could be increased to as many as 250.”
Tank testing for the FCS 7011 was conducted at the Delft University of Technology (TU Delft), the Netherlands throughout 2018, in which a 2.8m-long, 1:25 scale model was demonstrated in simulated significant wave heights of 2-3m Hs. Damen was thus able to study the effectiveness of its internally designed Sea Axe bow shape, developed to reduce slamming at high speeds. “The Sea Axe is now optimised to reach 40knots without slamming impacts,” says Albert Rijkens, Damen product portfolio manager, research. “Moreover, the slender hull allows it to propel itself to speeds at which the large forward kinetic energy of the ship, together with the resulting large hydrodynamic hull-damping forces, significantly reduce the ship’s motions as it reaches cruising speed.”
A Veem VG1000SD gyrostabiliser will reduce roll motions by up to 80% during transfers. The FCS 7011 is also the first aluminium vessel of this size that Damen is building.“This lightweight construction material is a key element if you are aiming for transit speeds of up to 40knots,” Rijkens says. “The material properties of aluminium, however, do differ significantly from its steel counterpart, and the vessel construction plan should be designed accordingly to make maximum use of aluminium weight savings. The design philosophy was to develop the superstructure in such a way that its geometry effectively works as a primary part of the vessel’s construction.” A conventional, steel-built FCS vessel, he says, will typically use its main deck “to handle the majority of global wave bending moments”. However, the FCS 7011 “raises this primary construction element by two deck levels”, resulting in a “high and very rigid boxed-shape geometry, without having to add excessive amounts of aluminium that would be required to handle those forces in lower parts of the construction”. Rikjens adds: “This smart, lightweight geometry enables the vessel to reach high transit speeds at a reasonable rate of fuel consumption in serious wave conditions.”
The personnel accommodation area has been located aft of midship, where there is reduced exposure to vertical accelerations. This contrasts with previous FCS types, which typically accommodated the passengers in the bow section – an area, Rijkens says, that is “the worst location you can possibly be, as relative motions will be the highest”.
The completed FCS 7011 will meet the requirements of the High Speed Craft (HSC) Code for Category A vessels, and will be capable of operating in mid-sea state 5 conditions – “roughly equivalent to a significant wave height of 3m”, says Rijkens. It will be possible to re-engineer the vessel type to also accommodate Category B requirements. Power for the first-in-class FCS 7011 will be provided by four MTU engines driving waterjets, though lower power arrangements for future builds will be available on request, Damen says.
(For the full lowdown on the FCS 7011, including technical particulars and GA, see Ship & Boat International September/October 2019)