take the marine environment into account, and therefore provide training on working at significant wave heights, transferring crew from the boat to the turbine and related safety training.” For an authentic, hands-on experience, the NWFTC incorporates actual turbine structural parts, such as the transition piece, into its courses.


Fuel cost savings Asherah was conceived two years ago, when White was assisting DONG Energy to construct the 172MW Gunfleet Sands offshore wind farm in the North Tames Estuary, UK. Perceiving existing wind farm support vessels to be unnecessarily heavy on fuel consumption, without the subsequent benefits of increased speed and flexibility, White began to tinker around with a Blythe Cat, which would later serve as the prototype for the CTruk 20T MPC class, building for which began in earnest in June 2010. Tis design features a beam of just over 6m, forward deck space of up to 37m2 deck space of up to 34m2


, aſt and a bridge deck


clearance distance of 1.55m at midships. Firstly, to drive the vessel’s weight down,


CTruk incorporated resin infusion into her hull structure and doors. “Compared to an aluminium boat, we estimate that we’ve made the vessel 65% lighter and halved the amount of fuel consumption, saving around GBP£400 [US$645] a day in fuel costs alone,” White claims. “Offshore wind farm support


vessels typically operate seven days a week, for 12 hours at a time, or even round-the- clock on some projects, so the potential cost savings are really evident.” Next, the CTruk team concentrated


on enhancing the vessel’s speed and manoeuvrability. A pair of Rolls-Royce FF41 waterjets, fuelled by twin Cummins 47.8kW engines, were installed, granting the MPC a top speed of 30knots and enabling her to better handle operation in shallow draughts, as well as to avoid potential complications caused by the presence of debris or junk in surrounding waters, and to provide a higher degree of safety should a member of personnel fall overboard. To make steering as simple as possible,


the Rolls-Royce FF41s are connected to twin Vector Stick controllers; one controlling the rudder and the other responsible for engine and jet bucket controls for ahead and astern control. White opines that this is a particularly important consideration at the stage when the MPC actually arrives at the wind farm and needs to be able to safely manoeuvre around the structures, particularly during busy periods.


Lift and reposition However, Asherah’s most striking feature may well be her bespoke detachable pod system. As Ben White, co-managing director of CTruk Boats, puts it: “Te pod system enables [Asherah’s] operators to change the


The 12-man crew pod can be detached to make room for equipment and generators aboard the catamaran’s deck.


vessel’s layout within a few hours, to suit the work being carried out that day.” Te centrepiece of this system is the ability


to detach and move the wheelhouse to both the fore and aſt of the vessel, as required. White explains: “Te skipper can have the wheelhouse positioned at the fore when he is carrying passengers out to the turbines or sailing to or from the wind farm. When he is actually at the turbine, touching on the transition piece, he can reposition the wheelhouse at the aſt of the vessel, giving him better visibility to check on the welfare of personnel who may be embarking / disembarking the turbine or moving equipment between the turbine and the boat.” Te flexibility of this system also enables


the MPC’s 12-man passenger pod to be removed from the vessel via crane, instantly creating more deck space for equipment such as service generators, cranes or survey tools, when required. In this way, the vessel can switch its tasks on a daily basis and, for example, be used to conduct hydrographical surveys, marine mammal observation missions and even military work, thereby increasing Asherah’s charter appeal and helping to make the most of her periods at sea – thus tying in with White’s concept of the most cost effective boats in this sector being those able to operate on a “one boat for two or three jobs” basis. Asherah’s versatility is reflected in the


specifications laid down by Brian Croucher, owner and operator of the vessel, who took on the MPC as part of CWind’s boat share scheme in Barrow-upon-Furness. Croucher comments: “Rather than just being a refuelling boat, we requested a passenger pod, separate dirty fuel and refuelling pods, a pressure washing pod and a pod for launching amphibious rescue craſt. Tis means we can quickly respond to the varying demands of the wind farm support work without compromising on safety and efficiency. In addition, none of the pods are heavy enough to cause restrictions, as the vessel has a large carrying capacity.” Te vessel’s electronics were supplied by


Simrad, while the interior features a WC, shower, changing area, stretcher facility, air conditioning and heating, two TV sets and WiFi capabilities. White confirms that another three CTruk 20T MPC class vessels are under construction. SBI


Ship & Boat International July/August 2011 33


Feature 2


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