Fit for purpose

The checklist set out by Tidal Transit for the future of offshore wind vessels

New vessels need not only to do the job but look great too.

 The vessel must not be more than 24 metres long — if it is longer, the charter cost will be uncompetitive with the rest of the market.

    It must be able to transfer passengers in excess of 1.5-metre sea states, with an objective to achieve minimal movement of the bow at up to 2.5-metres. The industry norm is 1.5 metres, which only allows access for up to 70% of the year around the UK and elsewhere.

    The ability to transfer passengers in those conditions must only rely on the vessel’s capabilities rather than bolt-on extras -— we felt that it was important to keep our vessels as simple as possible to minimise the potential for equipment failure far from shore.

    The ride must be dampened to reduce the potential for sea sickness — our passengers are unlikely to be hardened mariners, unlike the skipper and crew, and must arrive after their long commute ready to work.

    The vessel must be able to carry enough cargo without affecting the comfort of the passengers or speed of transit, or compromising the vision from the helm — at least 20 knots need to be maintained, as even the Round 2 projects can have up to two-hour transit times. Containerised cargo can adversely affect the vessel ride by not distributing weight evenly and potential limiting the skipper’s view, leading to top-heavy vessels with a knock-on effect on the ride.

    The vessels need to be able to operate 24 hours while accommodating crews and passengers — too much time is wasted on Round 2 projects in transiting from ports daily. Flotels will not be feasible after final commissioning. Round 3 will make daily transits unfeasible.

    Fuel efficiency is important and weight savings are needed, as long as they do not affect the transit comfort and transfer ability — if the vessel is too light then this can make it uncomfortable in transit. Good grip on the boat landings can be achieved through the right mixture of thrust and buoyancy for the hull design.

    The vessels need to be multifunctional — there is no need for dedicated marine mammal observer, dive support, survey and crew transfer where one vessel can carry out more than one task.

    The vessels need to be more than just taxis — passengers need to be looked after and kept entertained to maximise their productivity upon arrival on site.

    The vessel design needs to allow for efficient maintenance — the opportunities for maintenance are greatly reduced when vessels are working for up to an extra 20% of the year due to their increased ability to operate in unfavourable sea conditions.

    As new entrants in to this sector, these vessels need not only to do the job but look great too.