‘Rolldock Storm’ delivered
Beyond a simple ‘heavy lift’ capability Rolldock’s fleet centres on flexibility: the recent 151m, 8,000dwt ST-class addition from the Flensburger Schiffbau Gesellschaft (FSG) yard is no exception.
Rolldock Storm is, like its three sisters, multi-functional: a pair of 350 tonne Liebherr heavy lift cranes give it tandem lift capability and its ro-ro ability is supported by a heavy duty, 4,000 tonne stern ramp with adjustable heights, allowing the vessel to adapt to port piers at differing levels. As a result single loads weighing up to 3,000 tonnes can shipped in classical ro-ro mode, a useful point given the tendency toward increasing individual parcel weight.
This combines with its modest 5.67m fully-loaded draft; if necessary it can ballast down at the quayside to load the upper decks, then deballast and reposition the ramps to load the lower decks. Plus, of course, the neat hull also gives the vessel flexibility to call at remote ports with little water depth.
The ship can also be submerged by 12m to permit cargo to be floated in or out: unlike the more usual sloping sides, the vessel’s dock hold is carved out to be a 119.44m by 19.40m box shape. Rik Hofst of Rolldock explains that “calculations for submerging a square box are much easier than a sloping hold, and it’s also better for the sea fastenings”. He adds that the space between the hull and square sides is mostly taken up with 36 ballast tanks with a total capacity of 15,000 cu/m.
Propulsion consists of a pair of big MAK 9M32’s with a total installed power of 9,000kW: these twin engines, shafts and propellers both providing the necessary redundancy and giving Storm a sailing speed of around 17 knots.
By Stevie Knight
