Anchor-handling tugboat (AHT) offshore support vessel Boka Keeper

(First name: ALP Keeper) Ultra-long towing distance, oceangoing tug. With a bollard pull of approx. 300 t, the vessel is designed for towing very large structures over long distances, such as oil rigs or FPSOs from the building yards to the installation site at the oil field. The vessel has fuel capacity to tow at full power for 45 days. The ALP Future-class vessels of the SX157 design were developed in close collaboration with ALP Maritime. The vessels are outfitted with DPII and anchor handling capacity in order to assist during the installation/hook-up phase for the towed objects. When developing the design, Ulstein had to ensure that each vessel had the sufficient bollard pull and operational reliability to handle even the heaviest tows with only two vessels. Environment and fuel efficiency have also been important criteria. The vessels are classed with DNV's Clean Design and Ice Class 1B notations, which allow operation also in restricted zones. Additionally, they are equipped as anchor handling vessels including stern roller, a three-drummed winch with 400t hoisting capacity, and with chain lockers for rig chain. The ships have comfortable and spacious accommodation reflecting long periods at sea. Ulstein, in addition to providing the design, was also responsible for the deliveries of main components, such as engines, thrusters and propellers, winch, power distribution and thruster drives, control system and communication system.