ALP Sweeper

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.



Built by

Niigata Shipbuilding & Repair, Japan



Owned by

ALP Maritime Services

Designed by

Ustein Design & Solutions AS

Ordered by

ALP Maritime Services

IMO Number


Principal dimensions

88.9 m
21 m
Dead weight:
4250 tonnes
Draught (max):
8.5 m
Speed (max):
19 kn
35 POB
Deck area:
550 sqm

Note: Subject to selected variant configuration


Bollard pull, approx.:
300 t
Ballast water:
2900 cbm
Fresh water:
300 cbm
340 cbm
3200 cbm


  • DNV +1A1, Offshore Service Vessel+, Anchorhandling, Towing, E0, SF, Iceclass 1B, FiFi II, TMON, BIS, DYNPOS-AUTR, Naut-OSV(A), Clean Design, COMF-V(3), BWM-T, Recyclable

Featured solutions

Ship history

The 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.

The ALP Future Class family of vessels have a fuel capacity of 3400 m3 of IFO/MGO – sufficient for non-stop Trans-Atlantic/Indian, Pacific Ocean towing operations without fuel calls. These long distance towing vessels have bollard pull of 300+ tonnes, a service speed of 13 knots and a top speed of over 19 knots. Additionally, the vessels are equipped with dynamic positioning capability (DP II) allowing ultra-long distance towing, offshore installation and decommissioning of large floating production, storage and offloading (FPSO) units, floating liquefied natural gas (FLNG) units and floating drill rigs at the highest safety levels.

The ALP Future vessels measure approximately 88.9 metres long, weigh 4250 deadweight tonnes and reach maximum speeds of over 19 knots.

At the time of the contract signing, this was a new market to Ulstein, and the largest single contract so far to Ulstein Design & Solutions AS. Ulstein, in addition to providing the design, is 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. When developing the design Ulstein had to ensure that each vessel has the sufficient bollard pull and operational reliability to handle even the heaviest tows by 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 a comfortable and spacious accommodation reflecting long periods at sea. Vessel overview:

Vessel overview

  • ALP STRIKER - delivered September 2016 - IMO Number: 9737230
  • ALP DEFENDER - delivered June 2017 - IMO Number: 9737242
  • ALP SWEEPER - delivered October 2017 - IMO Number: 9737254
  • ALP KEEPER - delivered February 2018 - IMO Number: 9737266

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