VESSEL REVIEW | Skawlink V – Towing and supply workboat for Danish marine services company

Danish marine services provider Saga Shipping has taken delivery of a new workboat capable of supply, towing, and anchor handling duties under a broad range of weather conditions in both harbour and deeper offshore waters.

Built locally by Hvide Sande Shipyard (HSS) to a design by OSK-ShipTech, Skawlink V will complement an older workboat that was delivered by HSS to the same owner in 2012. With a larger fleet, the owner will be able to serve more clients and perform a greater number of functions within the same window.

In addition to being slightly larger, the newbuild will also boast more advanced electronics as well as compliance to the latest maritime regulations.

"Besides being used for towing and supply, the vessel can also perform bunkering of lubrication oil and drinking water," HSS told Baird Maritime. "There is a large aft deck for hauling cargo and equipment, and it can even be used for crew transfer duties."

The builder added that construction of the workboat involved using its predecessor Skawlink IV as a starting point and then working on from there to identify any requirements that needed to be satisfied. The design work resulted in the vessel being 1.5 metres (4.9 feet) longer, more durable, and highly efficient in performing its assigned tasks.

Enhancing an already proven design

The main requirement stipulated by the owner was that the new workboat should still bear some resemblance to its predecessor, but with newer technology and greater operating power.

"We made the vessel longer to ensure a greater capacity for transporting cargo and other supplies to larger coastal vessels," added HSS. "We also worked towards satisfying the owner's desire for simpler operation, thus guaranteeing crew safety."

The all-steel Skawlink V has an LOA of 25.5 metres (83.7 feet), a beam of 7.5 metres (25 feet), a draught of 3.5 metres (11 feet), a depth of 4.08 metres (13.4 feet), a gross tonnage of 153, and interior seating for 12 passengers. The aft deck has a total area of 70 square metres (750 square feet) for the transport of up to 50 tonnes of assorted payloads including two 20-foot containers as well as spare parts, equipment, and basic goods.

"There are two controllable-pitch propellers, each of which is driven by one of the two main Volvo Penta D16 551kW (739hp) IMO Tier III diesel engines via a Mekanord 350HS gearbox," said HSS. "The individuals have individual controls for enhanced manoeuvring. To provide additional manoeuvring capability, the vessel is equipped with a transverse thruster."

The propulsion setup delivers a bollard pull of 24 tonnes, a top speed of 11.7 knots, and a service speed of nine knots.

A traditional diesel propulsion arrangement was selected in anticipation of the vessel having a normal operating profile that entails up to 20 hours of use in one day. HSS also said the propellers were optimised with the aid of CFD to improve their performance for towing and normal sailing.

Outfitted for multiple roles

Crew transfers can be done via three boarding points, giving the vessel greater operational flexibility. Fitted on the aft deck are a crane, a Mampaey towing hook, and a custom-manufactured tailing winch.

Also fitted is an integrated control, alarm and monitoring system (ICAM), which controls the generators, valves, the bilge alarm, lights, and ventilation.

"Bunkering operations were incorporated into the ICAM, allowing the crew to perform bunkering remotely," HSS told Baird Maritime. "We also optimised towing operations by allowing the propellers to be operated individually."

Making sure the new vessel was more technologically advanced, had greater power, and was simple to operate and maintain while still possessing the general layout of the earlier Skawlink IV was the main challenge HSS encountered in its work on Skawlink V.

"We resolved this issue through close coordination with the customer," the builder remarked.

HSS said it was able to align with the project timeline and deliver a useful vessel, thanks to close coordination with the customer throughout the construction process.