VESSEL REVIEW | UKD Seadragon – UK Dredging welcomes new water injection dredger into service
UK Dredging (UKD), the dredging division of port operator Associated British Ports, has welcomed the newbuild water injection dredger (WID) UKD Seadragon into service.
UKD said the addition of a water injection dredger to its fleet will allow it to extend intervals between hopper dredging operations, enhancing operational efficiency.
The vessel was designed specifically for UKD and will be used for surveys, buoy handling, bed levelling, and water injection maintenance dredging.
Water injection dredging capability suitable for sensitive areas
UKD Seadragon has an LOA of 27.05 metres (88.75 feet), a beam of 11.6 metres (38.1 feet), a maximum draught of only 2.55 metres (8.37 feet), a depth of 4.25 metres (13.9 feet), a gross tonnage of 321, and an open aft deck with a total area of 75 square metres (810 square feet).
The WID features a diesel-electric propulsion system fed by three independent generators, which allows it to operate on a single engine to improve fuel efficiency. The generators drive two water-cooled, permanent magnet motors that each produce 750 kW at 1,600 rpm to deliver a service speed of 9.5 knots and a bollard pull of 25 tonnes.
A 145kW bow thruster meanwhile provides additional lateral manoeuvrability.
In place of conventional submersible jets, UKD Seadragon is equipped with a fully electric dredge pump with a capacity of 4,000 cubic metres (140,000 cubic feet) per hour.
The vessel's hull was also optimised for its specialised role, which allows dredging to be undertaken by fluidising sediment to enable it to be dispersed with water currents instead of having to extract it mechanically. Because this method of dredging minimises the risk of turbidity, it is ideal for use in environmentally sensitive areas.
Full survey and dredging electronics suite
The dredger is also fitted with an eight-tonne, 10-metre (30-foot) wide plough and a Huisman A-frame for added versatility and to enable dredging at a working depth of 25 metres (82 feet). When not in use, the A-frame can be tilted to allow the WID skid to be securely stored on the aft deck.
Fully equipped with DGPS and digital mapping capability, the WID’s survey equipment is fully compatible with all of UKD’s fleet and able to act on a stand-alone basis. A winch encoder accurately determines plough depth so that the combined package offers a complete survey and bed levelling service.
UKD Seadragon has been performing maintenance dredging duties in Welsh ports in the weeks following its delivery in February, including trials in Cardiff, Swansea, and Newport.
Mark Pearson, UKD General Manager, said the vessel has also completed various water injection dredging trials at different locations, and that its dredging performance at low fuel consumption has proven to be “impressive.”
The WID was built in compliance with Bureau Veritas class rules including the offshore support vessel and unrestricted navigation notations.
