Offshore Marine Technology: 3rd Quarter 2017
A total power output of nearly 24,000kW, a pump ashore capacity of 15,600kW and what is reported to be the heaviest cutter ladder ever installed are all key features of Royal Boskalis Westminster’s new mega cutter, Helios.
The self-propelled, 8,981gt vessel is described as a heavy-duty, rock-cutting dredger developed for dredging work within 15 miles from shore or within 20 miles from port. She was built by fellow Dutch company Royal IHC and Uljanik Shipyard in Pula, Croatia. The latter builder completed Helios’ hull and launched the vessel in Q2 2016. The ship was then transported to Royal IHC’s yard in Kinderdijk for fitting of the cutter ladder and spud carriage, among other equipment.
Measuring 152m loa (or 127.5m bpp), 28m in moulded breadth and 8.9m in moulded depth, Helios' main and auxiliary MAN engines generate a combined 23,886kW. The vessel’s maximum cutter output of 7,000kW is impressive but necessary, as Helios will be tasked with dredging missions in “extremely hard ground”, Boskalis says. The cutter ladder has a length of 47m and weighs 2,060tonnes: not only does this make it the heaviest cutter ladder installed on a vessel to date, Boskalis says, but it is actually heavier than a typical small cutter suction dredger. Royal IHC used floating sheerleg cranes to install this unit aboard Helios.
In a similar heavyweight class, Helios’ spud carriage weighs 325tonnes. Meanwhile, cut material is collected in a suction pipe with a 1,000mm diameter.
Helios has been developed to draw 6m max, with design draught rated 5.35m, and the vessel is capable of dredging in water depths ranging from 6.35m to 35m. She can accommodate a 45-man crew and has a sailing speed of approximately 11.5knots.
One of Helios’ preliminary missions will see the vessel deployed in Oman, where her dredging capabilities will be used to assist the Port of Duqm’s development programme. Boskalis has subsequently placed a follow-up order with Royal IHC for a sister vessel for Helios, featuring the same installed power arrangement and pumping / cutter capacities. If all goes to plan, this sister vessel is expected to enter service in 2020.