October 2009 saw the launching in Spain’s Basque country of the dredger “Leiv Eiriksson”. A sister ship to the record-breaking “Cristóbal Colón” that was launched in July 2008, the vessels share common specifications, each featuring two MAN 16V48/60B medium-speed main engines and complete propulsion trains.
The two vessels were ordered by Dredging and Maritime Management S.A., a subsidiary of leading dredging contractor, the Jan de Nul Group, based in Luxembourg. Construction took place at the La Naval shipyard in Sestao, Spain, part of Spanish shipbuilder Construcciones Navales del Norte.
The Leiv Eiriksson and Cristóbal Colón are, by some distance, the largest trailing suction hopper dredgers in the world. With a hopper capacity of 46,000 cubic metres and 78,000 tons of deadweight, the new, mega-hopper suction dredgers are capable of sailing at speeds of up to 18 knots. For both propulsion and working functions, the dredgers are powered by two MAN 16-cylinder, vee-configuration type 16V48/60B main engines, each rated 19,200 kW at 514 rpm. These drive twin, controllable-pitch propellers via single input and output shaft-reduction gears, as well as two 18,500 kW shaft generators located on power-take-offs on the reduction gears.
The shaft generators will cover electrical power for working functions during dredging, at berth or at anchor. This also includes the hotel load for the 46 crew members and is supplied by a generator set based on an MAN Diesel inline nine-cylinder type 9L27/38 engine, rated 2,970 kW at 720 rpm.
The vessels have an overall length of 223 metres, a breadth of 41 metres, a loaded draught of 15.15 metres, and are capable of dredging down to 142 metres using a 1,300 mm suction pipe.
Prime-movers of choice
The MAN Diesel 48/60B engine type is prime-mover of choice in the dredging sector as these two reference dredgers have proven.
The type 48/60B diesel has a standard rating of 1,200 kW per cylinder at 500 and 514 rpm, and is offered in 6-, 7-, 8-, and 9-cylinder inline and 12-, 14-, 16-, and 18-cylinder vee-configuration versions. These MAN Diesel medium-speed engines are especially appreciated in these applications for their robust load-acceptance characteristics.