Posted on March 29, 2018
By Larz Bourne, Maritime Journal
Belgium headquartered global dredging contractor Jan De Nul has ordered three trailing suction hopper dredgers which will feature fully diesel-electric propulsion systems.
Cosco (Dalian) Shipyard Co Ltd will build an 18,000 m3 trailing suction hopper dredger at its yard in China while Keppel Singmarine Pte Ltd will build to 6,000 m3 trailers in Singapore.
The diesel-electric propulsion system is an exceptional feature for a trailing suction hopper dredger as large as the 18,000 m3 capacity vessel. All main drives, including the main propellers, are electrically driven via frequency converters, enabling each system to run at its optimal operation point, resulting in lower fuel consumption and lower emissions. Power is supplied by three diesel driven gensets, A-symmetric load sharing, fuel mapping and automatically starting/stopping of the engines in response to power demand also expedites lower fuel consumption and emissions.
In addition to the above measures, an exhaust gas treatment system is also installed. This SCR system reduces NOx emissions to the future EU Stage V level, which is more stringent than the requirements of IMO Tier II and IMO Tier III. Fuel mapping enables JDN engineers to select the operational regimes of the engines. Specific fuel consumption can be optimised with regard to the loading on the engines and in synchronisation with the exhaust gas treatment system.
The 18,000 m3 vessel will measure 166.1m LOA with a beam of 36m. It will be capable of dredging to depths of up to 86m through a single 1,200mm diameter suction pipe equipped with a submerged dredge pump. The hopper will be sub-divided into two parts, enabling sailing on an even keel in all loading conditions. Two double-walled shore discharge pumps with a total power of 14,000 kW will be installed.
Source: Maritime Journal
