Jan de Nul Group Orders 2 More TSHDs
“The features of these compact and medium-sized vessels make them the best in their class for efficiency and emissions”, says Robby de Backer, Director Newbuilding Department at Jan de Nul Group.
Both newly ordered hopper dredgers will be in fully diesel-electric execution. This is exceptional for a hopper dredger as large as the 18,000m3 vessel. All main drives, including the main propellers are electrically driven via frequency converters. This way, each system runs at its optimal operation point, resulting in lower fuel oil consumption, and lower emissions. Power is generated by three diesel-driven generator sets. A-symmetric load sharing, ‘fuel-mapping’, and automatically starting/stopping the engines in function of the power demand is implemented. This again allows reduction of fuel consumption and emissions.
In addition to these measures, an exhaust gas treatment system is installed. The 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. The operational regime of the engines can be selected through ‘fuel mapping'; specific fuel consumption can be optimised in function of the loading of the engine, and in synchronization with the exhaust gas treatment system.
The 18,000 m³ vessel is equipped with a single suction pipe, with a submerged dredge pump. The hopper is subdivided in two parts, enabling sailing on even keel, at all loading conditions. Two double-walled shore-discharging pumps with a total power of 14,000kW are installed.
Cosco (Dalian) Shipyard Co.Ltd. will build the 18,000m3 vessel in its Dalian shipyard in China. Delivery is foreseen in 2020. Keppel Singmarine Pte. Ltd. will build the two 6,000m3 TSHDs in Singapore.