Jan De Nul Group orders 6,000 m³ and 18,000 m³ Trailing Suction Hopper Dredgers

“These compact and medium-sized vessels are provided with features making it the best in their class for efficiency and emissions”, says Robby de Backer, Director Newbuilding Department.

Lower fuel oil consumption and lower emissions
Both hopper dredgers are in fully diesel-electric execution. This is exceptional for a hopper dredger as large as the 18,000 m3 vessel. All main drives, including the main propellers are electrically driven via frequency converters. In 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.

Exhaust gas treatment system
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. ‘Fuel-mapping’ allows us to select the operational regime of the engines; specific fuel consumption can be optimized 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 14,000 kW are installed.

Cosco (Dalian) Shipyard Co.Ltd. will build the vessel in its shipyard in Dalian in China. Delivery is foreseen in 2020. Keppel Singmarine Pte. Ltd. will build two 6,000 Trailing Suction Hopper Dredgers in Singapore.

Main characteristics of the 18,000 m³ dredger

Hopper capacity

18,000 m³

Deadweight

30,000 ton

Length o.a.

166.1 m

Breadth

36.0 m

Draught loaded

9.75 m

Maximum dredging depth

86.0 m

Diameter suction pipe

1,200 mm

Pump power (trailing)

3,400 kW

Pump power (discharging)

14,000 kW

Propulsion power

2 x 7,500 kW

Total installed diesel power

22,540 kW

Speed

15.5 kn

Accommodation

32 p


Main characteristics of the 6,000 m³ dredger

Hopper capacity

6,000 m³

Deadweight

9,880 ton

Length o.a.

111.7 m

Breadth

24.6 m

Draught loaded

7.0 m

Maximum dredging depth

35.0 m

Diameter suction pipe

1,000 mm

Pump power (trailing)

1,500 kW

Pump power (discharging)

4,000 kW

Propulsion power

2 x 2,150 kW

Total installed diesel power

7,700 kW

Speed

12.5 kn

Accommodation

16 p