Trailing suction hopper dredger extension

Jumboising Queen of the Netherlands

In 1999, the Dutch dredging contractor Royal Boskalis Westminster N.V. took delivery of the trailing suction hopper dredger ’Queen of The Netherlands’. Built by Verolme Shipyard Heusden, she belongs to world’s largest trailing suction dredgers. The vessel underwent an extensive modification which resulted in an enlargement of the dredger’s hopper capacity with more than 50 percent and improved deep-water dredging capabilities.

Principal dimensions




Before lengthening

After lengthening

Length o.a.



Length b.p.p.



Breadth, moulded



Depth, moulded



Draught at international loadline



Draught at dredging loadline



Gross tonnage

22 689

33 423








31 326

59 168 ton

Hopper capacity

23 347

35 500 m3

Service speed


16.0 kn




Dredging equipment



Two trailing suction pipes, diameter

1 200

1 200 mm

Dredging depth

33, 55, 85 & 112

67 & 83 m

Total installed power

27 634

27 634 kW

Dredge pump output

12 000

SB : 7 000 kW
PS : 6 000 kW

Jet pump output

3 000

3 000 kW

Pump ashore output

12 000

12 000 kW

Propulsion power sailing

20 000

23 000 kW


1 400

2 650 kW

Bow discharge

1 000

1 000 mm

Bottom doors

2x 10

2x 12



To achieve the new dimensions and capacities, the dredger was rebuilt as follows:

  •  inserting midship section of about 54 metres
  •  increase of main deck depth with approx. 4 metres
  •  addition of bulbous bow
  •  addition of a ducktail of about 5 metres
  •  replacement of bow thruster
  •  modification of hopper loading and discharge system
  •  removal and replacement of trailing suction suction pipes, complete with
    gantries and winches

The lengthening section was prefabricated and fully equipped with bottom doors, hydraulic cylinders and piping in Thailand. On completion the section was towed to a shipyard in Singapore. Before arrival of the original ’Queen of The Netherlands’, all prefabrication and preparations were finalized. The vessel was then brought into dry-dock and was cut
into two pieces. Next the fore ship was floated out and the aft ship remained in the dry-dock. Then the lengthening section and the fore ship were floated back sequentially. After the dock was dry again and dock blocks were settled, both sections were skidded to the right position, aligned and welded to the aft ship. In the meantime deck sections, other steel sections and additional equipment were fitted. The vessel was put back into service after a series of extensive tests.

Vuyk scope of work

In close cooperation with the owners, Vuyk Engineering Rotterdam carried out a major part of the total engineering package required for the works in Thailand and Singapore.


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