Queen of The Netherlands - State-of-the-Art Jumbo Hopper Dredge

Category:

Dredge Plant

Description:

The Queen of The Netherlands is a 24,000 m trailing suction hopper dredge that was undergoing

sea trials when we visited the vessel. Several innovative designs were incorporated into the

vessel that could have direct application on vessels in the United States. Some of the innovations

are associated with the draghead and how it is designed and outfitted with cutting jets. The newer

design has the draghead much wider than dragheads currently used in the United States. The

draghead utilizes jets of water to fluidize the sediment before it's captured by the draghead's

suction. In addition, the dragheads are designed to dredge at an approximate 30-deg angle to the

bottom for better efficiency. These modifications have allowed the dredge to sustain a 30-percent

by volume sediment-to-water ratio. In addition, The Queen of The Netherlands employed a

recirculating system that takes the decant water from the hopper back to the draghead. This

system eliminates conventional overflow and reduces water column turbidity. Also, the dredge

pumps employ the high efficiency impellers that can operate at 92 percent efficiency while

pumping dredged materials.

Reviewer:

B. Hopman

Company / Organization(s):

Information Sources:

Interviews:

Interviewee:

Gerard H. van Raalte, Boskalis

Interviewer:

Bob Hopman, Neil McLellan

Interview Date:

7/23/98

Interview Location:

Dredge The Queen of The Netherlands

Field Investigations: Location:

Dredge The Queen of The Netherlands

Date:

7/23/98

Photos:

Yes

Photo Location:

Hartman Consulting Corporation, Bellevue, WA

Chapter 5 Other Technologies Reviewed