International Dredging Review

International Dredging Review

Westminster Dredging Company a Boskalis company has received the contract for deepening the Harwich deep-water channel on England’s East Coast.

The trailing suction hopper dredge Queen of the Netherlands arrived on site on November 18 and will be joined by the Cornelis Zanen to dredge 17.5 million cubic meters (23 million cubic yards) of material in the £26 million project. Completion date is early 2000.

The channel is 12.5 meters deep (41 feet) and will be dredged to 14.5 (47.6 feet) meters. The dredged material consists of 2.5 million cubic meters of silts sand and gravel and the remainder is stiff clays compacted sand and rock. The hopper dredges equipped with special dragheads have dredged this material in the past and will be able to remove all the compacted material said Richard Allen harbor engineer for the Harwich Haven Authority. Sweeping beams and stone trawling barges pulling large nets will remove the large rock he said.

The purpose of the project is to use the Port of Felixstowe which is within the Harwich Haven more efficiently. Felixstowe now handles more than 50 percent of all box traffic into the United Kingdom and this project will allow the port to accept the latest generation 6000+ TEU container ships. Two berths within the port will be deepened as part of the project.

Dredging began on November 1 with a small gravel dredge. The contractor will have 17 disposal options for beneficial use of gravel and silts as environmental mitigation for the deepening. One of these is to recharge the estuaries of the Stour and Orwell Rivers which feed into the harbors.

The deepening is completely financed by shipping fees collected by the port.

“We don’t anticipate having to raise the shipping fee” said Allen because the increased traffic should cover the cost. The port is well situated to receive cargo ships from Europe and overseas.