Monster dredger ready to bed in new Tyne Tunnel

Mar 10 2010 by Tony Henderson, The Journal

A HUGE dredger arrives in the Tyne today to complete a million-tonne recycling operation.

The dredger Alexander von Humboldt’s main task will be to backfill the riverbed trench following the immersion last month of the last of four concrete sections which make up the new Tyne tunnel.

The vessel’s length is equivalent to 14 double decker buses and its width is 10 buses across. The trailing suction hopper dredger will remove clean sand and gravel from the mouth of the Tyne and place it via a pipeline into the tunnel trench between East Howdon and Jarrow.

That operation will help to ensure the tunnel beneath the riverbed remains securely in place.

The material will be piled against the sides and over the top of the tunnel sections, and will be topped by a protective layer of granite from a Lake District quarry.

The operation is expected to take up to seven days.

The material from the river mouth would have been part of routine maintenance dredges of the Tyne, carried out by the Port of Tyne and normally disposed of at sea.