New Tyne tunnel reaches a crucial stage

Jan 18 2010 by Tony Henderson, The Journal

TEN thousands tonnes of concrete were floated down the Tyne yesterday as the river's new vehicle tunnel reached a crucial stage.

The first of four pre-fabricated concrete tunnel units was manoeuvred out of dry dock at Walker in Newcastle.

Four 90-metre long units have been built inside the dock. One unit at a time is being floated out this and next month to coincide with high tides. Yesterday, the first made its 3km journey downstream to the site of the second Tyne vehicle tunnel.

Permission has been granted to close the Tyne to ships for up to 48 hours while each unit is immersed.

Three tug boats were used to transport the tunnel unit, which was floated using a ballast tank system, to its temporary mooring at Howdon Basin in North Tyneside.

There it will stay for a week as preparations are made for it to be lowered into place within the pre-dredged trench in the river bed between East Howdon and Jarrow.

Trevor Jackson, managing director for tunnel concessionaire TT2, said: “By mid-February we will have a tunnel across the Tyne. This is a historic achievement for the North East and one which I am very proud to be associated with.

“The flotation and immersion of each unit takes patience and a great deal of skill and I’m looking forward to watching this piece of history playing out on the Tyne over the next few weeks.”

Specialist marine contractor VolkerStevin Marine, based in Gateshead, was appointed by New Tyne Crossing design and build contractor, Bouygues Travaux Publics, to construct the four concrete tunnel segments at Walker Dry Dock.

VolkerStevin Marine’s project manager, Gerrit Smit, said: “This is an extremely precise procedure for which we have been preparing for many months.

“We have a very short window of time when the water levels and currents are exactly right to transport the tunnel section downstream.”