Major milestone as dry dock flooding begins

Construction of the second Tyne vehicle tunnel took a major step forward today, (Friday 11th) when the sluice gates were opened to flood the dry dock in Walker containing the four river-section units.

dry dock image

It will take around four hours to fill the dock in readiness for the floating out of the concrete units into the River Tyne in the New Year.

Councillor David Wood, Chairman of the project’s promoter the Tyne & Wear Integrated Transport Authority, started the flooding accompanied by Trevor Jackson, Managing Director of New Tyne Crossing Concessionaire TT2, Nicolas Caille, Project Managing Director for main design and build contractor Bouygues Travaux Publics and Gerrit Smit, Project Manager at VolkerStevin Marine who undertook the construction of the units.

Councillor Wood said: “The flooding of the dry dock marks an exciting phase of construction. The river section tunnel units will be positioned in the river early next year and it will be possible to walk through them from one side of the river to the other in the spring. That’s an amazing thought.

“The Transport Authority is proud to be associated with such an innovative project. I pay tribute to everyone who has so far applied their skills and expertise to bring the project to this stage and look forward to the new tunnel opening to traffic on schedule in February 2011.”

Trevor Jackson said: “Flooding the dry dock takes us one significant step closer to completing the river works for the new vehicle tunnel. The project is roughly 50% completed now, with just over a year of building works left before the new tunnel opens to traffic and the existing tunnel closes for refurbishment. I’m delighted with the progress we’re making.”

Nicolas Caille said: “It has been quite challenging to build the tunnel units at the dry dock. There is very little space within the dock, just enough room to construct the units in fact. However, we are extremely pleased to have been able to carry out this vital element of work here on the Tyne. Once the dock is flooded we can begin preparations for the flotation of the tunnel units in the New Year.”

Gerrit Smit said:  “We are pleased to have reached this stage of our construction and immersion contract.  Our site team will be making the final preparations over the Christmas period before we begin the immersion of the sections in the New Year.”

Once the dry dock in Walker is full, the units will be carefully floated out into the river on successive high tides in January and February and towed to Howdon basin where they will be prepared for lowering into a dredged trench in the river.

Dredging works began on 9 November 2009, using a cutter suction dredger that pumps all the excavated material via pipeline direct into Port of Tyne’s Tyne Dock. Dredging of the trench is due to be completed between Jarrow Riverside and Howdon Basin by next week.

Each tunnel unit is 90 metres long, 15 metres wide and 8 metres high.  The tunnel sections have been constructed at the dry dock by Gateshead-based contractor VolkerStevin Marine.