This immersed section was made up of four elements, which were cast nearby by VokerStevin UK, who was appointed by the design and build contractor Bouygues Travaux Publics to construct the reinforced concrete tunnel segments at Walker Dry Dock and transport them 3km downstream to their final destination. The fourth and final one was lowered in to place last Tuesday 23rd February, completing the under-river link of the new vehicle tunnel.

The river section of the tunnel is made up of four 90 metres long, 15 metres wide and 8.5 metres high concrete units. Despite weighing in at 10,000 tonnes each, the units must be weighted with water through use of internal ballast tanks in order to lower them into position.

This series of images shows these four elements being constructed in the dry dock from May 2008.

May 2008

2nd September 2008

19th September 2008

24 October 2008

21st January 2009 

March 31st 2009

17th April 2009

11th June 2009

With all tunnel units now positioned beneath the Tyne, a loading fill and rock armour will be placed above the tunnel, within the river bed, to protect it from potential damage. The internal bulk head walls and ballast tanks will be removed so that by late spring 2010 there will be clear passage from one side of the river to the other.

The next stage in the project is to refurb the existing Tyne Tunnel which dates from 1967. When this is completed, the new tunnel will carry traffic north to south and the existing tunnel, which currently carries vehicles in both directions, will carry vehicles south to north, reducing congestion and improving quality of life for those in the North East of England.

You can read my article about the new Tyne crossing in April's issue of Tunnels and Tunnelling.