Spirits rise as the new Tyne Tunnel sinks
Feb 24 2010 by Tony Henderson, The Journal
THE final section of the new Tyne Tunnel was floated into position yesterday to complete the connection of the two sides of the river.
It followed the previous three concrete sections in being towed two miles downriver from Walker Dry Dock in Newcastle, where they were constructed and marked another milestone in providing the missing dualling link of the A19.
Managing director of concessionaire TT2 Trevor Jackson said: “With the successful immersion of the final unit we can proudly say we have a new tunnel under the Tyne.
“The river works represent the essential part of this project, providing the much-needed connection beneath the Tyne between North and South Tyneside, and completing the dualling of the A19.”
Each section is 90 metres long, 8.5 metres high and weighs 10,000 tonnes.
The final section was immersed into position into the dredged trench on the river bed, which goes down 18 metres at its deepest point.
A circular tower on the last section, which stands above the surface of the river, will enable workers to enter the submerged structure.
Cables and a floating crane were used to manoeuvre the last section into position on the Howdon side of the Tyne.
The section was lowered by filling its ballast tanks with water and four jacks, or pins, on the section then rest on a corresponding number of concrete pads in the trench.
Liquefied sand will be pumped into a small gap between the bottom of the section and the trench floor to stabilise the structure, and the jacks will then be withdrawn.
