THE LAST major section of the Shannon tunnel has been put in place beneath the river in Limerick.
The concrete section, which weighs 20,000 tonnes, is the length of a football pitch and the height of a two-storey house, was successfully sunk into a pre-dredged channel shortly after 11.30am.
The tunnel will be 915 metres long when completed in September 2010, will contain four lanes of traffic, and will form part of the €500 million Limerick south ring road project connecting the Dublin Road, N7, to the Ennis Road, N18.
It will also give Limerick its fourth river crossing.
Building the tunnel presented many engineering challenges to the company behind the project, Direct Route Limerick Ltd, including how to transport concrete sections that weighed 20,000 tonnes.
To solve the problem, the company flooded the basin where the sections were cast and floated them down the river and into position. Then one by one, each section was sunk into a channel already dredged for it in the river bed.
Yesterday, the process began at 5am and the section was in place and connected to the adjoining section by 11.30am.
Tom King, general manager of the company, said they expected to be able to walk under the Shannon by the end of November.
When work is complete in 2010, the city will have a new bypass and the banks of the Shannon will be restored as they were.
