Two-thirds of Ireland's maritime trade is handled by the Port of Dublin. Thousands of trucks force their way through Dublin's city center every day. Planned is a tunnel to link the outer-urban highways and major roads directly with the port.
The S-194, a partial-face excavation machine, bored an initial section of the tunnel in 2002. After the work was completed, the machine was replaced by the Single Shield TBM S-193. Using these two different types of machine was the solution adopted by Herrenknecht to deal with the widely varying geological conditions along the tunnel route. Following the final breakthrough by the TBM in 2004, the tunnel was opened in December 2006.