It was realised relatively early on that the Mainz railway hub could not be adequately serviced by means of the 2-track rail tunnel in use since 1887. The Old Mainz Tunnel (AMT) consists of 2 successive tunnel tubes – 654 and 242 m in length as well as an intermediate cutting that is some 300 m long and 27 m deep. To eliminate this bottleneck initially a second 2-track tunnel was constructed below the Citadel at a cost of 82 mill. euros, which was opened in 2003: the 1,297 m long New Mainz Tunnel (NMT). As a result it was possible to close train services completely on the 1,200 m long old line running parallel to it between the Central Station and the Südbahnhof to renovate the AMT some 3 years later.
Following 4 years of construction the refurbished AMT (70 mill. euros) was reopened at the end of 2010. As a result there are now 2 parallel running tunnels available with 4 tracks in order to accommodate the flow of traffic involving in excess of 300 trains per day more effectively in future. In addition enlarging the tunnel cross-section from 42 to 74 m² represented an important prerequisite for ensuring that the safety and evacuation facilities were ungraded to the latest standard in the AMT as well. ⇥GB