On 26 April 2021, a passenger train passed the eastern Gasworks Tunnel to the railway station King’s Cross for the first time in 40 years again. The ballast-less track was designed by FCP together with the executing company Rhomberg Sersa UK.

The East Coast Main Line connects Edinburgh in Scotland with the railway station King’s Cross in London. Directly before the terminal King’s Cross there are the three Gasworks Tunnels (West, Middle and East), which were built between 1852 and 1892. The tracks in the eastern tunnel were removed and closed in 1977.

Within the scope of a major modernization in 2020 and at the beginning of 2021 extensive construction measures were carried out at the East Coast Line and in particular in the area of the railway station King’s Cross. As part of it the eastern Gasworks Tunnel was equipped with two tracks and respective overhead power supply systems so that the railway station can now be reached by two additional tracks, which considerably increases the total capacity. Due to the constricted space available in the existing tunnel the ballast-less system Slab Track Austria by the company. Porr using track base plates with a width of 2.12m was especially suitable. The route in the tunnel partly runs directly below a residential building which is why the track base plates were equipped with elastic mats at the bottom side for a mitigation of vibrations in this area. In the tunnel a transfer point with the system LVT was established as well.

The ballast-less track was designed together with the executing company Rhomberg Sersa UK:

• detailed structural design of track base plates according to UK standard for soled and unsoled systems
• calculation and determination of the vibration-related properties for the soled track base plate
• design of the expansion joint between slab track and earthwork with transition module V-TRAS
• design of ballast-less track in the tunnel (track base plate and turnout), the transition areas at the adjoining earthwork incl. drainage in BIM at a collaborative overall model (Project Wise, Bentley Open Rail), which displays all subsections as a whole