Coloured MARO plugs for the Cornberger Tunnel – Part 1

After 145 years of busy train traffic, the Cronberg Tunnel is getting a well-deserved replacement.

The new portals are to blend into the landscape alongside the existing heritage-protected structures. For this reason, through-coloured, reddish-brown exposed concrete is being used, which closely matches the colour of the red sandstone.

Using a sample slab, we were able to reproduce the colour and provide the construction company, Josef Rädlinger GmbH, with a range of shades to choose from. 1,000 MARO plugs are ready for installation and will become part of the railroad.

The east portal will be constructed first. From there, the tunnel will be driven through the ‘Großer Bärenkopf’ using mining techniques over a distance of 681 metres.

We will provide further insights in the next instalments until the shell of the portal is complete.

Baustelle am Cornberger Tunnel. Rechts der alte Tunnel mit Buntsandstein. Links die Vorbereitung des (noch nicht gebohrten) Tunneleingangs.

The new east portal is being built to the left of the existing structure.

Bohrpfähle sichern die zukünftigen Balken und Wände des neuen Portals.

Drilled piles secure the future beams and walls of the new portal.

Farbmuster im Abgleich mit MARO Kegeln

Test cones in various gradations were produced based on the pattern (angular).