TPA goes underground

14 Oct

The TPA team in Austria are used to working on projects in spectacular settings, and non-more so, than on an important rail infrastructure project, where they had to also work in the tightest of conditions 100 m underground. 

Just over halfway through the construction of the Semmering Base Tunnel, a new twin-bore railway tunnel under the Semmering Pass in the Austrian Alps, TPA provided a temporary foundation solution to accommodate moving a heavy formwork carriage between tunnels.


Work on the new 28km-long tunnel between Gloggnitz in Lower Austria and Mürzzuschlag in Styria on behalf of the ÖBB Infrastruktur AG began in 2012 and is expected to complete in 2027, meeting a requirement for a vital high-performance line in the Trans-European Transport Network.

The original Semmering railway, which was constructed between 1848 and 1854, was the first railway to cross the Alps and is commonly referred to as the world's first true mountain railway. Despite being one of the busiest routes in Austria, it is also a UNESCO World Heritage Site.

The Semmering Base Tunnel is being constructed at a significantly lower altitude, and shallower incline (at 0.85%), than the original 41km route which will enable trains to travel at an increased speed of up to 230km/h.

This will allow for a significant reduction in the travel time between the cities of Vienna and Graz, and perhaps more importantly, also enable heavy freight trains to use it with just one engine, instead of two, cutting emissions and providing a more viable alternative to road freight.


In October 2019 (ARGE SBT3.1 Grautschenhof) a joint venture between Marti GmbH Austria and the well-known Swiss tunnelling company Marti Tunnel AG started work on the Grautschenhof tunnel part of the project near Spittal am Semmering.  ARGE SBT3.1 Grautschenhof appointed TPA Portable Roadways to install a stable transport platform to allow them to move a heavy formwork carriage between the two tunnel bores, 100 m underground. 


To access the site TPA’s two-man installation team had to take their truck on an elevator down to the site and then drive through the 10m-diameter tunnel to the site to install 76 aluminium panels to create a safe access route for the formwork carriage to travel 70m to the parallel bore.

The following day the team removed the panels, loaded up the truck and returned to the surface.

TPA sales representative Gerhard Hohenthanner said: "This was our first underground project and for it to be on a project of the century, you could get sweaty palms, but our team did an excellent job.”

TPA project coordinator, Rene Hellmich, added: "It was actually a normal job, if it weren't for the narrowness. The whole operation was precise to the millimetre from start to finish. The closer we came to the site, the less room we had to manoeuvre. Particularly when using the crane to install the panels, extreme care had to be taken to avoid damaging any pipes, installations or ventilation ducts."

Thomas Thumulla, TPA operations manager, puts the success of this first underground project down to the training and professionalism of the operations team.

"Our operations teams are regularly trained and prepared for unusual operating conditions. This ensures that our employees do a great job even under challenging conditions like here in the Semmering tunnel," he said.