TBM Ida completes her first 2 km: a new milestone for the 'giant in the mountain' at the H41 Sill Gorge-Pfons construction site

TBM Ida is moving southward, excavating the west line tunnel as part of the Austrian construction lot 'H41 Sill Gorge-Pfons'. Meanwhile, the Ahrental tubbing ring factory continues its production at full capacity.

"Ida's journey is certainly not an easy one. However, our TBM, having passed the Viggartal area, is showing great resilience and the ability to cope with challenges. Thanks are owed to the entire team, who work day and night with great professionalism and commitment.” Romed Insam, project manager for lot H41 Sill Gorge-Pfons, expresses his satisfaction with Ida's progress.


The ‘H41 Sill Gorge-Pfons’ lot TBM is travelling southwards apace, excavating the west line tunnel. Ida started out on 27 June 2023 and completed her first 2 km of excavated tunnel on Sunday 25 February, progressing at an average of about 12 metres per day. It will excavate, in total, for 8,4 km. At the same time, Ida is also installing the inner ring lining of the tunnel. Each ring consists of six concrete segments weighing a total of approximately 60 tonnes each. A tubbing ring consists of several elements, each of which has to be installed precisely where it is meant to go during production, in order to obtain a perfectly circular tubbing ring.


The TBM, as well as her counterpart Lilia, has already passed the critical fault zone called 'Viggartal' without any major problems.


The real feather in the cap of the construction lot “H41 Sill Gorge-Pfons” is the tubbing factory, which here in Ahrental is located directly on the construction site. The production directly on site of the precast concrete segments for the final lining of the tunnels will avoid approximately 27,000 truck transports, which would otherwise have been necessary to transport the segments from the factory to the construction site.


The Ahrental factory, which went into operation just over a year ago has produced and partially installed 2,360 complete rings, i.e. 6 ring segments plus one base segment per ring, for a total of 16,520 segments produced.


While Ida is swiftly making her way through the depths of the mountain, in the outer area of the construction site this very well-planned and forward-looking plant is producing tubbing ring segments with an eye to both environmental sustainability and efficiency.