Data and facts

Project name:
Koralm Tunnel KAT2, Österreich
ÖBB Infrastruktur AG
Contract value:
570.0 million EUR (as part of a consortium)
Construction period:
2011 - 2019

The Koralm tunnel is the central part of the 130 km long Koralm Line, a high capacity railway link between the provinces Styria and Carinthia in southern Austria. The Koralm Line is, in addition, part of the extension of the high priority TEN Corridor 23 to Northern Italy. It is thus part of the internationally important Baltic-Adriatic axis that extends from Gdansk via Warsaw and Vienna to Trieste, Venice and Bologna.

The 32.8 km long twin-tube tunnel is divided into three main lots, the longest of which is the KAT2 contract, with an approximate length of 19 km. The two single-track main tubes (North / South tube) have an approximately 82 m² excavated section and are connected by cross passages every 500 m. The construction of an approximately 900 m long underground emergency station in the central part of the tunnel is also included in this contract.

KAT2 is an intermediate lot between KAT1 (east portal) and KAT3 (west portal). One of its special features is that the underground installations of KAT2 are accessed via a 60 m deep shaft.

The overall construction period will be assessed to last 8 years. After a first stage (2011/2012) in which both tubes will be driven east-and westwards in both directions (North tube 2.2 km,  South tube 2.8 km) by drill & blast according to the NATM, the TBM excavations will start by end of 2012 respectively by beginning of 2013. Both 9.9m hard rock DS-TBM´s will be driven westwards passing the frontier between Styria and Carinthia (North tube 15.6 km, South tube 17.1 km).

On 29.01.2013 the tunnel patroness, Mrs. Margit Fischer put the first TBM of the main lot KAT2 into operation. From 2013 till 2016 two 10m Doubleshield TBM´s are going to excavate 17.1km respectively 15.6km of the twin tubes within the core section of the Koralm tunnel totalling 33km in length.

Completion of structural works is scheduled for 2019.


More project data and facts here:
Koralm Tunnel KAT2

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