The Wienerwald, or Vienna Woods, rail tunnel (T&TI April ’03, p10) construction contract has been awarded to a consortium of Porr Tunnelbau GmbH/Bilfinger Berger NL Tunnelbau/Bilfinger Berger Bau GmbH/Porr Technobau und Umwelt AG.

Four contractor groups submitted bids to client Eisenbahn-Hochleistungsstrecken AG (HL AG) for the 13.3km tunnel that has been designed as an extension of the Lainz Tunnel towards Vienna. The contract was awarded based upon a bid of US$414.7M.

Upgrading Austria’s westbound rail corridor is a priority for Austrian and European interests; the Wienerwald is the first section of a new 42km long scheme to improve the line.

The alignment varies between a double track tunnel and two single track tunnels. The double track segment is a railway engineering requirement as the new section links to a junction. After 1.8km the double track tunnel widens over 400m into two single branches. The lines in the single track tunnels run for approximately 11.1km in parallel roughly 30m apart towards the western portal.

For the double track section, three emergency exits in the form of galleries and shaft structures are provided for safety. Along the single track tunnel section, cross passages will be excavated every 500m. At the transition point from the widened section to the single track tubes, an emergency ventilation system in the form of a cavern and shaft will be constructed.

NATM will be used for the eastern part of the scheme and two 10.6m diameter TBMs are being mobilised for the single track tubes with launch scheduled for summer 2005.

As the tunnels cut through the hilly terrain of he Vienna Woods, the expected geology consists of flysch and molasse formations.

Related Files
Diagram of the 13.3km long Wienerwald tunnel in Austria