The Semmering Base Tunnel has reached a construction milestone. Austria’s Federal Railways (ÖBB) recorded the first full passage through the 27.3km twin-bore route linking Gloggnitz with Mürzzuschlag. This is reported by the railway transport news portal Railway Supply.

Semmering Base Tunnel targets 2029 services
Photo: ÖBB/Ebner

Almost 15 years after tunnel boring began, an official delegation travelled through the full tunnel length from Lower Austria to Styria. The journey was made by road vehicle rather than by train.

The trip, as reported by International Railway Journal, was led by Austria’s mobility minister Peter Hanke and ÖBB CEO Andreas Matthä. Doris Bures also joined the delegation. She is president of Austria’s National Council, the lower house of Parliament, and one of the tunnel’s three promoters.

Semmering Base Tunnel works move toward fit-out

Tunnel boring was completed in November 2024. A contract to fit out the tunnel had been awarded in June 2024. In March 2025, a separate contract followed for slab track installation.

These steps place the project in the equipment, lining and track-work stage. Trains cannot begin using the route until that work is complete.

ÖBB says, “Work is currently focused on the technical tunnel equipment and final work on the concrete inner lining in the Gloggnitz section and in the area of the emergency shafts at Fröschnitzgraben,” ÖBB says. “Due to the tunnel’s enormous dimensions, this work will take over three years before trains can begin running through it.”

Vienna to Graz journey time

Matthä said the tunnel will shorten the Vienna–Graz journey. Services are due to begin operating through it from the end of 2029.

“From the end of 2029, Vienna and Graz will be connected in approximately 1h 50min,” Matthä says.

At present, the trip takes 2h 36min. The existing route over the Semmering Pass is constrained by its winding alignment. Speeds on that route are limited to 60–80km/h. At the same time, the base tunnel is designed for operation at up to 230km/h.

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