Insights

Brenner Base Tunnel - Placement of a tunnel lining segment

Tunnel Boring Machine Wilma - H53 Construction Lot

The double-shield tunnel boring machine (TBM) Wilma is in operation in the western main tunnel of the Brenner Base Tunnel. It will excavate approximately 7.5 kilometers of tunnel towards Innsbruck between kilometer 24.1 and 16.7. Since its launch on September 18, 2024, more than a thousand tunnel lining segments have already been installed in the western tube.

In the video from May 7, 2025, the TBM Wilma is located approximately at kilometer 22.126 and ring 1040. The view is directed forward toward the cutterhead (right), while the already installed tunnel lining segments (left) can be seen behind us – the last fully installed ring is visible on the far left of the frame.

The video shows how a tunnel lining segment is placed in the haunch area using the erector's vacuum system. First, the erector arm slowly lowers the segment to the upper edge of the segment below. Then, the entire device, including the lifting platform, moves backward to align the segment with the last ring. Finally, the newly placed segment is fixed using pre-formed bolt openings in the concrete.

A complete tunnel lining ring consists of six individual segments, which are installed in a fixed sequence:

1. Segment A
2. Segments B1 and C1
3. Segments B2 and C2
4. Segment K (key segment)

Brenner Base Tunnel – Start-up Ceremony of the Tunnel Boring Machines Wilma and Olga

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