Implenia-led joint venture bags $478m Swiss tunnel deal

Implenia owns 60% of the joint venture, with the other 40% owned by Swiss civil engineering company Frutiger.

The project is lot 200 of the A4 Neue Axenstrasse road project, which has been underway since 2009. The existing Axenstrasse route, which runs between Brunnen and Flüelen was completed in 1864/5 and although it has since been asphalted and widened, it no longer meets modern requirements.

The project to replace the old road involves the construction of two tunnels – the Sisikon and Morschach Tunnel.

The Implenia-led JV’s deal to build the Sisikon tunnel centres on a single-tube, two-way road tunnel that will see the contractors blast through rock. The JV is also building other underground structures such as access tunnels, passing places, ventilation hubs and exhaust ducts.

Route map of the A4 Neue Axenstrasse (Image courtesy of Implenia)

Implenia said that with seven simultaneous tunnelling points and tight space conditions, the job presents “some unique challenges”.

In addition to the tunnelling, Implenia civil engineering units are carrying out various external works, including the construction of a large gallery to protect against natural hazards. The the various construction projects will produce two million tonnes of excavated material, most of which will be taken away by boat to a large renaturation project on the Reuss Delta in Flüelen.

Christian Späth, head division civil engineering at Implenia said, “We and our JV partner Frutiger are very pleased to be building this vital transport link in central Switzerland. The creation of the Sisikon tunnel involves challenging work in a very special location, making it a perfect fit for Implenia’s strategy as a specialist in large and complex transport infrastructure. We will be able to contribute our extensive expertise and experience in tunnel construction and civil engineering.”

The order is subject to a consultation period lasting until the end of July 2024. Construction of the lot is scheduled to start in mid-2025, and the work should be completed by 2034.