|

Tunnel project in the fast lane

Sadat Lataj and his team are in a hurry: they are responsible for repairing two tunnel tubes at Gubrist. As part of the Zurich northern bypass, important traffic axes converge here. The tunnel tubes should be fully available by 2028. To ensure that this happens on time and in the required quality, the team has been using lean construction methods since the start of the project – saving valuable time in the process.

"We are currently renovating the second tube of the Gubrist Tunnel and are several weeks ahead of schedule," explains project manager Sadat Lataj from Implenia Tiefbau Zürich. The pleasing construction progress does not surprise insiders: the team is known for its speedy working methods, and the work on the renovation of the first tube was completed a full 44 days ahead of schedule while traffic was still running.

Lean showcase project Gubrist: how it works

What is surprising when you visit the site, however, is that despite all the hustle and bustle, everyone involved seems relaxed and there is no sign of a hectic pace. The secret? "Lean!" Sadat answers without hesitation. "The lean working method has been with us on this project right from the start. We invested an enormous amount of time in work preparation, recorded all our experiences from the renovation of the first tube, planned and timed all the work steps with everyone involved right from the start. That involved many hours of exchanges, discussions, agreements and training. In the end, everyone knew what we wanted to build here, in what order and how they would contribute."

Up to 170 employees, tight schedule, little space

Tunnel construction project manager and site manager Thomas Geiger has been on site every day since the start of work on the 2nd tunnel tube at the beginning of January 2026 and confirms this: The challenge with this project lies in the very tight schedule, the many people involved and the limited space. Up to 170 employees work in two shifts every day from 6:00 a.m. to 10:00 p.m. and share only a few access points to the tunnel for their many tasks. It is therefore crucial that everyone understands the interdependencies and adheres strictly to the schedule. "If someone overfulfills, they get in the way of someone else," he explains.

Construction site manager Thomas Geiger: "Lean brings the industrial construction method to the construction site and ensures maximum efficiency."

Thomas Geiger has 32 years of experience in tunnel construction, where long linear construction sites favor industrial construction methods. "Lean continues this way of thinking and ensures maximum efficiency, e.g. here at the Weinigen cut-and-cover site, where all access roads on this side of the tunnel have to be combined with the ongoing construction work. A masterpiece of planning."

Recipe for success: successful communication

Both project managers agree that the key to success lies in successful communication. Thomas Geiger: "The consortium alone consists of three companies with different corporate cultures. Then there are the many subcontractors. When plans are discussed in advance, different approaches often lead to friction. By consistently discussing contentious issues, we eliminate many difficulties from the outset and deliver a better result overall. Our success proves us right."

Sadat Lataj is also convinced that the lean method not only makes the teams' work faster, but also better. "Forward-looking planning prevents many mistakes from even happening. We prevent waste – of time, materials and resources – and don't produce any surplus. Better logistics is automatically more sustainable."

Central to the success of the project: close exchange and good communication – Sadat Lataj with foremen Mefail Hashani and Enver Kadriu

A positive side effect: the teams are not only working better, they are also doing better. Sadat Lataj: "On many construction sites, the teams have to constantly respond to new challenges. This stress is largely eliminated with us. When things are running smoothly, everyone stays more relaxed and does their work more confidently. And I get home to my family on time!"

A power team for project success: CEO Jens Vollmar, foremen Mefail Hashani and Enver Kadriu and project manager Sadat Lataj
Efficiency all the way to invoicing: construction clerk Sandra Wanner and project manager Sadat Lataj
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist
Repair work on the Gubrist

The Gubrist Tunnel project

Between 2023 and 2027, Implenia is renovating the first and second tubes of the Gubrist Tunnel as part of the GUBRI consortium. The work also includes the removal of the roadway and the verges as well as the new construction of the service duct and the lowered roadway. 

     More about the project 

More on this topic

 | 

Water and frost protection for tunneling

 | 

Into the tunnel with BIM

 | 

At the end of the tunnel: collective success

 | 

Gubrist renovation: finished 44 days earlier thanks to Lean!