Partner from valley to peak

Solution

Remo Pinazza,
Project Manager for Marti Tunnelbau AG
 

The concrete dam at Lake Mutt is 36 meters high, 15 meters wide at the base, and over a kilometer long at the crown—the longest dam crown in Switzerland.

 

On the snow covered high ridge of the mountain, where the wind hits your face, you are at an altitude of almost 2,500 meters above sea level – making it slightly harder to breathe. So does the spectacular sight of the snow-dusted alpine lake just behind you, nestled against the peaks and crags.

This is probably the last place on earth you’d expect to find a ready-mix concrete plant. And yet there it is, its white, snow-capped silos looking themselves like small alpine peaks. Behind it, stretched out like an inverted “V” for over a kilometer, is the great dam for which the concrete is being made—among other things with material supplied by Holcim.

The dam is part of a major hydroelectric project here in the Alps, one of the largest and most spectacular such projects in recent Swiss history. The idea is to funnel water from Lake Mutt (pronounced “moot”) through massive tunnels down to a huge power-generating plant nestled deep inside the mountain. The water then empties into Lake Limmern, some 600 meters below Mutt, where it can be pumped up again when needed.

“Building on this scale in the mountains is extremely difficult,” says Remo Pinazza, Project Manager for Marti Tunnelbau AG. Marti leads the consortium which is responsible for the dam as well as the substantial tunneling and excavation work inside the mountain. “Success requires intense planning and reliable partners.”

Standing on the ridge watching the concrete works you can see that planning and partnership in action. There are no roads here, so the cement, fly ash, and binders supplied by Holcim are brought up by a specially constructed industrial cable car. Marti makes concrete both at a plant at the dam site and, for the tunnel and chamber linings, at a plant in the middle of the mountain. With limited room to store material, deliveries must always be correct and on time, or risk costly delays.

 

Cement silos and transport containers at the base station at Tierfehd: When the project is finished, Holcim will have delivered 140,000 tonnes of cement, 30,000 tonnes of fly ash, and 5,000 tonnes of special binders. see infographic, no. 3

Two aerial cableways were erected to transport cement and other materials up the mountain. They are in operation 24 hours a day, seven days a week. see infographic, no. 4

“Building on this scale in the mountains is extremely difficult”.

Remo Pinazza

Holcim is doing its part. Its plant at Untervaz has been guaranteeing an uninterrupted supply of cement (with backup from the Siggenthal plant). A constant rail link ensures timely delivery of the cement and binders as well as fly ash from Holcim Germany—a complex undertaking. Holcim experts have also provided Marti with technical assistance on the concrete mix, and Holcim has installed special electronic monitors on Marti’s material silos, giving both companies a real-time picture of the state of supplies. The result? Everything delivered as needed, with no delays—despite peaks with over 700 tonnes, or 14 rail car deliveries, per day.

“Marti has a long, successful relationship with the people at Holcim,” says Pinazza. “We know we can count on them. With Holcim, we have had one less thing to worry about on this project.”

Back on the ridge the wind whips up the snow on the crown of the great dam, now almost complete. As you turn to go you know how important—especially in the mountains—a reliable partner can be.
 

Ready-mix concrete plant at an altitude of 2,500 meters: The construction season at the dam site lasts only the warmest five months of the year. But even during this time, heavy winds and late snows have brought activity to a halt for days at a time. see infographic, no. 5

Within the mountain Marti is boring four kilometers of tunnels and two mammoth chambers for the turbines– the larger of which is 150 meters long and 50 meters wide. see infographic, no. 6