Dear Sir

What a great opportunity to celebrate with Heinz-Peter Mühlhäuser 100 years of business (T&TI July, p41). So much has happened in the 50 years of knowing Heinz-Peter. Among the memories, one thing keeps recurring. A lot of importance was placed on the TBMs at the face of the tunnel, while so much depends on the efficiency of the tunnelling process as a whole. The key element is the number of meters completed per month and that depends on the tunnel infrastructure. The backup system following the machine is as important as the performance of the glamourous machine at the face.

When I first became familiar with the Mühlhäuser Company, high stakes contractors in the USA were gambling on making their reputations by setting world records of advance on projects where the geology was ideal for high speed tunnelling. These were jobs for the US Bureau of Reclamation like the San Juan-Chama Project. Nice long tunnels in good self-supporting soft rock, usually shale.

The key was to keep the muck cars rolling fast with trains moving in, others moving out, and another waiting on the movable California switch set as close behind the machine as possible. It took a lot of coordination and a lot of men in the tunnel as well as on the surface out-side.

It began to define the North American approach to tunnelling in good ground. Speed was everything to bring the job to a close as quickly as possible to cut down on the fixed overheads.

That was the late 60s and early 70s. We then started to attract the attention of European tunnellers and saw our earliest Robbins machines used on jobs in very similar geology such as the Molasse shales in Switzerland, the Jura shales for the CERN project near Geneva, and the Bodensee tunnel near Stuttgart in Germany. The approach however was sometimes quite different.

We watched the Theiler-Kahlbermatter Company build a water tunnel in Zurich with three people in the tunnel – a machine operator, a labourer and a locomotive driver. The focus was on the lowest cost per meter of tunnel. Efficiency and low manpower seemed to be a way to drive tunnel, but it became clear that the proper balance of men and equipment to keep the job moving was the low cost way to organise the tunnel. That was where the Mühlhäuser Company came into the picture.

There are many cleaver ways to organise the complex job of the tunnel haulage infrastructure. Small details make a big difference. The Mühlhäuser arrangements were often innovative and allowed a higher level of efficiency that could be managed with one or two less men in the tunnel.

Heinz-Peter and his group became known as the inventors and innovators in backup systems. At a job site in Spain in the 70s the cantina had plumbed a hot water spigot next to the cold water one and used rubber hoses to connect them. I remarked about the clever arrangement to achieve warm water. Without hesitation our agent on the job replied: “That’s another Mühlhäuser invention.” Innovation continues to be a way of business.

At times when things seem not to be going well and you need a good friend to remind you that everyone goes through tough times, Heinz-Peter has been there to give me encouragement, a pat on the back and a kind word of advice. That means much in a business where you must depend on your partners and collaborators. Many congratulations to you Heinz-Peter and to your team.

Dick Robbins
Member of the Board of Directors and former CEO, The Robbins Company
Washington, USA


Heinz-Peter Muhlhauser and Dick Robbins (left) celebrate one of many successful Robbins+Muhlhauser collaborations, here for the Lesotho Highlands Water Project, in Southern Africa Heinz-Peter Muhlhauser and Dick Robbins