JÜRG SCHLUMPF, CORPORATE TARGET MARKET MANAGER CONCRETE

What was the most difficult challenge?

At the time of prequalification in 1996 the client required a concrete working time at > 25°C of six hours with subsequent high early strength. During the construction phase this requirement was increased by the contractor to a pumpability time of eight hours. This was totally unique at the time. Through extremely close cooperation betweenthe contractor responsible, Sika Concrete Technology and Sika Research & Development, these standards were reached unerringly throughout the construction phase. Ultimately these project requirements also became the starting point for theSika ViscoFlow® product range which is now so successful around the world.

What was the most memorable experience?

After I joined Sika as Product Engineer, Concrete Admixtures in 1993, only a year passed before I had my first contact with the Gotthard project. It was concerning high early strength concrete in the Piora exploratory tunnel. We developed a solution suitable for the client – Sikament® HE-200 – and were awarded the contract. Eventhen I spent days (and nights) on the site. Later during the prequalification process from 1995 onwards I even spent entire weeks in the Hagerbach test tunnel to check out our main concrete systems. At the end of 2001 the “actual“ concreting works began in the tunnel, where members of my teams turned the preliminary work into reality. For me the years that followed tended to be filled with meetings on the potential and limits of the systems on the Gotthard. It all ended for me on 15 October 2010 with the breakthrough between Sedrun and Faido. For 15 years the Gotthard Base Tunnel was part of and defined my working life. Almost anything is possible!

MICHAEL VORWERK, PRODUCT ENGINEER

What was the most important experience?

I met people on the Sedrun section who were prepared to put personal advantage behind them. I found very strong motivation and activity to achieve the team goals. This good experience was what I took away with me.

What was the most difficult challenge?

People from different nations and cultures coming together and stood side by side to create a monumental structure together that would continue to astonish many generations to come.

CHRISTIAN ANDERRÜTHI, SALES MANAGER TUNNELLING

What was the most memorable experience?

It was in 2000 only about 4 or 5 months after the start of the Faido access tunnel. After the blast round (around three metres of tunnel were blasted) I walked with the experienced older site manager from Amberg, Franz Walker, towards the working face and climbed with him onto the newly collapsed excavated material. Franz had seen a fissure and assumed there were minerals. It was dangerous to climb onto the broken rock because some of the corners and edges were razor sharp. When Franz and I were standing right at the open, unprotected working face and he was working at the fissure with a hammer, there was a loud bang. About a metre behind us a large lump of rock 2 – 3 m² insize and 25 – 30 cm thick fell down from the roof onto the heap of rubble. I was so frightened that my knees went weak and I was unable to climb down from the rubble without help from Franz. After that experience I am rarely to be found in the unprotected area in the tunnel bore, and unwillingly if so. I experienced in my own body how dangerous daily work is for miners and tunnellers and why they regularly give thanks to their patron saint, Saint Barbara. When I go underground I have great respect for the mountain and celebrate the Feast of Saint Barbara with the miners on 4 December. Now and again I make the sign of the cross to the blessed statue found on the portal of every gallery or tunnel.