With the completion of a vertical 800-metre vertical shaft at Sedrun, a new phase in the construction of the world's longest railway tunnel is about to begin.This content was published on September 21, 2001 - 14:06
The new Gotthard link will form the centrepiece of Switzerland's New Transalpine Railway scheme. With a length of 57 kilometres, the Gotthard base tunnel will be longer than the Channel Tunnel connecting Britain and France, which is just over 50 kilometres long.
The underground construction site created by an international consortium will help to speed up completion of the main tunnel, scheduled to open in 2013.
For the South African workers who have spent years burrowing into Swiss rock, the work has been an important achievement.
"My people in South Africa look up to me because I make this small contribution to the world's longest railway tunnel", says Kobus van den Heever, shift supervisor in the New Transalpine Railway (NTR) construction site far below the village of Sedrun. Van den Heever, 36, works for a South African firm, Shaft Sinkers RSA, which normally uses its specialist skills in the mining industry, but has been part of the NRT consortium at Sedrun since construction began in 1996.
When the base tunnel through the Gotthard mountain range is completed in 2013 according to schedule, van den Heever intends to return to Switzerland for a visit with his family. "I'll ride right through where we stand now on a train at 250 kilometres per hour, and I will tell my folks, 'this is what we made.'"
In December, van den Heever and 35 fellow South Africans will return home. Their contract has come to an end with the completion of the vertical shaft, a separate ventilation shaft, and a cavern more than 2,000 metres below the surface, which will turn into a loud and dusty site for the construction of the main railway tunnel next year.
The NTR is expected to cost a total of SFr15 billion ($9.5 billion) and includes several other major construction sites to the south and north of the Alps, as well as a second transalpine base tunnel cutting through the Lötschberg range in the western Alps. The NTR is designed to link the nation's north-south axes to Europe's high-speed train networks by the year 2016.
With its kilometre-long access tunnel and the 800-metre vertical shaft, Sedrun is the most spectacular of the construction sites along the future Gotthard tunnel. It is one of three so-called intermediate access points - underground construction sites from where the tunnel will be drilled in two directions to speed up its completion, in addition to drilling work at either end.
From the entrance point just below Sedrun, a village 75 kilometres west of the regional capital, Chur, the kilometre-long access tunnel reaches the upper cavern. Vital equipment will be installed here shortly - ventilation and air conditioning machines, conveyor belts for the extraction of more than four million tonnes of rock material, electric motors that operate the lift in the vertical shaft leading to the site below.
The chief engineer at the Sedrun construction site, Robert Meier, says the shaft is a challenge from an engineering point of view. "The purpose of the shaft is to build [a section of] six kilometres of tunnel here at Sedrun. Normally you'd access a tunnel construction site horizontally, but we'll have to transport all the logistics and material through this vertical shaft - that's very special", Meier says.
Descending in a bucket
This swissinfo reporter was one of the last visitors allowed to descend through the shaft in what looks like a giant but simple bucket. The three-metre tall all-purpose device, which the South African shaft sinkers call a "kibbel", isn't a comfortable means of transport - passengers have to wear gloves when climbing over the rim. But its advantage is that the kibbel can hold up to 10 workers or carry 14 tonnes of rock material.
But the kibbel will be stripped down in the coming weeks, to be replaced by a modern lift at a later stage. From next year, rock material from the construction of the tunnel will be lifted to the surface by a powerful conveyor system, using a separate shaft.
The descent is dark and silent; nothing but a cool breeze from the fast-moving kibbel and my popping ears are telling me that I am on the way down. In the cavern below - a cross of two tall, wide caves each some 50 metres long - workers are busy applying electrical fittings.
Van den Heever, who is responsible for operating the shaft, says the 150 builders who work in the cavern in three separate shifts have come to like the kibbel, which is common in South African mines. "The difficult part was at the beginning when we had to let people we worked with know how this thing functions - make them safety conscious", he says.
Sinking the shaft and operating the transport system is similar to a South African mine, van den Heever says, except for one crucial difference. "In a mine, you deal with production - so you work faster and it's more dangerous."
From the middle of next year to the end of 2007, up to 600 workers will drill and blast two pairs of tunnels from the cavern in both directions. With up to 2,500 metres of mountain on top of them - a burden that increases pressure, heat and the likelihood of water pouring in -, engineers and workers are facing greater challenges in this, the tunnel's most central section than elsewhere.
Later, the cavern below Sedrun will be extended and transformed into a 1,700-metre long underground railway station, where trains can cross tracks and passengers may be evacuated in case of an emergency.
Van den Heever says that in spite of living in a dire container camp during their three-year stay in Sedrun - with paid home leaves every six months, and visits by their families in between - he and most of his South African colleagues regret having to return home soon. "I'm not looking forward; with Swiss salaries and no taxes to be paid, I got to keep more of my own money here", he says.
by Markus Haefliger
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