The Gotthard Alptransit company has a base in Polmengo - near Faido in canton Ticino - where construction of an access tunnel has started. The hostel contains 460 rooms, with a 95-per-cent occupancy rate.
Walls are thin in the workers' village, with each container abutting other containers. Several hundred employees are housed here. Each month the canteen serves about 4,500 meals.
Thomas Holtz in the access tunnel, which is used to ferry people and materials to the multifunction station. The tunnel is 2.5 kilometres long, with a slight incline. The noise of the rattling transport train is deafening.
Shift change at the cutter head. Thomas Holtz, Heiko Gnauk and Sven Tumele are starting the night shift. Repair work at the head is almost complete.
Heiko Gnauk, a welder from Berlin, belongs to the army of tunnel workers. About 70 per cent of the workers come from Italy and Austria. The others are mostly from Germany, Portugal and Spain.
About twice a year, depending on the geology, the boring machine is moved backwards about 20 metres to carry out the necessary maintenance work on the head.
When this is being done, it reveals the blank wall of rock through which the 450-metre-long machine is gradually chomping its way.
There are almost no Swiss on the construction site. Sven Tumele welds specially hardened steel components onto designated spots.
Protective plates of Hardox 500 steel are welded on to compensate for wear and tear on the cutter head.
Cigarette break, something to read, half a bottle of salad oil - and more than 1,000 metres of rock above their heads.
"Lunch" at one o'clock in the morning in the rest container, some distance back from the cutter head. Outside generators and ventilators are humming away.
Man and machine appear as one. Sven Tumele crawls into the cutter head, which seems to be about to swallow him.
During daily maintenance work, the temperature close to the head is well over 30 degrees, and the air is very humid.
Thomas Holtz twists and turns to extricate himself from the machine, while Sven Tumele lends a helping hand. It is now 6 a.m., and their shift is coming to an end.
A stop at the Faido multifunction station. The work in the tunnel is still dangerous, although advances in technology have made it less exhausting.
There is no comparison with conditions in the 19th century, when the current Gotthard rail tunnel was built. In all 177 workers died during its construction, and when they went on strike, the militia who were called in fired into the crowd.
At peak times there are nearly 1,000 people from more than 20 countries working round the clock in very tough conditions at almost 2000 metres below the surface. The poster reminds them to observe the safety rules.
On the site of what will be the world's longest railway tunnel.
The Gotthard base tunnel is the centrepiece of a new railway line which will improve connections between northern and southern Europe. (Pictures and text: Thomas Kern, swissinfo.ch)