ÖBB railroad lines

“Salzach Valley requires many protective structures”

The net holds: Laimer and Wahl inspecting the recent rockfall in Lend in Pinzgau.(Bild: Roittner Felix)

The "Krone" accompanied ÖBB employees during the inspection of rockfall nets on the railroad line. Modern technology should bring more safety.

Nikolaus Wahl and Hans Jörg Laimer use a machete to fight their way through the dense undergrowth along a rockfall fence in the Salzach Valley. "We had another rockfall there recently," reports Wahl. During the inspection, it quickly becomes clear that the fallen rocks need to be removed from the net. This has already been done twice this year using an excavator. "We will have to blast one rock first," says geologist Laimer. In the past, large chunks of rock have already been blasted from the section between Lend and Taxenbach to prevent them from breaking through the net later. At the point where the fence protects the provincial road and railroad line, loads of up to 500 kilojoules are absorbed. "That's roughly equivalent to the force of a VW Golf in free fall," says Wahl, plant engineer for natural hazards.

A sensor monitors impacts in the grid.(Bild: Roittner Felix)

There are now massive protective structures in Taxenbach.(Bild: Roittner Felix)

Nikolaus Wahl and Hans Jörg Laimer sometimes have to fight their way through with a machete to assess the rockfalls.(Bild: Roittner Felix)

Nikolaus Wahl and Hans Jörg Laimer have to fight their way through the rockfalls, sometimes with a machete.(Bild: Roittner Felix)

State-of-the-art technology is now being used in field tests at the site in Lend. Sensors on the supports measure whether there has been an impact and report this to the control center. Using a camera, ÖBB employees can get a live picture of what is happening. "The nets still have to be constantly monitored," says the technician. In general, every protective structure means a lot of work. The vegetation has to be constantly trimmed and the material removed from the basins. ÖBB goes to enormous lengths to ensure that the tracks are safe.

The situation in the Salzach Valley is special. Geologist Laimer explains: "It is one of the most sensitive areas in Austria because the Salzach fault runs here." Two types of rock from the Alps collide tectonically at this fault, which causes the problems. Another main reason for rockfalls is massive rainfall. These have become increasingly extreme in recent years.