Is there now an exact cause of the derailment on Margaretastrasse?
According to KVB, in the curve in which the derailment took place, one of the curved rails embedded in the asphalt, also known as curved tracks, was worn out, so that a piece of the rail had broken out. The derailed train was carried out of the curve and drove a few meters on the asphalt.
At the point in question, the replacement of the rails in the curve was already scheduled according to the KVB. When should it have taken place?
According to the KVB, the construction work should take place “promptly”. But the wear and tear happened faster than was to be expected, according to the KVB. The first repair work had already been carried out there in October.
How often are rails replaced?
The useful life of the rails depends largely on the intensity of their use. That means: the more lines travel over a section of the route and the closer the cycle, the faster renovation measures are necessary. Rails and points can be used for 20 years, says the KVB. But there are also curved tracks that have to be renewed every two to three years. A fundamental renovation was last carried out on Margaretastraße in 2012.
Why is the wear higher in a tight bend than elsewhere?
In curves, the wheels do not roll up and along the rails as smoothly as on straight stretches. The metal wheel is repeatedly pressed against the metal rail in the curve because it cannot move in its longitudinal axis. The narrower a track curve, the stronger the pressure – this also leads to squeaking in curves.
Despite the wear and tear, the location was still classified as a “safe area”.
How can this be explained?
Wear processes always take place through use. Rail routes are regularly checked to see whether the metal rails are still at their minimum width despite the abrasion of the metal rails. This was the case with the Margaretastrasse curve. Nevertheless, according to the KVB, it can happen that the forces of the railways driving over the route cause damage to the track. Particularly in tight curves, very strong forces act on the rail from the side.
How was the curve on Margaretastrasse secured?
Yesterday, filler steel was welded to the damaged area so that it will last for the next few months. Nevertheless, according to the KVB, the repaired curved track will be replaced promptly.
What was the reason for the derailment of line 7 on the penultimate Saturday evening in Zündorf?
Contrary to the first assumption, there were no material defects in Zündorf. The driver, who entered the system at the prescribed speed of 20 km / h, must only have had an interruption in the last three seconds before the scheduled standstill, the KVB announced, since otherwise the safety driving circuit would have resulted in braking.
Are there other potentially endangered rail areas in the city that the KVB is investigating more closely due to the incidents in Ossendorf and Zündorf?
No, there are no other potentially endangered rail areas in the city. The condition of the railways is continuously checked through regular measurement runs with a draisine, which take place almost every night on the route network. The KVB reports that there are places where the construction crews have to work.
– .
