Damaged cable caused Praterstern fire, ÖBB says

A damaged cable insulation caused the cable fire at the Praterstern interlocking in Vienna, ORF reported, citing ÖBB. The short circuit occurred when the cable was switched back on after cabling work.

The cable was a 15,000-volt line that had remained without power during the summer closure. ÖBB said the insulation was apparently damaged during work to lay and renew hundreds of cable runs in narrow cable shafts. The damage caused a short circuit when the line was re-energised.

ÖBB said deliberate damage or sabotage could therefore be ruled out.

Newly installed cables must be tested individually before being put into service. Existing cables only require an individual test if they have been out of service for more than a year. In this case, the cable was an existing line that had been out of service for less than a year, so it was not tested again.

The fire damaged 20 kilometres of cable, all of which must now be replaced. Repairs are expected to continue at least until the start of the scheduled closure of Vienna’s main suburban rail line on September 7, 2026.

Trains cannot currently run between Praterstern and Vienna Central Station. Local trains towards Liesing are starting at Central Station, or in some cases at Meidling. The S7 airport service is also affected and currently runs only from Geiselbergstraße.