Salzburg trolleybus repairs expected before school starts

Salzburg’s transit operator expects to restore all affected trolleybuses by the start of the school year after identifying defective insulators as the likely cause of repeated electrical failures, ORF reported.

Heavy rain and thunderstorms in early August caused the electric drives of 35 modern buses made by Swiss manufacturer Hess to fail. Several trolleybuses stopped on August 2, and further failures followed during renewed rainfall four days later.

A specialist team from Hess has been investigating the problem for about two weeks at the trolleybus depot on Alpenstrasse in Salzburg.

The suspected fault involves brake insulators, which separate the high-voltage electrical circuit from the rest of the bus. If water enters them, the vehicle automatically shuts down.

Salzburg Linien, the city’s public transport operator, currently believes the problem stems from a production or design defect. The insulators must be replaced in all 50 Hess trolleybuses operating in Salzburg. Depending on material availability, technicians will replace either the complete housings or the 17 individual insulators in each vehicle.

Salzburg Linien expects the work to be completed by the start of the school year in mid-September at the latest.