SWISS metre gauge operator Montreux Berner Oberland Bahn (MOB) and standard gauge operator BLS have reintroduced the innovative Golden Pass Express (GPX) gauge-changing trains on the Montreux - Interlaken line following the suspension of through services in late February after just over two months of operation.

BLS detected abnormal wear to some turnout components, in particular frog sections, when the train was operated on the BLS standard gauge track. The GPX trains remained in service on the MOB metre-gauge section, meaning passengers had to once again change to a different BLS train at Zweisimmen.

MOB has said that following extensive tests a solution to the rail wear problem in switches has been found with spacing between wheelsets reduced by a few millimetres, restricting movement when traversing point work.

MOB reintroduced one train pair on June 11 from Montreux to Interlaken, operating at 09:35 from Montreux and returning at 14:08 from Interlaken Ost, and will progressively increase the number of through services so that by August four train pairs will operate daily on the route.

Supplied by Stadler, the push-pull trains are equipped with gauge changing technology including bogies built by Alstom in Switzerland to operate on both the 62.43km metre gauge line out of Montreux operated by MOB, which owns the trains, as well as on the 52.9km Zweisimmen - Interlaken standard gauge line operated by BLS, Switzerland’s’ second largest mainline operator.

The trains utilise bespoke stub axles mounted on a bogie frame that moves when changing gauge in the bespoke gauge changers installed at Zweisimmen. This is different to telescopic axles as used by other gauge changing systems.