World record

On 29 October 2022, Rhaetian Railway wrote a piece of railway history: the world’s longest passenger train travelled on the UNESCO World Heritage route between Preda and the famous Landwasser Viaduct. An event that attracted thousands of railway fans to Bergün and the Albula Line and fascinated spectators around the world.

Never before has such a long passenger train travelled on a narrow-gauge line with tight bends, tunnels and viaducts in the high mountains. The trip made high demands in terms of technology and coordination.

Synchronous control of the train structure and handling of braking forces The 25 trains all had to accelerate or decelerate at the same time, although only four trains each could be controlled from the same driver’s cab. An electric circuit ensured that all trains braked at the same time if the trains needed to slow down suddenly. Due to the heavy weight of the train (2,850 t without passengers), very high forces were exerted on the infrastructure and the carriages. A separate intercom system on the train, trained train drivers and clear instructions ensured the desired result. In addition, special software was loaded for the record-breaking train and the mechanical braking power was reduced.

Recuperation and effects on grid load On the descent, the train was fully braked using electric recuperation. This generated electricity that was fed into the overhead contact line and could be used by other trains on the RhB network (as well as other railways in Switzerland and abroad). In addition, the surplus electricity could also be fed into the public grid using converters (e.g. in Bever). The major challenge was that the overhead contact line voltage could increase too much (usually 11,000 volts), as 25 trains in the same section were generating electricity synchronously. The overvoltage could not have been absorbed by individual systems connected to the traction current. Various tests were carried out to this end and measures were taken to ensure the record-breaking journey could take place (including limiting speed and acceleration, reducing recuperation using special software on the train, and preventive switching of systems to local grid power supply).

Connection of trains The individual four-unit Capricorn railcars were connected to a fully automatic coupling. Four trains were driven by each train driver. There was mechanical and pneumatic coupling between four Capricorn railcars each, but not electric coupling. For this purpose, additional safety control lines were laid between the trains.

Ensuring safety and availability of track and systems The track was closed to other trains for the record trip. The record-breaking train was sometimes longer than various block sections. The trip was controlled from the operations centre in Landquart. It had to be ensured that the signals, as well as the level crossings and customer information, were triggered at the right time.

Live media production The record trip was recorded by Blick in a live production and broadcast on various channels. For this purpose, a wide range of cameras were used from drones, in the driver’s cab and on the track and had to be processed in real time. This alone was a major and exciting challenge on a route with limited mobile coverage.