Report on serious railway incident at Rosenholm stop on the Østfold line 14 April 2021
Railway report 2022/06
On 14 April 2021 at approx. 16:16, the catenary of the overhead contact line system snapped south of Rosenholm station on the Østfoldbanen line. There were no trains there at the time and no witnesses to the incident. The catenary, which is a live wire carrying a current of 15,000 V, came into contact with the track and short-circuited. This produced sparks that ignited a fire in vegetation near the track. At about the same time, a passenger train from Oslo was approaching Rosenholm station. The train lost power, but continued to roll so that the whole train set stopped alongside the platform. When the train passed Holmlia converter station, it entered an area where the overhead contact line was short-circuited and earthed, caused by the catenary breaking south of Rosenholm. The train’s first active pantograph caused another short-circuit at the overlap section between two catenary sections directly outside the converter. This short-circuit is likely to have burned through the catenary and/or the contact wire. The second active pantograph then became entangled in the contact line and brought it down until the train stopped at Rosenholm station. Components from the contact line broke windows in the train set, and two passengers suffered minor cuts from broken glass. The passengers had to be kept on the train for a while because of the risk that the contact line could still be live. The fire service put out the fire and helped to earth the contact wire so that the passengers could be evacuated.
The NSIA has not been able to reach a definite conclusion as regards the cause of the incident. In the course of the investigation, we have considered other forms of stress that components may be exposed to, their mechanical strength and other external factors. The most common cause of short-circuiting of overhead contact lines is birds or objects coming into contact with live components. No indications have been found that this was the case at Rosenholm, however.
The system’s electrical protection has largely functioned as intended, but an overhead contact line protection relay in Ski traction power distribution station allowed for repeated attempts to reconnect the power, resulting in the electricity on the section of track being switched back on during Bane NOR SF’s troubleshooting. The tools available to Bane NOR SF’s electrical power operators are not sufficiently precise to quickly identify the exact location where a fault has occurred. Troubleshooting is therefore carried out both automatically and manually by resetting the circuit breakers in the system to narrow down the area where the fault may be located. Personnel must then be dispatched to the location to verify the fault.
The NSIA’s view is that, as long as the cause of the catenary break cannot be determined, it is difficult to point to safety improvements that could have contributed to it being detected in time for the train to be stopped. Bane NOR SF has registered a number of incidents involving contact lines that have been brought down, but the cause of the incident is not always known. The incidents could be caused by vehicle faults, weather and wind, objects short-circuiting components, or other infrastructure faults, and the different causes would require completely different measures.
When contact lines are brought down, it rarely affects safety for humans, but it will cause traffic to stop, with all the inconvenience that entails. The NSIA recommends that Bane NOR SF, in its follow-up of an already submitted safety recommendation (Rail No 2021/06T), include the systematic mapping of circumstances surrounding contact line components brought down, for the purpose of identifying causes and implementing necessary preventive measures.
Photo: NSIA
Facts
| Location | Rosenholm station |
| Occurrence date | 14.04.2021 |
| Train No | 2745 |
| Type of Transportation | Passenger train |
| Type of occurrence | Other |
| Rolling Stock | Multippel Unit (MU) |
| Operator | Vy AS |