Report on railway accident at Arna station on 22 March 2024

The train driver sustained minor injuries. The accident resulted in extensive material damage. The locomotive was a total write-off, and three wagons were condemned, totaling an estimated 52 million NOK in vehicle damage. Infrastructure rebuilding costs were estimated at 27.8 million NOK.

The direct cause of the accident was that the train departed from the Bergen terminal with severely reduced braking power, making it impossible for the train to stop at Arna station where it was scheduled to cross a passenger train. The investigation established several contributing factors that allowed the accident to occur.

The main brake pipe cranes between the locomotive and the first wagon were closed during troubleshooting for a non-safety-critical error on the TDD-monitor in the cab. This was done to perform a shutdown and restart of the locomotive without emptying the main brake pipe. The troubleshooting was neither planned nor followed a set routine, and the dispatcher contacted the train to investigate whether the departure could be expedited. This occurred while the driver was troubleshooting. Neither the train driver nor the terminal worker remembered to open the cranes before departure, and consequently, no check that the main brake pipe was open was performed. As a result, the driver only had functional brakes on the locomotive, but not on the wagons.

The train driver performed a test brake while running in the Ulriken tunnel, as required. However, this test was performed while the train was on an ascent, and the driver perceived the braking effect as normal, failing to detect the train's severely reduced braking capacity.

OnRail AS had not risk assessed the Traxx F160 AC3 (BR187) locomotive type before use, nor did the company have a written procedure for error correction that required closing the main brake pipe cranes. The high frequency of faults on the TDD-monitor created the operational necessity for the troubleshooting procedure that resulted in the closed cranes.

The investigation identified that a similar dangerous situation could arise because the BR187 locomotive requires the ETCS-brake test to be conducted without connected wagons, or by closing the main brake pipe cranes to the wagons. This is a condition of use set out in the manufacturer's "Red Book" and is different from other known locomotive types. This condition transfers a residual risk to the end user.

The track equipment and interlocking system at Arna station functioned as intended. The diverting switch led train 5924 away from the main track, which prevented further travel into the tunnel. Norwegian and European infrastructure is not designed to handle trains operating with such severely reduced braking effect relative to their speed.

The situation after the accident was confusing, with several misunderstandings between the Bergen traffic control center and the emergency services. Notably, the emergency services were not made aware that passenger train 601 (with approximately 170 people on board) was stationary inside the Arnanipa tunnel until about an hour after the accident.

Bane NOR stated that it generally prefers to recover the train, keeping passengers safely inside, rather than conducting an on-foot evacuation along the track. The recovery process for train 601 was delayed by several factors, including police requirements for slow speed into the tunnel,
difficulties releasing the train's brakes, and logistical challenges with bus transportation, resulting in passengers being stuck for over five hours.

The Norwegian Safety Investigation Authority makes three safety recommendations following the accident. Two of the safety recommendations concern the use of the locomotive type BR187, in general, and in OnRail AS. One safety recommendation concerning exercises between Bane NOR SF and the emergency services.

The report also highlights three learning points related to risk assessment of new vehicles, use of emergency calls and the operational barrier test brake while running.

Drone picture. Photo: NSIA


Inside the tunnel. Photo: NSIA


Outside the tunnel. Photo: NSIA

Published 14.10.2025