Report on a runaway trailer on the Ekeberg Line in Oslo on 12 February 2024
Railway report 2025/01
On Monday 12 February 2024, a rail trailer ran away on the Ekeberg Line in Oslo. The incident occurred during construction work from the Ekebergparken stop in the direction of Oslo city center, on a part of the infrastructure with gradient up to 70 ‰. The trailer, which weighed about 7 tons with its load, rolled about 200 meters before it collided with an excavator that was placed in the track to stop the runaway. The construction work was carried out by private contractors. The infrastructure unit of Sporveien AS acted as the client and supplier to Sporveien Trikken AS. The Norwegian Safety Investigation Authority’s investigation has revealed inadequate internal control, safety management, and training by the contractor. The investigation also identified a need for Sporveien Trikken AS to strengthen its supplier management in accordance with current regulations, in order to be able to fulfil its responsibility as a client.
Causes and contributing factors
The direct cause of the trailer beginning to roll was that its braking force was insufficient to keep the loaded trailer stationary on the gradient of this track section. The trailer had previously passed a brake test carried out by Sporveien AS but had not yet been approved for use by Sporveien Trikken AS. Technical investigations after the incident indicate that the trailer most likely had an oil leak in its hydraulic braking system, which may have gradually deteriorated the braking effectiveness.
The NSIA’s safety investigation has identified several contributing factors to the incident:
- Risk assessments carried out in the project had not addressed the danger of rail-bound construction vehicles potentially rolling uncontrollably.
- No physical barriers had been established to mitigate the risk of runaway vehicles, as it was assumed that the vehicles to be used had sufficient braking force.
- There maintenance of the trailer was inadequate. The contractor who managed the trailer did not have established routines for operator-based control and maintenance.
- There was insufficient training in the use of the trailer, especially considering that it was to be used on a section with a steep gradient. The operator was newly hired and had not received type-specific training for the trailer.
- The contractor who used the trailer did not have established routines for vehicle inspection and maintenance, nor for training in its use.
- NSIA highligts in this report weaknesses in supplier management at Sporveien Trikken AS . Despite early indications that the work was not being performed in accordance with Sporveien Trikken's expectations , no compensatory measures were implemented. This includes, among other issues, the use of vehicles without the necessary use permit and inadequate HSE (Health, Safety, and Environment) routines among the contractors. NSIA also notes that the requirements for obtaining a operating permit for the vehicles on Sporveien Trikken’s infrastructure appeared unclear, and that the processing time for applications was long and unpredictable.
The incident could have had serious consequences
An employee of a subcontractor happened to stop the trailer with an excavator before it caused major damage. NSIA finds it concerning that no barriers had been established to prevent the trailer from rolling uncontrollably out of the construction area and into a street with mixed traffic, where it could have collided with pedestrians and other city traffic.
The NSIA has issued the report with the aim of improving railway safety, and It is not the NSIA’s task to apportion blame or liability under criminal or civil law. Based on the findings, NSIA has issued two safety recommendations to the Norwegian Railway Authority:
- NSIA recommends that the Norwegian Railway Authority ensure that Sporveien Trikken AS has systems for supplier management that comply with the provisions of the current legislation.
- NSIA recommends that the Norwegian Railway Authority ensure that Sporveien Trikken AS has systems that ensure that suppliers have the necessary resources and competence to ensure safety when working on or near the tracks.
Incident site. Photo: NSIA
Where the tracks meet Konow Street. Photo: NSIA
Safety recommendation
Safety recommendation Rail No. 2025/01T
On 12 February 2024, a rail-track trailer rolled uncontrolled in a construction area from the Ekebergparken stop down towards Oslo city centre. The trailer was on a steep gradient while being loaded with gravel. An undetected fault in the braking system meant that the weight of the trailer eventually exceeded the available braking power, causing it to start rolling. An excavator was driven onto the track to stop the runaway trailer. This prevented the trailer from derailing onto streets with mixed traffic.
The work was being carried out on behalf of Sporveien Trikken AS. Although it became clear at an early stage that Sporveien Trikken AS’ expectations of the work were not met, no measures were implemented to compensate for this.
The Norwegian Safety Investigation Authority recommends that the Norwegian Railway Authority ensure that Sporveien Trikken AS has supplier management systems that function in line with the provisions of the regulations.
Safety recommendation Rail No. 2025/02T
On 12 February 2024, a rail-track trailer rolled uncontrolled in a construction area from the Ekebergparken stop down towards Oslo city centre. The trailer was on a steep gradient while being loaded with gravel. An undetected fault in the braking system meant that the weight of the trailer eventually exceeded the available braking power, causing it to start rolling. An excavator was driven onto the track to stop the runaway trailer. This prevented the trailer from derailing onto streets with mixed traffic.
The work was being carried out on behalf of Sporveien Trikken AS. Although it became clear at an early stage that Sporveien Trikken AS’ expectations of the work were not met, no measures were implemented to compensate for this.
The Norwegian Safety Investigation Authority recommends that the Norwegian Railway Authority ensure that Sporveien Trikken AS has systems in place to ensure that suppliers have the necessary resources and expertise to ensure safe work on and around tracks.
Facts
| Location | Ekeberg line, Oslo |
| Occurrence date | 12.02.2024 |
| Type of Transportation | Tram |
| Type of occurrence | Runaway train, Collision |
| Rolling Stock | Arbeidsmaskin |