Report on tram derailment at the intersection between Nygata and Storgata in Oslo on 29 October 2024
Railway report 2025/02
The Norwegian Safety Investigation Authority (NSIA) has conducted a safety investigation and prepared a report on the derailment of an SL18 tram at the intersection between Nygata and Storgata in Oslo on 29 October 2024. The purpose of NSIA's investigation is to improve railway safety, not to apportion blame and liability. At around 11:04 on 29 October 2024, tram 414 derailed in the curve at the intersection between Nygata and Storgata in Oslo and crashed into a shop. The tram was on line 19 and suddenly increased its speed to 37 km/h at switch 17, far exceeding the switch's permitted limit of 15 km/h. The accident was caused by overspeeding at the switch. The overspeeding was caused by an acute illness in the driver that led to loss of consciousness. At the same time as the driver lost consciousness, the drive lever was placed in the full-thrust position, and the "deadman's grip" was released.
The driver experienced sudden and very severe abdominal pain and a strong urge to vomit immediately before the loss of consciousness, which was later proven to be due to Norovirus. Medical assessments concluded that the virus caused a strong activation of the vagus nerve, which led to a reduced heart rate, low blood pressure and fainting (vasovagal syncope). The condition occurred acutely, with no possibility of prevention.
The SL18 is equipped with a "dead man's system" that is supposed to stop the vehicle if the driver loses consciousness. The system worked as intended, but the sequence of events was very short (approximately 8 seconds from full application/release of the dead man's grip to the impact). The system takes 10 seconds to activate the brakes, which was too long in this case. The SL18 does not have anti-collision systems (CAS) or automatic speed monitoring (ATSM) installed. The NSIA's investigations have not identified issues regarding the maintenance of the tram or other technical or organizational issues that are considered relevant to the accident.
The driver and three passengers suffered minor injuries, while no one in the shop was injured. The tram was extensively damaged (estimated repair cost of up to 33 million NOK), and the shop was heavily damaged. The accident had less serious consequences than it could have had, as it could have affected more people at other times or places.
The NSIA does not make any safety recommendations following the accident, but highlights loss of consciousness as a result of Norovirus as a general learning point. The report emphasizes the importance of good hand and kitchen hygiene as preventive measures against Norovirus.
Tram 414 derailed in the intersection between Nygata and Storgata. Photo: NSIA
Tram 414 in the shop. Photo: NSIA
Tram 414 in the shop. Photo: NSIA
Published 12.08.2025
Facts
| Location | Intersection between Nygata and Storgata, Oslo |
| Occurrence date | 29.10.2024 |
| Type of Transportation | Tram |
| Type of occurrence | Derailment |