Report on fire in the signalling system at Sandefjord Station on 27 July 2021
Railway report 2023/03
On Tuesday 27 July 2021 a short circuit occurred and a fire broke out in the overhead contact line system at Sandefjord station. The fault was probably caused by a bird creating a connection between the bridging feeder and earth in the system. The protective devices intended to detect such faults and ensure that breakers disconnected the power supply did not work as intended. This caused the bridging feeder to burn through and fall to the ground. It was not until 9 minutes and 40 seconds later that the power supply was manually disconnected by Bane NOR SF’s electrical power operator monitoring the system. During the intervening period, the current found its way into several low-voltage systems and parts of the signalling system. A fire occurred in a technical room at Sandefjord station, and extensive damage was done to the railway infrastructure over a large geographical area. In addition to the extensive disruption of train traffic on the Vestfoldbanen line, the incident caused direct damage estimated to approx. NOK 90 million.
It is not uncommon for overhead contact system to be affected by external factors, for example birds or vegetation that come into contact with live parts of the system. Protective devices are therefore installed in the system to ensure that the power supply is disconnected until the problem has been remedied. They did not work as intended in connection with this accident.
The NSIA’s investigation has identified a number of contributing factors to the accident and its consequences. Shortage of resources and Bane NOR SF’s complex organisation contributed to faults in the system not being detected. This also meant that decisions about measures in the system were made without sufficient basis or risk assessments. As a result, further weaknesses were unintentionally introduced into the system. The investigation has also shown that several other measures proposed internally in Bane NOR SF following similar incidents in the past had not been decided or implemented. The NSIA therefore submits a safety recommendation addressed to Bane NOR SF in which Bane NOR SF is requested to consider the organisation of the discipline area tasked with planning, developing and operating the power supply system to reduce the risk of undesirable incidents.
The laws and regulations that regulate railway, light rail, subway and tram power supplies are the responsibility of the Ministry of Justice and Public Security and the Ministry of Transport through the Directorate for Civil Protection and Emergency Planning and the Norwegian Railway Authority, respectively. In order to keep power supply systems safe and secure, they are subject to requirements and provisions both at a very detailed technical level and at a more general level as regards, e.g., safety management. The NSIA’s investigation has shown that the differences between the two supervisory bodies in terms of regulatory framework, supervisory practices, resources available for supervisory activities and risk assessments, may have contributed to insufficient supervision of the objects they where charged with supervising. The NSIA therefore submits a safety recommendation on clarifying how the supervision of railway, light rail, subway and tram power supplies is to be attended to when responsibility for the regulatory framework is shared between two official bodies.
The investigation has not identified any single cause or action that allowed the short-circuit to have such extensive consequences. What the safety investigation did show, however, was that, over time, circumstances have arisen in the system that made it vulnerable in the event of such faults. As neither the established quality and safety work nor the supervisory authorities identified these circumstances, the system remained vulnerable.
Visible fire outdoors while the short circuit is active. Photo: Hans Morten Tamnes
Visible fire outdoors while the short circuit is active. Photo: Hans Morten Tamnes
Published 25.05.2023
Safety recommendation
Safety recommendation Rail no 2023/02T
On Tuesday 27 July 2021, a short circuit occurred in the overhead contact line system at Sandefjord station. This created a connection between the high-voltage and low-voltage systems that caused extensive fire damage to the systems and disrupted train traffic for a long time. The design, operation and maintenance of power supply systems are regulated by a number of laws and regulations that fall within two different supervisory bodies’ areas of responsibility. The interface between the Directorate for Civil Protection and Emergency Planning and the Norwegian Railway Authority needs clarification.
The Norwegian Safety Investigation Authority recommends that the Ministry of Transport clarify how supervision of power supply systems in railway infrastructure is to be attended to when responsibility for the regulatory framework is shared between two official bodies.
Safety recommendation Rail no 2023/03T
On Tuesday 27 July 2021, a short circuit occurred in the overhead contact line system at Sandefjord station. This created a connection between the high-voltage and low-voltage systems that caused extensive fire damage to the systems and disrupted train traffic for a long time. The design, operation and maintenance of power supply systems are regulated by a number of laws and regulations that fall within two different supervisory bodies’ areas of responsibility. The interface between the Directorate for Civil Protection and Emergency Planning and the Norwegian Railway Authority needs clarification.
The Norwegian Safety Investigation Authority recommends that the Ministry of Justice and Public Security clarify how supervision of power supply systems in railway infrastructure is to be attended to when responsibility for the regulatory framework is shared between two official bodies.
Safety recommendation Rail no 2023/04T
On Tuesday 27 July 2021, a short circuit occurred in the overhead contact line system at Sandefjord station. This created a connection with the low-voltage system that caused extensive fire damage and disrupted train traffic for a long time. The cause was related to the fact that, for various reasons, protective devices in the system did not work as intended. Bane NOR’s organisation of the planning, development and operation of the power supply system is complex, with multiple interfaces related to responsibilities and personnel.
The Norwegian Safety Investigation Authority recommends that Bane NOR SF consider whether the organisation can be changed to reduce the risk of undesirable incidents.
Facts
| Location | Sandefjord Station |
| Occurrence date | 27.07.2021 |
| Type of occurrence | Fire and smoke development, Infrastructure events |
| Operator | Bane NOR SF |