26. marrask. 2024
Safety Investigation Authority (Onnettomuustutkintakeskus OTKES) published its investigation report on the freight train derailment accident that happened one year ago on 22 November 2024. In the accident, Fenniarail's freight train derailed at the switch at the northern end of the Tampere yard at low speed. The locomotive and the bogie of the first wagon derailed. Fenniarail agrees with the conclusions of the OTKES investigation report and will implement the relevant recommendations. However, the statements made in the media related to the publication of the investigation report should be corrected.
In some media stories about the publication of the investigation report, attention was paid to the six-axle nature of the Fenniarail’s locomotive involved in the accident, or more precisely, the three-axle bogie of the six-axle locomotive. These stories talked about "risky locomotives", which is definitely a wrong interpretation. It is true that a 3-axle bogie causes greater horizontal forces in curves than a shorter 2-axle bogie. However, these horizontal forces can never by themselves cause accidents. As stated in the OTKES investigation report, the switch at the accident site was in very poor condition and there were deficiencies in the monitoring and maintenance of its condition. The poor condition of the switch had also been noticed with 2-axle bogies; when they had passed over the switch, the locomotives had been swinging exceptionally much.
The University of Tampere measured the horizontal forces of Fenniarail and other 6-axle locomotives used in Finland in a curve situation in a study carried out for the Finnish Transport Infrastructure Agency in 2022. Based on the research, the horizontal forces of the Fenniarail locomotive fall below the limit values set by the EN standard. The study was carried out in a steep curve with a curve radius of less than 200 meters. The limit values of the standards are given for gentler curves with a radius of 250-400 meters. The horizontal forces of the Fenniarail locomotive therefore fell below the standard's limit values even in a curve steeper than the standard.
Six-axle locomotives are commonly used to haul freight trains around the world. 6-axle locomotives have been used in Finland for decades. Fenniarail's 6-axle locomotives have operated three million kilometers in Finland and are based on the world's largest locomotive series, which contains thousands of locomotives. Before the Tampere accident, 6-axle locomotives were never referred to as "risky locomotives". In this regard, the only change is the level of track maintenance. The Tampere accident needed a switch that was in a poor condition to happen.
In the news related to the publication of the investigation report, the "worn wheels" of the locomotive were also mentioned. According to the investigation report, the wheels of the locomotive were within the approved operating dimensions for all inspection dimensions of the S1002 profile used in Finland. According to the investigation report, Fenniarail had monitored the condition of the wheels of the locomotive involved in the accident in an enhanced manner. No negligence in maintenance was found. As in any rolling stock, wheels in rail stock are always worn out other than at the time of installation. The limit values determine when the wheel needs to be turned or replaced with a new one. These limit values were not exceeded. Even when the limit values are exceeded, there is still a tolerance within which there is no immediate danger.
Fenniarail sees it as critical that attention is not shifted away from the importance of track maintenance by labeling the 6-axle locomotives, that have been used in Finland for decades and are in general use worldwide, as "risky locomotives". When the track is in bad enough condition, any train can derail. In heavy transport serving Finnish industry, six-axle locomotives have played an important role and will continue to do so in the future.
Lauri Helke
Managing Director
Fenniarail Oy