Inspection and maintenance procedures for the heel of the switch

The switch where the derailment occurred had been worn down to its critical operational and maintenance threshold. Due to its location, the wear on the switch was uneven, which resulted in an abnormal wear profile and thus increased the risk of derailment. Despite wear, no repair plan was drawn up for the switch and was not required by the client.
Maintenance does not systematically utilise measuring instruments, such as gauges, to monitor wear. Wear control is mainly based on a visual assessment, which depends on the individual's level of competence and experience. In addition, the current technical guidelines on railways (RATO) prepared to support maintenance work contain inconsistent instructions between different sections and cannot be considered easily accessible. The above factors impair the quality of maintenance.

The Finnish Transport Infrastructure Agency must ensure the uniformity of the guidelines and improve their accessibility, unambiguously define the method of measuring the maintenance needs of the heel of the switch, and specify accurate wear profiles for the heels of the switch.

As inspection methods develop, it is important to ensure the competence of persons carrying out maintenance by developing training and instructions.

The Finnish Transport Infrastructure Agency (FTIA) is in the process of combining the engineering guidelines for turnouts stage by stage. The work on guidelines is continuous, and the up-to-date guidelines are available via FTIA’s list of guidelines. The new list of FTIA’s guidelines introduced in May 2025 makes the guidelines easier to find. The first part of the study related to the use of a measuring gauge has been completed. It revealed the acute limits of the most important part of the turnout, the tip section of the switch blade. Instructions on how to use the measuring gauge will be added to the engineering guidelines for turnouts (Rato 14). The guideline will be piloted in summer 2026. Based on the experience gained from trial runs, the necessary clarifications will be made to the guideline, after which the final version will be published approximately in spring 2027. Further research on switch blades with Research Centre Terra has been launched in 2026. It will also ensure the acute limits of the base part of the switch blade and the optimal form of the switch blade. The Finnish Transport Infrastructure Agency’s superstructure training is currently being reformed, and the measuring issue related to switch blades has been added to the training section on measuring.