Development of the commissioning permit procedure for individual machines of the type in use

At the time the incident occurred, the brake system of the maintenance machine was worn and poorly adjusted. This was the case despite a Finnish Transport Safety Agency (Trafi) traffic worthiness and safety inspection that had been conducted on the machine before it was taken into use. At the request of Trafi, extensive tests and measurements were performed on the machine, analysing the characteristics of the machine type, despite the fact that the machine type has been used in Finland for over 20 years. The purpose of these tests remains unclear, as the visibly poor condition of the individual machine was not detected. One factor could have been the missing of the machine's maintenance documentation. The role of the party that conducted these inspections was unclear in the investigated incident, as the company also participated in the refurbishment of the machine.

The Finnish Transport Safety Agency should specify in more detail the checks required during a traffic worthiness inspection as well as the qualification and independence criteria for the party conducting the inspection.

In addition to the general safety regulations, the traffic worthiness inspection must be based on the requirements specified by the machine manufacturer; for this reason, the first step of the inspection should always be a check of the maintenance documentation. Based on this documentation, it can be checked whether the condition of the machine meets the requirements for safe use specified by its manufacturer. For example, the monitoring of the regular maintenance of safety-critical brake components is impossible without up-to-date documentation.

At the time the incident occurred, the brake system of the maintenance machine was worn and poorly adjusted. This was the case despite a Finnish Transport Safety Agency (Trafi) traffic worthiness and safety inspection that had been conducted on the machine before it was taken into use. At the request of Trafi, extensive tests and measurements were performed on the machine, analysing the characteristics of the machine type, despite the fact that the machine type has been used in Finland for over 20 years. The purpose of these tests remains unclear, as the visibly poor condition of the individual machine was not detected. One factor could have been the missing of the machine's maintenance documentation. The role of the party that conducted these inspections was unclear in the investigated incident, as the company also participated in the refurbishment of the machine.