Finland introduces new interlocking
A new interlocking device is in use in Kerava in the south of Finland from 21 June 2021. It is one of the largest deployments of the railway safety equipment system in Finland, and is necessary for additional tracks that will be constructed later. The Finnish Transport Infrastructure Agency commissions the interlocking, for which track closure is necessary, over the summer.
The renewal of the Kerava interlocking device is part of the Helsinki – Riihimäki capacity increase project. At current traffic volumes, the capacity of the line has remained insufficient and traffic on the line section is occasionally sensitive to interference. The new interlocking device is a prerequisite for the implementation of the additional tracks included in the next phases of the project. When completed, these will allow an increase in train services.
The works have a large impact on rail traffic in the summer. “The implementation requires that the track closes”, says project manager Riitta Parviainen of the Finnish Transport Infrastructure Agency (FTIA). “Despite careful planning, unexpected effects on train traffic, such as delays, are possible because the commissioning will take place on a very busy and already disturbance-sensitive section of the line”. Changes in train traffic will continue until 29 August.
What the system does
The interlocking device is a system that ensures the safety of rail traffic. The traffic controller sets the route for the train, and the interlocking device ensures that the switches are in a safe position and that the tracks are free so that the train can run safely, among other things.
During the commissioning phase, safety components, such as signals, switches and crossings, are connected to the new system and the necessary inspections and tests are carried out before handing over to traffic. The functionality of the interlocking devices in use is not fully compatible with current requirements.
Capacity increase project
The line Helsinki – Riihimäki is the busiest section of track in Finland in terms of train numbers, used by commuter traffic from Helsinki to Riihimäki and Lahti, long-distance traffic to Tampere and the Lahti straight line, and freight traffic from Pasila, Vuosaari, Sköldvik and Hanko to the main line.
The project to increase capacity on the line will be implemented in three phases, the first of which runs from 2016 until 2022, which the interlocking is part of. The operational reliability of the line section will be improved, and the aim is to improve the line section’s transmission capacity and interference tolerance.
The construction of the second phase, which will start in early 2022, includes additional tracks between Kerava and Jokela. For the third phase, the track design is underway. When the entire project is finished, the line section between Kerava and Riihimäki will be four-track.