Interlocking systems

Enabling safe rail operations in the UK

Interlockings ensure any train movements are safe. They check that track sections are clear, and set routes following command from control centre, if it is safe to do so, and provide movement authorities via lineside signals. With the Trackguard portfolio, Siemens Mobility supplies modern, compliant interlocking solutions for all needs.  

Interlocking systems for mainline railways: solutions for any application, anywhere

The Trackguard product family contains interlocking solutions which have been used in rail networks across the world.  Common hardware components as well as joint research and development benefit all solutions in terms of cost savings and technological advances.

Siemens Mobility Limited manufactures, configures and deploys two interlocking products:  

  • Trackguard WESTLOCK, successor to Solid State Interlocking (SSI)
  • Trackguard WESTRACE MKII

Westrace Trackside System

Trackguard WTS (Westrace Trackside System) is Siemens Mobility’s high performance, high availability trackside signalling system for main line railways. WTS is hosted on the proven, flexible and highly reliable Trackguard Westrace MKII platform, which has been successfully deployed by Siemens Mobility on metro and main line rail infrastructure projects around the world since its introduction in 2010.


Benefits include reduced equipment quantities and lower whole life cost, full compatibility with existing interlocking systems, improved reliability and faster processing which allows for a faster response.


WESTLOCK interlocking will control both legacy SSI trackside datalinks and Trackguard WTS equipment.



Proven technology


Increase alue sustainably over the entire lifecycle - with Siemens Mobility solutions and products for the digitalisation of mainline and regional railways.

Global interlocking solutions

For information on our global level crossing solutions, please visit our global website.

Would you like to know more about our global solutions?

Visit our global site