RETB is operating around the clock in some of the UK’s harshest environments
The Comms Design RETB Next Generation digital in-cab signalling system delivers safe and efficient train control across major rural routes on the UK rail network.
The iconic West Highland and Far North Lines in Scotland are signalled using the RETB Next Generation digital signalling system – a flexible, cost effective in-cab signalling system based on a SIL level 4 interlocking provided by our partners Park Signalling.
The Comms Design RETB Next Generation system delivers safe and efficient train control across major rural routes on the UK rail network.
In 2013 Comms Design were selected by Network Rail to design and deliver a new RETB system for the North and West of Scotland. Additionally, as experts in RF systems, we planned the full radio network to ensure high quality radio coverage throughout the route.
RETB equipment operates reliably in the toughest conditions in the UK. The RETB base station at White Corries in Glencoe is the highest piece of infrastructure on the UK rail network.

Comms Design’s RETB system controls long routes in the far North and West of Scotland.

Comms Design planned and simulated radio site locations to optimise coverage.
RETB lowers driver & signaller workload and adds remote management and diagnostic tools.
4 systems covering 700km of route in the North and West of Scotland
Low cost infrastructure: only 38 radio zones cover the entire route in Scotland
300+ train installations across 23 rolling stock types
Next generation full system renewal completed in 2016
Fully approved for UK rail, designed and delivered by Comms Design
Comms Design RETB in-cab signalling equipment is installed in a wide range of rolling stock types operating in the UK:
- Class 66 heavy freight loco
- Class 37 loco during RETB antenna installation
- Class 47 operated by West Coast Railways
- Class 73 light freight loco
- Class 57 loco operated by DRS
- Class 67 loco exiting an RETB single section
- Class 33 loco pulling a steam charter on the West Highland Line
- Class 20 goods locos
- Class 156 DMU
- Class 158 DMU
- Heritage K1 Class on the world-famous Glenfinnan viaduct
- Tampers and Grinders use RETB in-cab signalling
- Rail support vehicles operate on RETB lines
- Network Rail snowblower
- Rail maintenance vehicles
- Track Recording Unit fitted with RETB equipment