Amey Launches ‘Tessera’ Digital Signalling System with Modular, Future-Ready Design

Amey has unveiled Tessera, the official brand for its digital signalling technology, highlighting its modular, future-proof architecture designed to integrate smoothly with both existing and next-generation railway signalling systems.

At the core of Tessera is the HiMatrix programmable logic controller (PLC) from Hima—technology already widely used across Europe and certified to Safety Integrity Level 4. Its compact size, low manufacturing cost, and minimal power requirements make it suitable for off-grid renewable power sources such as solar and wind.

By basing the platform on a commercial off-the-shelf PLC, Tessera offers a cost-efficient alternative to the proprietary signalling systems commonly used across the UK. Amey notes that the PLC can be programmed using standard languages, eliminating the need for specialist rail-specific training. It also features strong diagnostic tools to support fault-finding, condition monitoring, and early-warning alarms.

Amey collaborated with Hima’s UK business, Sella Controls, to produce a fully tested prototype and complete a safety case for use on the UK rail network. This means suppliers and contractors can now license the technology when bidding for signalling contracts on Network Rail infrastructure.

Tessera was first trialled at Magdalen Road level crossing on the Ely–King’s Lynn route. It has since been adopted for the Walnut Tree Depot in Taff’s Well, the operational hub for the Core Valley Lines and home to Transport for Wales’ Class 398 tram-train fleet, where it forms part of the site’s interlocking and signalling control system.

Peter Anderson, Managing Director of Transport Infrastructure at Amey, said:“The launch of Tessera marks a significant milestone in our mission to deliver safer, smarter and more sustainable rail networks. Tessera’s advanced digital signalling capabilities give our clients the tools to modernise with confidence, ensuring long-term reliability and efficiency.”

The system is built for a 25-year operational life and is fully backward-compatible with traditional signalling. Amey expects Tessera to offer major whole-life cost savings through reduced training requirements, fewer spare parts, lower fault rates and less network disruption compared with conventional systems.