A new type of technology is being tested on the Tonbridge to Hastings railway line to help keep trains running in hotter weather, and more reliable journeys for passengers and freight customers.
South Eastern Railway has partnered with UK green tech start up Flint Engineering to tackle excessive heat in railway signalling cabinets that can exceed 70°C, with a new patented system that requires no power, maintenance, or internal cabinet modifications, and can be installed in under an hour.
Flint’s IsoMat technology provides peak temperature reductions of over 21% on the hottest days, transferring thermal energy thousands of times more efficiently than copper or aluminium alone.
The partnership will see the deployment of Flint’s IsoMat technology on 10 of the Kent route’s highest risk cabinet locations this summer, strengthening resilience against increasingly frequent hot weather events. Flint Engineering’s collaboration with South Eastern Railway will combat the growing challenge of heat-related failures in critical railway signalling infrastructure.
Network Rail, which owns and manages 20,000 miles of track, 30,000 bridges, tunnels, and viadaucts and thousands of signal crossing, has been struggling with a significant operational challenge: excessive internal temperatures in signalling cabinets during hot weather, which can exceed 70°C. This can subsequently lead to system failures, resulting in train delays, service disruptions, and substantial maintenance costs.
Following a successful pilot trial, Flint is now preparing to deliver an increased number of IsoMat units for deployment across more of the route’s highest-risk cabinet locations in time for summer 2026.
Working closely with Network Rail’s Technical Authority and Contracts & Procurement department, this trial forms part of a wider exploration of sustainable solutions to combat the impacts of climate change, such as passive technologies, with future large-scale deployments subject to Network Rail’s standard procureemnt and evaluation processes.
“As extreme weather events become more common, we need innovative solutions to protect our infrastructure, and most importantly keep our passengers and freight customers on the move,” said David Davidson, COO, South Eastern Railway. “Flint’s IsoMat technology provides a simple, effective solution to a complex problem, helping us maintain service reliability even during heatwaves without requiring power, maintenance or complicated installation procedures.”
“Our partnership with Network Rail represents a perfect application of our technology where it can make a real difference to critical infrastructure,” added Mark Robinson, CEO of Flint Engineering. “The IsoMat demonstrates how innovative engineering can address climate resilience challenges while delivering significant operational benefits. This collaboration highlights exactly the kind of practical applications we envisioned when developing this breakthrough technology.”
The IsoMat system offers ease of installation as it requires only two people in an under an hour to fit with no modification to the cabinet itself. It also has no moving parts and zero maintenance requirements.
This partnership comes as Flint Engineering begins commercial production of IsoMat this year, with interest already emerging from the UK, North American, and Middle Eastern markets. The technology has applications across construction, and commercial refrigeration and electrificiation.
IsoMat is a patented passive heat exchanger that mounts to cabinet roofs without requiring power, maintenance, or internal modification. It reinvents traditional heat pipe technology through a flat aluminium sheet design featuring an internal network of sealed channels.
When exposed to extreme temperatures, the liquid within these challenges undergoes a rapid cycle of evaporation and condensation, resulting in near-instantaneous heat transfer.
