What is a Tram Train?
A tram-train is a versatile public transport vehicle that acts as a bridge between a traditional tram and a heavy rail train. It combines the accessibility and frequency of a tram with the speed and range of a train, allowing a single vehicle to run on both street tramways and mainline railways.
How they work
- Dual voltage: Tram-trains can switch between 750V DC (used on tram networks) and 25kV AC (used on mainline railways), allowing seamless transitions between the two systems
- Wheel profile: The wheels are designed to handle both shallow street grooves found on tram tracks and the deeper flangeways on mainline rail
- Crashworthiness: Tram-trains are built sturdier than standard trams to meet the safety requirements for mixed running with freight trains and other heavy rail traffic
History and rollout in the UK
Tram-train technology has been successfully deployed across Europe, particularly in Germany where the Karlsruhe model pioneered the concept in the 1990s. The UK has been slower to adopt the technology, but progress is now being made.
The Sheffield–Rotherham pilot (2018)
- The UK's first tram-train pilot launched in October 2018, running between Sheffield city centre and Rotherham Parkgate
- The route uses the existing Supertram network through Sheffield, then transitions to Network Rail tracks via the Tinsley Chord — a purpose-built connecting link
- The pilot demonstrated that tram-trains can operate reliably on shared infrastructure in a UK context
South Wales Metro
- Transport for Wales is converting the Valleys lines north of Cardiff to tram-train operation as part of the South Wales Metro project
- The Core Valleys Lines are being electrified and new tram-train vehicles will replace aging diesel trains
- Services will run at much higher frequencies, transforming connectivity across the Valleys
Future prospects
There is growing interest in tram-train technology across the UK. Greater Manchester's Metrolink has explored tram-train extensions, and there have been proposals for a Glasgow airport link using tram-train vehicles. Edinburgh's South Suburban Railway is an ideal candidate for tram-train operation.
Tram train in Sheffield