Stadler CITYLINK tram-train for South Wales Metro – Image ©Transport for Wales
The West of England Mayoral Combined Authority is currently considering its options for Bristol’s long-awaited Mass Transit system. Various choices are being discussed. Could tram-trains be the solution?
Mass transit corridors
The Joint Local Transport Plan (JLTP4), published in 2020, identified four mass transit corridors radiating from Bristol City Centre: The North and East Fringes, Bristol Airport, and Bristol to Bath.
JLTP4 recognised that it would be difficult to find space above ground for some of these routes. It proposed that underground running may be necessary in some cases. This has become a very contentious issue, with senior local politicians clearly at odds over whether this could ever be delivered. The recent Future4West report appears to suggest a very low benefit:cost ratio for tunnelled sections.
The Combined Authority’s studies continue to be ‘mode-agnostic’, and estimate that a ‘rubber wheeled’ solution would be about 20% less expensive than light rail. But we should be under no illusions about what a rubber-wheeled solution means. At best it would be a gadgetbahn, using incompatible, unusual or untried technology. At worst it would be a bus. Either way it will emit rubber particulates.
Extending MetroBus may be a useful way to tide us over until a light rail system can be delivered, but it cannot be transformative. It should only be seen as a stopgap.
Can we really deliver a light rail mass transit system?
Since the 1970’s Bristol has recognised the need for light rail mass transit. But it has failed to deliver it. Local politics have certainly got in the way, but other problems such as Bristol’s geography and narrow arterial roads have also made it hard to find a viable solution.
So is there a way forward? We think so.
A tram-train is a vehicle which runs on the existing rail network alongside main line passenger and freight services, but can also run on the street. Unlike conventional trains, they can go round tight corners and up steep hills. This means suburban rail services can be extended at a lower cost.
Battery-electric tram trains will soon be introduced in Cardiff, following successful implementation in other cities. Initially they will run on the existing rail network, but later street running will be introduced so that they can serve the Cardiff Bay area.
Build on what we already have
Tram-trains could allow us to build on the success of MetroWest rail services. We believe that a mass transit system which can be extended incrementally, using known technology, is much more likely to be deliverable than one which relies on novel or untested systems.
Start at Temple Meads
A tram-train system could serve Bristol Temple Meads Station directly. The topology of Temple Meads makes it very difficult to access using road-based transport. Vehicles either stop on Temple Gate, a minimum 250m walk from the platforms, or potentially take a 300m detour into Friary – still leaving passengers 200m from the platforms.
Tram-trains could connect to the existing rail network at Bristol Temple Meads Station adjacent to Platform 1, giving direct interchange with other train services. The JLTP4 routes to Bath and Bristol Airport could connect the existing rail lines at Avonmeads, using a disused railway route as far as Callington Road. Other JLTP4 routes could also make some use of existing rail corridors.
Ditch the diesels
New tram-trains could replace the unsuited and dirty diesel trains currently used for MetroWest services. This could act as a catalyst for electrifying these services, and could be done ahead of the JLTP4 routes.
These vehicles use tried and tested zero-emission propulsion. And their batteries allow tram-trains to operate in areas where providing overhead wiring is difficult.
Experience elsewhere suggests that once a tram system is built and seen to work, it becomes easier to make a case for extending it. We CAN do this!
Thanks to Mott McDonald, whose report Tram Train Principles and Guidance provided much of the background information for this post. We also thank Transport for Wales for additional practical information. We hope to visit Cardiff shortly to see these vehicles in action. Perhaps it would be useful for West of England decision-makers to do so too!