London's St Pancras Station is finally breathing cleaner air, but the journey to a diesel-free future is far from over. Once a smoke-filled, grimy hub, St Pancras, alongside King's Cross, has undergone a stunning transformation into a gleaming, modern transport center. But a lingering cloud of diesel fumes still hangs over one corner of the station – a reminder of a bygone era. That's about to change, though. East Midlands Railway (EMR), serving cities like Derby and Sheffield, will silence its diesel engines in London by the end of 2026, marking a significant milestone in the fight for cleaner air.
This shift is long overdue, and the road hasn't been without its bumps. The arrival of EMR's sleek new Aurora trains, built by Hitachi, is years behind schedule. Adding to the delay, plans to fully electrify the Midland Main Line, their designated route, have been scaled back.
But here's where it gets controversial: while rail travel is undeniably greener than most other forms of transport, it's not without its environmental footprint. While 70% of Britain's trains are electric, only 39% of the rail network is electrified, leaving a significant portion reliant on diesel. This disparity raises questions about the pace and scope of the government's commitment to a truly sustainable rail system.
And this is the part most people miss: even with electrification, the benefits aren't always clear-cut. Bi-mode trains, like the Aurora, switch from electricity to diesel mid-journey. While they reduce emissions significantly on electrified sections, the overall environmental impact depends on the length of the diesel-powered portion.
The cost of electrification is a major hurdle. The Great Western Main Line project, for instance, faced massive delays and budget overruns, leaving policymakers wary of similar ventures. This hesitation was evident in the decision to halt Midland Main Line electrification south of Leicester, a move that sparked disappointment and frustration.
Despite these challenges, progress is being made. Electrification continues on routes like the TransPennine east of Manchester and the South Wales Metro. However, cities like Leicester and Derby, soon to be home to Great British Railways, will still see brand new trains running on diesel in their city centers, a stark contrast to their electric journeys from London.
The health risks associated with diesel emissions, highlighted by the 'dieselgate' scandal and London's Ulez scheme, are undeniable. Research shows that NOx exposure on some trains can even exceed levels found on busy roads, posing a threat to both passengers and station staff.
Is the current pace of electrification fast enough to address these health concerns? Should the government prioritize cost-effectiveness over a more comprehensive and immediate shift to electric trains?
London's main line stations are gradually phasing out diesel, with Euston and King's Cross leading the way. However, Marylebone station remains a notable exception, where the cost of full electrification is deemed prohibitive due to aging infrastructure.
Innovative solutions are emerging, though. Battery-hybrid trains and partial electrification, as seen in South Wales, offer a promising alternative for challenging routes. Network Rail's exploration of fast-charge technology, demonstrated by GWR's record-breaking 200-mile single charge, showcases the potential for a more flexible and sustainable future.
Chiltern Railways, facing similar challenges, is introducing more efficient diesel trains and incorporating hydrotreated vegetable oil into their fuel mix, reducing emissions. While not a perfect solution, it's a step in the right direction.
The Department for Transport is working on an updated electrification plan and a new rolling stock strategy, with the ambitious goal of phasing out all diesel trains by 2040 under review. Will this target be met, or will financial constraints and logistical challenges push it further into the future?
The arrival of new trains, like EMR's Aurora and Chiltern's Mark V fleet, promises a more comfortable and environmentally friendly travel experience. But the journey towards a truly sustainable rail network requires continued investment, innovation, and a commitment to prioritizing public health and environmental well-being over short-term cost considerations. The question remains: are we moving fast enough?
