The resilient journey of the British Rail Class 175 diesel multiple-unit train fleet

Countries & Cities · Published 10 October 2026 Swipe more like this →

In short: Built by Alstom between 1999 and 2001, the Class 175 fleet has navigated a turbulent quarter-century of service. From early reliability struggles and high-profile safety incidents to a recent second life with Great Western Railway, these diesel-hydraulic units remain a complex case study in British rail operations and maintenance.

The Class 175 Coradia was developed by Alstom as part of their Coradia 1000 platform, with an initial order of 27 units placed by North Western Trains in 1997. Designed with a focus on ride smoothness and aerodynamic efficiency, the fleet featured innovations like floating floors and acoustic ceiling panels to minimize noise. Despite these advancements, the units faced significant reliability hurdles upon entering service in June 2000. Early operations were frequently disrupted, necessitating remedial work on brakes and bogies to stabilize performance.

Throughout its lifespan, the fleet has been managed by various operators, including First North Western, Arriva Trains Wales, and Transport for Wales Rail. The trains underwent a comprehensive refurbishment starting in 2019 at Alstom’s Widnes facility, which introduced modern amenities like USB sockets and updated interiors. However, the fleet’s history is marked by recurring safety challenges, including multiple fires attributed to debris accumulation in under-floor engine bays and several collisions at level crossings. These incidents often led to temporary fleet-wide withdrawals for safety inspections and cleaning programs.

Following their withdrawal by Transport for Wales Rail in 2023, the Class 175s were leased by Great Western Railway, entering service in late 2025. Their reintroduction to the network, particularly on routes in Devon and Cornwall, was again met with reliability issues during the summer of 2026. This prompted GWR to implement a rigorous testing program, requiring each unit to complete 1,000 miles of fault-free simulated operation before returning to revenue service. This ongoing saga highlights the persistent difficulties in maintaining older diesel-hydraulic rolling stock within a modern, high-demand rail network.

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