Elizabeth line (Crossrail project) - Class 345 Aventra Fleet
UK (London) · 2015–2019 (initial construction), 2017 (first service), 2022 (Elizabeth line opening), 2026 (additional units delivery) · Over £1 billion (initial 70 units); £370 million (additional 10 units, 2024 prices)
The judgement call
Account-gated at launchThe procurement process was subject to political scrutiny regarding domestic manufacturing, influencing future large-scale rail projects. - Delays in the tender process were strategically implemented to align with infrastructure completion, highlighting the importance of integrated project planning. - Innovative financing through a sale-and-leaseback deal was used to fund other critical transport projects. - Higher-than-anticipated passenger growth necessitated an order for additional units, underscoring challenges in long-term demand forecasting.
Key engineering challenges
Designing trains compatible with platform screen doors in the central tunnel section. - Achieving high energy efficiency targets (14 kWh per train-km achieved). - Integration of advanced signalling and communication systems (ETCS Level 3). - Meeting the high capacity and frequency demands of a major urban railway.
Project facts
- Client / owner
- Transport for London (TfL); 345 Rail Leasing; GTS Rail Operations
- Lead contractor
- Bombardier Transportation (initial); Alstom (additional units)
- Lead designers
- Bombardier Transportation (Aventra)
- Project type
- vehicle/fleet programme
- Scale
- 70 x 9-car units (initial); 10 x 9-car units (additional); Total 80 x 9-car units; 1,500 passengers per train; Train length: 204.73 m; Max speed: 90 mph (145 km/h); Energy efficiency: 14 kWh per train-km
- Disciplines
- Mechanical; Electrical; Systems; Software; Civil (depot)
- Standards & frameworks
- Rail Technical Strategy (RTS); European Train Control System (ETCS) Level 3
Sources: British Rail Class 345 - Wikipedia (https://en.wikipedia.org/wiki/British_Rail_Class_345) - Alstom: First of Alstom’s ten new Elizabeth line Aventra trains rolls off production line in Derby, UK (https://www.alstom.com/press-releases-news/2026/6/first-alstoms-ten-new-elizabeth-line-aventra-trains-rolls-production-line-derby-uk) - IMechE: 5 engineering innovations on the journey to the Elizabeth line opening (https://www.imeche.org/news/news-article/5-engineering-innovations-on-the-journey-to-the-elizabeth-line-opening)