Class 710

Class 710
Name	Class 710
Service	2018–present
Manufacturer	Bombardier Transportation
Family	Aventra
Yearconstruction	2017–2019
Numberbuilt	54 units
Formation	4 cars per unit
Operator	Transport for London
Depot	Ilford Depot
Lines	Gospel Oak to Barking Line; Great Eastern Main Line; North London Line
Gauge	1,435 mm
Traction	IGBT-VVVF
Maxspeed	100 mph

Class 710

The Class 710 is a class of electric multiple units introduced in 2018 for suburban and inner-city services in and around London. Built by Bombardier Transportation as part of the Aventra platform, they were procured by Transport for London to replace older diesel and electric units on services managed by London Overground. The fleet entered passenger service after complex acceptance and testing with responsibility shared among Transport for London, Network Rail, and the Office of Rail and Road.

Overview

The procurement arose from a franchise and rolling-stock programme coordinated with Department for Transport policy and the Mayor of London's transport strategy. The Class 710 order was announced alongside other modernisation projects involving Siemens and Alstom vehicles, and was influenced by capacity studies undertaken by Transport for London and consultants from Arup and Mott MacDonald. Units were planned to operate on corridors including the Gospel Oak to Barking line, the North London Line, and suburban services radiating from Liverpool Street station and Stratford station.

Design and Technical Specifications

The Class 710 draws on the Aventra family design principles used in fleets for National Rail operators and regional projects. Each four-car unit employs aluminium bodywork and is equipped with regenerative braking compatible with National Grid electrification standards where available. Onboard systems include Automatic Train Protection-capable equipment interoperable with Thameslink signalling upgrades and cab features influenced by European Railway Agency specifications. Passenger amenities mirror contemporary standards seen on units serving Crossrail preparatory routes and include wide gangways similar to those in London Underground rolling stock.

Manufacturing and Delivery

Manufacture occurred at Bombardier's factories with final assembly and testing coordinated through sites tied to the UK rail supply chain, involving suppliers such as Siemens Mobility sub-contractors and component firms in Derby and Durham. Delivery schedules were governed by contractual milestones tied to Rail Delivery Group acceptance procedures, with driver training programmes run at Ilford depot and simulation sessions referencing signalling layouts at Willesden Junction and Willesden training areas. Certification involved the Rail Safety and Standards Board alongside Network Rail route acceptance teams.

Operations and Deployment

Upon introduction, units were deployed across London Overground routes, supplementing services at Gospel Oak and extending capacity on the North London Line. Timetabling adjustments coordinated with Greater Anglia and infrastructure works at Barking and Forest Gate enabled phased service increases. Crew rostering and depot maintenance were organized through Transport for London personnel policies and involved interactions with unions such as RMT and ASLEF during induction and industrial consultations.

Performance and Modifications

Real-world performance figures were evaluated against targets from the procurement contract and benchmarked with fleets like the Class 345 and Class 710 cousin designs from the Aventra family. Energy consumption, acceleration profiles, and passenger load metrics were monitored using data feeds integrated with systems developed by Siemens Financial Services and analytics teams inspired by projects at Imperial College London and University College London. Minor software updates and hardware retrofits addressed issues identified during early operations, coordinated with Bombardier engineering teams and overseen by Transport for London's engineering directorate.

Incidents and Reliability

Initial introduction saw punctuality and reliability scrutinised by Office of Rail and Road performance metrics and media coverage by outlets including BBC News and The Guardian. A series of technical teething problems prompted additional testing and depot rectification works, with incident reports filed to the Rail Accident Investigation Branch where applicable. Reliability improvements followed collaborative efforts between Bombardier, Network Rail route teams, and Transport for London maintenance staff.

Legacy and Impact

The Class 710 project influenced subsequent procurement and fleet modernisation decisions within Transport for London and the wider UK rail industry, informing debates in Parliament and studies by transport think tanks such as Centre for Cities and Institute for Government. Lessons from the introduction have been referenced in later contracts involving Alstom and Stadler and in policy documents produced by the Department for Transport and the Mayor of London's office. The units contributed to increased capacity on key London orbital and suburban corridors and shaped conversations around future electrification and rolling-stock strategy.

Category:Electric multiple units of Great Britain