Class 720 Aventra

Class 720 Aventra
Name	Class 720 Aventra
Manufacturer	Bombardier Transportation
Family	Aventra
Yearconstruction	2017–2022
Yearservice	2020
Numberbuilt	120
Formation	5, 10 cars
Operator	Greater Anglia
Depot	Crown Point Depot

Class 720 Aventra The Class 720 Aventra is a British electric multiple-unit built by Bombardier Transportation as part of the Aventra family for suburban and regional services in the United Kingdom. Ordered to replace older British Rail era units and to expand capacity on commuter routes, the type entered service amid debates involving Department for Transport, Transport for London, and multiple train operating companies. Design, procurement, and introduction intersected with procurement disputes, industrial policy discussions in Westminster, and technological trends exemplified by contemporaneous fleets such as the Class 345 and Class 710.

Design and Development

Bombardier developed the Aventra platform following commercial requirements set by Network Rail and franchising authorities including Abellio and the Greater Anglia franchise. The programme was influenced by prior Bombardier projects delivered to Transport for London and continental programmes for Deutsche Bahn and SNCF, reflecting European supply chains and standards from the European Union technical framework. Early design work referenced accessibility mandates from the Equality Act 2010 and environmental targets championed by the Committee on Climate Change, while certification processes engaged Rail Safety and Standards Board and Office of Rail and Road procedures. Industrial aspects involved negotiations with Unite the Union and supply contracts with component firms in Derby and Crewe.

Technical Specifications

The trains employ aluminium bodyshells and modular bogies drawing on Bombardier’s experience with the Electrostar and Voyager families, featuring regenerative braking and distributed traction motors supplied by international manufacturers contracted via Siemens-era supply chains. Traction control, onboard diagnostics and passenger information systems integrate software influenced by standards used on the Elizabeth line and test regimes overseen by Rail Safety and Standards Board. Units are built as five-car and ten-car formations with standard gauge chassis complying with Railway Group Standards and loading gauge constraints set by Network Rail. Safety systems incorporate European Train Control System principles alongside UK ATP legacy arrangements and compatibility tests coordinated with Train Operating Companies and Infrastructure Managers. Passenger amenities include air conditioning conforming to UK rolling stock regulations, CCTV meeting British Transport Police requirements, and seating layouts influenced by capacity studies commissioned by Greater Anglia and predecessor franchise holders.

Variants and Fleet Configuration

The fleet exists primarily in five-car sets that couple to form ten-car services; specific configuration choices were guided by timetable modelling performed for peak services into Liverpool Street station and inter-urban services towards Ipswich and Norwich. Interior variants reflect route-specific requirements similar to distinctions seen between units supplied to South Western Railway and MTR Corporation subsidiaries, with options for first-class conversions, bicycle storage, and PRM-compliant doorways per guidance from Department for Transport rolling stock accessibility policies. Depot stabling patterns and unit numbering follow conventions used across fleets such as the Class 700 and Class 378, with operational diagrams coordinated with Greater Anglia planning teams.

Delivery, Entry into Service, and Operators

Delivery schedules were set out in contracts awarded to Bombardier and later overseen post-merger by Alstom compliance teams; entry into passenger service required approvals from Office of Rail and Road and final acceptance tests on lines managed by Network Rail Eastern region. The primary operator, Greater Anglia, introduced the units on suburban and regional routes from 2020, replacing older Class 321 and Class 360 sets on inner and outer suburban diagrams. Rollout timing affected franchise performance metrics overseen by Transport for London advisers and impacted service patterns at hub stations including Stratford and Southend Victoria. Secondary operational interactions involved depot staff seconded from contractors with prior experience on Bombardier Electrostar fleets.

Performance and Incidents

Operational performance metrics—punctuality, reliability and mean distance between failures—were reported against benchmarks set by Office of Rail and Road and compared with contemporaries like the Class 345 and Class 707. Early service introduction encountered software integration issues paralleling those experienced on other modern fleets, prompting coordination between Bombardier engineering teams, Network Rail signalling engineers, and the Rail Accident Investigation Branch when technical incidents required formal review. Service disruptions and fault rectifications were managed through collaboration with unions such as ASLEF and RMT, and with suppliers in Derby and York delivering modifications under warranty programmes.

Maintenance and Depot Facilities

Maintenance responsibilities center on Crown Point Depot in Norwich and out-station facilities at Ilford and Clacton-on-Sea, with heavy overhaul cycles scheduled in accordance with asset management plans approved by Greater Anglia and overseen by Rail Safety and Standards Board auditors. Depot upgrades included changes to lifting equipment, staff training accredited by City & Guilds standards, and inventory logistics coordinated with national supply chains including component sourcing from firms formerly partnered with Bombardier Transportation and now integrated with Alstom operations. Lifecycle maintenance strategies reference frameworks used by Network Rail and major rolling stock maintainers on similar fleets to optimise availability and capital expenditure.

Category:Bombardier multiple units