SWR's £1bn Arterio fleet ran four years late — 54 of 90 trains idle in sidings

The first of South Western Railway's £1bn Arterio fleet will not enter service until the end of 2023 — four years behind the December 2019 date the high-capacity trains were initially due to run on SWR's Reading and Windsor routes. Of the 90 Class 701 trains ordered from Alstom's Derby works, only 54 had been delivered, and only 42 of those were accepted as suitable. The delay was blamed on the pandemic and software issues.

The drivers' union ASLEF had earlier reported problems with door obstacle detectors, the coupling process, faulty windscreen wipers and cab doors that were difficult to open. Yet mechanically similar trains were working effectively on the Elizabeth Line, London Overground and elsewhere — pointing the finger at project-specific software and integration rather than the basic design.

SWR's own figures underlined the hole: none of its 768 mainline drivers had started training on the new trains, with only 50 depot drivers on simulators. Gregg Evans of SWR conceded 'yes, it's late', citing Covid's impact on the supply chain, but said the company was 'increasingly confident' the trains would reach customers 'as soon as possible this year' — with the BBC understanding December 2023 at the earliest, on the Reading and Windsor lines first.

Four years late; 54 of 90 trains delivered, 42 accepted; the fleet sat in sidings at Long Marston, Eastleigh and Marchwood while 768 drivers awaited training.

Software acceptance became the bottleneck: hardware delivered but not accepted cannot carry passengers.

The same platform works on the Elizabeth Line and London Overground, pointing to project-specific integration failures rather than the design.

A four-year gap on a £1bn fleet left SWR running old stock while new trains sat stored at empty sidings.

Acceptance testing is the schedule: a train that cannot pass software acceptance is a cost parked in a siding, not an asset.

SWR planned to introduce the trains on the Reading and Windsor lines before extending across its suburban network in south west London; no committed entry-into-service date had been given when the BBC reported in June 2023.