The impact on SWR

“The passenger benefits of the new trains are delayed,” said SWR engineering director Neil Drury.

“More capacity, airconditioning, WiFi and at-seat power - the things associated with the latest trains are all put back.

“Everything moves to the right. Big timetable changes, and different options in terms of cascading other trains. And it affects our training programme - the competency of drivers and guards, and how we can move people around to best effect.

“The first Aventra is due to arrive for testing at the beginning of the year. We will only get to operate it for ourselves around the middle of the year.

“It is now a 12-month programme, as opposed to what was originally a 17-month delivery schedule. So, by the middle of 2021 all the new trains will be with us. The original schedule was summer 2019 through to December 2020.”

The new trains will replace mixed fleets maintained at Wimbledon depot, with 750 new vehicles taking over from today’s total of 742.

Out go suburban Class 455 and ‘456’ trains dating back to the mid-1980s but fitted with new traction only in the last four years. Out go mid-life Class 458s on Reading and Windsor services. And out go almost-new Class 707 Siemens Desiro City trains, after less than three years in traffic.

Drury said: “The proposition of this franchise was about moving as many people as possible as efficiently as possible. We have several different suburban fleets to operate. Doors are in different places, the fleets accelerate and decelerate in different ways, and people get on and off in different ways. Staff training also varies.

“By introducing a homogenous fleet we can really focus on moving people quickly.

“Because of the delay we are now looking to change the cascade order. We were going to replace the ‘707s’ and ‘458s’ first, but we are reassessing that. We need the right way to maintain performance on the network and also in terms of balancing cost and risk.”