30 New Trains Now Operating on South Western Railway

Local services including Hounslow Loop seeing smaller capacity boost

One of the new Arterio trains. Picture: SWR

December 17, 2025

South Western Railway (SWR) has marked a milestone in its £1 billion Arterio fleet rollout, with the 30th train entering service and delivering a boost to commuter capacity into London Waterloo.

The new trains, which replace 40-year-old Class 455s, have already transformed journeys for tens of thousands of passengers. Since SWR transferred into public ownership in May 2025, the number of Arterios in service has more than quadrupled, increasing weekday suburban capacity into Waterloo by 12% during the morning peak.

Each 10-car Arterio carries over 50% more passengers than the eight-car trains they replace. The uplift has been particularly strong on routes, many of which stop at Putney, such as Chessington (21%), Kingston (20%), Aldershot via Staines (24%), Reading (17%) and Shepperton (23%). However, the Hounslow Loop has seen only a modest 5% increase, meaning stations including Chiswick, Brentford, Syon Lane and Kew Bridge have experienced limited improvement.

The Arterios bring modern amenities including Wi-Fi, charging points at every seat, real-time information screens, accessible toilets and air conditioning. Customer surveys show satisfaction with space on board has risen to 86%, compared with 77% for the outgoing Class 455s.

The 30 Arterios now operate more than 390 daily services, covering all 96 stations on SWR’s suburban network, from Ascot and Barnes to Wimbledon, Woking and Reading. SWR plans to introduce two more trains before Christmas and aims to have three-quarters of its planned Arterio schedules running by summer 2026.

While passengers have welcomed the new blue Arterios, enthusiasm for the retiring red Class 455s was evident when a special charity farewell tour sold out in just 15 seconds. A second tour, scheduled for 21 December, has also sold out, with more than 900 rail enthusiasts expected to mark the end of a fleet that has served South West London, Berkshire and Surrey for 42 years.

Lawrence Bowman, Managing Director of SWR and Network Rail Wessex, said, “This is a major milestone for customers on our suburban railway, who are now more and more likely to catch an Arterio for their morning commute. The new trains provide a step-change in capacity, reliability and comfort for the tens of thousands of customers who travel through Waterloo every day.”

Rail Minister Lord Hendy added, “The introduction of the 30th Arterio train is a clear example of the kind of improvement publicly owned rail operators can deliver to put passengers first. The increased capacity and better on-board facilities will make journeys more comfortable, encouraging more people to choose rail.”