British Rail Class 701

The British Rail Class 701 Aventra is a class of electric multiple unit passenger train built by Bombardier Transportation (now Alstom) at Derby Litchurch Lane Works. Built on the Aventra platform, they are branded as Arterio trains by South Western Railway, and operate some services between Waterloo and Windsor. In the future the trains are planned to operate services on the Reading, Windsor and South West London suburban lines.

Ordered in 2017, the trains were originally due to enter service from mid-2019, but were subject to several delays which prevented this. By December 2023, 50 units had been accepted by SWR.

SWR began their phased entry into service from January 2024. They will eventually allow the withdrawal of SWR's fleets of units and the cascade of the  fleet to longer-distance services.

Background
In March 2017, SWR was awarded the South Western franchise with a commitment to introduce 750 new carriages. In June 2017, SWR awarded a contract to Bombardier Transportation for 90 Aventra DC EMUs, with 60 ten-car and 30 five-car trains to be introduced from mid 2019 at a cost of £895million. There was an option to purchase a further five ten-car units if required by October 2020. The units will be maintained at Wimbledon depot and the new Feltham depot.

It was planned that the new trains would replace all of SWR's suburban fleets, which at the time of the order comprised Classes 455, 456, 458, and 707. At the time that the trains were ordered, buying a fleet of new trains was cheaper than the leasing rates for existing trains. Original plans called for the rollout of the full Class 701 fleet to take two years after the first units entered service.

The new trains would increase peak capacity on suburban routes into London Waterloo by 46%, as well as including improvements over existing suburban trains such as air-conditioning, an open gangway design and toilets.

The order was initially split into two separate classes, with five-car units placed in Class 705 and ten-car units placed in Class 711, but this was later changed to place ten-car units in Class 701 subclass /0 and five-car units in subclass /5.

Construction and delays
Following a brief halt to production in March 2020 as a result of the COVID-19 pandemic, the first completed ten-car unit (number 701002) was delivered to Eastleigh Works on 10 June 2020 so that the testing and certification processes could commence. At this point entry into service was already more than five months late. By June 2021, only 19 units had been delivered, none of which had been formally accepted by SWR.

In January 2022, SWR announced that continued delays to the Class 701 introduction had "created a challenging situation" on its suburban network, and that it was still waiting for Alstom (which acquired Bombardier Transportation in January 2021) to "supply a train that performs to specification". This caused SWR to extend the lease on its remaining 12 Class 707 units until late 2022, which in turn delayed their planned transfer to Southeastern. The Class 456 fleet was withdrawn without replacement in January 2022 following cuts to service levels.

In January 2022, Railway industry journalist Roger Ford observed that the programme met the "ultimate standard for lateness", given that none of the finished units had yet been accepted by SWR and at least 280 vehicles had not yet even been built—while the original contract specified that the entire fleet was to be in service by the end of 2021. He noted that the delay was, in part, due to "endemic software issues" that had affected the introduction of all Aventra fleets to date. Other issues include complaints from driver's union ASLEF that the cab environment in the production units differs unacceptably from the standard previously agreed with SWR, and a high level of manufacturing defects in the finished vehicles.

SWR's Business Plan for 2022–2023, published in July 2022, acknowledged that "continuing problems ... have prevented the start of driver training and delayed the programme of train acceptance", and included a commitment to "introduce the new Arterio fleet as soon as possible". This will involve SWR agreeing on new roll-out milestones for the project with the Department for Transport.



A further update in December 2022 stated that 24 finished units had been accepted, as well as repeating the commitment to introduce the fleet into service "as early in [2023] as possible". A concurrent statement from the Department for Transport indicated that work to finalise a service-standard software package for the trains was still underway and that driver training had not yet commenced.

In May 2023 it was announced that entry into service was planned for December 2023. In June 2023 it was reported that 42 finished units had been accepted and that training for depot drivers had begun, and in July it was confirmed that they were planned to be introduced in 2023. In December 2023 it was reported that 50 finished units had been accepted and that training for mainline driver was being prepared.

In December 2023 the National Union of Rail, Maritime and Transport Workers (RMT) published an update to members advising that they recommended SWR suspend any plans for entry into service or training until "several key areas" are amended to make them suitable for the union and its members. RMT formally rejected the updates to the role of the guard and implementation of driver-only operation on the new rolling stock.

In February 2024 it was reported that seventy one accepted finished units had been accepted, and that the entire fleet is planned to be in service in 2025 following the completion of driver training.

In April 2024 it was reported that all 90 units have been built and that 70 of the 90 units have been accepted.

Entry into service
In late December 2023 it was reported that South Western Railway had reached an agreement with the unions allowing for a "Soft Launch" of the Class 701 fleet. The first unit entered service on 9 January 2024 between London Waterloo and Windsor & Eton Riverside. Since then 2-3 services have run each day using some of the trains, mostly between London Waterloo and Windsor & Eton Riverside. Full entry into service is expected to take 24 months.

Features
The Class 701 features regenerative braking, wide gangways between coaches, wide doors for ease and efficiency of boarding and alighting, 2+2 seating arrangement throughout, Wi-Fi, at-seat USB charging points, real-time passenger information screens, air conditioning, and bicycle spaces (three for each five coaches).

The trains also have Universal Accessible Toilets (UATs) - one toilet in each five coaches, and for the first time in Britain, they are bioreactor Controlled Emission Toilets (CETs), rather than the "conventional" CETs of other British trains. By releasing onboard-treated wastewater, the waste tanks last longer before being emptied.

Each five-car train has 274 seats with room for 361 standing passengers, while a ten-car set will seat 556 passengers with space for 746 standing. The trains also feature external door cameras, and monitors within the cab, to allow for driver-controlled operation (where the driver is responsible for the opening and closing of passenger doors).