Background The replacement of the and fleet that has been in use on the Merseyrail commuter rail network since the late 1970s, had been proposed by
Merseytravel as early as 2011. However, the older
1972 stock and
1973 stock are still in service on the
London Underground. In 2014, Liverpool City Region set out a 30 year rail vision, outlining investments that would and could be made to improve rail transport in the region. This included replacement of both the Class 507 and 508 trains with a new high capacity, dual voltage train fleet. In 2015, Merseytravel gained approval to go out to tender to replace the train fleet. In January 2016, Merseytravel announced that a total of five rolling-stock manufacturers had been shortlisted to build the new fleet –
Bombardier,
Siemens,
CAF,
Stadler Rail, and a consortium of
Mitsui,
Alstom, and the
East Japan Railway Company.
Contract award On 16 December 2016, Merseytravel announced Stadler Rail would manufacture a new fleet of 52 dual-voltage-capable articulated four-car units as part of a £460million fleet replacement project. Merseytravel has an option for a further 60 units. This is unlike the preceding fleet, owned by the private leasing agent
Angel Trains.
Infrastructure modifications To accommodate the new Class 777 fleet, extensive infrastructure changes were necessitated. Accordingly, while the fleet was initially to be launched under driver-only operations, in September 2018 it was announced that there would be a second member of staff on board, ending a two-year dispute between the
National Union of Rail, Maritime and Transport Workers (RMT) and Merseyrail.
Testing and delivery in Switzerland, with a temporarily-fitted windowless front emergency door During early October 2018, the bodyshells for the first unit were completed. This unit subsequently underwent pre-delivery dynamic testing in both Switzerland and Germany during late 2019. The first unit was delivered to Kirkdale TMD on 16 January 2020. On 16 March 2020, the unit commenced test runs on the Kirkby branch of the Northern Line. By October 2020, ten units had been delivered to Kirkdale TMD. In 2018, it was announced that a train configured as a
battery electric multiple unit was to be tested on sections of unelectrified track. Following the trial, it was announced in July 2021 that the units tested had been able to travel up to without the need for recharging. The
Liverpool City Region Combined Authority announced that the battery-powered trains will run to the new Headbolt Lane station at Kirkby, which opened on 4 October 2023. In December 2022, a maximum test range of was achieved, which was "much longer than we expected". In July 2021, full daytime testing of the units was underway. In August 2021, the
Office of Rail and Road (ORR) authorised the introduction of these units into passenger operation. Passenger services with the class commenced on 23 January 2023. The fleet was further rolled out over the following weeks, and from 6 March 2023, the 4 train per hour service was restored on the Kirkby line, with Class 777 units being exclusively used, however on some dates, old
Class 507 and
Class 508 stock was used due to various technical faults. In preparation for the
Grand National, the Class 777s were introduced in small numbers on the Ormskirk branch from 10 March 2023, Rollout on the Ormskirk branch continues as of May 2023, with further rollout of the units to other parts of the Merseyrail network expected later in 2023. In preparation for the
Eurovision Song Contest 2023, which took place in Liverpool, units received a special Eurovision decal, with one train receiving a full Eurovision livery.
Metro Mayor Steve Rotheram criticised Stadler, requesting compensation for the "frustratingly poor" roll-out of the trains. ==Design==