SubSurface Lines S7/S8 Stock

Built:
S7 Stock: 2012 – 2014
S8 Stock: 2008 – 2012
Manufacturer: Bombardier Transportation
Entered Service:
S7 Stock: 2012 – 2014
S8 Stock: 2009 -2012 (additional set delivered in 2016)
Number in Service: 
S7 Stock: 133
S8 Stock: 58
Number of Carriages per Train: 7/8
Seats per Train:
S7 Stock: 256
S8 Stock: 306
Passenger Capacity:
S7 Stock: 1209 (approx.)
S8 Stock: 1350 (approx.)

S7 Stock

Train Formation:  Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Driving Motor

Train Length: 367ft 6ins
Train Width: 9ft 3ins
Train Height: 12ft
Train Weight: 213.7 tonnes

Lines Operated: Circle, District, Hammersmith & City

S8 Stock

Train Formation:  Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Non-Driving Motor – Driving Motor

Train Length: 418ft 2ins
Train Width: 9ft 3ins
Train Height: 12ft
Train Weight: 241.2 tonnes

Line Operated: Metropolitan

Subsurface Lines S7/S8 Stock History

With the implementation of the Public Private Partnership on the London Underground in 2003, the infrastructure of the sub-surface lines namely the Circle, District, Hammersmith & City, and Metropolitan Lines was placed under the charge of Metronet.

This consortium, consisting of Atkins, Balfour Beatty, Bombardier Transportation, EDF Energy, and Thames Water decided to replace the rolling stock on the lines to standardise the fleet.

Bombardier Transportation, as part of the consortium, was charged with the design, planning, and construction of the order for 192 trains (1403 cars) to replace the existing A, C & D stock units in operation at the time, along with the ongoing required maintenance of the new units.

December 2006 saw Metronet and London Underground unveil the design for the new units for the new trains, introducing a uniform design across the board, with the only difference being the number of carriages per train. At this time, London Underground announced an addition of 40 cars to the order, leading to a final project cost of £1.5billion.

Construction was due to commence in 2007 but, with the collapse of Metronet due to financial difficulties in July of that year, London Underground had to enter negotiations with Bombardier to continue the construction of the 2009 stock, along with that of the S Stock. This led to Transport for London taking ownership of Metronet in May 2008.

With the construction of the first S8 stock trains for the Metropolitan Line complete, they were delivered for testing to Bombardier’s test track at Old Dalby in March 2009. This prevented the closure of the line at weekends and accelerated the process, allowing the first unit to be delivered to Neasden Depot in October of that year.

Line testing of the new trains began in November 2009 between Amersham and Watford, with driver training commencing in early January 2010. The first S8 Stock train entered revenue service between Wembley Park and Watford on 31 July 2010.

27 June 2011 saw the S8 Stock commence operation along the full Metropolitan Line. Further deliveries of new trains were suspended by TfL following concerns about reliability, with several trains having been delivered to Neasden but not accepted into service until deliveries resumed in December.

The final S8 Stock set was delivered to Neasden on 15 September 2012 with the final A Stock set being withdrawn from service eleven days later. However, in November 37 of the new trains were returned to Bombardier at Derby for urgent modifications. During this time, three S7 Stock units meant for the Hammersmith & City Line were supplemented with an additional car to allow the Metropolitan Line service to continue.

Alongside the S8 Stock Units, the first S7 stock units were also being constructed with the initial units being delivered and tested, alongside driver training on the Hammersmith & City Line in May 2012. The first revenue-earning runs began between Hammersmith & Moorgate on 6 July of that year. The first train to pass Moorgate and head to Barking was a testing run on 4th December 2012, with the S7s commencing full service on the line on 9th December.

The Circle was the next to receive its new trains, with the first entering service on 2nd September 2013, with full service being assumed, replacing the C Stock units, on 11th February 2014.

The final line to receive its units was the District, with the first unit entering service between Kensington Olympia and West Ham on 2nd September 2013. This was followed by the assumption of services from Wimbledon to Edgware Road on 6th February 2014, to Ealing Broadway on 13th June, and to Richmond on 16th January 2015.

With the new stock in service, the withdrawal of the D78 stock from the District Line commenced three days later and the final unit withdrawn on 21st April 2017.