London Underground C69 and C77 Stock

The London Underground C Stock, consisting of C69 and C77 stock, was a type of sub-surface rolling stock used on the Circle, Hammersmith & City and District line of the London Underground, between 28 September 1970 and 29 June 2014. The fleet's lifespan was just under 44 years.

The C stock were replaced by S7 Stock between January 2013 and June 2014. A farewell tour for the stock took place on 29 June 2014.

History
In 1968 C69 stock 6-car trains were ordered from Metropolitan–Cammell of Birmingham to replace O Stock and P Stock on the London Underground's Circle and Hammersmith & City lines for delivery from 1969, but trials of a four-car unit were delayed until summer 1970. The first entered service on 28 September 1970.

The C69 stock was constructed using the then-standard form of a load-bearing aluminium underframe with a non-load-bearing body of riveted panels on aluminium framing. The high-density nature of the Circle line service meant that loading times were important; consequently all cars were fitted with four double sets of air-operated sliding doors per side. Seating was mainly transverse, and total seating capacity was 32 per car. The 106 DM cars (Nos 5501-5606) were each coupled to one of 106 T (Nos 6501-6606) forming semi-permanent two-car units, with an automatic coupler at each end. Three such units were then marshalled as six-car trains for normal service. The DM cars were slightly longer to accommodate the drivers' cabs, the saloon dimensions in all other respects being the same.

To replace the CO/CP stock on the Edgware Road to Wimbledon section of the District line, a further eleven trains designated C77 were ordered of identical layout. The 33 DM (Nos 5701-5733) and T (Nos 6701-6733) were also formed as 2 car units and could and did interrun with C69. The first was delivered in July 1977.

Equipment as built included load sensing "Metacone" air suspension, rheostatic braking, hydraulic parking brake, pneumatic camshaft control by GEC and Brush DC motors of type LT117, with each Dm car having four motors. Air supply was by Reavell reciprocating compressors and braking equipment was by Westinghouse. The guard's door controls were in the driver's cab; this eased conversion to one-man operation in 1983-4, the first LU line to do so.

A car was added to the C77 order to replace C69 car 5585, which had been damaged in the West Ham IRA bomb attack in March 1976. Unit 5585-6585 became a hybrid C69/C77 unit and was selected for a trial refurbishment in 1989 at BREL, Derby.

Unit 5606-6606, which had been used for various equipment trials, was scrapped in December 1994. Cars 6505 and 6713 were damaged in the 7 July 2005 London bombings and were scrapped above the solebar. The remains were used in the building of new cars 6606 (the second car with this number) and 6734 as C08 stock. They were paired with 5505 and 5713, renumbered 5606 and 5734 to match their partners. 5548+6548 were rebuilt in part following the bombings.

The stock operated on the Hammersmith & City and Circle lines, as well as the District line between Edgware Road and Wimbledon. The last stock was withdrawn on the Hammersmith & City and Circle Lines on 10 February 2014, and on the District line on 3 June 2014, having been replaced by S7 Stock trains.

The stock was replaced between 2012 and 2014 by S7 Stock. Set 5595+6595 was cannibalised in 2011 as a trial programme, and resulted in a planned withdrawal until 2014. In July 2012 set 5532+6532 and 5575+6575 was damaged beyond economical repair in a side-swipe at Hammersmith depot. It was sent to the Northwood sidings on 15 October 2012, and taken to Eastleigh Works to be scrapped.

Final withdrawal of the C Stock commenced on 2 January 2013, when the first full 6-car train, 5515+6515, 5519+6519 and 5732+6732, was taken to Northwood sidings and loaded on lorries to be scrapped. A withdrawal was made every week or two weeks until 2014, but because of delays to the introduction of S7 Stock owing to modifications needed to be made to the S8 Stock, the withdrawal process was temporarily halted.

On 26 April 2013 the process resumed, with 5528+5588+5701 being transferred to Acton Works for removal from the system. The C stock was completely withdrawn on the Circle and Hammersmith & City lines on 11 February 2014.

On 3 June 2014 the final scheduled working of C Stock on the London Underground system took place, consisting of 5533/6533+5517/6517+5592/6592. (Train 074). Unfortunately the last journey was cut short by four hours and ended at 9:30am, and the train went to Hammersmith Depot instead. Otherwise, the train would have ended service at 1:39pm where it would have headed to Neasden Depot.

A tour took place on 29 June 2014 traversing much of the mileage covered by the stock during its working life. One train (5721+5531+5578) was retained for this tour with one held as a reserve in case of breakdown (5533+5517+5592).

The second-last train, the reserve train for the tour (5533+5517+5592), was taken to Ealing Common Depot on 4 July 2014 and loaded onto trucks to be scrapped at Rotherham Works, the same place where many A Stock and C Stock trains were scrapped. The final train, the railtour train (5721+5531+5578), was taken to Ealing Common Depot on 9 July 2014 to be scrapped at Rotherham Works as well. Only Car 5721 was preserved at the Acton Museum Depot.

Post-withdrawal use
Transport for London has donated two C77 driving motors to educational establishments, and another from the same sub-series to the London Transport Museum: these are 5701 and 5720.