CO and C Stock at Whitechapel
CO and C Stock at Whitechapel (District). The CO
Stock (on the left) was originally call the O Stock and, with its sister stock, the P
Stock, was introduced on the District and Metropolitan Lines between 1937 and 1940.
It was equipped with a regenerative braking system controlled with what was called a
"Metadyne". The Metadyne was a rotating machine designed to replace the
normal resistance traction controls used at the time. The system was replaced by
conventional resistance controllers in the early 1960s and the O and P Stocks became CO
and CP stocks, the C meaning "converted". The stock was replaced on the
Metropolitan and Circle Lines by the new C Stock, seen on the right.
The man visible in the rear cab of the red CO Stock is the
guard. Trains were two-man operated until conversion to OPO began in 1984.