On Sat, 29 May 2010 13:45:19 +0100, MIG
wrote:
My memory is that the whole fleets of 1972 mark 1 and 1972 mark 2
stock were already running on the Northern line alongside 1938 stock
while the 1959 stock was just starting to be displaced by 1973 stock
being introduced on the Piccadilly, and moving over to replace the
rest of the 1938 stock (and the 1972 mark 2 stock eventually).

And my memory, FWIW, is that the 73 stock was introduced in about 1975,
not 1973.

Since tube stock seems to be good for at least 40 years' service, I don't
suppose the world would end if they delayed replacing the 73 for 5 years
(from now).

Colin McKenzie

--
No-one has ever proved that cycle helmets make cycling any safer at the
population level, and anyway cycling is about as safe per mile as walking.
Make an informed choice - visit www.cyclehelmets.org.