"Mark Brader" wrote in message
...
Benjamin Nunn:
I thought the W&C tunnels were big enough to take regular stock...

John Rowland:
No, in fact they had to be enlarged slightly to take the 92 stock.

CULG gives the Waterloo & City Line tunnel diameter as 3.70 m
(12' 1.75"), which if I remember correctly was taken from Rails
Through the Clay. This is *larger* than the nominal 11' 8.25"
of the Central Line, so what had to be enlarged?

The metal ribs (I don't know the correct name) on the inside of the rings
had to be trimmed on some of the curves. This may be more to do with the
length of the 92 stock than their width, or it may be to do with their
kinematic envelope differing from that of the previous stock. Perhaps the
Central Line already used larger rings on some or all of the curves.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes