On Wed, 06 May 2009 23:15:06 +0100, Tony Polson
wrote:

wrote:

"rail" wrote in message
...
In message
wrote:

[snip]

I know that the 62As on the Metropolitan Line are due to be replaced in
the
next year or so. Would they not make a more suitable alternative for the
Island Line? Would the loading gauges be an issue?


Yes, there's a very low bridge[1] in Ryde that requires the use small
stock,
hence the reason for choosing tube stock in the first place.

[1] And possibly others elsewhere on the system.

--
Have they always used Tube stock on the Island Line since its
electrification in the 60s?



Yes, they started off with 1929 "Standard" Stock, which had some of the
traction equipment mounted above the floor in motor cars. It was
intended that the Standard Stock would last for 10 years, presumably
during which permanent replacements would be designed, built and shipped
to the Island. Of course that didn't happen. ;-)

They eventually became BR Class 485 and 486:

http://en.wikipedia.org/wiki/London_...Standard_Stock

The Standard Stock struggled on until replaced by the 1938 stock in the
late 1980s. The 1938 Stock became BR Class 483:

http://en.wikipedia.org/wiki/London_...und_1938_Stock

AFAIR another reason for the continuing use of older tube stock is
that the motors and underfloor equipment on newer types would need
extra protection against salt spray at Ryde Pier, the alternative
being truncation of the service away from the sea.