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Old August 9th 03, 11:58 AM posted to uk.transport.london
Nathan Whitington Nathan Whitington is offline
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First recorded activity at LondonBanter: Jul 2003
Posts: 11
Default Shielding 750 volt 3rd rail ?

Michael Bell wrote in message ...
It has always seemed to me that the 750 volt 3rd rail is a bad
idea. Rather it is the idea that somebody (Sprague?) first thought of
and it got made permanent. Its drawbacks in its present form seem to
me to be :-

* The possibility of electrocuting somebody. Are there many
casualties? More difficult to answer; how much do the procedures to
avoid electrocution cost in direct and indirect costs?

* It too often gets covered with ice in winter (and wet leaves
in autumn?)


So does the Overhead Line.......

* The danger of electrocution means that voltages cannot be
raised to increase power delivery. Italian state railways (FS =
Ferrovia della Stato) started with 3000 volt overhead wires, but
everything has now been done so that they can increase the voltage to
6000 volts, so doubling the power that can be delivered.


Well how many people do you know that get up in the morning and take
the dog for a walk down the third rail? I know some idiots do it but
the majority don't!

So I have been thinking of the possibilities of shielding the
3rd rail. The shield would be made of springy plastic, with square
holes moulded in the bottom, to allow rainwater and leaves to drop out
of the bottom and cooling air to rise through them. The holes would be
too small to allow a hand to be put through and too far for a finger
to reach the 3rd rail.


And whos going to pay for this?

To be honest I'm supprised your not complaining at overhead
powerlines, street cables etc. Someone could easily kill themselves by
sticking a knitting needle into a plug socket and turning it on, and
many places have high voltage sockets for cleaning equipment. Are you
one of these doughnuts who is trying to dieselise the country?