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Old August 9th 03, 09:28 PM posted to uk.transport.london
Michael Bell Michael Bell is offline
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First recorded activity at LondonBanter: Jul 2003
Posts: 130
Default Shielding 750 volt 3rd rail ?

In article , Dr Ivan D. Reid
wrote:
On Fri, 8 Aug 2003 23:43:59 +0100, Michael Bell

wrote in :

* 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.


Redo your maths; V*2 = P*4, modulo foibles of inductive loads.


I don't see that. Current can't be increased because it is
limited by the crosssection of the overhead wire, at least not
without it overheating, sagging and other undesireable behaviour. But
if you double the voltage at the same current, you double the power.
At least that's my thinking.


--
Michael Bell