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Re: Kopp and SF continue to fight over downtown hsr station
Author: Ernest H. Robl
Date: 09-23-2009 - 18:02
Okay, I'm not OPB, but I have followed electrification issues
for many years, and don't see any connection whatsoever between
BART and Caltrain electrification. BART is a heavy rail
(subway) system that runs off third rail and is broad gauge.
Caltrain is standard gauge and would work off overhead catenary.
Third rail requires fairly low voltages (under 1,000 volts) and
is normally DC; mainline electrification with catenary using
modern standards is AC and fairly high voltage (25,000 volts or
more). Light rail, though it uses catenary, is usually also DC
and in the lower voltage range.
Yes, it is possible to build equipment -- without using much
weight or space -- that can operatge on both lower voltage DC
and high voltage AC. Such equipment exists in Europe.
But, with the difference in gauge, you're never going to get
equipment going from one system to the other.
It would, however, make sense to provide a place for cross-
platform transfer, for passengers who want to go from one system
to the other.
But, other than that, the two electrical systems would be
completely independent of each other.
-- Ernest
for many years, and don't see any connection whatsoever between
BART and Caltrain electrification. BART is a heavy rail
(subway) system that runs off third rail and is broad gauge.
Caltrain is standard gauge and would work off overhead catenary.
Third rail requires fairly low voltages (under 1,000 volts) and
is normally DC; mainline electrification with catenary using
modern standards is AC and fairly high voltage (25,000 volts or
more). Light rail, though it uses catenary, is usually also DC
and in the lower voltage range.
Yes, it is possible to build equipment -- without using much
weight or space -- that can operatge on both lower voltage DC
and high voltage AC. Such equipment exists in Europe.
But, with the difference in gauge, you're never going to get
equipment going from one system to the other.
It would, however, make sense to provide a place for cross-
platform transfer, for passengers who want to go from one system
to the other.
But, other than that, the two electrical systems would be
completely independent of each other.
-- Ernest
