BART weight, gauge & cross winds
Adrian Brandt
Regarding the myth that BART needs broad gauge to resist cross winds,
cha...@net.bio.net (Michael Chalup) wrote:
> I've recently heard the same story from a mechanical engineer who
> works for BART - the person does know what he is talking about.
I'm not so sure. There are lots of "engineers" who repeat/believe
myths--some of them probably work at/for BART.
> BART cars are extremely lightweight for their capacity (forgot what
> Lbs / passenger is, but some of the lowest around for modern RT
> equipment).
I can look it up if need be, but as I recall, BART cars weigh in at
about 30 tons apiece. They seat just under 70 people. So that's
about 860 pounds of car weight per seated passenger--provided the
car is full. As is typical of subway trains BART trains are not
tall at all (helps cut tunneling cost): 10 feet from rail to roof.
I just wanted to point out that the French TGV has cars that weigh
about the same as a BART car, run on standard gauge track, and run
186 mph in everyday revenue service. New lines are reportedly being
built for revenue cruising speeds in excess of 200 mph--also on
standard gauge track--using new double deck equipment. Lastly, the
current issue of Railway Gazette International shows a picture of a
new Japanese narrow gauge high speed train. Those cars are almost
certainly in the same weight range as--if not lighter than--BART cars.
I guess the BART engineers forgot to warn people that you need tracks
that are just a few inches wider than standard gauge to run a train
where there just might be some cross winds... hmmm.
The resistance to cross-wind thing is BS. It may well be one of the
original stated reasons for the slightly wider gauge. But 30 ton, 10
foot high equipment, will do fine in all but near hurricane force
cross winds on just about any *reasonable* track gauge. You don't
design for hurricane force winds anyway--it'd be over-engineered--
nobody expects to operate or ride trains in those conditions (nor
should they).
--
Adrian Brandt (415) 940-2379
a...@ntmtv.com
Silas Warner
> Regarding the myth that BART needs broad gauge to resist cross winds,
> cha...@net.bio.net (Michael Chalup) wrote:
>
> > I've recently heard the same story from a mechanical engineer who
> > works for BART - the person does know what he is talking about.
>
> I'm not so sure. There are lots of "engineers" who repeat/believe
> myths--some of them probably work at/for BART.
>
story was exactly why BART was supposed to be broad-gauged. That was
also supposed to be the reason for the streamlining of trains, with
their pointed noses.
Now remember that in 1965 when BART was proposed, no American subway
had been built since 1949 (except the Lindenwold Line, which used
an abandoned railroad ROW) and BART was supposed to be a 21st century
subway, with no possible connection to those old rattletrap subways
in Chicago and New York. IMHO, that was the real reason for selecting
a broad gauge -- so none of that ancient-rattletrap miasma could
infiltrate the brand-new future of rapid transit.
Silas Warner
sh
: >
: > Regarding the myth that BART needs broad gauge to resist cross winds,
: > cha...@net.bio.net (Michael Chalup) wrote:
: >
: > > I've recently heard the same story from a mechanical engineer who
: > > works for BART - the person does know what he is talking about.
: >
: > I'm not so sure. There are lots of "engineers" who repeat/believe
: > myths--some of them probably work at/for BART.
: >
: It's not a myth. Although it's been proven unnecessary, the crosswind
: story was exactly why BART was supposed to be broad-gauged. That was
: also supposed to be the reason for the streamlining of trains, with
: their pointed noses.
Gee, the myth I heard was that Southern Pacific didn't want another
line capable of carrying freight in the East Bay - Thus the non-standard
gauge. I'm sure SP still carried plenty of political clout in the early
60's, when BART was being planned. Anything to this?
--
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Bill Brown
>Gee, the myth I heard was that Southern Pacific didn't want another
>line capable of carrying freight in the East Bay - Thus the non-standard
>gauge. I'm sure SP still carried plenty of political clout in the early
>60's, when BART was being planned. Anything to this?
I seem to recall reading thaat the broad gauge idea came out of a study
done by the boffins at SRI. But that was a long time ago, and the applicable
neurons may have been toasted by the odd cosmic ray in the meantime.
Disclaimer: Any opinions are my own and have | -bill
nothing to do with the official policy or the | wlb...@lbl.gov
management of L.B.L, who probably couldn't | Berkeley, CA
care less about employees who play with trains. | aka wlb...@netcom.com