Why are those tracks 5 ft 6 inches wide?

[FJ and G]

BART

Dave Vergun

[Hugh Jampton]

Didn't the original plans call for the construction of a lower deck on the bay bridge for the trains to run on? If this is so then the wider gauge would be helpfull in preventing the trains from blowing over. This is just a guess though.

[Anonymous]

Wider gauge means wider cars witch also means more stability.....


I am not going to pretend to know anything about BART though, are the cars wider than usual?

5'6" actually also used to be standard gauge in Canada before we switched over to 4'8.5" so it would be easier to connect with the US....

Could you imagine if Canada was still 5'6".......what a mess that would be.

[CSSHEGEWISCH]

In regards to the mess if Canada still had 5'6" gauge, our Australian colleagues know all about the folly of different gauges, three different gauges to be sure.

I don't think that BART ever planned to run on the Bay Bridge, even though Key System interurbans did so prior to World War II.

[espeefoamer]

I herd a rumor that the Southern Pacific forced the wide gauge, because it was afraid that a standard gauge system would use SP tracks and get in the way of its freight trains.
This rumor was floating around in the early days of BART.

[Anonymous]

QUOTE: Originally posted by CSSHEGEWISCH

In regards to the mess if Canada still had 5'6" gauge, our Australian colleagues know all about the folly of different gauges, three different gauges to be sure.

Yeah, same thing in Europe.

It was done to prevent invasions by rail, but now they have to live with the inconvenience.

[Hugh Jampton]

QUOTE: Originally posted by macguy

Wider gauge means wider cars witch also means more stability.....


I am not going to pretend to know anything about BART though, are the cars wider than usual?

I thought that, but according to the BART website (http://www.bart.gov/) the cars are only 10 and a half feet wide. Although they only weigh 31.5 tons

[Isambard]

QUOTE: Originally posted by macguy

Wider gauge means wider cars witch also means more stability.....


I am not going to pretend to know anything about BART though, are the cars wider than usual?

5'6" actually also used to be standard gauge in Canada before we switched over to 4'8.5" so it would be easier to connect with the US....

Could you imagine if Canada was still 5'6".......what a mess that would be.

What year did that switch over occur? I assume it was prior to the CPR's last spike be driven in 1885.

[bwatt]

The answer IIRC was that the designers of BART started with a completely clean sheet, and built their system data from first principles, ie:-
"How many people will there be on a fully loaded train ?"
"How much room will those people need to be comfortable ?"
"How big must a car be to give people that much room ?"
and so on, until they had a pretty good idea of the size, weight etc. of a train.
Then, and only then, did they ask the question:-
"Given the highest likely wind speed in the Bay Area, what track gauge do we need to ensure the stability of a train on above-ground track in the worst conditions ?".
And the answer was 5ft 6in.
I don't think linking to other RRs was seen as a likely event.

[stmtrolleyguy]

LIghter cars might actually be less stable. A lot of weight is in the trucks, and when you have a lighter car going around a curve, it could be more prone to derailment. In other words, a heavier car has more keeping it down on the tracks, or more weight lower down. A lighter car lacks that downward or railward force.

[DSchmitt]

QUOTE: Originally posted by Hugh Jampton

Didn't the original plans call for the construction of a lower deck on the bay bridge for the trains to run on? If this is so then the wider gauge would be helpfull in preventing the trains from blowing over. This is just a guess though.

Do you mean the Golden Gate Bridge. The Bay Bridge has two decks and standard gauge trains ran on the lower deck into the mid 1950's.

[Anonymous]

There were several plans to put tracks or a fixed guideway on the Golden Gate bridge, including BART. All of them involved lots of $$. If I recall corrrectly, Marin County opted out of BART, which rendered the matter moot.

[Murphy Siding]

I know! I know! That's to prevent an invasion from the west. No, wait a minute-that was that thread about guage in Russia.[:)]