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Re: New Bart Cars found to be too heavy
Author: mook
Date: 02-22-2017 - 09:02
Trying DuckDuckGo, I also had little luck finding a document explaining WHY 5.5' was chosen for BART. We "all know" that it was for stability, but what PBQD document explains that?
BTW, initial top speed for BART was 80mph. It was only reached under ideal conditions in the long tunnels. During the first energy crisis in the 1970s, it was reduced to 70 because it had little impact on schedules but an actual impact on energy use and maintenance. Not sure if they even reach 70 any more.
Wiki list of transit trach gauges ... BART shares 5'6" with a couple of Indian lines. [en.wikipedia.org]
We aren't the only ones who've had arguments about the BART gauge. Progressive Railroading's forum did too. Some of the comments sound like they came from the Mouse? [myprogressiverailroading.com]
Quora quoting at one point another blog: [www.quora.com]. However, the quoted blog [theoverheadwire.blogspot.com] doesn't have any more reliable information; just speculation.
And on and on ... several other blog references, but no clear direct source. Close out with a comment on Bay Rail Alliance: [www.bayrailalliance.org]. The search returns then wandered off into other spaces.
The bottom line seems to be that there are engineering reasons why the wide gauge would be useful. Stability is a major one. But the primary reason for the stability concern (trains on the GG Bridge) had gone away before final decisions to use the wide gauge were made. So unless somebody has access to deep, top secret archives of BART, PBQD, and maybe other engineering and project management documents that can shed more light on the subject, it'll have to stay in the realm of speculation and conspiracy theories.
Just for fun - ran across this while searching: Engineering Geology of the Bay Area Rapid Transit (BART) System, 1964-75. Has nothing to do with track gauge; it was just in the list of search returns.
BTW, initial top speed for BART was 80mph. It was only reached under ideal conditions in the long tunnels. During the first energy crisis in the 1970s, it was reduced to 70 because it had little impact on schedules but an actual impact on energy use and maintenance. Not sure if they even reach 70 any more.
Wiki list of transit trach gauges ... BART shares 5'6" with a couple of Indian lines. [en.wikipedia.org]
We aren't the only ones who've had arguments about the BART gauge. Progressive Railroading's forum did too. Some of the comments sound like they came from the Mouse? [myprogressiverailroading.com]
Quora quoting at one point another blog: [www.quora.com]. However, the quoted blog [theoverheadwire.blogspot.com] doesn't have any more reliable information; just speculation.
And on and on ... several other blog references, but no clear direct source. Close out with a comment on Bay Rail Alliance: [www.bayrailalliance.org]. The search returns then wandered off into other spaces.
The bottom line seems to be that there are engineering reasons why the wide gauge would be useful. Stability is a major one. But the primary reason for the stability concern (trains on the GG Bridge) had gone away before final decisions to use the wide gauge were made. So unless somebody has access to deep, top secret archives of BART, PBQD, and maybe other engineering and project management documents that can shed more light on the subject, it'll have to stay in the realm of speculation and conspiracy theories.
Just for fun - ran across this while searching: Engineering Geology of the Bay Area Rapid Transit (BART) System, 1964-75. Has nothing to do with track gauge; it was just in the list of search returns.
