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It is a nice article. Summary is they wanted lighter cars so accel/decel would require less power and the gas/brake system would be lighter/smaller. So then the

It is a nice article. Summary is they wanted lighter cars so accel/decel would require less power and the gas/brake system would be lighter/smaller. So then the wider gauge is helpful to increase lateral stability (to prevent tipping over) since the cars are so light. In my opinion these kinds of historical mechanical/civil engineering stories are quite interesting. Would love to see more.

arinlen 4y ago
> So then the wider gauge is helpful to increase lateral stability (to prevent tipping over) since the cars are so light. If they didn't wanted to reinvent the wheel, they could have adopted another standard railway track gauge: the Iberian gauge https://en.wikipedia.org/wiki/Iberian-gauge_railways https://en.wikipedia.org/wiki/Iberian-gauge_railways There's a fun story about BART: the US decided to go with a blank slate approach to railway design by hiring not railway engineers but aerospace engineers, and consequently the project relied heavily on reinventing the wheel. This track gauge thing happens to be one of many examples. As BART decided to forego any standard way of doing mundane railway tracks, they had to endure decade-long delays and huge budget overruns to cover up their loss. Otherwise there would be nothing to talk about a mundane rapid transit system which already covers pretty much the whole Europe.
phnofive 4y ago
Anti-tipping was also an important consideration due to the intense Bay Area winds against the sides of the cars.
- Redoubts 4y ago
  Only for the route to Marin, which Marin didn’t want and was never built.
  - wpietri 4y ago
    That's not what the article says: "On aerial trackways during high wind events – which the engineers knew were not uncommon in places such as Contra Costa County -- the light BART cars could potentially tip over, the engineers hypothesized."
    - bastawhiz 4y ago
      It does say later that it was also a consideration for running BART on the lower deck of the golden gate bridge.
      - wpietri 4y ago
        Yes, I was objecting to the false "only".
  - mjg59 4y ago
    Marin /did/ want it, but after the Golden Gate Bridge authority insisted that the bridge couldn't support the extra deck needed for BART there was a risk that if Marin were part of BART they'd be on the hook for the money without ever receiving service. That, unsurprisingly, reduced enthusiasm - and if a reduction in the Marin vote had dropped the overall bond vote below the required 60 percent, none of the system would have been built, so Marin was kicked out.
- nerfhammer 4y ago
  > intense Bay Area winds the Bay area has intense winds?
  - WWLink 4y ago
    Some parts of the east bay are really friggin windy. I used to live on top of a hill near the carquinez strait and during windy season they'd easily exceed 60mph during a storm. Like once every other year a bunch of fences would get demolished lol.
  - 0xB31B1B 4y ago
    Yes, thermal winds in the afternoons in summer and fall.
  - phlakaton 4y ago
    Not hurricane force or anything, but gusts of 50 mph (45 knots) or more are not uncommon during Diablo wind events or storms. Gusts up to 70 mph (60 knots) have been recorded at times. Just this winter we had 90+ mph winds recorded in Sonoma (wouldn't have affected the current BART system, but still).
sofixa 4y ago
> Would love to see more. There's the Toronto gauge, the Japanese high speed rail gauge (which is standard, 1435mm, for the world but wider than what was used before in Japan, 1000mm and less) and the Spanish high speed rail gauge (which is also standard, 1435mm, even though they usually use Iberian gauge which is wider - and on this, they have some interesting train designs that are capable of automatically switching between the two).
- gpvos 4y ago
  I recently read that although the Spanish high speed lines don't have many passenger trains (the recent Perpignan-Figueres tunnel only has two per day, although that's partly because of corona), they also carry through freight traffic from France because there's no break-of-gauge. A bit unusual for a high speed line, but why not.
  - ehnto 4y ago
    That really interesting. I wonder how much that impacts maintenance if at all. They definitely couldn't do that if timing on passenger rail was increased, but while there's sufficient gaps then as you said, why not.
  - ThePowerOfFuet 4y ago
    >(the recent Perpignan-Figueres tunnel only has two per day, although that's partly because of corona) It was four per day in each direction pre-Covid.
  - martinald 4y ago
    Yes I was shocked at this too. Even the flagship Madrid Barcelona line only has 1 train per hour. This seems ridiculously low given HS2 in the UK is planned to have 18tph on the core line (to various destinations, but still). To make matters worse the spainish high speed lines have mandatory reservations so once the train has sold out you are not allowed to board - unlike the UK where you can still board but may have to stand for some of the journey - which is not ideal but at least you don't have to stand around for another hour waiting for the next train anyway.
knolan 4y ago
There’s also the 1600mm Irish gauge which historically was down to picking a compromise between two standards used in lines built in the 19th Century. Some Irish rail engineers brought it with them to places like Australia and Brazil.
johnwalkr 4y ago
There's a small gauge (I think 2 feet) used mainly for moving pineapples and sugar cane around on plantations. The rail is readily available so it's used for other purposes too. I saw it used for material handling in rail shops in Canada, and it was always called "pineapple gauge".
nimbius 4y ago
another reason they're nonstandard is to keep freight rail companies from demanding to use them. part of the reason rail on the us is so slow is freight companies have had a 150 year monopoly on the right of way.
- reaperducer 4y ago
  another reason they're nonstandard is to keep freight rail companies from demanding to use them. part of the reason rail on the us is so slow is freight companies have had a 150 year monopoly on the right of way. You're confusing two different topics. Freight railroads cannot "demand" to use rail lines owned by passenger railroads. Passenger railroads can, if they choose, allow freight lines to use their tracks, and vice-versa. You can see examples of both in Chicago. CTA, a passenger railroad, used to carry freight traffic, but chooses not to do so anymore. Meanwhile, the local freight railroad companies choose to allow Metra, another passenger railroad, to use their tracks and rights-of-way. It's not anywhere close to the black-and-white situation you present. Where passenger railroads own their tracks, they get to decide what runs on them. The problem is that passenger railroads in the United States own very little actual track, and rely too heavily on using freight-owned tracks. There's lots of railroad magazines that write about this ongoing problem every month.
  - IIAOPSW 4y ago
    No, CTA cannot do that. If they did, CTA would have to take a bunch of expensive steps to make their stuff complaint with FRA regs. And no, the local freight railroads aren't "choosing" to let Metra be. They pretty much have to. That was part of the agreement when the regulators allowed the railroads to drop passenger services (which they were previously legally obliged to keep). There's a process, which hasn't been put into practice for a while but is still on the books, for Amtrak to demand the right to use certain tracks (the exact scenario where this happens escapes me).
    - reaperducer 4y ago
      No, CTA cannot do that You should tell the CTA. It will be news to them.

arinlen 4y ago

> So then the wider gauge is helpful to increase lateral stability (to prevent tipping over) since the cars are so light. If they didn't wanted to reinvent the wheel, they could have adopted another standard railway track gauge: the Iberian gauge https://en.wikipedia.org/wiki/Iberian-gauge_railways https://en.wikipedia.org/wiki/Iberian-gauge_railways There's a fun story about BART: the US decided to go with a blank slate approach to railway design by hiring not railway engineers but aerospace engineers, and consequently the project relied heavily on reinventing the wheel. This track gauge thing happens to be one of many examples. As BART decided to forego any standard way of doing mundane railway tracks, they had to endure decade-long delays and huge budget overruns to cover up their loss. Otherwise there would be nothing to talk about a mundane rapid transit system which already covers pretty much the whole Europe.

phnofive 4y ago

Anti-tipping was also an important consideration due to the intense Bay Area winds against the sides of the cars.

Redoubts 4y ago
Only for the route to Marin, which Marin didn’t want and was never built.
- wpietri 4y ago
  That's not what the article says: "On aerial trackways during high wind events – which the engineers knew were not uncommon in places such as Contra Costa County -- the light BART cars could potentially tip over, the engineers hypothesized."
  - bastawhiz 4y ago
    It does say later that it was also a consideration for running BART on the lower deck of the golden gate bridge.
    - wpietri 4y ago
      Yes, I was objecting to the false "only".
- mjg59 4y ago
  Marin /did/ want it, but after the Golden Gate Bridge authority insisted that the bridge couldn't support the extra deck needed for BART there was a risk that if Marin were part of BART they'd be on the hook for the money without ever receiving service. That, unsurprisingly, reduced enthusiasm - and if a reduction in the Marin vote had dropped the overall bond vote below the required 60 percent, none of the system would have been built, so Marin was kicked out.
nerfhammer 4y ago
> intense Bay Area winds the Bay area has intense winds?
- WWLink 4y ago
  Some parts of the east bay are really friggin windy. I used to live on top of a hill near the carquinez strait and during windy season they'd easily exceed 60mph during a storm. Like once every other year a bunch of fences would get demolished lol.
- 0xB31B1B 4y ago
  Yes, thermal winds in the afternoons in summer and fall.
- phlakaton 4y ago
  Not hurricane force or anything, but gusts of 50 mph (45 knots) or more are not uncommon during Diablo wind events or storms. Gusts up to 70 mph (60 knots) have been recorded at times. Just this winter we had 90+ mph winds recorded in Sonoma (wouldn't have affected the current BART system, but still).

sofixa 4y ago

> Would love to see more. There's the Toronto gauge, the Japanese high speed rail gauge (which is standard, 1435mm, for the world but wider than what was used before in Japan, 1000mm and less) and the Spanish high speed rail gauge (which is also standard, 1435mm, even though they usually use Iberian gauge which is wider - and on this, they have some interesting train designs that are capable of automatically switching between the two).

gpvos 4y ago
I recently read that although the Spanish high speed lines don't have many passenger trains (the recent Perpignan-Figueres tunnel only has two per day, although that's partly because of corona), they also carry through freight traffic from France because there's no break-of-gauge. A bit unusual for a high speed line, but why not.
- ehnto 4y ago
  That really interesting. I wonder how much that impacts maintenance if at all. They definitely couldn't do that if timing on passenger rail was increased, but while there's sufficient gaps then as you said, why not.
- ThePowerOfFuet 4y ago
  >(the recent Perpignan-Figueres tunnel only has two per day, although that's partly because of corona) It was four per day in each direction pre-Covid.
- martinald 4y ago
  Yes I was shocked at this too. Even the flagship Madrid Barcelona line only has 1 train per hour. This seems ridiculously low given HS2 in the UK is planned to have 18tph on the core line (to various destinations, but still). To make matters worse the spainish high speed lines have mandatory reservations so once the train has sold out you are not allowed to board - unlike the UK where you can still board but may have to stand for some of the journey - which is not ideal but at least you don't have to stand around for another hour waiting for the next train anyway.

knolan 4y ago

There’s also the 1600mm Irish gauge which historically was down to picking a compromise between two standards used in lines built in the 19th Century. Some Irish rail engineers brought it with them to places like Australia and Brazil.

johnwalkr 4y ago

There's a small gauge (I think 2 feet) used mainly for moving pineapples and sugar cane around on plantations. The rail is readily available so it's used for other purposes too. I saw it used for material handling in rail shops in Canada, and it was always called "pineapple gauge".

nimbius 4y ago

another reason they're nonstandard is to keep freight rail companies from demanding to use them. part of the reason rail on the us is so slow is freight companies have had a 150 year monopoly on the right of way.

reaperducer 4y ago
another reason they're nonstandard is to keep freight rail companies from demanding to use them. part of the reason rail on the us is so slow is freight companies have had a 150 year monopoly on the right of way. You're confusing two different topics. Freight railroads cannot "demand" to use rail lines owned by passenger railroads. Passenger railroads can, if they choose, allow freight lines to use their tracks, and vice-versa. You can see examples of both in Chicago. CTA, a passenger railroad, used to carry freight traffic, but chooses not to do so anymore. Meanwhile, the local freight railroad companies choose to allow Metra, another passenger railroad, to use their tracks and rights-of-way. It's not anywhere close to the black-and-white situation you present. Where passenger railroads own their tracks, they get to decide what runs on them. The problem is that passenger railroads in the United States own very little actual track, and rely too heavily on using freight-owned tracks. There's lots of railroad magazines that write about this ongoing problem every month.
- IIAOPSW 4y ago
  No, CTA cannot do that. If they did, CTA would have to take a bunch of expensive steps to make their stuff complaint with FRA regs. And no, the local freight railroads aren't "choosing" to let Metra be. They pretty much have to. That was part of the agreement when the regulators allowed the railroads to drop passenger services (which they were previously legally obliged to keep). There's a process, which hasn't been put into practice for a while but is still on the books, for Amtrak to demand the right to use certain tracks (the exact scenario where this happens escapes me).
  - reaperducer 4y ago
    No, CTA cannot do that You should tell the CTA. It will be news to them.