• Empire Builder on the Ground in MT

  • Discussion related to Amtrak also known as the National Railroad Passenger Corp.
Discussion related to Amtrak also known as the National Railroad Passenger Corp.

Moderators: GirlOnTheTrain, mtuandrew, Tadman

  by David Benton
 
photobug56 wrote: Mon Oct 04, 2021 8:02 pm
BandA wrote: Mon Oct 04, 2021 5:37 pm There was a school bus rollover accident in maritime Canada (from the US) where there were fatalities that would have been prevented if the students were belted. That city now requires seatbelts on their school buses. (Driver who was unfamiliar with the route, who didn't speak English, multi-hour trip and was driving much too fast on an off ramp.)

I have read that three-point seatbelts would require stiffer seats that would cause more injuries in unbelted passengers. This doesn't seem to make sense to me but I am not an expert.
School bus seats are stiff to begin with.
Must be all the chewing gum. :wink:
Strange rules here , if a bus is a schoolbus , the drivers seat does not need a seatbelt. Convert the same bus to a motorhome and it does . It must be attached to the vehicle body , as Excon says, or alternatively , the whole seat must be engineered if attached to the seat. now they have decided the seat must be certified anyway, don't want seats turning into missiles.
A train is different , as people are free to move around. Would be nice to have seatbelts there as an option though, for people who feel safer with one on.
Riding backwards is safer too, Though i don't expect that would ever go down in the USA. Ever wonder why the air crew are belted in facing you ???
  by R36 Combine Coach
 
NJ is the only state that require seat belts on school buses and enforces use.

Newer "over-the-road" buses for long distance, suburban and interurban service (such as MCI coaches)
now have belts for passengers, due to revised Federal Motor Vehicle Safety Standards.
  by justalurker66
 
David Benton wrote: Mon Oct 04, 2021 10:03 pmRiding backwards is safer too, Though i don't expect that would ever go down in the USA. Ever wonder why the air crew are belted in facing you ???
Other than it being safer in a crash it also allows the crew to look at the passengers and watch for idiots unbelted and pulling stuff from the overhead compartments before the seat belt light is turned off.

Yes, people are idiots on airplanes as well as on trains although the additional effects of alcohol at altitude are not on a train and it is a lot easier to drop off a passenger to the nearest police agency when on a train. Not so much need to "duct tape to a seat until we land".

Somehow I think that the NTSB report on this incident will focus more on surviveability than the cause of the derailment.
  by John_Perkowski
 
justalurker66 wrote: Tue Oct 05, 2021 12:09 amSomehow I think that the NTSB report on this incident will focus more on surviveability than the cause of the derailment.
The preliminary report will focus on causes. The final report will provide the recommendations.
  by Marcop23
 
photobug56 wrote: Sun Oct 03, 2021 1:42 am And from what I've seen and what you are saying, the wheels on a given axle are solidly attached to the axle so that the 2 wheels and axle normally spin as one. I'm wondering if that's just to save money or if there is another reason.
It's not to save money, the solid axles are actually essential to how a train steers itself. As someone else already explained, the wheels are conical. If a truckset is riding too far to the right side of the rail, the difference in diameter of the wheels combined with the fixed axle cause the train to steer back to the left.
TurningOfTheWheel wrote: Sun Oct 03, 2021 12:12 am The Wiki article on hunting oscillation has a useful animation to see what's going on. I can't explain the phenomenon very well, but as I understand it, at high enough speeds, slippage can occur and the two wheels on each axle can start spinning at different speeds. When this happens, there is an oscillation induced in the vertical axis—from a bird's-eye view, the axle will appear to turn back and forth. It's called a "hunting oscillation" because the wheels are "hunting" for some equilibrium where they are either both spinning at the same rate or agree on the direction they should be headed given the difference in their rotational speeds.

https://en.wikipedia.org/wiki/Hunting_oscillation
The wheels on an axle cannot spin at different speeds. Let's say that a train is pushed to the right side, by some kind of unevenness in the railroad. The steering action of the axles will steer the train back to the left side, but it continues moving left until it's steered back again to the right again. Compare it with a pendulum clock, once its moving, it keeps oscillating, although with trains it only happens if the train is moving fast enough.

To combat it, there are often dampers installed between the truck and the body of the train. That absorbs the energy of the side-to-side motion. Compare it with the shocks in a car: Without it, if you drive over a bump, the car would be really bouncy.

There is one exception though: The Talgo cars don't have rigid axles at all. Instead, the wheels steer like a car, by a linkage that steers the wheel dependent on the angle between two adjacent cars. That way, there is no hunting.
  by Gilbert B Norman
 
An aside to our seat belt discussion here, why is it that First and Business Class passengers on airplanes get three point belts while those in Coach only get two.

Strikes me as "Titanic like" thinking that some human lives matter more than others.
  by photobug56
 
Marcop23 wrote: Tue Oct 05, 2021 6:20 am
photobug56 wrote: Sun Oct 03, 2021 1:42 am And from what I've seen and what you are saying, the wheels on a given axle are solidly attached to the axle so that the 2 wheels and axle normally spin as one. I'm wondering if that's just to save money or if there is another reason.
It's not to save money, the solid axles are actually essential to how a train steers itself. As someone else already explained, the wheels are conical. If a truckset is riding too far to the right side of the rail, the difference in diameter of the wheels combined with the fixed axle cause the train to steer back to the left.
TurningOfTheWheel wrote: Sun Oct 03, 2021 12:12 am The Wiki article on hunting oscillation has a useful animation to see what's going on. I can't explain the phenomenon very well, but as I understand it, at high enough speeds, slippage can occur and the two wheels on each axle can start spinning at different speeds. When this happens, there is an oscillation induced in the vertical axis—from a bird's-eye view, the axle will appear to turn back and forth. It's called a "hunting oscillation" because the wheels are "hunting" for some equilibrium where they are either both spinning at the same rate or agree on the direction they should be headed given the difference in their rotational speeds.

https://en.wikipedia.org/wiki/Hunting_oscillation
The wheels on an axle cannot spin at different speeds. Let's say that a train is pushed to the right side, by some kind of unevenness in the railroad. The steering action of the axles will steer the train back to the left side, but it continues moving left until it's steered back again to the right again. Compare it with a pendulum clock, once its moving, it keeps oscillating, although with trains it only happens if the train is moving fast enough.

To combat it, there are often dampers installed between the truck and the body of the train. That absorbs the energy of the side-to-side motion. Compare it with the shocks in a car: Without it, if you drive over a bump, the car would be really bouncy.

There is one exception though: The Talgo cars don't have rigid axles at all. Instead, the wheels steer like a car, by a linkage that steers the wheel dependent on the angle between two adjacent cars. That way, there is no hunting.
I'm guessing that Talgo style wheel sets cost more, but sound better. But I'm no engineer.
  by photobug56
 
Gilbert B Norman wrote: Tue Oct 05, 2021 9:34 am An aside to our seat belt discussion here, why is it that First and Business Class passengers on airplanes get three point belts while those in Coach only get two.

Strikes me as "Titanic like" thinking that some human lives matter more than others.
When did airliners start getting 3 point seat belts for some passengers? 15 years ago I flew a fair amount of Trans Atlantic business class, just 2 point.
  by eolesen
 
photobug56 wrote:
Gilbert B Norman wrote: Tue Oct 05, 2021 9:34 am An aside to our seat belt discussion here, why is it that First and Business Class passengers on airplanes get three point belts while those in Coach only get two.

Strikes me as "Titanic like" thinking that some human lives matter more than others.
When did airliners start getting 3 point seat belts for some passengers? 15 years ago I flew a fair amount of Trans Atlantic business class, just 2 point.
Anything in a herringbone pattern (angled seating) has had a shoulder strap for at least 20 years. I don't recall staggered seating before then. I flew backwards on Southwest in 1998 and it was just a two point.

Sent from my SM-G981U using Tapatalk

  by MBTA3247
 
photobug56 wrote: Tue Oct 05, 2021 9:46 am I'm guessing that Talgo style wheel sets cost more, but sound better. But I'm no engineer.
Talgos have a radically different design from anything else on the rails. The low-slung body requires very different engineering solutions, especially for the wheels and suspension, than you find on rolling stock with traditional trucks at either end. Whether Talgo wheels are any better than solid wheelsets is irrelevant, because they're designed for different things.
  by photobug56
 
Understood, but that leads to a new question - outside of trains needing 2 level cars, is the general Talgo design a better way to go in passenger rail? Also, on 2 level cars (I ride LIRR bilevels), how can you get the center of gravity AND total height down? While curious from the LIRR view, I would think that it would be a good thing for passenger rail safety if you didn't lose too much in the process. Not that it's likely to be a big issue in this accident.
  by justalurker66
 
Gallery style cars (open centers up to the second level) can help but on most two level cars one has to have enough room for people to walk upright. No overhead storage shortens the height of each level. Allowing people to walk upright is the beginning of defining a minimum interior height. Then you just have to wrap the structure of the car around that space.

Center of gravity can be controlled by putting heavy things down low. The Superliners have heavy things above the wheel sets so I'd say that they are balanced well between being "top heavy" and keeping heavy things low. Single level cars put those heavy things between the wheels (close to the tracks) but that reduces passenger space on a two level car.

Some two level cars are designed with heavy things (such as air conditioner units) up high. The Superliners don't have that potential problem. Yes, four cars of this train ended up on their sides. We have seen single level cars end up on their sides or rolled.
  by photobug56
 
Part of what we look forward to hearing is how those Superliners behaved and why. What can we learn from this. I know, could be a few years off.
  by Gilbert B Norman
 
Messrs. Lurker and Bug, your immediate comments lead me to hold that bi-level equipment is "done for" on Amtrak. Single level will be "the order of the day" systemwide.

Joplin is hardly the first incident in which Superliners have overturned, but with Amfleets and Viewliners, it takes an incident rising to the level of Frankford Jct ('15; lest we forget there was also a 1943 incident there as well) to overturn single level equipment. At Cayce, none of the cars overturned.

While we don't know for certainty at this time, the Joplin passenger fatalities, all occurred in overturned cars.

While bi-level equipment will not vanish overnight much as have the Talgos, I think Amtrak will not order anymore, with the Nippon Shyaru fiasco reminder enough - especially when driving by the Rochelle IL facility on I-88 and seeing it decaying. The S-II's have some ten years of service life remaining, so may as well use it with fingers X'd for no more of Hyder, Crescent City, Joplin, et al. I think with the uncertain future the LD trains have, as the reality that Amtrak will get funded without them sets in, any future equipment orders for them should be readily convertible to short distance use. This is not the case with any equipment placed in service today. While of course, the A-II's evolved from the A-I's, they were hardly designed to be short distance convertible (this could have been "by design" of the factions about Amtrak that wanted LD to continue indefinitely).
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