3 ms·

I was wondering if this could be an actual problem. Assuming a maximum length of 700m, you get 2.73m per axle. So - 2 axle cars must be longer than 5.76m - 4

by dukoid 10y ago

I was wondering if this could be an actual problem. Assuming a maximum length of 700m, you get 2.73m per axle. So - 2 axle cars must be longer than 5.76m - 4 axle cars must be longer than 10.92m - 6 axle cars must be longer than 16.38m Found this 6 axle car with a length of 15.0m: https://de.wikipedia.org/wiki/Flachwagen#S-Wagen_f.C3.BCr_schwere_Lasten https://de.wikipedia.org/wiki/Flachwagen#S-Wagen_f.C3.BCr_sc... So yes, this seems to be a real problem, as it is possible to arrange a train with with 256 axles with this type of car that does not violate the maximum length restriction.

masklinn 10y ago
> I was wondering if this could be an actual problem. In Switzerland? Probably not. In other places definitely, large-countries (USA, Canada, Australia) freight and coal/ore trains are hundreds of cars long (and each car has at least 2 bogies of 2 axles), the record is 682 cars and 8 locomotives.
- reustle 10y ago
  This has some really interesting info https://en.m.wikipedia.org/wiki/Longest_trains https://en.m.wikipedia.org/wiki/Longest_trains
- andyv133 10y ago
  Although not all rail systems in all countries use axle counters for presence detection. In the US freight industry we use track circuits - https://en.wikipedia.org/wiki/Track_circuit https://en.wikipedia.org/wiki/Track_circuit
  - Symbiote 10y ago
    That's not a replacement, that's the older technology. Axle counting guarantees that there isn't a detached, derailed wagon fouling the line, or a wagon with dirty wheels which aren't completing the track circuit.
    - andyv133 10y ago
      Nonetheless, it is what is used on freight lines in the U.S quite successfully, and provides other protections such as broken rail detection. Detached cars are detected using the FRED/braking system, and secondarily by axle counts given by hot box detectors read over the radio.
- imtringued 10y ago
  Is there any reason why those 8 locomotives have to form a single train? Can't they just have 8 seperate trains?
  - Symbiote 10y ago
    A single train only needs one driver, not eight. Eight trains would need a gap between them — typically several km per train — so the capacity of the line is increased by having longer trains. Air resistance would be higher for eight trains.
  - Viper007Bond 10y ago
    Those 8 locomotives can be controlled by a single team of people. Additionally it allows greater freight throughput because you need to maintain minimum distances between trains. It's actually extremely uncommon where I live to see a train with a single locomotive.
  - masklinn 10y ago
    Well technically that specific train was a stunt (at the time BHP Billiton's regular run used 336 cars and 6~8 locomotives, now 264 cars and 4 locomotives), other commenters have answered as to why you'd want to run longer trains (and AFAIK modern trains rarely run a single locomotive these days, a pair is just more efficient and convenient even on passenger trains) See https://en.wikipedia.org/wiki/Distributed_power https://en.wikipedia.org/wiki/Distributed_power for more information on running distributed power.
    - pm24601 10y ago
      Not to mention, if a loco had a failure the second loco would get the train off the main or to a convenient yard swapping out the failed locomotive.
- dukoid 10y ago
  No? What's wrong with my calculation then?

by dukoid 10y ago

masklinn 10y ago

> I was wondering if this could be an actual problem. In Switzerland? Probably not. In other places definitely, large-countries (USA, Canada, Australia) freight and coal/ore trains are hundreds of cars long (and each car has at least 2 bogies of 2 axles), the record is 682 cars and 8 locomotives.

reustle 10y ago
This has some really interesting info https://en.m.wikipedia.org/wiki/Longest_trains https://en.m.wikipedia.org/wiki/Longest_trains
andyv133 10y ago
Although not all rail systems in all countries use axle counters for presence detection. In the US freight industry we use track circuits - https://en.wikipedia.org/wiki/Track_circuit https://en.wikipedia.org/wiki/Track_circuit
- Symbiote 10y ago
  That's not a replacement, that's the older technology. Axle counting guarantees that there isn't a detached, derailed wagon fouling the line, or a wagon with dirty wheels which aren't completing the track circuit.
  - andyv133 10y ago
    Nonetheless, it is what is used on freight lines in the U.S quite successfully, and provides other protections such as broken rail detection. Detached cars are detected using the FRED/braking system, and secondarily by axle counts given by hot box detectors read over the radio.
imtringued 10y ago
Is there any reason why those 8 locomotives have to form a single train? Can't they just have 8 seperate trains?
- Symbiote 10y ago
  A single train only needs one driver, not eight. Eight trains would need a gap between them — typically several km per train — so the capacity of the line is increased by having longer trains. Air resistance would be higher for eight trains.
- Viper007Bond 10y ago
  Those 8 locomotives can be controlled by a single team of people. Additionally it allows greater freight throughput because you need to maintain minimum distances between trains. It's actually extremely uncommon where I live to see a train with a single locomotive.
- masklinn 10y ago
  Well technically that specific train was a stunt (at the time BHP Billiton's regular run used 336 cars and 6~8 locomotives, now 264 cars and 4 locomotives), other commenters have answered as to why you'd want to run longer trains (and AFAIK modern trains rarely run a single locomotive these days, a pair is just more efficient and convenient even on passenger trains) See https://en.wikipedia.org/wiki/Distributed_power https://en.wikipedia.org/wiki/Distributed_power for more information on running distributed power.
  - pm24601 10y ago
    Not to mention, if a loco had a failure the second loco would get the train off the main or to a convenient yard swapping out the failed locomotive.
dukoid 10y ago
No? What's wrong with my calculation then?