3 ms·

The space on tube carriages is used for ... passengers. Unlike long-distance trains (where the locomotive is a rather sizeable unit of its own and has pretty mu

by fch42 1y ago

The space on tube carriages is used for ... passengers. Unlike long-distance trains (where the locomotive is a rather sizeable unit of its own and has pretty much an electric substation of its own in it), the parts of a tube train reserved for driver, engines, electrical distribution are comparatively tiny. see https://tfl.gov.uk/corporate/transparency/freedom-of-information/foi-request-detail?referenceId=FOI-0732-1920 https://tfl.gov.uk/corporate/transparency/freedom-of-informa... Seems not trivial to just put extra batteries and the circuitry for regen breaking charging in.

altairprime 1y ago
How many watts of extra energy would be required to accelerate each kilogram of batteries on the train? Would the additional thermal load introduced by battery charge and discharge effects counteract or worsen the desired cooling outcome? It may be better to install such batteries somewhere on each track circuit as fixed stations, that can vent their charging and dispersal heat away from passenger tubes, rather than mobile — assuming that onboard emergency power needs are already met.
- rsynnott 1y ago
  > How many watts of extra energy would be required to accelerate each kilogram of batteries on the train? That's not really the problem; the problem is there is _no space_. Ever been on a London Underground train? You certainly wouldn't want the interior getting _smaller_.
  - Symbiote 1y ago
    It's also a fire hazard. I'm sure they'd consider the worst-case scenario, and at present that's probably some serious arcing within a motor causing a fire. Cutting the track power (easily done by the driver) then makes that a fire that can be handled with water and/or foam. Smoke from large batteries would be very hazardous.