Not sure I understand the concern here. Absolutely, coupling rail cars at speed would be a big problem with existing rail equipment. I didn't see that requirement in the list :-) If you "squint and turn your head a bit" this is what's being discussed as the future of self driving cars. Automatically merge and separate from other traffic. Follow very (very) close at speed. I would think that doing it on a fixed track would simplify the process by removing several variables. On Wed, Nov 1, 2017 at 6:17 AM, rossano gobbi < straighttowardsextinction@gmail.com> wrote: > Interesting thanks. A problem with this has been pointed out by David. > Another is that you could only leave the train. > Coupling a coach on a running train would be very dangerous. With some > very sofisticated help from technology (or some late 18th century boldnes= s > :-)) it could surely be done, but it would need to be failproof and the > space needed to do it would be great, increasing proportionally with the > running train's speed. Surely undoable in cities or urban areas. > > These days a modern train can stop and restart in very few seconds, thank= s > to the traction tecnology but also to the train and platform designs. It'= s > even faster for trams and such. > > Besides the fact that a decrease in the trains running times would mean > more trains but then you would have to find the $$$ to buy those trains, > the technology to allow them to run faster, the place to build the needed > infrastructure, the terminal stations where to fit them in, etc... > Actually, these are today's problems. Trains could perform better, but th= e > infrastructure can't handle them. Old (or new old-style-built) tracks > designs, old block systems, single track lines, no place/no money/no > political will to build new infrastructure... > > Greetings from Switzerland, land of trolley buses... > Rossano > > Il giorno 29 ott 2017, alle ore 00:34, < > alan.b.pearce@stfc.ac.uk> ha scritto: > > >> Back in my youth British mail trains had a sytem for picking up mail > bags > >> without stopping https://www.youtube.com/watch?v=3DUN9GxmtfX90 > >> Surely this could be adapted to pick up passengers :-) > >>> > >>> I've always thought could be done with trains, whether commuter or > >>> long distance, would be to have a self-powered train car at each > >>> station. People wanting to get on the train would board this car. > >>> People on the train who wanted a particular stop would get into the > >>> last car. As the train approached the station, the last car would > >>> disconnect and roll into the station. The car that was in the station > would > >> then catch up with the train and join it. > >>> Passengers not wanting the next stop would move into the rest of the > >>> train. What slows trains down, in my opinion, is all the stops. This > >>> would avoid that delay. > > > > I surprised David didn't mention that British railways (back in the day= s > of steam trains) had what were known as 'slip coaches' which did almost > exactly this. The last coach on the train would be uncoupled and then a > guard on the slip coach would apply braking to bring the coach to a halt = in > the station. Once everyone had got off the local shunting engine would mo= ve > the coach into a local siding. I never saw them in operation, just seen > descriptions in books. I don't know how the coaches were picked on the > return journey, which had to involve a stopping train, I guess it would b= e > possible to load the coach on a side platform, then when the train came > along couple the full coach to the train. > > > > There was a certain amount of danger to the process of slipping a coach > from the train, and a considerable amount of skill on the part of the gua= rd > to uncouple the coach at the right place and then get the braking just > right to stop in the platform, especially in some of the pea-souper fogs > that abounded in the UK back then. I was reading a piece recently where t= he > guard on the slip coach was describing exactly this problem. If you didn'= t > stop in the station then no-one knew where the coach was, had it not > uncoupled, had it not made the station, or had it had some other problem? > Any of these could result in a blocked line which had the potential to > result in a significant accident. > > > > > > > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .