Railroad Forums 

  • Coupling in motion?

  • General discussion about railroad operations, related facilities, maps, and other resources.
General discussion about railroad operations, related facilities, maps, and other resources.

Moderator: Robert Paniagua

 #1542588  by jwhite07
 
Promotional literature I have from the 1996 US demonstration tour claims that the Adtranz Flexliner was capable of coupling and uncoupling units while moving at low speed.
 #1542602  by bostontrainguy
 
jwhite07 wrote: Wed May 13, 2020 5:53 am Promotional literature I have from the 1996 US demonstration tour claims that the Adtranz Flexliner was capable of coupling and uncoupling units while moving at low speed.
Yes, that's the one. I was trying to remember that train with the rubber donut up front that could do this. Thanks!

https://en.wikipedia.org/wiki/IC3
 #1543794  by Allen Hazen
 
I believe there was some development work and experimentation done in France on an automated (no on-board crew) "people mover" system called Aramis. Self-propelled cars would leave stations when passengers got on, but (to save track space?) they would form up with other cars in trains for the line haul. A first idea was that the trains would be united by "virtual couplers": no physical connection, but controlled to maintain a constant, short, distance between cars. Precise enough control to make "virtual couplers" practical was... not possible with the technology of the time. (1970s, I think, but I'm not sure.) So, I believe, later iterations of the scheme involved cars making physical contact to form trains. I don't think the scheme ever reached the stage of a usable system, but the basic ideas seem feasible.
 #1543820  by bostontrainguy
 
Allen Hazen wrote: Mon May 25, 2020 11:13 pm I believe there was some development work and experimentation done in France on an automated (no on-board crew) "people mover" system called Aramis. Self-propelled cars would leave stations when passengers got on, but (to save track space?) they would form up with other cars in trains for the line haul. A first idea was that the trains would be united by "virtual couplers": no physical connection, but controlled to maintain a constant, short, distance between cars. Precise enough control to make "virtual couplers" practical was... not possible with the technology of the time. (1970s, I think, but I'm not sure.) So, I believe, later iterations of the scheme involved cars making physical contact to form trains. I don't think the scheme ever reached the stage of a usable system, but the basic ideas seem feasible.
I have this crazy idea (or maybe fear) that the future could be exactly this with self-driving trucks. Think of a moving " train" of self-driving trucks running along a rail line at 100 mph. WIth advanced technology, certain trucks drop out of the string and go their merry way to online yards for local delivery. Others leave the same yards and catch up with the "train" and head to their destinations.

When I heard that self-driving trucks will be able to go coast to coast in three days I started thinking. Time to join the revolution or keep my stocks in Buggy Whips, Inc.?
 #1549223  by D Alex
 
I'm certain with today's technology, it would be possible. Something like this could be used for helper locomotives coupling to the end of a train. Suppose that a line was mostly flatlands, with only 1 relatively short steep section; a helper could couple 'on the fly' just for the ascent, then decouple, go onto a siding, and wait for the next train going the other way. Heck, this could even be completely robotic!

But, the problem here is that, as the railroad federal rules stand today, this would be legal nowhere at all.
 #1550663  by ExCon90
 
The Carstens book on the NYS&W says they were doing that when the Russian decapods were hauling Pennsylvania anthracite across northern New Jersey (at some risk to the train crew, but all in a day's work at the time).
 #1553373  by D Alex
 
The problems with all these ideas is that they would all still require multiple crews. The 'slip coach' idea is based on there being a switching locomotive standing by at the station in order to switch the car off the track, then onto the back of the next through train that stops. The idea of a commuter car joining a longer train also makes little sense, since if it needs it's own crew anyway, why not just have them pilot the thing on it's own? There WAS a time when RDC cars were included in longer passenger consists, and were dropped-off (while stationary!) at various locations in places like Texas and New Mexico in order to serve branch lines, but there was never the sort of urgency needed to resort to cutting them loose at speed. Trains are designed to be able to stop, after all.