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  • 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

 #1452862  by CLamb
 
Has there been any experimentation on coupling of two trains in motion? I'm imagining something like one train in motion and another coming up behind it and coupling on.
 #1452868  by DutchRailnut
 
no matter how you tried both trains would end up with emergency braking . trains are designed so two control stations can never be active at same time.
 #1452870  by radio
 
If the trains were only coupled mechanically, how would a control station know to initiate emergency braking? What the OP describes sounds similar to the Crazy 8's incident in 2001, which the movie Unstoppable was based on.
 #1452891  by DutchRailnut
 
Mechanically coupling yes it can be done , but to stop a train the air has to be connected too.
if it were a automatic coupler the air would connect, but so would control .
 #1452918  by CLamb
 
There are automatic couplers which make all connections automatically. I'm assuming the control system would be adapted to allow for such an event. It sounds like no one here has heard of it being tried.
 #1452949  by DutchRailnut
 
it would be a no no under most railroad guidelines to have more than one control station active.
Only one who would support such insane idea would be ISSIS.
 #1452973  by CLamb
 
DutchRailnut wrote:it would be a no no under most railroad guidelines to have more than one control station active.
Only one who would support such insane idea would be ISSIS.
Of course, no railroad allows it yet. It hasn't been developed. It's no more insane than powered a ship by building a bonfire under her decks.
 #1456910  by BR&P
 
While "thinking outside the box" is fine, I'm not sure exactly what you would hope to accomplish, nor how exactly you propose it would work.

As stated above, physical coupling in motion is possible now, but not the braking nor propulsion/control systems. Unless you can conceive of a radicaly adaptive method, the cost of changing the nation's rail equipment to such a different design would far, far outweigh any advantages.
 #1456949  by ExCon90
 
An interesting engineering challenge would be how to arrange for PTC to permit a train to get close enough to a preceding to train to couple to it while both trains are in motion.
 #1456954  by Wayside
 
I don't understand what the advantage would be to coupling while in motion.
 #1456957  by DutchRailnut
 
There is non, you would still require two crews, be it at last stop or at jct .
 #1457005  by CLamb
 
Wayside wrote:I don't understand what the advantage would be to coupling while in motion.
There would be no need to slow down to add or remove cars. Consider an MU commuter train making multiple stops. Instead of stopping to pick up passengers at each station a car could be pre-boarded and then join the train en route.
 #1457038  by Wayside
 
Interesting concepts. Many things would have to change in order for them to become reality with today's equipment and practices.
 #1457177  by talltim
 
In the UK and possibly elsewhere, they used to have slip coaches, which were uncoupled as an express came towards a station and were braked to a halt in the platform while the train carried on non-stop.
https://en.wikipedia.org/wiki/Slip_coach" onclick="window.open(this.href);return false;
 #1542162  by urr304
 
That practice in the UK would be definitely against the rules in the US for cars occupied by other than employees.

In the US, it was fairly common to drop off pusher engines on the fly when we had cabooses [cabin cars, vans, whatever]. Many cabooses were equipped with a extension handle to the air brake hose valve. Shut the valve and pull the pin to drop the pusher off while continuing on, most likely at a slow or limited speed. IIRC, the pushers used on NYC passengers up West Albany Hill were cut off on the fly too, but I do not know that particular arrangement.

It was also quite frequently that cabooses would be dropped off on the fly as they entered a yard and routed onto a caboose track. As many of you know that was called a Dutch drop and was used for switching freight cars out. Of course, you had to have someone onboard to set the hand brake to stop the car.

Most of these practices are not needed now, and in most cases are against the rules anymore.