# A method of more efficient train travel: would this work? **URL:** \ **Category:** Factual Questions\ **Created:** [November 3, 2003, 4:39am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099 "2003-11-03T04:39:53Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Freiheit](https://avatars.discourse-cdn.com/v4/letter/f/e8c25b/32.png) [@Freiheit](https://boards.straightdope.com/u/Freiheit)\ **Post date:** [November 3, 2003, 4:39am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/1 "2003-11-03T04:39:53Z")
Say a train is going from Hamburg to Stuttgart, and is passing through Göttingen. To get to Stuttgart the soonest, a stop through Göttingen would not be the best choice. But there are Hamburgers that need to get to Göttingen. On my train are two sections. Those on their way to Stuttgart get in section A, and the Göttingen-bound get in section B in the rear. Somewhere before its destination, section B breaks away from section A. It puts on the brakes and rolls into town. The rest of the train keeps on going without need to stop, and everybody’s happy. Anything wrong with this idea? Does anything like this actually happen? ---
**Author:** ![Shalmanese](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@Shalmanese](https://boards.straightdope.com/u/Shalmanese)\ **Post date:** [November 3, 2003, 5:26am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/2 "2003-11-03T05:26:35Z")
What about people who want to get from Göttingen to Stuttgart? ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [November 3, 2003, 5:28am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/3 "2003-11-03T05:28:52Z")
Existing passenger trains can’t be coupled and decoupled without stopping. Besides the main coupler, there are electrical and pneumatic lines to be connected/disconnected. Even if you develop a fully automated coupler, is there much benefit in doing it that way? It seems far easier just to have two separate trains, a nonstop express train and a slower train with more stops. That’s how it’s usually done. The commuter train in my area has 3 classes of trains: a “local” that stops at every station, a “rapid” that stops at about half of the stations, and the “express” that only have 4 or 5 stops. ---
**Author:** ![Bumbazine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bumbazine/32/362_2.png) [@Bumbazine](https://boards.straightdope.com/u/Bumbazine)\ **Post date:** [November 3, 2003, 5:36am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/4 "2003-11-03T05:36:36Z")
What about the people who want to get ON at Göttingen? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 3, 2003, 5:46am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/5 "2003-11-03T05:46:56Z")
**scr4** covered the problem with decoupling commuter trains while they’re moving. (Not that this has never happened; in the old days of the first Grand Central Terminal in New York, engines would decouple from trains and switch tracks while the train coasted to stop at a platform.) But anyway, the plan leaves out people who want to get on at the intermediary stop. Since it’s a given that in most instances people will want to do so, it makes sense to simply have express and local trains. If people are traveling all over, such as in the New York subway system, you can have expresses that skip three or four stops at a time. On the other hand, if the bulk of people are going to or coming from one place, as in the various commuter railroads that go into New York City (MNRR, LIRR, NJT) then you can have express trains that skip the first half of the line and make stops on the second half. ---
**Author:** ![jovan](https://avatars.discourse-cdn.com/v4/letter/j/0ea827/32.png) [@jovan](https://boards.straightdope.com/u/jovan)\ **Post date:** [November 3, 2003, 5:54am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/6 "2003-11-03T05:54:16Z")
> [@](#): > > \*Originally posted by scr4 \* > \*\*The commuter train in my area has 3 classes of trains: a “local” that stops at every station, a “rapid” that stops at about half of the stations, and the “express” that only have 4 or 5 stops. \*\* Around where I live, JR does a low-tech version of what the OP is proposing. You’ll have, for instance, a twelve-car train leaving Nagoya with the front six cars going all the way to Maibara, and the last six stopping halfway at Ogaki. It still takes about a minute to separate the cars. The economy here is that the Ogaki-Maibara leg is quite rural and there is no reason to pull twelve cars when six are more than enough. ---
**Author:** ![Trygve](https://avatars.discourse-cdn.com/v4/letter/t/4af34b/32.png) [@Trygve](https://boards.straightdope.com/u/Trygve)\ **Post date:** [November 3, 2003, 8:05am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/7 "2003-11-03T08:05:32Z")
What Jovan mentioned exists in Europe too. On some trains they get split along the way (so make sure you are in the correct car!!) ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [November 3, 2003, 8:29am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/8 "2003-11-03T08:29:30Z")
> [@](#): > > \*Originally posted by jovan \* > \*\*Around where I live, JR does a low-tech version of what the OP is proposing. You’ll have, for instance, a twelve-car train leaving Nagoya with the front six cars going all the way to Maibara, and the last six stopping halfway at Ogaki. It still takes about a minute to separate the cars. The economy here is that the Ogaki-Maibara leg is quite rural and there is no reason to pull twelve cars when six are more than enough. \*\* The Narita Express does the same thing at Tokyo Station. Half of the train arrives first, and then shuffles down the platform while the second half chugs in. They connect up and zoom off to Narita. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [November 3, 2003, 9:18am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/9 "2003-11-03T09:18:03Z")
> [@](#): > > \*Originally posted by Trygve \* > \*\*What Jovan mentioned exists in Europe too. On some trains they get split along the way (so make sure you are in the correct car!!) \*\* Indeed. But the trains stop at the station where they’re spliting. And the OP doesn’t want the train to stop. Smae answers than the other posters. If there are people who want to stop in Göttingen, likely, there will be people who want to get on the the train in Gottingen too. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [November 3, 2003, 11:16am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/10 "2003-11-03T11:16:45Z")
> [@](#): > > \*Originally posted by clairobscur \* > \*\*If there are people who want to stop in G?tingen, likely, there will be people who want to get on the the train in Gottingen too. \*\* One exception is if the two stops are close together. For example, it might make sense for the Narita airport express to split in half as it approaches the airport. The rear half stops at Terminal 2, and the front half could go on to Terminal 1 without stopping. Nobody uses the express train to get from Terminal 2 to 1 anyway. It would save about 3 minutes for Terminal 1 passengers. ---
**Author:** ![Spoons](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spoons/32/3141_2.png) [@Spoons](https://boards.straightdope.com/u/Spoons)\ **Post date:** [November 3, 2003, 3:51pm UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/11 "2003-11-03T15:51:43Z")
Agree with the problems of uncoupling while moving. Too many other connections, among which would be a live 480 VDC electrical line (it’s 480 VDC on trains I’ve been on; others may use different voltages, of course) left hanging in the breeze. For safety’s sake, somebody would have to physically remove the electrical cable and recap the receptacles. Except for the uncoupling-while-moving, though, such trains do exist. VIARail’s trains 56 (Toronto-Montreal) and 42 (Toronto-Ottawa) leave Toronto at the same time (0930 weekdays) as a single train, and except for the locomotive smack in the middle of the train, look and work like pretty much any other train. Near Brockville, the train stops, and the middle-of-the-train locomotive and passenger cars are uncoupled. The front half of the train now continues to Montreal, while the back half switches to the Ottawa track, and heads for there. Yes, the train stops, but barring any serious problems, the whole operation doesn’t take long. I’ve been a passenger on that train (those trains?) many times, and except for the fact that nobody gets on or off, the length of time is not much different from a regular station stop. ---
**Author:** ![Mops](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mops/32/16494_2.png) [@Mops](https://boards.straightdope.com/u/Mops)\ **Post date:** [November 3, 2003, 3:52pm UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/12 "2003-11-03T15:52:29Z")
Uncoupling two parts of a train while rolling would also violate the principle of block signalling that only one train can be within a block at any time. Consider the following scenario: 1. Front half and rear half of train separate en route. 2. Front half accelerates; distance to rear half widens to some meters, and is expected to widen further, _but_ 3. Front half brakes unexpectedly (adverse signal/person on the line/someone pulls the emergency brake) Result: rear half crashes into front half. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [November 3, 2003, 6:02pm UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/13 "2003-11-03T18:02:29Z")
But they were in regular use on the Great Western Railway of Britain; from [http://www.glue-it.com/trains/general-information/glossary/s\_summ.htm](http://www.glue-it.com/trains/general-information/glossary/s_summ.htm) Slip Coach A railway coach which can be uncoupled from the back of a moving train, and then coast under the control of a guard to stop at the next station. ---
**Author:** ![GreyWanderer](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@GreyWanderer](https://boards.straightdope.com/u/GreyWanderer)\ **Post date:** [November 3, 2003, 6:14pm UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/14 "2003-11-03T18:14:54Z")
> [@](#): > > \*Originally posted by tschild \* > \*\*Uncoupling two parts of a train while rolling would also violate the principle of block signalling that only one train can be within a block at any time. > > Consider the following scenario: > > 1. Front half and rear half of train separate en route. > 2. Front half accelerates; distance to rear half widens to some meters, and is expected to widen further, _but_ > 3. Front half brakes unexpectedly (adverse signal/person on the line/someone pulls the emergency brake) > > Result: rear half crashes into front half. \*\* You could make a system that coordinates the brakes on the second train with the first one. So if the first one brakes for a reason, the second one will too. That won’t be much different than if they are attached to eachother. ---
**Author:** ![Pandoradox](https://avatars.discourse-cdn.com/v4/letter/p/9e8a1a/32.png) [@Pandoradox](https://boards.straightdope.com/u/Pandoradox)\ **Post date:** [November 4, 2003, 12:00am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/15 "2003-11-04T00:00:52Z")
but how much time would it really save? not very much when you look at time as a whole, i mean most people who travel by train have those stops planned in their day cause it is expected ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [November 4, 2003, 12:10am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/16 "2003-11-04T00:10:15Z")
I was going to post about the former “slip coach” method in Briotain, but **eburacum45** has beaten me to it. It does seem though that the subsequent need for a shunting locomotive and crew to remove the coach from the main line (and later to return the coach to its depot) would remove any efficiency gained. It also seems unlikely that modern safety regulations would allow an unpowered, coasting rail vehicle containing passengers and under the control of a non-engineman. A cool idea though. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [November 4, 2003, 12:40am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/17 "2003-11-04T00:40:44Z")
looking at a handydandy Amtrak scedual a normal train trip that takes: 2 hrs with 5 stops, 1 h 58 m on a run that makes 3 stops and 1 h 55 m on a run that makes 2 stops Now I’m sure there is some speed varing to make up for the stop time, as it seems a stop is longer then the scedual allows, but on this run the difference it mimimal, and there can be less crew onthe train(s). ---
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [November 4, 2003, 9:22am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/18 "2003-11-04T09:22:36Z")
Amtrak does something like this without the speed. On the Chicago to NYC / Boston run. In Albany the front part goes to NYC and the back part is uncoupled in Albany and gets a new locomotive and goes to Boston. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [November 6, 2003, 2:08am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/19 "2003-11-06T02:08:20Z")
Ok here’s a way something like this might work (not exactly the OP). Train 1 goes from point A to point B Train 2 goes from point C to point D Somewhere along the route the trains run on parrell tracks. While the 2 trains are moving side by side a support from one train joins the other,linking the 2 trains. Control is now given to a single train. An outer door and small extention is extended from one train matching up with the door of the other, while the interior doors are still closed. Once the doors are linked up they can open to allow passengers to cross from one train to another. When it’s time to delink the outer doors are shut, if the doors are not shut the train (combined train) brake automatically before they must sepperate (due to the track configuration). When the doors are closed the extention can be retracted and the trains can go their seperate ways. How this can help the OP: Before the train gets to Göttingen a train waiting on a siding matches speed with the train, the 2 link up and exchange passengers. At the same time people waitign at the platform board a 3rd train at Göttingen , as the thru train approaches the 3rd train sets off matches speed and passengers can board. ---
**Author:** ![Trigonal\_Planar](https://avatars.discourse-cdn.com/v4/letter/t/0ea827/32.png) [@Trigonal\_Planar](https://boards.straightdope.com/u/Trigonal_Planar)\ **Post date:** [November 6, 2003, 4:18am UTC](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099/20 "2003-11-06T04:18:47Z")
I ride the VIA trains (76, I think it is?) frequently between London and Oshawa. They have a really bizzare system when the train pulls into Toronto, where it always stops. They make everyone en route to Oshawa (or to London, if you’re going the that way) get off the car they’re in and move to another car…on the same train! Any ideas why they wouldn’t just load the “correct” destination car right from the beginning? Its quite an annoyance. [Next page](https://boards.straightdope.com/t/a-method-of-more-efficient-train-travel-would-this-work/211099.md?page=2)