Does the end car of a train shake and move around more than the other cars of the train?

Question

Sorry we cant all be mechanical engineers.

Answer 1

They sure do.

Keep in mind there is at least three or four inches, and in most cases up to a foot or more of slack between each car.  So, with a 100 car train, the cars at the end are like being at the end of a whip.  If changes in slack are not made gradually, as the slack runs through the train, it gathers momentum.  By the time it reaches the end of the train, the action can be quite violent.

When watching a train pass, you will note from time to time a boxcar with the end bulging outwards, or a bulkhead flat with the wood of the bulkhead all blown to bits.  This is due to shifted loads, because of excessive slack action.

This was another argument for doing away with the caboose.  The slack action has injured and killed many crewmen on the rear of the train.  Cabooses are the only piece of railroad equipment (outside of a 'flanger') I ever saw equipped with seat belts (on the SP).

This is why when now running without a caboose, the last car in the train cannot be an "open load," such as pipe on a flat car, or lumber on a flat car with no bulkeads, etc.  Semi-trailers on flat cars (piggy backs) must not have the doors pointing toward the rear.  These restrictions are in place so that harsh slack action doesn't 'unload' the car or van onto the right of way, creating a serious hazard.

When the slack is all stretched, when under power, or all bunched, when using dynamic brake, all cars are moving at the same speed.  But, in undulating territory, when cresting grades, etc., the cars do run, momentarily, at different speeds, until the slack has been reconfigured.  One of the more important jobs for the engineer is to keep control of the slack, while still observing speed restrictions and other rules compliance.

The ability to understand and appreciate this concept is one of the differences between a "locomotive engineer" and a "mechanical engineer"......

So, I'll promise not to design anything if the gentleman above promises not to run any trains.

Answer 2

The answers above are correct, when i started training, i was told by an "old timer" (who at the time was younger than I am now) that all you gotta do to be an engineer is "control the slack".

If you can do that, everythign else is secondary.

Back in the day of cabooses, that was the best mark you could get as a hoghead, to be known by the rear brakemen and conductors as a smooth ride.

I remember the first time a grizzled old conductor walked in the depot after a trip and said "good ride kid".

That was almost as good as s*x LOL.

Answer 3

derail:  a 50 car auto train with certain type s of cushion devices can have 1 1/2 ft. of slack PER CAR.  thats 75 feet of slack action in one 50 car train

Answer 4

Yes, the last car does move around more than the rest, as, there is no supporting action on the free end of the car, not to mention the slack-action as noted in the excellent answers above.  I noted the extra movement on a train hauling automobiles when I lived next to the CNW in Hudson, Wisconsin.  The last 2 cars were of the open-frame type autoracks and the very last car's autos were bouncing around a lot more than the car ahead of it.  I'd hate to be the buyer of any of the autos on that last car, the suspension systems will be shot by the time it gets to its destination.

K. Kaas

Answer 5

The mechanical engineer assumes that railroad tracks are as level as a sheet of glass. No way!

To add a little on Hoghead's answer, it's useful to note that the last few cars on a train have the least tension in their couplers. They're being pulled by the rest of the train, but they're not pulling anything else behind them. As the train passes over a low joint and the cars dip in, they swing less and less as the center of the train approaches. This is because the center cars have half a train pulling on both ends, which is a buttload of longitudinal force. Once the center point passes, the swaying picks up, and sometimes those last few will rock like h**l. We had a combine on our excursion train that had to stay in the center for this very reason. Often times you won't notice the difference in sway, because there are so many other factors. Springs wear out, frames get twisted, wheels get chewed up, empty cars get mixed with loaded ones, and on and on.

And as Hoghead said, the mark of a skilled engineer is his or her ability to control slack action. Small power adjustments and brake applications do their part, but a good share of it is in the idiosyncrasies of the track and the equipment. There's a lot to consider here, way beyond textbook physics.

Answer 6

Yes.

The cars in the middle are being "pulled" by the cars in front so there is tension forward.   The same cars are being "held back" by the cars behind,  so there is tension to the rear.   So the cars in the middle are like beads on a tightly stretched necklace and there is little room for motion to the sides.

The car at the end is being "pulled" by the cars in front so there is still the same forward tension.  But there is nothing behind it,  so there is no tension to the rear and it has much more ability to move to the sides.  

Another example that makes it easy to understand.   Look at a flag the next time there is a high wind.   It is only the very end that is not under tension that flaps.  The end next to the flag pole is rock steady,   the center is pretty solid but the edge is going like crazy.

Answer 7

I am going to say "no". I think the cars in between will rock  because they are connected front and back they will pull on each other and pass along the motion. But the end car does not push that rocking motion. The rocking ends with the last car.   My best guess and explanation.

Answer 8

People who believe this are way too gullible and fall for the power of suggestion.  It is on a track so why would it shake more?  Every car follows the exact same track and goes the exact same speed.  I've actually heard somebody say the last car is faster.  That makes no sense at all.  Just because your friend says something is true doesn't make it so.  Use common sense.

Answer 9

Yes - just like a roller coaster, the last car always shakes more.

Answer 10

this is where allthe slack movement cab felt at other wise no

Answer 11

I can understand your reasoning. The thought would be that the rear car is secured, so to speak, at only one end. Unlike the other cars which are coupled at both ends, and may be more stable. The truth is that the rear car rides just like all the others. There is a phenomenon called "slack action". The couplers fit rather loose - they're designed that way. The locomotive can start out from a stop, move a couple feet before the 10th car begins to move. This is pulling the slack out. On a 100 car train, therefore, the engines could potentially move ahead 80 feet before the rear car moves. Back in the days of cabooses, this could mean the caboose could go from 0 to 10 mph instantly, and throw the occupants out of their seats and against the rear wall. But that was rare. Any Engineer with more than two weeks experience can  control the slack action. I used to work with the same Engineer quite often back then. He had  excellent train handling capabilities. As part of our custom, just before starting a trip, he'd call back to us in the caboose on the radio and say, "Lay down and hang on to something boys, here we go."