Rotary Coupler End

I have noticed some coal/hopper cars have a colored panel on one end, that has the text "Rotary Coupler End" on it. Could someone please explain what this is?
 
Its so a string of cars like that can be rotated one (sometimes more) at a time to unload. The cars don't need couplers that can rotate at both ends if the cars are placed together so its always a rotatable coupler coupled to a non-rotatable coupler. As long as one end is rotatable everything works just fine. Get some clod to put a car in the consist backwards and you will (eventually) have a mess on your hands, lol.

Probably doesn't happen very often as consists like that are usually unit trains and only get broken up to extract a car for repairs.

Its a quick and slick way to empty a lot of cars in a small amount of time. Quite automated.

Ben
 
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Is this used for rotating dumpers? OHHHHHHHH, its so that one car can rotate in the dumper while the others stay connected to the train and don't turn over.
 
I fail to see how this is any faster than bottom-dump hoppers though.
It is a technical choice. Both will work.

When using a rotary dumper, cars do not have to have a bottom opening to dump coal. This is technically easier on the car, but requires as more technically difficult solution on the dump site.
 
You do not need men to open the bottom doors and in winter ice and snow can make the coal load into one big lump, so you save money.
 
Simple structural rigidity purposes if I had to venture a guess. Otherwise the walls would just be sheets of aluminum and those would deform pretty quick under dense loads like rock and coal.

I see the convenience aspect of rotary dumps, but it appears to come at the cost of speed/time. Assuming each car takes about a minute or so to unload (don't forget you need to inch each one forwards very precisely), a standard 100+ car consist would take in excess of 2 hours to finish unloading. Just a casual observation - I know nothing about these things and Wikipedia doesn't say much.
 
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The coal tipplers here at Richards bay Coal Terminal have mechanical horses driven by gears on tracks that move the consists automatically and positions each car precisely by means of electronic sensors and an arm that fits between the cars . Sometimes the rotating couplers stick during tipping and the cars derail. When cars are marshalled the wrong way round the tippler either breaks the coupler off or slaps the car onto it's side , there are directional arrows throughout on each car to show that they are all marshalled correctly, but despite this it still happens that they are the wrong way around.
 
An interesting question might be why not put rotating couplers at both ends? They are almost certainly spring loaded in a way so they are always "right side up" when not being rotated. $$$ perhaps? Re-railing a car or repairing one can't be cheap and it stops the entire unloading process when it occurs.

Ben
 
That is a good idea,I can't imagine some springs and some extra steel, and a ball bearing or whatever would cost that much, and if you were going over bad track, it would keep the consist on the tracks because the cars could tilt independently of each other. I have an idea for making a lego rotary coupler...
 
Check this out. Pretty cool.

I fail to see how this is any faster than bottom-dump hoppers though.

Because they can unload 1 car in about 1 min. Where as bottom dumping can take up to 30 min to pour all out. If the coal is not all clumped.

An interesting question might be why not put rotating couplers at both ends? They are almost certainly spring loaded in a way so they are always "right side up" when not being rotated. $$$ perhaps? Re-railing a car or repairing one can't be cheap and it stops the entire unloading process when it occurs.

Ben


They are not spring loaded. And this is why you have one rotary and one normal coupler. So the normal one rotates the rotary back to the level position. This reduces the number of parts needed to maintain.

Painting the rotary end helps keep the cars all pointed the right way in the event they have to set any out for repairs. To make things easier, they often set out 2 when one needs repaired. Then when the car is repaid, it is put on the next loaded coal train going to the consignee. This way there is no need to turn the car on a wye.
 
So if the rotatable coupler is not spring loaded how do they keep it from turning when uncoupled? If its upside down it isn't going to couple. Granted these are usually used on unit trains so are rarely by themselves but couplers aren't light. Take a certain amount of oomph to rotate one by hand for coupling I'd think, lol. Probably so much of a rare occurrence its not worth worrying about.

Ben
 
So if the rotatable coupler is not spring loaded how do they keep it from turning when uncoupled? If its upside down it isn't going to couple. Granted these are usually used on unit trains so are rarely by themselves but couplers aren't light. Take a certain amount of oomph to rotate one by hand for coupling I'd think, lol. Probably so much of a rare occurrence its not worth worrying about.

Ben


Well last I checked, they are heavy. And they have plenty of rolling resistance to keep them form rotating. And in the off chance that they do, a pry bar and some elbow grease can move them.

They aren't just flopping around as the train rolls like a mud flap on a truck.
 
I see the convenience aspect of rotary dumps, but it appears to come at the cost of speed/time.

It's not the time per car that counts - it's the time per ton of load. If the cars carry a greater load because they don't need tapered bottoms and hopper gear then the throughput can be higher, even if the time per car is greater.
 
Gondolas still need thawing if the load is frozen; you don't exactly want 120+ tons of solid ice and coal falling onto whatever is underneath. Even if it's just more coal, it's going to roll down the pile. The load is probably frozen to the car as well.

Still, as others have said, it's a lot faster to dump a load than wait for it to clear hopper doors; it doesn't require as much labor or car shaking.

Wasn't there someone who built covered hoppers with hinged tops for rotary dumping in the 70s?
 
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