In June, we took our annual family vacation to Lake Superior, a trip I would recommend to everyone. The sightseeing boat through the harbor at Duluth/Superior gives you a good view of many railorad related things. Among them, it steams by the big pile of coal on the BNSF line in Superior at Midwest Energy(?) The loaded coal trains circle the big pile of coal at speeds of something like 3 mph, so they can go through a rotary dumper. Some time back, some posters on this forum that are more knowledgable than me (and that’s just about everybody) explained that the end of each coal car is painted with a stripe. It may be different in other places, but around here, the stripe is red or yellow. The stripe indicates which end of the car has the 360 degree swivel feature built into it. It’s my understanding, that all the swivel couplers have to be at the same end, in order to go through the rotary dumper.
Now a question: One of the trains I watched going around the loop had the first half of the cars with the stripe to the front. The balance of the cars had the stripe to the back. Doesn’t this throw a monkey wrench into the system at some point? Wouldn’t something like this have been caught long before it got to the destination?
I could be wrong, but seems like I’ve heard of rotary dumpers that handle more than one car - thus two adjacent cars without a rotary coupler between them wouldn’t be impossible to handle. Inconvenient, maybe, but not impossible…
You’re probably correct, about the 180 degrees. That just makes it more complicated though. The first part of the train would have to be rotated clockwise(?), the second half would have to be rotated counter-clockwise(?). The coal trains I’ve seen, and I’m not on a coal route, usually have the stripe to the front, I think.
The dumps only rotate in one direction. The couplers allow the car to be rotated in either direction, and that eliminates the need to all the cars alligned with the rotary coupler in one or the other direction. If two cars are connected at the fixed coupler end there is a simple solution: Uncouple the cars.
Usually, when you see cars having stripes on different ends on a train where they meet there is a car that has stripes on both ends denoting a car with 2 rotary couplers. As I said its usually this way, as far as uncoupling the train if there are fixed couplers together. This would cause a considerable delay as the train on a rotary dumper is not moved on its own power. This would require removing the device moving the train, uncoupling outside the building as it is a no go area for the train crew, and than recoupling the train putting the train back in position, than repeating the steps for the second car.
Well, if nothing else, a car that goes into a rotary dumper without having or being connected to a rotating coupler seems pretty likely to come out with one…probably not very good as a pulling coupler anymore, though.
The dumps can usually handle 2 cars at a time. If two cars are together that dont have the rotary coupler end, you hope that the car they are coupled to has that end close to you.
Most likely you are looking at two different smaller train sets that were combined together at a yard and taken to the dumper.
After dumping, each set ends up going back to a different supplier/mine…as for the middle two having non rotary couplers…just make sure those two cars go into the rotary at the same time…(no big deal, they do this all the time).
We often combine the Sweeny Coke train with the Aarco Coke move at North Yard, then haul both trains out to the Bulk Material Handling Dock at the same time…saves on crews and locomotive use.
It is most common to find one car in the train with two rotary couplers and thus stripes on both ends of that car. That way the unloading crews do not have to hope they are luck enough to find the two solid drawbars in the train spotted so they are both in the dump mechanism at the same time. Crew on the empty coal train can also fill the train out to the proper number of cars with mtys with stripes on either end of the depending if they fill ahead of the double rotary or behind the rotary car. Note the car behind the loco always needs a rotary end coupled to the unit to avoid breaking the drawbars.
Until the later 1970s coal trains had the stripes in the train headed the same way. The double rotary was either next to the caboose of the units. The railroads spent lots of money turning emty coal cars or a wye or turntable until someone figured out if the double rotary was in the middle of the train the fill cars could have a rotary in either direction. Getting a cluster of rotary cars around the wye in Alliance, NE to fill trains in the yards was sometimes a 12hr assignment until the rotary secret was figured out.