Looking at a map of the PRB, it shows some of the coal loading loops run clockwise while other loops run counterclockwise. Is there any rhyme or reason to this? Is it because they want to load coal trains running uphill, so they just follow the lay of the land? Maybe they want the engineer to be on the inside of the circle, for better visibility of the whole operation? Is the engineer even involved in loading? Maybe it’s done by a hostler, or even by remote control?
It has to do with what happens before and after loading, the site characteristics, and the configuration of connection to the main track, not what happens during loading. Some of our loops we lay out counterclockwise and some clockwise – and some are set up to load in either direction. Factors that matter include
-
if trains are inspected, where tracks will be spread to do this
-
if locomotives fueled and inspected, where this will be done
-
where bad-order setouts are made and make-up cars are picked up, which has to be done without blocking other trains and without occupying the main track
-
if there is need for an acceleration/deceleration track to connect to the main track
-
if there are other rail functions at the mine such as delivery of diesel fuel and ammonium nitrate, and construction materials, and if so, where it’s convenient to do that.
-
Geography - ideally the loop is flat but if it can’t be, it’s better to go upgrade into the loader than downgrade out of the loader.
-
Where the weigh-in-motion scale is located
-
Where its convenient given the best place to put the silo or slot storage for the mine
-
Where staging tracks and storage tracks will be located
That’s a brief list; there’s a lot of thought that goes into it.
Most big-volume mines load use a creep-control set by the crew. The loader operator will tell them what speed he wants them to move at and if he needs them to slow up or slow down, or stop, or back up, he tells them. Many mines use a third-party crew to load the train now, not the Class 1 crew.
RWM
Who actually does all the design,planning, layout, and building for things like that? Let’s say, The Murphy Siding Coal mine wants to build a new coal loadout. Who do I call? The railroad…“hello DM&E…err…CP”? The Acme Coal Load-out Builder Company?
Why upgrade into the loader? To better control speed?
The engineering company hired by the coal mine designs it to specs set by the railroad and the FRA. The railroad will approve the design before they will connect to the mine trackage. If you search the websites of the major roads they often have their track standards posted.
Murphy -
I believe the primary reason for favoring an upgrade into the loader is simply the general rule that if the terrain compels you to drag something uphill in the process, it’s better that it be the empties rather than the loads, because the empties weigh less and are easier to move.
What I don’t understand is why downgrade out of the loader is not favored, per the quote from RWM above. That’s almost SOP (standard operating procedure) at single and multiple car load-outs where the terrain allows it - let gravity do the work to move the loads away - same rule, just the next corollary. Unless it’s because it’s not a good idea to have the train’s creep-control being pushed down by the loads, because it’s harder for that system to precisely control braking as opposed to power ? I don’t have any knowledge or experience with those systems, so perhaps RWM can enlighten us on this point ?
- Paul North.
Since railroad air brakes don’t have a graduated release feature it would be harder to control the speed on a downgrade, especially when the train is to creep along at a very low speed. As I recall, the dynamic brakes on locomotives don’t work at less than 10MPH or so and thus it would be necessary to set the air brakes at some level and have the power drag the train against the brakes. Very hard on brake shoes.
In the old days when life was cheap and fuel was expensive, running loose cars downhill through a tipple was favored because it was cheap. If you ran over a few people with coal cars every now and then, it wasn’t the end of the world. A rider went to an empty car in the empty track, uncoupled it from its mates, climbed on the end, released the hand brake, rode it down into the tipple, tightened the handbrake at the right moment, and stopped the car. When the car was loaded, he repeated the process to a coupling in the loaded car with other loaded cars.
Today, the loading is whole-train, and the idea is to keep the train moving continuously, use as little labor as possible, and accurately load each
OK - basically account of potential for slack and train-handling/ control issues, esp. with respect to close dimensional and weight tolerances for the operation of the loadout chute. Makes sense - similar - but different - to what I suspected. Thanks for the detailed explanation.
BTW - you really ought to be teaching this stuff someplace ! (I know, it probably doesn’t pay as well - yet - maybe someday ?) You’ve really added a lot of value to this forum, in my opinion.
Thanks again.
- Paul North.
Loading up hill so you dont have slack action and you can controll the speed the speed controll ( or as you guys call it creep) only works in power not in dynamic now it will work while the engine brake is on. but the only way to load is up hill as you can controll the speed
Does that mean the engineer is riding the train the whole time it’s being loaded with coal, so he can speed up, slow down, or stop, based on communication from the guy dumping the coal? That would be a long shift!
Usually only takes 1-2 hours to load a 135-car train at a modern loadout with a loop track, assuming they don’t run out of coal (which does happen because mine storage is usually very minimal). At most of the mines a contract crew does the loading, moving from train to train throughout their shift.
RWM
Flood loading out of silos is probably nominally rated at 10,000 tons per hour or so. At worst maybe 3 hours or so to load a train. It might be kind of boring, but not long.
Yes we load the trains at 3 tenths of 1mph and it takes 4 hrs we unload it also and it takes 4 hrs at the plant. we work 12 hr shifts. and load and unload all our coal trains plus the time it takes to go from mine to power plant