Seen on Coal Hopper Cars. Also for what ever reason the car exceeds plate F when brakes are applied according to the sign on the side of the car? What the Freek is Plate F ?
Also on other cars, as appropriate.
http://trn.trains.com/railroads/abcs-of-railroading/2006/05/freight-car-markings
It’s no freak; it is commonplace.
Thanks, Larry for responding quickly.
So why when the Brakes are apllied the car would exceed Plate F ?
Scroll down the page to find Plate F and all the others
Having brakes applied or not should make no difference in it’s Clearance Plate designation.
The only kind of hopper I can think of that would exceed Plate F would be a wood chip hopper, where the car sides are raised above level that a normal coal hopper goes to.
It probably has some sort of visual indicator that pops out the side of the car a couple inches when the brakes are applied, which probably makes it a couple inches wider than plate F. Same thing happens on automatically dumped hoppers that have a contact shoe that sticks out from the car. That shoe, when extended makes it wider than the plate.
Such devices are normally only used where disk brakes are on the car and the application of the brakes cannot be visually confirmed in a normal walking inspection. Very few if any freight cars are equipped with disk brakes, most all have clasp brake shoes against the wheel tread and thus have a separate easily visible piston assembly to apply and release the brakes. The brake valves and piston are on the B end of the car.
A reporting mark and car number would be helpful to see what is meant.
- PDN.
Very common to see this on bottom-dump unit coal trains; as dhusman noted, there are shoes on the side corners that control the doors, which extend out about 2" when armed and have to be “gagged” for travel. There is usually a note about this painted on the car side close to the ‘exceeds plate F’ notice.
it would be interesting to know the specific procedure used on these trains to set them up for unloading and then to prepare them to return light. I know only the theory, not the practice.
“+1”, especially since bottom-dump is much more efficient than rotary dump.
- PDN.
Yep The side of the car said some valve has to Gagged whatever that is…
The shoes involved on these cars have nothing to do with brakes and everything to do with the dumping operations.
Paul, you’re right about the efficiency–it doesn’t take long to unload these cars, since it’s basically like the bottom falling out when those gates are opened. The rub comes when building the facilities for unloading them and gettng the coal away from underneath the cars efficiently. Rotary dumpers cost less (probably in terms of space as well as construction) to operate. And that’s why you’ll often see rotary couplers on the quick-dumping hoppers as well.
There is a coal fired Southern Company power plant on CSX’s Lineville Sub. the plant is also serviced by NS. They use air dump hoppers with the entire train pulled onto a unloading trestle, the command is given and the entire train is unloaded in about 6 minutes. Which is great - EXCEPT it takes Southern Company about 8 hours to clear out the contents from one train before another train is allowed to dump. Trains from each carrier are frequently recrewed waiting for their opportunity to dump.
Not perzactly true, because the air used to work the dump mechanism comes from the brake system*, and there is a switchover (which has been described in posts on this forum), probably when the dump shoes are gagged/ungagged and their valves armed - I suspect this is also the reason the shoes are not automatically armed or actuated in some way.
Anyone still remember the wonderful system an ore operator, I think Erie or Oliver, used to automate their bottom-dumps? They had a rubber-tired wheel on the side that engaged a raised ramp, and in a squealing cloud of blue tire smoke this winched the conventional door opener around. Another wheel on the other side did the closing honors. Now THAT system exceeded plate F…
A problem with coal in general, but some PRB subbituminous in particular, is triturition (self-grinding) during handling. That is an additional consideration in using hoppers vs. gons. Someone here with numbers can give us the exact tare vs. loaded weight of a coal gon and self-dumping aluminum hopper, and then extrapolate to weight and length of full consists (I am too lazy to wait for local coal trains and do this myself) - that may make it easier to assess the relative advantage of straight pull-through (with bottom dump) vs. stopping every couple of cars for the rotary.
*EDIT - as indicated in a later post, the air comes from the main RESERVOIR, not the brakeline per se. As noted in that later post, multiple or distributed power speeds the pressurization.
The rubber-tired wheel system was used by Erie Mining Co. to open and close their bottom dumps at Taconite Harbor. Erie Mining was an intraplant operation and did not have to worry about interchange.
Association of American Railroads Equipment Diagrams for Interchange Service
(that is “Plates”)
Thanks! I forgot completely that the OP might not know what was involved with “plate” clearances.
MC and others: can you provide links to both modern and ‘porcupine’ clearance cars so he can see how the ‘plate’ measurements are actually translated into clearances, and checked in the ‘real world’?
One of these two, but I’d have to check:
The other Erie
Erie Mining�s railroad
by Patrick, Howard S.
from Trains September 1973 p. 41
“Porcupine” = Bamboo Peacock (more descriptive)…shoving that square car template through the round, real world hole can be a challenge, especially when it involves a load on a schabel car. You stay inside those plates to avoid contact with things like docks, passenger platforms (the people at SMART got stupid and thus all the gauntlet tracks out north of the Bay Area), switch stands, and all the other things expected to be out there. The Sperry Clearance (digital)cars are still making regular runs and there are still old manual systems like bamboo peacocks around (Just in case) to see what potential loads will foul, especially in curves and congested areas.
