What does "plates" on freight cars mean?

[Trainman101]

Does this letter stand for weight or something? Whats the meaning of each letter?

[DutchRailnut]

conforms to plate C means it falls within a certain load gauge.

Here's an example of a plate:

http://www.icrr.net/plateB.jpg

[ex Budd man]

'Plate C' refers to a drawing or 'plate' which gives clearance dimemsions for equipment. If a car has 'plate -C' designation it means it is able to clear obstructions that fall outside of the listed dimensions. Conversly anything within these dimensions will foul the equipment. Tunnels, bridges, loading docks, all come to mind.

[Engineer Spike]

I was the conductor on a local job one time. We were switching a mill, and the tracks were very close together. I was shoving a cut of cars past some on the next track. The first car made it by, but the next car caught the ladder. The result was a big investigation. The hearing officer asked me i I had considered that the cars might have been different sizes. I replied that both were plate C cars, sot they should be the same size. I still got points, but that is almost automatic. I did however win the appeal!

[ex Budd man]

Is it possible the car was past the fouling point? It may have been too close to the switch, or the car might have been a "leaner". As is often said "excrement occures"!