Discussion relating to the PRR, up to 1968. Visit the PRR Technical & Historical Society for more information.
  by nydepot
In PRR ETTs, there is a section on locomotives and which ones can be used on which lines and sidings.

My question concerns the difference between prohibited (X) and restricted due to light rail (R). A branch line may have (R) next to it for larger power. I take it to mean that power is restricted from being used on the branch, due to the light rail. Isn't that the same as prohibited? Either way, you can't run on it with that particular power.

What happens when a siding as all X's beside it for all power? That means all engine classes are prohibited from using the track. So how would you service the siding?

Another two adjacent sidings had (X) for the two classes for 6-axle power on one and (R) for six-axle on another. Again, isn't this accomplishing the same thing?

  by Statkowski
Can't comment on the "X" vs. "R".
What happens when a siding as all X's beside it for all power? That means all engine classes are prohibited from using the track. So how would you service the siding?
We're assuming that a "Siding" is "A track auxiliary to the main track for meeting or passing trains," right? If it were a spur track, it would have to be serviced using idler cars between the prohibited/restricted engine and the car(s) being placed or removed. If the "siding" was used merely for car storage, then idler cars would also be required to place or remove such cars.

All engines prohibited? Perhaps an example of such might help.
  by Statkowski
Well, since there was no response from the original poster I looked for some examples, and there were a few in the Panhandle Division time table for 1950 (http://www.multimodalways.org/docs/rail ... 0-1950.pdf).

Still don't understand the difference between Prohibited and Restricted.

Anyway, the engine restrictions in the time table (pages 74 to 89, inclusive) show restrictions for specific industrial tracks (also known as spurs). These were not sidings (used for the meeting and passing of trains).

Actually, thinking about it, if a siding (as defined in the rule book) cannot accept any engines, then it's not a siding since all trains have an engine.
  by ExCon90
I found some examples in a Northern Region ett, most with X, some with R, and one with R for 270 feet in from the switch for lighter-weight classes, and X for others, and I'm still none the wiser.
  by NYCRRson
Pretty sure that "Prohibited" ("X") means a class of engine that is not allowed on that track ever. I suspect a dispatcher could in an emergency (wreck, weather emergency, etc) override the rule book and order a crew to use a prohibited track at very reduced speed.

"Restricted" means a class of engine may operate on that track but at the reduced speed called for at that location.

One or two of the examples prohibit a class of diesels from a track if more than a certain number of units (3) are coupled together. But one of the notes says you can operate if idler cars (empty flat cars) are between the engines.

Most of the locations that prohibit all engines seem to be under coal tipples, loading docks, inside factories (maybe inside buildings), etc. These would be serviced by using extra freight cars between the engine and cars being dropped or pulled at that location. A crew might have to service that location from both ends to keep the engine off the prohibited section.

Cheers, Kevin.
  by Statkowski
It could be that Restricted was due to weight only, while Prohibited was due to weight and clearances.

Such prohibitions would have been enacted by the Engineering Department, not the Operating Department. Such being the case, no dispatcher would have the authority to overrule such a prohibition.