Classification/marker lights on the PRR steam engine

I think in more "modern" times they dropped the marker lights.  

But relative to the use, I think is defined in the employee timetable or rule book.    I can't remember where I read it, but it said that a "train" and train was defined to include a light engine had to display marker light to the rear.    So an engine running in reverse or pushing string of cars would in theory need to red markers displayed to the rear. 

I don't remember the details but I think it would not apply to switching in a yard or for a local working industries but meant for movement along a main track.

Read the attached history.

I just checked the rule book for 1925 that I have.   it says a locomotive when running in reverse either pushing or alone must display red markers to the rear.    The class depend on class of train.    This is the short version!

@Ray of sunshine posted:

I have several PRR engines and have always wondered about the front classification/marker lights.

Read the attachment in Bob's post, it has all the data you need on light location.  Basically, the steam engines had marker lights on them to the end of steam, but the classification lights were dropped in 1940.

Ray of Sunshine, thanks for bringing this topic up.  I had never noticed that some PRR engines had lights on both the pilot beam and the smokebox.  I saw the pilot beam lamps and just thought they were the classification lights.

Bob Bartizek, thanks for lifting the curtain on this unusual PRR practice, especially for those of us who grew up a couple of thousand miles from the nearest PRR steam engine.

So now I realize, after all these years, why my Lionel PRR B6 had amber markers to the side! Thanks for that information.

Thanks for the info helps me to understand which would be the correct lites for the era I model.