Looking to learn about prototype practice for diesel lights in the early 1950's

What I can answer is number boards are independent of the headlight.  All lights are under manual control, there is no automatic reversing of lights.

Cab lights should be off when running at night.  It inhibits night vision.  Try driving at night with your dome lights on to see what I mean.

Rusty

Keystoned Ed posted:

I'm installing DCC controlled lighting in a pair of O scale PRR E8 A units and want to set up the models' 4 lighting circuits (headlight, number board, cab, backup light) with circa 1952 prototype practice in mind. Several questions come to mind.

Am I correct to understand that headlights were not required to be on when running in daylight hours until around 1954?

Must admit that I never heard that. I remember as a kid in the late 1940s through the mid to late 1950s, the headlights were on (I grew up on the CNJ and DL&W railroads).

Was this practice governed by FRA  or railroad rule? 

Back in that era I believe it was still the ICC, but I'm pretty sure it was each railroad's individual practice.

When the crew turns on the headlight of a diesel did the number board lights automatically turn on or were they controlled by a separate switch?

Headlights, Mars Lights, Number board lights, and class lights were all controlled by their on individual & separate switch.

In the case of a trailing A unit, (back to back configuration) with that unit's headlight turned off were the number boards on or off?

Yes, they should have been, i.e. turned off as well as the cab interior lights.

How was the backup light on the B end of an A unit used/operated?

Manually controlled by the Engineer or Hostler, used when back a light unit, or pulling cars coupled to the front end.

Did the headlight or backup light turn on/off (or dim) with a change in direction automatically, or by crew control?

No. Controlled by the crew.

Am I correct to assume that cab interior lights were generally off when running at night?

Absolutely YES!

Thanks in advance for feedback.

Thanks for the replies guys.  I can wire the lights so DCC function keys individually control the 4 lighting circuits 

One thing I would mention, since you are setting these engines up your own way, Normally, the classification lights ("class lights"), which many on these forums incorrectly refer to as marker lights, were not illuminated on passenger trains.

I won't go into great detail, but, in the era you are modeling, passenger trains were typically Regular Trains, which means that they were authorized by their timetable schedule and didn't display any class lights.  Only when they ran as extra trains did they display white class lights, or when running as sections of the regular schedule (i.e., First No.7 and second No.7) would there be lighted green class lights.  Since your E8's are passenger engines and you are not, presumably, going to operate sections or extras, I would suggest that you not illuminate the class lights on either the leading or trailing E8A units.  You don't need red class lights to the rear, serving as true marker lights, either.  They would be only for long distance light engine moves as a train.

However number lights were required to be illuminated -- normally on the leading diesel unit -- both day and night, for train identification purposes

Doing a little inquiring, my source says that it was in 1956 that headlights were required by the ICC to be lit in daylight.

Thanks again guys.