Prototype diesel exterior lighting,SD40-2 in particular....

Model Railroader Prototype information for the modeler
1

I’m about to fit sound in an SD40-2 (CN’s) and in the process,I’d like to reproduce the exterior lighting (LED’s).My problem is I don’t live near a track so never get to see any loco pass by specially at night.Models come with a headlight,a rear light and now many have operating ditch lights (steady or flashing),and lighted front number boards.What about the prototypes?Do they have side markers?Do they have red tail lamps for when they’re not hauling cars or they simply turn their backlight on?Are the rear number boards also lit?What else is missing on our models not counting interior lamps?

I may be dreaming a bit but with decoders that offer more and more functions and LED’s that barely draw any juice…well…it’s fun to give it some thoughts.Thanks.

2

They may have changed the rules, but at one time the rules stated that the end of a train had to have red marker lights displayed. So if the train had a pusher set of engines, the last engine would have had to display red marker lights (not tail lights). Also, if an engine or a number of engines were to run down the main by themselves, that would constitute a “train” and again the last loco would have to display red markers.

3

There are often step lamps to the crew cna see when climbing on and off, and also track lights, under the cab over the trucks to illuminate the ground and track so that at night you can tell if you’re moving or stalled.

It’s possible to do some of this with the latest small SMT LEDs. Proper markers currently need at least 2 LEDs, a red/green and a white. There is a new red/white bicolor LED, if you never run extra sections (green) - that gets you red, white for an extra, and off for normal scheduled trains. The problem with most locos that currently have workign markers is that they are green when running forward and red when runnign backwards. Not very prototypical. Late model Alcos are easier - they have 3 distinct lights on each side for the markers rather than a single light with changeable color lenses like EMD - for an EMD it would require light pipes to a pair of LEDs to get allt he colors.

–Randy

4

There are also a light at each end of the car body to illuminate the deck (porch) area as far as the MU walkway.

On left side there is a small light mounted in side of hood just above deck level at lower portion of step down in the walkway.

Dick Haave

5

Lights over the front trucks. Lights at each end of the carbody, to light up the walkway. Some have lights in the step wells, like the 4051 below.

!(http://i184.photobucket.com/albums/x218/MFJ_album/WSOR engines/WSOR 4051/7-4-08029.jpg)

The class lights on most SD40-2s are long gone, but some still exist.

CN ditch lights don’t flash.