Lighting Terms

Model Railroader Prototype information for the modeler
1

My apologies if this question is too Noddy, but I have looked in the glossaries on this site and in previous threads, and it seems that everyone else knows except me. [D)] The utility of the glossaries on this site might be compared to the utility of hip pockets in a singlet, but that is another story, and a bit of a cheap shot, sorry. But then it is true.[:I]

For now please enlighten me:

  • What is a “ditch light”?
  • What is a “mars light”?
  • Any other lighting terms you would like to lay on me.

This is increasingly relevant because of the range of lights available and the DCC options to operate them.

2

Pardon me while I put on my Noah Webster mask:

  • Ditch light(s) - found at or near the ends of the pilot beam on modern (and refitted older) diesels (installation began in the early '90’s.) White lights pointing forward, may or may not flash alternately when the horn or bell are activated. So called because they are low enough to illuminate the ditches alongside the roadbed.
  • Mars light was a brand name for a forward-facing gyratory warning light - the second big headlight lens on some covered wagon cabs, or part of the stack of lights SP inflicted on its hoods. The other popular design was the “Gyralight(sp??).” One moved the beam in a circular pattern, the other in a horizontal figure eight. (Which brand did which deponent knoweth not.) Mechanical drives were a maintenance nuisance, so they disappeared when ditch lights came in.
  • Classification lights - found high on both sides of the front of a locomotive. In TTTO days they were required to be dark for scheduled trains, green for all but the last section of a schedule slot being operated in sections (the final section would be dark) or white for an extra - train not on the employee timetable. Those are the lights at the front of the number boards on covered wagon cab units.
  • Marker lights - lights on the rear of a train (including a locomotive or locomotives running without cars.) When moving, show red to rear, green or yellow (depending on company rules) to sides. When stopped clear of the main track, they would be changed to show the side color to the rear and red to the sides. An A-B-B-A consist of covered wagons running light w
3

As always, Chuck, a good answer. I might add that Mars lights were also fitted to many steam locos in the US. I can’t now remember which light has which pattern - have to check up on that one. John, if you’ve ever seen an NSW 81, 82, 86, or 90 running at night, then you’ve seen ditch lights. Likewise ANs, DLs, ELs, NRs, etc. Cheers, Mark.

4

Thanks Chuck and Mark,

Next time I am back in Oz I will have to look for some with ditch lights. However, anything I have in model form is pre-81 etc. 44s and 48s are in their youth at my place.

Thanks for the information, and Chuck, I agree with Mark. Well written up. [tup]

5

Mark,

Here’s a pair of 90s in daylight, but I think he has the ditch lights on?

Are those the ditch lights on the same level as the coupler on the front pilot?

Is there any code to the twin headlights? One on, both on or both off?

What are those weird boards at the side down the back??

6

Yes, John, they’re his ditch lights, next to the coupler. Unlike the US locos, ours are just on or off, there is no flashing pattern. The gadgets at the rear are sound baffles or deflectors, intended to reduce the number of noise complaints from residents living next to the coal roads. They work, too. Good to hear you’re an Alco fan - I was on a ballast train the other day with a pair of 44s. They may be old, but they can still pull like a dentist! Cheers, Mark.

7

Mark,

I did not realise I am an Alco fan, but now that you mention it I have just ordered Loksound V.35 decoders from Gary at MRC for 40 (RSC-3), 44 (DL500B) & 48 (RSD-8). [:D] They have the right engine sounds, and he will change the horns.

http://home.iprimus.com.au/casula/dieselsounds.htm

Anyone with an interest in Oz diesels might find that URL interesting.