Union Pacific Ditch Lights

Trains Magazine Locomotives
1

How do UP ditch lights work on their ES44AC units? Do they flash when the horn is blown or are they on constantly?

I have two of the Athearn units and they are set up differently.

2

The only flashing ditch lights that UP has are on former SP units. All others are on constantly.

Jeff

3

Thanks Jeff,

We would frequently get UP locomotives on CSX but I didn’t remember how the ditch lights worked.

Mark

4

I didn’t know the flashing ditch lights were an SP idea – just assumed it was some FRA requirement or something. What other RRs flashed?

5

The eastern roads seem to favor flashing ditch lights. SP also specified the flashing option when they ordered engines.

IAIS has flashing ditch lights on their GE’s that they bought new because the order for the first were tacked onto, and built to, CSX standards.

The FRA regulations allow ditch lights to be either flashing or constantly on.

Jeff

6

Eastern roads tend to operate in more populated areas, guess humans need more ‘variety’ to discern a train than do the wild animals that inhabit the areas of the Western roads.

7

The flashing ditch lights get your attention much better than the steady ones. Since they start flashing when the horn is blown, they are a better indication that the train is moving toward a crossing.

Mark

8

Well you mentioned IAIS Most of their units are designated ES44AC but in reality they are ES44AHs a unit - don’t remember what one was sent to IAIS still in full CSX Paint and is dubbed ‘the missing 50’ a few pictures of the unit are on the rrpicturearchives.net website when it was patched and renumbered I found a picture from when it was at a KCS Yard I also know this is kind of a late post

9

Prior to 1996 when ‘ditch lights’ were mandated, GE called them ‘crossing lights’ and they were arranged to come on and flash alternately for 30 seconds when the horn was blown or sequenced. The P42s as built (1992) featured this arrangement.

I do not expect that by the time of the ES44s the contemporary GEs still had that arrangement; aknots any ex-SP engine by definition would be pre-ditchlight mandate.

My personal opinion is that, just like blink characters on IBM terminals, the ditch lights should alternate between bright and dim, not ‘on’ and ‘off’. That preserves the ‘triangle’ recognizable as an approaching train while maintaining the flashing alert pattern.

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10

I believe the “ditch lights” are properly referred to as “auxiliary lights.” Some BC Rail locomotives had both - five lights on the head end.

11

GE referred to them as ‘auxiliary’ and ‘crossing’ lights at least four years before the FRA mandated “ditch lights” or whatever they are called in the CFR.

On the same general principle that led SP to get rid of all that fun stuff they were putting on locomotives, I’d think that whatever two lights form the ‘bottom of the triangle’ are called whatever the FRA says, and that’s it for non-headlight lights.

Now, I don’t know if the ditch lights are supposed to be ‘cross-eyed’ as I thought they were in traditional Canadian practice, aimed so the beam converged on the opposite-side ‘ditch’ at some specified distance in front of the locomotive. The GE lights on the P42 just pointed forward, like the little auxiliary light on the facelifted T1s in the '40s.

12

I remember Amtrak used to buy those tiny little strobe lights on top of their cabs thinking they helped visibility. SP used to put Mars lights (they still make them for fire trucks) on their locomotives. I think the Mars lights are still more noticiable than the flashing ditch lights. Flashing ditch lights are probably cheaper to maintain though.

13

They are called Mars lights and the company that makes them is still selling them (you can google MARS 888 to find the company). They switched from them I think because of the expense over their useful life of buying and keeping them running.

14

I meant the previous comment about having FRA-compliant lights and actual “ditch lights” on the same locomotive.

The modern use of a Mars or Gyralite (as on KCS) is in part to get around the need for the aimed and focused Canadian “ditch” lights – part of the aim of the moving beam sweeps the areas of interest, and presumably persistence of vision does much of the rest.

See This Useful Reference™

https://railroads.dot.gov/sites/fra.dot.gov/files/fra_net/19093/19092[1].pdf

and 49 CFR 229.133 (note the statutory difference in focus between ditch lights and crossing lights…)

15

We’re descending into details:

But from https://railroads.dot.gov/elibrary/locomotive-auxiliary-lights-questions-and-answers

Seems that auxiliary lights is the proper term now. That encompasses things like ditch lights, crossing lights, oscillating lights, and strobes. See the link above.

I have seen an old Amtrak work GP running around that still has strobes on the pilot.

Some of our engines have “auxiliary lights” that are a little crossed. But that may be more the result of grade crossing collisions bending them than anything.

16

The markings on the headlight switch can say “crossing lights,” “ditch lights,” “auxiliary lights” or on the newest engines, symbols denoting the headlight and ditch lights on.

On the older engines that were retrofitted, the ditch light switch is separate from the headlight switch. We had one order of GEs where there was an option for bright headlight and ditch light and a dim headlight and ditch light. The bad thing was the dim and ditch light had the switch all the way to the right, past the bright option. At night normally all you had to do was turn the switch all the way to the right. Those different ones were a pain and I think they’ve all been replaced with normal switches. I haven’t seen one in years.

Jeff