I noticed something interesting when watching a dvd of the Rio Grande. In one scene a local was running with two GP’s facing in opposite direction, and the engines both had their headlights on for most (if not all) of the time. In another scene a local was headed by a single GP, and although it was going back and forth, switching cars in and out of industries, the light was always pointing in the same direction. Both of these scenes were shot during daytime.
How common is it that the lit headlight doesn’t changing with the direction of travel, or that you have lit lights pointing in both directions? Is it something we should try to mimic, instead of having the light flip back and forth every time we change the direction our engines are running?
There were/are a few, rare instances where real diesels had reversing headlights - i.e. the headlight only on in the direction of travel - but generally if the headlights are on, they are on in both directions. [:O] (BTW having headlights on during the day wasn’t normal until maybe the seventies.)
When diodes became available (maybe in the sixties??) some model railroader worked out that while hooking them up with a bridge rectifier into a ‘constant lighting’ circuit, you could hook them up in such a way that only one headlight would be on at a time. This became a fairly common modification, to the point that model manufacturers began wiring their engines up that way at the factory.
Rule 19 requires that headlights be dimmed when meeting another train (the train stopped in a siding would dim it’s headlights while waiting for a train on the mainline coming the other direction) and with DCC you can set up engines so that the light dims when the engine stops, that’s probably a more prototypical choice - although the most realistic would be using a function button to dim the lights.
FWIW I prefer to set the lights up so they’re both on, but the one in the direction of travel is full brightness, and the one in the reverse direction is slightly dimmed. It helps to be sure which direction the model is going to go while switching, but isn’t as extreme as having the light go out completely in one direction.
No actual locomotive has headlights that automatically reverse when it changes directions. This is strictly a model railroad myth.
Daytime use of headlights actually dates from the early to mid-1950s. As diesels replaced steam locomotives, railroads noticed that the new power didn’t make itself noticed over distance by tall smoke plumes and such, and changed Rule 17 – the rule governing use of headlights – to require that headlights be displayed at full brightness at all times, day as well as night. In yard operation, locomotives were required to display dim headlights in both directions at all times. These are essentially the practices that we see today.
Ideally we should be able to control the lights of our models independently of their direction, with independent control of headlights and backup lights, and our headlight controls should have three positions (like the prototype’s): full on, dim, and off. This is possible with many DCC decoders today, but unfortunately not with all of them.
Directional headlights are another “model myth”. A prototypes front and rear headlight are independently controlled.
Your rule numbers may vary. Italics are my comments.
Rule 22:
The headlight facing the direction of movement on every train and engine must be displayed brighty by day and night.
The headlight must be dimmed:
1.) While standing or passing through yards where other engines are working.
2.) When standing or moving on a main track at meeting points
3.) When standing or approaching another train operating in the opposite direction in multiple track territory.
Engines in yard service must display the headlght to front and rear by day and by night. The headlight on the end coupled to cars may be extinguished - when running light BOTH headlights need to be on.
Rule 24:
On a main track or controlled siding outside of yard limits, the rear of the train must be identified by a marker as prescribed below:
Engines:
Light engines, and engines operating at the rear of a train must:
1.) be equipped with an illuminated marking device
or
2.) Have the rear healdight on low beam at all times. - again when running light or when shoving a train, both headlights must be on.
So technically, directional headlight on our models are not prototypically correct for all situations. Light engine moves, yard switching, and helper movements require both headlights to be on.
A train stopped clear of the main track, especially in “dark” or non-signalled territory, with the switches lined for main track movement should have it’s headlight off. In TT/TO era, a train entering a siding would leave it’s headlight on bright until it was clear of the main track and the switch lined back. Once clear and the switch restored further movement on the siding would be with the headlight on dim. Once stopped, the headlight
Thanks guys, very interesting. I had no idea it was like that. I totally bought the “myth”, and I weren’t aware of the rules about dimming either. You always learn something when watching the prototype, and the asking them who knows.
How common would you say it is for a train running with multiple units at the head end, to have both the first and last engine’s lights turned on (pointing in different direction, and not counting any rear end helpers)? If both engines have lights on would each of them only have lights on in one direction, and would any be dimmed when the train is moving down the line? Also would you say it’s more common on freights setting out and picking up cars en route then on trough freights?
How about the different kind of flashing lights do you also dim them, or do you turn them off? That’s something to look for in a decoder, dimmable and flashable lights.
If the units are MUed correctly, only the headlights on either end will operate, and the headlights in the middle will remain off.
The vast majority of the time, when coupled to a train, only the headlight on the lead unit will be on, and the headlight coupled to the train will be off. Although, it’s not uncommon to see the headlight facing the cars set to dim.
The ditch lights are either on bright or off. They don’t dim. When the headlight is set to dim, the ditch lights turn off. If they are set to flash when the horn sounds, they will flash regardless of the headlight setting.
As an aside, many railroads require that only the number lights of the leading locomotive be illuminated, and all others be extinguished.
Just to go back a step…as I pointed out, real engines with reversing headlights were rare - but not non-existant. This subject came up on either this or the Atlas forum a couple of years ago, and someone pointed out that they had worked on a shortline RR that used GM switchers that were in fact set up to only have the headlight on in the direction of travel. So it did happen, but I’m sure less than 1% of diesel engines (and no steam engines) were set up that way.
If you’re setting the CV’s on a decoder, the instructions for doing this can range from crystal clear (TCS) to nonexistant (Digitrax). The decoder’s instructions or the company website should somewhere explain how to set the CV’s to get what you want.
I would much prefer to have independent control of the headlights, ie- NON directional. I have become frustrated with trying to program headlight control using Decoder Pro. There is an option of having NON directional headlight control but I can’t get it to work. It keeps reverting to directional headlight function using a DH-123 decoder. Am I doing something wrong?
I wired the lamps so that FOF would be the headlight and FOR would be the number board lamp. I thought I could program the FOR bulb to use F4, non directional but it doesn’t seem to work!
Some have separate front and rear ditch light switches.
Some have front and rear controlled from the same switch.
Some have the ditch lights controlled by the headlight switch. Those go Off-Dim-Med-Bright-Bright and Ditch.
Some engines have separate front and rear rotary switches for the headlights. .
Others have slide switches to turn on the front and rear lights. Intensity is controlled by a rotary switch. This type goes Bright Rear-Med Rear-Dim-Med Front-Bright Front. With both slides on, if the intensity is bright to the front, the rear will automatically be dim. Turn the rotary all way, and bright to the rear, dim front.
BTW headlights weren’t univerally used during daylight hours until about 1970 more or less. Kinda like driving your car, you turned the headlights on when it got dark, no need on bright sunny days.
I have a Kato Sd80 mac painted i NS colors, on the rear and on the front, there are some red lights. none of them are conected to the headlight or for that reson not conected at all. What are the prototypical use fore these Lights. Are these Ditchlights or directionalheadlights or are they not in use at all?
Nick, that piece is just what I’ve been looking for for a while now.
Been modeling US protortype for years(SP Black Widows in HO), with DC lights did’nt come into it realy as long as it worked. When I started the change to DCC I knew nothing about the subject of protortype loco lighting apart from books, mags, videos Etc and even trying the forums got nothing.
The red lights on your SD80MAC are called marker lights. Conrail ordered the SD80’s and pretty much everything else they had with marker lights. They were used for a variety of reasons:
-The trailing unit in a light power consist would have it’s headlight dimmed and markers on.
-A train stopped, regardless of location, would usually have the markers on.
-Since Conrail operated on the NEC with Amtrak, Amtrak required that they had them, for some reason.