Model Railroading > What is Rule 17 lighting?

Many DCC decoder support 'directional lighting OR rule 17 lighting.'

What is Rule 17 lighting?

Thanks.

"Rule 17 lighting" is the ability to dim the headlight without turning it off. It refers to Rule 17 in most prototypical North American rulebooks, which basically requires that the engineers of passing oncoming trains dim their headlights as they approach so as not to blind each other.

-fm

To be "hip" and "with it", the referral should be changed to "Rule 5.9.1" (Per GCOR Revision 4--with many more to come!)

Thanks!

Ok then. But I guess I don't understand why the DCC mfg's tend to say that the decoder supports directional lites *OR* Rule 17. Seems to me that directional hdlites are desireable, even if you also have the ability to dim the lites.

Note that I doubt many operators will bother to dim the lead loco's lites when an oncoming train approaches or when in a yard, even if the decoder provides such a feature. That's a bit extreme, and hardly worth dealing with.

It really depends on how you like to operate. For instance, if you want to operate prototypically, then you would dim the headlights. Also, it gives you constant forward lighting, instead of directional lighting.

Another thing is that on prototype locos, the headlights do not change direction just because the loco did. If you have a consist, and the headlight on the lead loco reverses, what's the point?? It just shines into the cab of the next loco. The lights on a real loco would stay on in the forward direction not just for the engineer to see, but so the train is seen by others.

Corey

Harron is right. Prototype headlights are strictly manual control by the Engineer. There are two separate switches, one for the front and one for the rear both allowing bright, dim, and off. When diesels are MU'ed the rear switch will control the rear facing headlight in the last unit, even if that happens to be the front headlight of that unit. Current rules result in a set of light engines running on the main having the front headlight on bright and the rear on dim (as a marker). Dimming the headlights for an HO scale meet is not a safety issue, but I will sure enjoy being able to do it now that DCC makes that possible.

Rule 17 is now 5.9.1+

5.9.1 Dimming Headlight
Except when the engine is approaching and passing over a public crossing at grade, dim the headlight during any of the following conditions:

1. At stations and yards where switching is being done.
2. When the engine is stopped close behind another train.
3. In non-signaled territory, when the engine is stopped on the main track waiting for an approaching train.
4. When approaching and passing the head end and rear end of a train on the adjacent track.
5. At other times to permit passing of hand signals or when the safety of employees requires.

5.9.2 Headlight Off
Turn the headlight off under either of the following conditions:

1. When the train is stopped in the clear of the main track to meet a train. However, an extinguished headlight does not indicate to an opposing train that a train is clear of the main track.
2. Within block system limits, when the train is stopped on the main track to meet a train approaching on the same track.

5.9.3 Headlight Failure
If the headlight on the train fails, ditch lights must be on, when so equipped. Headlight failure must be reported to the train dispatcher.

At night, if headlight and ditch lights fail to operate and no other unit can be used as the lead unit, continue movement with a white light displayed on the lead unit. Stop the train before each public crossing, so a crew member on the ground can provide warning until the crossing is occupied, unless:

Crossing gates are in the fully lowered position. or No traffic is approaching or stopped at the crossing.

5.9.4 Displaying Headlights Front and Rear
When engines are moving, crew members must turm on the headlight to the front and rear, but may dim or extinguish it on the end coupled to cars.

So, as you can see, some of this would be neat to do with DCC.

Roger Hensley