Mars lights on steam locomotives

fisch330 posted:

I have question about the use of Mars lights on operating steam engines;  When would the Mars light be illuminated?  (assuming it is red, although I have heard of white Mars lights)   I realize that it's controlled by the engineer, rather than automatically turned on under some conditions, but when would the engineer likely turn it on?

There were a number of different Mars Signal Light installations, and features:

1) Plain "white" Mars Light, controlled (ON or OFF) from the cab, usually by the Engineer. The Southern Pacific, however, had both the headlight AND Mars Light controls on the Fireman's side of their steam locomotives.

2) Dual color Mars Light, controlled by the Engineer, but upon an emergency air brake application, would immediately rotate to the red indication. Thus on those railroads with lots of double track, an oncoming train was NOT permitted to pass the train stopped and displaying the red light.

3) Oscillating constant red light for the rear of passenger cars/observation cars.

4) Single red light, activated automatically by an emergency air brake application. Could also be turned on manually by the Engineer.

I have one of Lionel's Milwaukee Road S-3 Northerns and it is really a beautiful engine in appearance and in operation.  BUT, I think that Lionel got it screwed up when they designed the electronics for the engine.  On the Lionel model, the Mars light goes on when the engine is running forward.  When it is just standing OR when it backs up the light goes out.  Isn't this backwards?  

Yes. Lionel git it wrong, do to information provided by someone within the Milwaukee 261 group that inadvertently provided information about the operation of the oscillating Mars Light mounted on the REAR OF THAT SKYTOP OBSERVATION CAR. Thus, the information provided was just backwards for the 261 steam locomotive.

Shouldn't the Mars light go on when the engine is simply standing or when it is backing up?

For model trains, yes that function works nicely, especially since model trains do NOT have any air brakes that would/could go into emergency.

 Of course, there are other times when the engineer might turn the Mars light on like if it's approaching a loading platform or just a large group of people.  

No, not if the Mars Light is red.

I would have been nice if Lionel could have figured a way to control the Mars light from the hand-held controller, but that would have been too much to expect.

I wuld just like to hear from someone more familiar with the rules on Mars lights than I am.

Paul Fischer

Paul I have the Lionel S-3 #261 and just pulled the boiler off, unhooked the red Mars light, and put the boiler back on. 3 screws, thats it.

Jack:  thank you for your insight on the operation of Mars lights.  I kind of thought that Lionel had it backwards.  I'm wondering if the #26 1 crew was having a laugh at Lionel's expense when they offered their advice.  It is a beautiful engine, nonetheless, and I wonder if any of our electronics experts could figure out a way to correct the problem.

Paul Fischer

As a member of the "Friends of 261" I doubt anyone gave Lionel wrong info as a joke. I think the earlier post, that it was a misunderstanding re the rear flashing red light, is more likely.

Keep in mind Mars lights - red, white or whatever - were optional accessories. They were not mandated or required, or standardized in use. They started to be used in the 1930's as streamliners came into being. The new trains went much faster than most older passenger trains, and the flashing light was a way to alert motorists that a train was coming...similar to the flashing 'ditch lights' of today. Some railroads used them, some didn't, and those that did may not use them the same as their neighboring railroad.

When it used its own Rules* book, Santa Fe -- only Santa Fe, as far as I can tell -- required that the Engineer manually display the red oscillating headlight on locomotives so equipped (in Santa Fe's case, passenger diesels only) when advancing on a Stop and Proceed signal indication, in single track Automatic Block Signal System territory.  This would be the scenario:

• Train stops before passing a signal bearing a number plate on its mast and displaying a red aspect, indicating Stop and Proceed.  Train waits 5 minutes if the track cannot be clearly seen all the way to the next signal.  If track can be seen to be clear of trains or other obstructions, 5 minute wait is not required.
• Engineer manually displays red Mars light or Pyle Gyralite and begins movement through the block governed by the Stop and Proceed signal.  Train proceeds to next signal at Restricted Speed, continuously displaying red oscillating headlight.
• If next signal indicates Stop and Proceed, entire process is repeated.
• If next signal has a more favorable indication (such as Approach [yellow] or Proceed [green], or Restricting [flashing red]), after passing that signal, Engineer extinguishes red oscillating headlight and proceeds as prescribed by timetable, train orders, and current signal indication.

Although this may seem puzzling, the purpose was to indicate to any opposing train (such as one which had stopped at a meeting point, or another train having opened the switch and waited the required 5 minutes before entering the main track within that block), that the train displaying the red oscillating headlight had completed any required waiting time and was on the move at Restricted Speed.  Santa Fe only did this in ABS territory, not in CTC or on Double Track ABS, where it would have served no purpose and the protection was provided by different signal rules than single track ABS.

*  The book's title was "Rules".

What was the reason ATSF had that equipment ONLY on passenger engines?  Freights could run on "Stop and Proceed", right?

Laidoffsick posted:

Paul I have the Lionel S-3 #261 and just pulled the boiler off, unhooked the red Mars light, and put the boiler back on. 3 screws, thats it.

I thought that Lionel had issued a software update that enabled the Mars light function to be switched off from the CAB 2 remote (rather than having to physically disconnect the wiring)? I don't have the Legacy S-3 but with some later Legacy engines that are Mars light-equipped I can turn the light off from the remote.

The red "hazard" (if that's the right term) Mars light is a specialized feature and I don't think that Lionel, MTH or 3rd Rail models offer more than a representation of its operation, which I guess reflects the software limits of their systems. In the latest Legacy FEF-3 for example it is only triggered by the emergency stop sequence. In the earlier Legacy FEF-3 the light flashed only when the engine was stationary (and by default would be on whenever the engine was sitting still on a powered track section).

In both cases the light itself is simply a blinking LED and not one that emulates the oscillating/figure 8 light pattern of the prototype, which is available with DCC control, third party light simulator boards (like Ngineering's) or some other TMCC/Legacy models. 

Dominic Mazoch posted:

What was the reason ATSF had that equipment ONLY on passenger engines?  Freights could run on "Stop and Proceed", right

Yes.  All trains proceeded under the same rules on Stop and Proceed indications.  The unique Santa Fe rule additionally requiring the additional display of the red oscillating headlight only applied to engines "so equipped."  It did not matter if the passenger engine was being used on a freight train or if a freight engine was being used on a passenger train.  The only stipulation was that it applied to locomotives equipped with an oscillating red light.

Santa Fe was one of a few railroads which applied oscillating headlights to its passenger diesels, but not to its freight diesels.  Others which come to mind were Missouri Pacific, Katy, Frisco*, Rock Island*, Great Northern, and Seaboard Air Line.

There is not any consistent answer to "Why?" Those kind of decisions were made internally by the individual railroads, and the one thing we can say for sure is that some Mechanical Department and Finance Department managers were very clear thinkers, while others knew little about how these devices might be used or whether, in fact, they were or were not required.  I have a strong suspicion, shared by another retiree who actually participated in the purchase of  locomotives, that the Mars and Pyle sales teams did their work well, both at mechanical conventions, and in personal calls on the railroads.  A lot of decisions regarding optional equipment purchased on a railroad's locomotives resulted from suppliers knowing how to extend hospitality.  I won't be more specific, but you get the idea.

*  Frisco later retrofitted its freight F7's and FA1's, and began purchasing SD45 and GP38 units with Gyralites.  Rock Island purchased its F2's with Mars lights, but removed them from some.  Inconsistencies like this were common on Rock Island locomotives.  Except for the F2's, Rock Island freight diesels lacked Mars lights.