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I recently got this signal with the PRR type signal head and was wondering how this is wired.  It currently has two black and two green wires.  I can jump the two greens and get the lite to work, I see there is a mechanism to change the aspect but can't get it to work...



Last edited by Martin Derouin
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It is a tall, about 8 inch signal made out of gray plastic.  The signal head is round and lit with one light bulb.  You either get three verticle or three horizontal indications.  There seems to be a relay in the base that moves a arm up or down to operate some sort of shutter mechanizm to display the proper aspect.  Since there is only one bulb, this must be some sort of shutter device...



Okay, thanks.  Greenberg identifies your signal as 

"#1404A block signal position light, plastic type"


I have the 1404 prewar tin version.  The center light is always hot, and operation is by switching between the two top and bottom lights being hot or the two side lights being hot.  


I don't have yours and apparently they changed the mechanism and the wiring, so I'll have to hope somebody familiar with the postwar version will chime in here.


Here's what Greenberg says about your light in case it is helpful to you:


"Plastic round face mounted off center, no platform, with five plastic yellow lens lights to show "proceed" by vertical or "stop" with horizontal display by use of an internal slotted disk in head; chrome ladder to rectangular elevated base; wire from bottom of ladder to lights and coil in base to operate aspects, 8-3/4" high."



Marty, in the absence of anyone else chiming in here on this, I am trying to decipher the Greenberg description.


Is it possible that the "coil" in the base is a solenoid, which when activated (by an insulated track section?) would, by means of a rod running up the post, rotate the "slotted disc" in the head, changing the contacts to the bulbs?


If that were the case, then the two black wires would operate the solenoid, and the green wires would be to the lights?


Is there any way to open up and look inside the base and/or head?


We need a postwar Marx expert here.



I know nothing about this light. However,it may be wired the same as a Lionel 440 signal bridge.


Forgot which is which but it would go like this. One wire hot or common. The other 2 would be hot or common with one operating vertical bulbs and the other horizontal bulbs.


I do not think there are any moving parts in this. 

As I think how the 440 is wired I remember the whole thing is common. Thus the other 2 wires on each side would be hot.


Find which wire is common. By energizing the other 2 wires should light all 5 bulbs. Energizing just one wire will make it horizontal or vertical the opposite wire will reverse.


Now to trigger the hots. In 1956 they probably used a Lionel 153 contacter or a Marx equivalent. Today we have many options. I use a relay with the wiper being hot and N/C being horizontal. When the train approaches the signal the relay becomes energized and turns to N/O and a vertical signal meaning to proceed. After the last car of the train passes the signal the relay is de-energized turning it back to horizontal which means stop. My trigger device for the relay is an insulated track block that starts a few feet above the signal and ends just past.

Last edited by F&G RY

Jim, what you say makes sense.  It is a position light so there are similarities with the 440.


I'm trying to make sense out of the Greenberg description, and from the fact that Marty's light has two wires going to the head and two wires going to the base.  You've got four wires here, not three.  The two green to the head could be the two sets of lights, like you say.  The two black to the base, one must be the common, it makes me think the other goes to the other side of the "coil".


If the "coil" in the base is not a solenoid, is it a bimetallic delay strip?  What else could they mean by "coil"?


Jim, this light is plastic, so it can't all act as a common like the 440.  One of those wires gotta be a common.


Marty, is there any evidence on the head of a way of manually turning a "disk" inside the head?  A lever of any kind?  If not, then the "disk" must be turned somehow internally, because that's how the lights are changed.


I'm gonna have to find myself one of these and take it apart, this is bugging me...



some directions.


numbers match but i can not see how it would work like a semaphore.


OK now I see it. 2 hots one for the mechanism and 1 for something that makes the bulb change color. One common keeps the center light on. The triggered common activates something to make the bulbs change color and reformat the lights.


Could be 1 bulb and celluloid lenses on a disc. I guess they would alternate red lense for vertical and covering the horizontal aspect. With the opposite for green.

The pole could have a wire to make it go up and down.


The 2 green wires go into the light and would be hot and common. see 1st photo. The black wires would be for a solenoid with 1 being hot and the other intermittent



This is now my guess as to how it works. I guess it does have moving parts. 




Last edited by F&G RY
Originally Posted by F&G RY:

I do not get the green lens. My theory would make it difficult to change the color of the center bulb. Maybe, the lights are green all the time with just the aspect changing?

All 5 lights are yellow and stay yellow all the time.  In that sense it's a true position light, (like the 440) relying on only the configuration (aspect) to change the message, not a change in color. The center yellow light is on all the time.



I really do appreciate everyone taking the time to respond to this.  To answer some questions; the two green wires go to the light blub socket and lite the light only.  There is a type of solinoid in the base because if you look carefully at the last picture you can see some of the actuating parts that operate the internal shields that cover and open the approiate lens covers.  Only the center one is lited..Will have to try this later today...



Originally Posted by F&G RY:

How does it work? With a disc on a arm that would open and cover the holes with a shaft or rod? Or with 5 bulbs, like the 440?


They directions imply one bulb.

My guess is there's one bulb in the head which lights up the chamber inside the head.  The center hole in the face is always open and the light shines out thru it.  The solenoid, activated by track trip, pulls the rod down which turns the disc a few degrees: holes in the disc are arranged so that when rotated, the horizontal holes in the face are uncovered and the light shines out, but the vertical holes in the face are covered.  When the train passes, there is no longer power to the solenoid, and either a spring or gravity returns the disc to its default position, covering the horizontal holes and uncovering the vertical holes in the face which the light then shines out through.  


The two green wires are hot and common for the light. They are wired to track or accessory power 12V so they are on all the time.

The two black wires are hot and common to the solenoid.  The hot is wired to track or accessory power 12V.  The common to the solenoid is attached to the outside rail of an insulated track section, or other trip device.


At least, sight unseen, that's how I can best explain and reconcile Marty's findings, the instruction sheet, the Greenberg description, and keeping in mind that Marx accessories were as simply and inexpensively made as possible.


It's pretty ingenious, this little device.



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