Jan. 17th, 2016

lionkingcmsl: (Trained lion)
I had mentioned previously that I had wired up three light assemblies from a Position Light Signal, and they were stacked on the corner of my deck's railing.

The thing is they were balanced somewhat precariously, as the 1.5" PVC pipe was holding them in line and preventing them from going over backward. However it did not have enough mass to keep them from falling off the front of the railing. This was something I was concerned about, as the hood on each assembly is 15 inches long and good snowfall would have enough weight to move the balance point too far forward and then they would tumble ~5 feet to the ground. Something I did not want to happen.

While it was not on my list of things to do yesterday, I located a 5 foot length of pressure treated 4x4 in my scrap pile and proceeded to plant it in front of the deck.

So now the signal looks like this:

I had wanted to mount the "spider", the black thing in the background, that would allow me to mount all 7 lamps, but I did not have large enough bolts and it would have put the bottom lamp to close to the ground. I also realized later that the target, or background, would've protruded into the driveway.

I took off the lower lamp hoods as you could not really see the lights with them on.

As you can see in the picture it is snowing today, at last. :=3
lionkingcmsl: (Trained lion)
While the three lamp assemblies in the previous photo were not repainted, they were cleaned up and new screws/bolts used where needed. To show how complicated one of these things really is I present one of the lamp assemblies disassembled. This is one I'm in the process of totally restoring.

Front left to right we have the mounting bracket that holds the PLA (Position Light Assembly) to the spider. Note that it has a ball and socket joint to the PLA, and a hole through the middle of the socket. The joint allows precise aiming of each PLA, while the hole allows the wiring to pass through it and into a hole on the spider arm. Also the bracket has holes on 45 degree angles to allow the same bracket to be angled for each arm position.

Here is a view of the socket joint showing the hole through the center and holes around the perimeter:

Next are two of the 4 bolts that hold the bracket to the main casting. Interesting to note that all screws and bolts, except those for the bracket clamp, are brass. I guess that was done so the screws/bolts didn't rust to the main casting. Next is the main casting or body. It is all one big casting except for an aluminum vent screen at the bottom. this piece weighs about 15 lbs by itself. Above the main casting is one of the side panels. It is interesting to note that the wing "bolts" are cast iron, the only other non brass fasteners on the signal.

Below the main casting we have the other side panel, the lamp housing/reflector/terminal strip assembly. Note that the bulb faces away from the front of the unit and towards the reflector. And next we have the bulb. While an 1156 light bulb does work, they were originally equipped with 20S11 Philips 10V light bulbs, with the resistor in the relay cabinet. Yes, you can still buy the same bulbs from Philips. Next up is the "Phankill" unit. This is used to avoid a "false indication" from appearing. That would be when a locomotive's headlight or the sun would shine through the lens assembly and give the appearance that the lamp was lit, when it was not. The "Phankill", short for "Phantom aspect Killer", allows only direct light from the bulb and reflector to shine through.

In front of the main casting we have a lens to focus the beam. This lens is mounted at an angle to the Z axis of the reflector, something like this "\" (top angled towards the bulb), to also eliminate phantom aspects.There is a definite top and front to this lens for that reason. In front of that we have the retainer ring for that lens which is also the stop for the "fog penetrating yellow" lens. This lemon yellow color was chosen as it is more easily seen through dense fog. In front of that lens we have the end cap and bracket for the 15" long visor.

The mounting bracket, main casting, side panels and both retaining rings are cast iron, so you can see that it is not a light weight unit.

I hope this explains how a simple looking railroad signal is actually a very complicated item.

When I do my restoration I "chase" out all the threads with the proper tap.

The signal was made by Union Switch and Signal (US&S), and was probably made in the 1940s.
The photos were taken in my living room. :=3

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