Ever wonder what is inside?

[M3019C LPS20]

Ever wonder what is inside that green cabinet at the corner of a signalized intersection?





I legally acquired this retired electro-mechanical signal controller from a contact of mine last year, and it saw service somewhere in New York City. Unfortunately, it does not have its original paperwork, so I do not know what intersection it had originally controlled. This one in particular was manufactured by General Traffic Equipment (A.K.A. G.T.E.), and it is a fairly young signal controller. Probably between 12 to 14 years old. It operates well, and it is composed of movable parts, such as a dial timer, a solenoid, cam assembly and shaft, and cam finger/circuit assembly, that control signals that are wired to it correctly. A really great piece of traffic control memorabilia.

My second electro-mechanical is older than my first one, and it was manufactured by Marbelite in June of 1969. Same concept. This one, too, did not come with its original paperwork, so it saw service somewhere in the five boroughs.





It, too, operates well for its age. Computerized signal controllers of today control countless intersections throughout the city, but many original electro-mechanical signal controllers still remain in service. They'll be eventually be replaced, though.  See them while they last.

[empirestate]

There's one right outside my building. :-)

(Same one I mentioned in the other thread that had malfunctioned between the yellow and red phases.)

[M3019C LPS20]

There's one right outside my building. :-)

(Same one I mentioned in the other thread that had malfunctioned between the yellow and red phases.)

What's the intersection?

[empirestate]

There's one right outside my building. :-)

(Same one I mentioned in the other thread that had malfunctioned between the yellow and red phases.)

What's the intersection?

http://goo.gl/maps/KLVpd

[NE2]

Related blog post: http://commuteorlando.com/wordpress/2013/02/15/who-ya-gonna-call/

[M3019C LPS20]

This is what the inside of a New York City A.S.T.C. (advanced solid state traffic controller) looks like. A far more complex signal controller when compared to an electro-mechanical signal controller. Note that the cabinet above it contains the necessary battery back-up system for the signal controller.

[Scott5114]

So how do you operate one of these things (i.e. set up the timings)?

[M3019C LPS20]

So how do you operate one of these things (i.e. set up the timings)?

With regards to electro-mechanical signal controllers, they are fairly simple to set-up and operate. Most, if not all, are generally composed of movable parts, such as cams, solenoids, and dial timers, that work together to control signals that are wired to them correctly. These parts are generally important for one to function properly. I'll discuss the main parts.

The dial timer is a simple mechanism that is generally responsible for the time lengths of signal intervals, like a green indication, for example, not to mention cycles (how long it takes for signals to complete their assigned pedestrian or vehicular phases). In essence, the dial timer is operated by a synchrnous motor, which, in turn, rotates the actual dial itself. A gear is connected to the electrical motor, and it is meshed with what is known as a cycle gear. Cycle gears come in various sizes (depends on the time length), and they are in increments of five. The smallest gear is 30 seconds, while the largest one is typically 120 seconds. The signal controllers that I have were each originally timed for 90 seconds, since most of New York City's electro-mechanical signal controllers used that particular cycle. Others were timed for 60 seconds, though. The dial itself has individual slots (100 to be exact), and within some of these slots are small metal pieces known as dial keys. Between each dial key on an actual dial is typically the duration of a given signal interval, and these could be adjusted (either farther from each for a long duration or closer to each other for a shorther duration). Dial keys activate the process to advance the cam shaft, which, in turn, changes a signal indication. On the dial timer is a set of contacts, and each type of dial key has its own corresponding switch (one type is used to advance the cam shaft). Others have other purposes, such as synchronization and interconnection. When a dial key comes in contact with its corresponding switch, the dial key gently raises the contact (has a tip on top of it) to a certain point, in which an electrical current is created. This is sent from the dial timer to a magnetic coil, which controls the action of solenoid. Once this magnetic coil is energized, the solenoid drops forward, and it advances a set of cams on a shaft. That neat "KER-CHUNK" or "KER-BUZZZ-CLUNK" is produced at that very moment.

Each cam generally corresponds to a signal indication. Cams are like wheels that have segments on them. Each segment represents an interval. Segments could be removed or left alone (if necessary). Each cam has its own finger, and, when one is in rotation, it either closes or opens the circuit. When a signal circuit is closed, the corresponding signal indication is illuminated. A signal circuit that is open is when the corresponding signal indication is not illuminated. The broken and intact segments come into play here, and determine when a circuit should either be opened or closed. 

Electro-mechanical signal controllers are quite flexible, so they could be adjusted many times with ease.

[M3019C LPS20]

Computerized signal controllers are somewhat similiar to electro-mechanical signal controllers. The major difference that is rather obvious is in that today's signal controller has no movable parts at all. No requirement to lubricate parts periodically.

With regards to timing, one would have to manually enter the ideal amount of seconds for each interval within the system itself. Each type of compturized signal controller typically has its own menu, in which one could navigate to find different features it contains, such as timing, actuation, and pre-emption.

My knowledge about these in general are rather limited, so I don't work on one too often as I enjoy to work with my electro-mechanical signal controllers. In my opinion, electro-mechanical signal controllers are really neat to watch in operation, since there are many movable parts to see in action, and you develop a clearer understanding of how one operates in the field.

[roadfro]

If the computerized controller is part of an integrated network of signals, there are software programs available that allow remote programming of the signal from a centralized facility. These software are generally a bit less cryptic in operation compared to navigating through the small screen on the physical controller, but operate the same functions.

Watching a computerized traffic controller work in the field can be pretty interesting as well. You can set the screen to show inputs (i.e. if there are vehicles on the detectors or when a ped button is pressed) or particular operating functions (such as when a particular phase is going to gap out). This is pretty useful for techs in the field to diagnose signal issues.

[roadman]

Up until the 1990s, nearly every signalzed intersection on Western Avenue in West Lynn, MA, still had 1950s-era General Electric pre-timed electromechanical controllers.  One morning riding the bus into Boston, it took us forever to get through one particular intersection.  As we finally passed the location, I discovered the reason why.  The signals were on flash, and a DPW worker was on a ladder against the signal cabinet, which was open.  In his hand he had the biggest can of WD-40 I'd ever seen at the time.

[M3019C LPS20]

Up until the 1990s, nearly every signalzed intersection on Western Avenue in West Lynn, MA, still had 1950s-era General Electric pre-timed electromechanical controllers.  One morning riding the bus into Boston, it took us forever to get through one particular intersection.  As we finally passed the location, I discovered the reason why.  The signals were on flash, and a DPW worker was on a ladder against the signal cabinet, which was open.  In his hand he had the biggest can of WD-40 I'd ever seen at the time.

I sometimes came across minor problems with electro-mechanical signal controllers in the city of New York. Some problems that I remember in particular were unintended "dark-out periods" that happened between the transition of two signal indications, such as from amber to red, for instance. Signal indications that flickered were fairly common to see as well.

D.O.T. inspected its signal controllers periodically, and D.O.T. continues to do so, since they are still in use.

Electro-mechanical signal controllers from Marbelite were what mainly controlled countless intersections throughout the boroughs for several decades, and newer signal controllers from General Traffic Equipment first appeared in the picture in the 1990s. You'd be surprised that the city continued to install them at typically newly installed intersections that were constructed in the 1990s and early 2000s. They were still strong at this time.

[M3019C LPS20]

Here's a video of my N.Y.C. signal controller from G.T.E. It controls the signals that you see in this video, and I am aware that the lighting is not exactly superb. Nevertheless, the signals appear decent.

Everything was not powered up for quite a while, since I recently reconfigured the cam assembly in the signal controller. The set-up I have here displays four vehicular phases and two pedestrian signals (one for the cross street and one for the main street). I replicated a set-up from my hometown of Staten Island, New York that displayed this exact sequence (still does today).

[Milepost61]

Is that walk light actually green, or just something with the video coloring?

[D-Dey65]

There used to be this super old, loud, and clunky one for the signal at Oak Street and Maple Avenue in Patchogue, New York. I don't know if it's still there anymore.

[M3019C LPS20]

Is that walk light actually green, or just something with the video coloring?

Yes.

That pedestrian signal is a Marbelite model LPS-20, and it saw service somewhere in the city of New York at one time. Generally speaking, like some other pedestrian signals that were similar to it, the model LPS-20 from Marbelite used two pairs of colors for its signal indications. The first pair was "Portland Orange" and "Lunar White," while the next pair was red and green. Both were in use throughout the city; however, it seems that the second pair I mentioned was popular at first. It was not until the mid 1970s or so that the city slowly transitioned from red to green to the second pair, though.

Although it is likely that my pedestrian signal used the first pair, I prefer red and green signal indications instead.

Here's a better video of it in its cycle.

[Billy F 1988]

Was that an actuator (or the electronic timer box) that made those sounds in the background when the sign transitioned between "DON'T WALK" and "WALK"?

[M3019C LPS20]

Was that an actuator (or the electronic timer box) that made those sounds in the background when the sign transitioned between "DON'T WALK" and "WALK"?

It is typically known as an electro-mechanical signal controller. Although, yes, that pedestrian signal is controlled by one of my New York City signal controllers. It's actually the first one (from General Traffic Equipment) that is shown in my original thread here.

[Billy F 1988]

Interesting. Most of the signal boxes in Missoula are, I believe, GTE boxes.

Growing up in Missoula, I see a phase.

1970's through the 1990's had the advent of the "DON'T WALK"/"WALK" signals which were either red or blue-ish green, or white. Then they go to the human walking icon and orange hand later in the 2000's to what we have now with the little white walking human icon and a reddish-orange hand with a timer controlled remotely for pedestrian phases. Most I believe have a 20 second phase, though several minor intersections have 15's. I haven't seen the insides of the boxes, but that's what I think they do. Some are controlled remotely, like Higgins Avenue and Pine Street for example. There's no pedestrian signal button. Some others have the old clunky metal buttons, others have some sort of touch sensor that beeps. The one closest to my appartment beeps when pressed.

[M3019C LPS20]

Since the signal equipment company Marbelite was originally based in New York City, most of the city's e/m signal controllers were manufactured by Marbelite. Although Eagle, General Electric, and Crouse-Hinds were in use as well; however, Marbelite was superior to them. It was not until probably the 1990s that new e/m signal controllers from G.T.E. first appeared in the picture. They soon became widespread, and, with that said, the city's D.O.T. installed them typically at newly constructed signalized intersections until the early 2000s. Since the early 2000s, solid state signal controllers have been in use throughout various locations of the city, and the D.O.T. is still in the process of replacing the original e/m signal controllers that are still in service with these newer signal controllers.

With regards to pedestrian signals, I recall that New York City used several different kinds of worded pedestrian signals prior to 2000, and what were in use were Crouse-Hinds, Winko-Matic, Marbelite, and G.T.E. Since 2000, of course, all of the city's pedestrian signals have been since retro-fitted with L.E.D. hand and man module inserts. A lot of original housings were left intact, and they could still be found today.

It was not until recent years that Marbelite reappeared in the signal manufacturing business, and the company manufactures its own polycarbonate pedestrian signal for the city of New York. Today, it contains the standard countdown module insert, which is commonly in use throughout the city nowadays.

[D-Dey65]

Is that walk light actually green, or just something with the video coloring?

You know I remember when they changed the walk signals from green to white. At first I thought the green paint on the lenses just faded, and then I realized they were actually changing them to white, and I thought "What the hell is this shit?!"

[Mdcastle]

The first walk signals were usually done by adding a 4th "Walk" section to a standard 3 section vehicle signals, I have a 4 section Crouse-Hinds art deco signal that this was done to in the field. The lettering was skinny white on black, in a standard 8" round lens. Later it was decided to add a negative command, and an orange "Wait" was selected, and the "Walk/Wait lenses were installed in a standard two section signal mounted. "Wait" was changed to "Don't Walk" because it looked too much like "Walk" from across the street.


The Walk was apparently added later because if you look very carefully inside it has the late style of reflector frame, while he R-Y-G has the early style.




I've never seen an actual green lens. Typically the bulbs were what was green. Some incandescent lenses were a light blue to produce lunar white instead of regular white, but many weren't.

I don't have an electro-mechanical controller, but I do have a hybrid where the timing it generated with vacuum tubes and the switching is done with the solenoid / cam shaft, I've posted pictures and videos of it before.

[M3019C LPS20]

Here's a video of the inside of one of my e/m signal controllers. This one in particular is my Marbelite M-3019C signal controller.
The other signal controller from General Traffic Equipment has the same concept as well. It's always interesting to observe them in person while they're in operation.

[Mdcastle]

Actually I don't believe I've posted this one here. My Electro-Matic in operation, just the controller I don't have a complete cabinet.

[M3019C LPS20]

Nice signal controller. That model from Electro-Matic is quite compact I have to admit. Takes up little space.