Hello. This is a homepage of sorts for The Scrolling CTA Sign Thingy™
1 that I made. To read more, just click on a heading below, or if you just want to play with the sign, there it is. Click on the knob, go nuts.
 | A Little History |
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This is a graphical, functional simulation of a destination roller-sign which I purchased a few years ago from a gentleman involved with the Illinois Railway Museum.
The window/crank/gear fixture is likely original to a 5-50 series car (built in the '50s), while the roll itself dates from 1991, a time when CTA was getting ready to implement color-coded line names, but while still officially using the old-fashioned names ('Ravenswood', 'Lake', etc.) This roll was still also following the old convention of displaying both terminals or the line's name, in place since the late '50s, so that the sign would not need to be changed for return trips (an arduous process - each sign was hand-cranked and there were 4 of them on each car!) This makes for an interesting combination of the old and the new.
Today, CTA train destination roll-signs have kept their line colors, but now are controlled electronically from the motorman's cab, display a single terminal (instead of naming both ends), and use the updated terminal names ('East 63rd', '54/Cermak', etc.) It is rumored that the next order of rail cars, likely to appear within the next 5-10 years, will have LED illuminated destination displays.
The last of the 5-50 series was retired from passenger service in 1998. It is uncertain how many years of service my rollsign saw, but it is in excellent condition with no fading. Its most common in-service display was probably Linden-Howard, the Evanston shuttle, where several of the 5-50 cars spent the last of their years.
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| Real vs. Mock-Up |
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Actually, the sign was not meant to be displayed as you see it here. The faceplate with the roller knob on it is actually the back of the sign, with the front of it (the display) simply facing out of the front or side window of the train:
 
To give you a better idea of what these signs actually looked like on the trains, here are a few photos2: [ #1 #2 #3 #4 ]
For novelty purposes, I rigged up my sign to display through the back, so that the display faces through the neat little window and it can be controlled from the 'front'. This is the configuration you also see in this graphical recreation.
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| Technical Stuff (or, 'How It Works') |
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This simulation is powered by GIF images, HTML, and JavaScript. A JS-enabled browser will be needed to view it. Also, it loads in an IFRAME, so your browser will need to support that. Tested and supported browsers include IE 5.0 and above, Firefox 0.7 - 1.x, and Opera 7.x - 8.x.
The technical challenge for me in coding this was the fact that I'm not amazingly proficient in JavaScript. I basically had to study other scripts providing similar 'scrolling' animation capacity to see what made them tick.
The script also has a hidden feature worth noting: all of the images do not load up all at once, as you might think, and as they would if this were done in something like Flash. This is nice because it reduces the initial loading overhead to under 30kb, whereas the total of all files involved is 150+. This functionality is achieved by caching the sign readings immediately above and below the current one, so that they will be ready when you click to get the next reading, and then when the new reading is displayed, the next one is preloaded, and so on.
Also, a smidgen of PHP is used to provide for the 'saving' functionality. Each time the sign is switched, the new position is saved to the server, and each person who (re)loads the sign will see it set to the last-viewed reading.
The most repetetive (and yet, easiest) part of the project was creating all of the images - the sign fixture, with separate images for the knob rollover, not to mention all of the sign readings - which were all produced from scratch using Photoshop.
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| So, uh... Why? |
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Why, you ask? I bought the real rollsign for two reasons: 1) It was there, and 2) as soon as I saw it I knew I had to have it. Some people might lock it away in dry storage or something. I got it so it could actually be seen. Currently it rests on a purpose-installed shelf in my TV room. One day I'll get around to building some sort of proper backlight box for it.
As for the reason why I made this simulation, well... I was bored? Honestly, the idea just struck me one day when I had nothing better to do, and I thought it would be a neat (if useless) project as well as a little bit of a technical challenge. Plus, the finished product was an opportunity to spread CTAfanning cheer across the lands Internets.
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eric at doorsclosing dot com
1 Patent (not really) pending.
2 Linked photos are from the Rolling Stock galleries on
Chicago-L.org. (Great site, highly recommended.)
† This page is not affiliated with, nor approved by, the
CTA. No intellectual property infringement is intended. The content herein is for entertainment purposes only.