RAILROAD SIGNALS of the U.S.
"DOMINO" SIGNALS
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In the 1920's, a new style of signal was born out of necessity. These signals were installed as part of the upgrade in the signaling for the soon to be completed Chicago Union Station.
The station designers did not want 24 foot high semaphore poles blocking the view of the many beautiful overpasses, not to mention that the overpasses were spaced about 800 feet apart, so a locomotive engineer would have difficulty in seeing the upper signals.
This signal is a variation of the Pennsy PL (Position Light) signal. The background is 4'-2" square, and uses the same equipment as a PL signal. Instead of placing the heads equidistant from the center (18"), as on the Pennsy, the top and bottom middle heads were placed in line with the outer two, giving the signal it's square shape. In addition, the aspects of two signal heads were now displayed on one.
Another variation of this signal can still be found in service in Northumberland PA, and pictures can be found here.
I would like to thank Mike Spencer for the use of his photos, as he has one of the few units still surviving from when they were taken out of service (I think) back in the late 80's.
Disclaimers:
I love trains, and I love signals. I am not an expert. My webpages reflect what I find on the topic of the page. This is something I have fun with while trying to help others. My webpages are an attempt at putting everything I can find of the subject in one convenient place. There are plenty of other good websites to help me in this effort, and they are listed in my links section on my indexa page, or as needed on individual pages. Please do not write to me about something that may be incorrect, and then hound the heck out of me if I do not respond to you in the manner you would like. I operate on the "Golden Rule Principle", and if you are not familiar with it, please acquaint yourself with how to treat people by reading Mathew 7:12 (among others, the principle exists in almost every religion). If you contact me (like some do, hi Paul) and try to make it a "non-fun" thing and start with the name calling, your name will go into my spambox list! :-)
If this is a railfan page, every effort has been made to make sure that the information contained on this map and in this railfan guide is correct. Once in a while, an error may creep in, especially if restaurants or gas stations open, close, or change names. Most of my maps are a result of personal observation after visiting these locations. I have always felt that a picture is worth a thousand words", and I feel annotated maps such as the ones I work up do the same justice for the railfan over a simple text description of the area. Since the main focus of my website is railroad signals, the railfan guides are oriented towards the signal fan being able to locate them. Since most of us railheads don't have just trains as a hobby, I have also tried to point out where other interesting sites of the area are.... things like fire stations, neat bridges, or other significant historical or geographical feature. While some may feel they shouldn't be included, these other things tend to make MY trips a lot more interesting.... stuff like where the C&O Canal has a bridge going over a river (the Monocacy Aqueduct) between Point of Rocks and Gaithersburg MD, it's way cool to realize this bridge to support a water "road" over a river was built in the 1830's!!! Beware: If used as a source, ANYTHING from Wikipedia must be treated as being possibly being inaccurate, wrong, or not true.
My philosophy: Pictures and maps are worth a
thousand words, especially for railfanning. Text descriptions only
get you so far, especially if you get lost or disoriented. Take
along good maps.... a GPS is OK to get somewhere, but maps are still
better if you get lost! I belong to AAA, which allows you to get
local maps for free when you visit the local branches. ADC puts
out a nice series of county maps for the Washington DC area, but their
state maps do not have the railroads on them. If you can find em,
I like the National Geographic map book of the U.S..... good, clear, and
concise graphics, and they do a really good job of showing you where
tourist type attractions are, although they too lack the railroads.
Other notes about specific areas will show up on that page if known.
Pictures and additional information is always needed if anyone feels
inclined to take 'em, send 'em, and share 'em, or if you have
something to add or correct.... credit is always given! BE NICE!!! Contact info
is here
Beware: If used as a source, ANYTHING from Wikipedia must be treated as being possibly being inaccurate, wrong, or not true.
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RAILROAD SIGNALS HOME
Created 11/8/2006
Last Modified:
21-Apr-2014