In General
Housings
Bulbs
Color Filters
Issues/Problems
Detail Pictures
Location Pictures
Clarks Summit PA
New Milford PA
CSX Baltimore
Model IW10RT
Floobydust
Catalog Drawings
Remote Head Drawing
RACO 50th Anniversary Paperweight
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Unilens signals are relative newcomers to the railroad signaling scene. Originally developed by RACO of Minneapolis, they are currently manufactured by Safetran. Not sure when RACO first introduced the Unilens, but the 50 year anniversary paperweight from 1970 (shown below in the "Flooby" section) highlights the Unilens.
These signals use multiple light sources to emit that light out of a single lens, hence the name "Unilens". They accomplish this by using fiber optic cables to direct the light output from the bulbs to the lens.
Like almost any other other signal, the Unilens can be mounted in just about any fashion - a mast mounted high signal, a ground mounted dwarf, or anything in between.
In looking at the following pictures, you will notice a subtle variation within the different models of the signal, and with any sort catalogs to go on, other than the 1998 one sent in to me by Dave Verzi, I'm kinda flyin on autopilot without my INS working :-) Any help would be appreciated!
-- Housing Styles
Almost all Unilens housings are similar to searchlight signals, where everything is in a single housing. The only variance to this design are the signals designed for BART (where the lens is mounted remotely from the light sources - thanks to the use of fiber optics), and the side-by-side version shown in the catalog (which I don't know if any were ever installed in a prototype installation).
A standard Unilens IW20 housing.
A standard Unilens IW20RT housing (pix from WorthPoint).
The customized Unilens for BART - photo: Mike Brotzman.
Here we have
a pair of earlier signals (IW10RT? - judging from Zach's pictures
below) with brackets mounted on them and small gauge wire connecting them
up (it almost looks like thermostat wire :-), indicating they might have
been mounted to the side of a tunnel, or maybe, more likely, in a yard or shop
building where the wire did not require protection. photo: Marty McGuirk.
Low
clearance side-by-side variation, from the catalog.
Thanks to
Dave, we have a picture of an original RACO version of the Unilens. Notice the
unique cover plate style on the back. More pictures below.-- Bulbs
Because of the design of the interior of the signal case, the signal can employ one to four bulbs for almost any combination of colors, although red, yellow, green, and lunar white are the standard signal colors offered in the catalog.
As you go thru the pictures, you will also notice that some installations included an adjustable series resistor, while others do not.
The first version of the Unilens signal uses a very special bulb - very rare and difficult to find. It is a bayonet based, miniature piano bulb with a bulge in the middle, and the bulge has a flat spot on it where the light exits without distortion from a curved section of glass. It just HAD to be an expensive bulb to produce!
First generation Unilens light source.
A piano bulb.
A flaking Unilens bulb - Marty McGuirk.
Output side of the original bulb
Backside of the bulb with the voltage and wattage.
3 close-up pictures by Marty McGuirk.The second generation Unilens, the Unilens II, uses a "standard" signal bulb with a reflector, one version of which is shown below.
-- Color Filters
Small colored filters provide the colors. They are very similar to those used in searchlight signals, and are ~1" in diameter.
photo: Marty McGuirk
The three pictures below come from this WorthPoint listing:
-- Issues / Problems
Some of the problems which I have read about the Unilens, that "pop up" with them are:
- With the original design, the reflective coating begins to flake off the specially designed light bulb, reducing light output.
- With the updated design, the same thing can happen to the bulb reflector, again, reducing light output.
- The fiber optic cables yellow over time, changing the color slightly.
- The fiber optic cables have melted due to the heat from the bulbs.
- Engineers have complained about the lack of brightness from the signals.
A couple of comments from Mike's page concerning the issues with the Unilens from his position-blogspot page:
Observation: If these type of LED replacements were available AND reliable, why replace the searchlight signal housings to begin with?
It's interesting to note, that many searchlight signals use a 10 watt bulb, but their light can be seen up to a mile away. My guess is because the light doesn't have to travel thru the fiber optic cable (every cable has loss), with (probably) some loss in signal strength (note, I'm an RF guy :-) when the light enters and exits the fiber cable; and because the optics is more efficient (read: better focused). Just my two cents.
My guess, is that word of the inherent problems with the signal prevented it's widespread adoption by other railroads, especially those that "liked" searchlight signals. According to Mike, railroads that did like them included BART, the CP, and the D&H. CSX currently uses them, at least around here in Baltimore, as a dwarf CPL replacement, one example is here, my page for the CSX "wall fall" that happened years ago in Baltimore.
As I have trolled the internet for info on these signals, many railfans have asked why they just can't replace the bulb with an LED. I am guessing it is because most bulb out detectors rely on the current drawn by the bulb to pull a relay in - figure a 10 watt bulb at 12 volts draws slightly less than one amp, a 25 watt bulb draws about 2.5 amps, so this current is sufficient to pull in a series relay. LED's draw much less current, and without retrofitting the entire relay system, the "bulb out" detection system may not not sense that the LED is either failing (reduced output) or failed completely. I don't know this for a fact, but based on my 50+ years working in electronics, that is my educated guess. If someone who works in the field knows why, please shoot me an email so I can be corrected :-)
Acknowledgements:
Marty McGuirk
Dave Verzi
John Atkinson
Zachary Gillihan
Mike Brotzman
A.J.__ via Wikimedia
Denver Todd
Subchat
Worthpoint
Google Maps
Bing Maps
Open Railway Map
Wikipedia
Websites and other additional information sources of interest for the area:
https://commons.wikimedia.org/wiki/File:Safetran_Unilens_color_signal_02.jpg
https://www.trainorders.com/discussion/read.php?2,2023915
http://position-light.blogspot.com/2015/05/no-respect-safetran-unilens.html
https://generalsignals.com/railroad-signal-lenses/
https://picclick.com/Set-of-Railroad-Signal-Light-wing-bolts-NW-284333251645.html oodles of auctions of railroad signals and lanterns
http://www.rrsignalpix.com/SSC-15D.pdf IW-10 drawings courtesy Zach
http://www.subchat.com/readflat.asp?Id=457687&p=1#458114
An Original RACO Unilens 1W-10 Signal
Pictures courtesy Dave Verzi
Inside an older Unilens
Photo by Marty McGuirkSimilar to the housing above, we have a picture with one of the bulbs illuminated.
Inside the Unilens II
Picture by A.J.__Found this picture of a full Unilens housing on the SUBCHAT link above, but don't know who to credit the photo to, maybe John L.?
Clarks Summit PA
On a trip I took to visit Steamtown and Nicholson Viaduct back in 2009, I stopped off north of the viaduct to get these pictures here and in New Milford....
These pictures will also be found on my railfan guide page for Nicholson Viaduct at:
https://railfanguides.us/pa/nicholson/index.htm
I also found a whole slew of my pictures here (un-credited, other than the page heading): http://barrysmodelrailroad.blogspot.com/2015/02/the-manufacturers-of-american-railroad.html
New Milford PA
CSX Baltimore
This is where the WB CSX mainline through Baltimore heads under Charles Street. Here, the Unilens signals are used as a dwarf signal. The red/red signal is in a new location than the other three. In 2014, a retaining wall along this stretch of track collapsed, covering the track and everything else nearby, with about 35 feet worth of dirt, along with a whole slew of cars. More pix and info on the page linked above. As the clean-up continued, they moved the signal to the opposite (left) side in an effort to get trains rolling again.
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Safetran's Rapid Transit Unilens Signals - Model IW10RT
Here are a few pictures of a Unilens installation taken by Zachary Gillihan, not sure where....
Safetran Catalog Covering the Unilens Signal, dated 1998
Catalog pages courtesy Dave Verzi
Additional Drawing for Remote Head Installation
Photo courtesy John Atkinson
Unilens Paperweight
Found on EBay/Worthpoint, June 2023
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.
Please Note: Since the main focus of my two websites is railroad signals, the railfan guides are oriented towards the signal fan being able to locate them. For those of you into the modeling aspect of our hobby, my indexa page has a list of almost everything railroad oriented I can think of to provide you with at least a few pictures to help you detail your pike.
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 :-)
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.
Aerial shots were taken from either Google or Bing Maps as noted. Screen captures are made with Snagit, a Techsmith product... a great tool if you have never used it!
By the way, floobydust is a term I picked up 30-40 years ago from a National Semiconductor data book, and means miscellaneous and/or other stuff.
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! Please be NICE!!! Contact info is here
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Last Modified 17-Jun-2023