Updated videos for my article.

Duncan McRee, the author wrote:

There are updated videos for the article at my youtube channel:

An easier to follow alignment video:

And a video made with the scenery completed.  Also I had a bad logicrailtech chip in the first video so that it skipped the yellow position on the semaphore return. You can see the correct behavior with 3 positions in this video.

Would BD 20 Dector Work

Would a BD 20 Block Detector replace photo cell in you system?  IE If block is occupied it remains red and green if not. I already have BD 20,s on layout for layout editior.  Looking for Signals that do exactly what you discribed in Video. 

Would a BD 20 Block Detector

Hi Art,  A BD20 will work fine.  In fact you can wire it directly to the dual 3-way board and then use the animation feature built in to that board..

Duncan

Three-position semaphores

Hi, Duncan. Enjoyed your article, and have always been interested in signals as a modeler and as a longtime professional railroader.  Not to belittle your nice modeling, but I do have a comment concerning prototypical three-aspect signaling.

Almost all 3-aspect semaphore heads were of the upper-quadrant type, as it was found that lower quadrant 3-aspect semaphores were confusing to crewmen ..... not enough difference between caution and clear to be easily recognised. A few eastern roads (B&M for example) used three-aspect lower quadrant semaphores for train order signals, but they used  horizontal, 45 degree, and vertical (clear.) SP, UP, ATSF (in earlier years,) B&M, etc., etc. used two-aspect lower-quadrant semaphores as block signals, usually with two heads, and in some cases three heads. Top head governed the block just following the signal, and lower head with forked blade was the "distant" signal showing the aspect of the next signal at end of the block. Here's a good site complete with animation:  http://mysite.du.edu/~jcalvert/railway/railhom.htm ..... So, the 3-aspects were: green over green: clear; green over yellow: approach next signal prepared to stop; red over yellow: stop. 

Of course, it is your railroad and you are free to do it however you like. I just want to make sure that newer modelers know that a single lower-quad 3-aspect semaphore was not generally prototypical. 

Skip Luke
Retired Dispatcher, Engineer, Switchman, Conductor, etc. 
 

Great Article

I was looking at doing something similar to this in that and enjoyed reading your approach, I just like to make animated items,  some day I will connect them to some kind of control system.  I was wondering if there is a bill of materials list for this project.  I would like to try and build something like this.  The major items I can easily get,  I always seem to get burned by some of the smaller items as electronics for me is trial and error.

Thanks,