Greetings from Minnesota - and thanks to Bob Sobol!


I’ve been following the progress on your beautiful layout, in particular the CTC panel design and construction. I have a small “vignette”-style HO layout of approx. 12’ x 13’ based on a proto-freelanced section of the joint Rock Island/Milwaukee Road trackage south of Davenport, Iowa. I designed the layout on 40" by 40" graph paper after reading as many John Armstrong books as I could find, then had the paper scanned and printed in pieces at full-scale (which I used as a series of track templates). The layout has DC sections, and I wanted to have a CTC “island” to control the crossovers, within an ABS current sensor-controlled system.

Based on the CTC panels I found on this website, I contacted Bob Sobol for help in finding the dimensions of the panel and design details. Thanks to him, later this year I’ll be able to approach a local Twin Cities (MN) metal fabrication firm to build a small panel for my layout. I’m pretty excited about that! Below is an image of the layout:


Brian -

It appears that you have a great start. Keep us informed as to your progress.

You and others are certainly welcome to the US&S panel dimensions that I have. Although all US&S panels had 2" wide columns, the layout within a column varied according to railroad preference. Doug Geiger posted drawings to the Railway-Signaling group on Yahoo and I forwarded copies of those. the .dxf file for the A&O panel was extended by 3/4" on each side to provide an attachment flange.

There are many excellent references on the web including a site (don’t remember the URL) for US&S builder’s photos. I highly recommend Mike Burgett’s DVD (available from and Bruce Chubb’s CMRI volume on signaling.

Here’s a photo of the early Burlington machine preserved at the Colorado Railroad Museum in Golden. I’m not entirely certain but the toggle switches located above the code buttons were for “Maintainer Call”. Flipping the switch up and coding the column caused a lamp to illuminate on the side of a relay cabin near the points of an interlocking. The amber lights at the bottom of the panel would also illuminate as a reminder to the DS. To “call” a crew, the dispatcher would set the home signal to red, and illuminate the light. Any RR personnel not on moving equipment who observe the light should immediately go to the phone box and call the dispatcher.

On the A&O our MC switches are at the top of each column. Some columns have two pushbuttons. The lower is the standard code button. The upper is “Call On”, which removes certain interlocks to allow a DS to let a local crew head back into a siding occupied by the rest of their train. On the A&O this aspect is a flashing red.


Hi Bob. I am making progress on the CTC and signals on my Rock Island-themed layout. All signals are installed, and the ABS signal heads are all functioning. I am currently creating a CTC panel using 16 ga sheet steel and a maple frame that I constructed. I purchased LEDs, rotary switches, and bezels from Logic Rail Technologies and will be mounting them in the panel next month. CTC Components provided the switch and signal plates.

A challenging and interesting facet of this project is using the current detectors, which are the operational foundation of the ABS signals, as a CTC control mechanism. I plan to run the green or yellow signal aspect wires for the lower signal heads through some of those current detectors. When I turn a signal lever to clear a diverging route, the current flow from the lower head signal (green or yellow) will be routed through the correct current detectors such that the upper aspects display red. Just like the real world. Hopefully it will work. I have a wiring diagram that shows all of this logic.

The signal bridges and signals look great. The model is loosely based on the combined Rock Island-Milwaukee Road route near Muscatine, Iowa. Thanks again for your help in providing information about the panels, steel, etc. Brian Davis