Model Railroad Historical Society


Infrastructure - Brains Behind the Signals:

The standard gauge layout has embarked on prototype signaling for the S.P. and the W.P. mainlines. Our plan has evolved to implementing Bruce Chubb's CMRI (Computer-Model Railroad Interface).

Diagram of network topology - click here to open: CMRI Network

Detection of trains is being done by our old "EDA" detection circuit boards left over from the previous layout (Kermit Paul's Progressive Cab Control System) with a few modifications to update some components.

Track-Side Signal Fixtures:

Signals were a daunting expenditure - a search was on to source kits, components, whatever, literally from anywhere on the planet.  Surface mount light emitting diodes (LED's) were procured directly from China.Separate spec sheet and diagram - click here.

Signal structure parts are from *Class 5 or are modified from retail castings (with the manufacturer's permission) to match prototype and used as patterns for our own resin castings.

*Class 5 makes super detailed H-2 and H-4 Searchlight Signals. They are outstanding kits. The SMRHS made some modifications to make a more damage resistant signal at the expense of some detail and to make Western Pacific signals. Though the Class 5 signals are not lighted they could be easily modified using the diode package we have developed to light them. Vendor Information:

Class 5
P.O. Box 747
Santa Rosa, CA. 95402

A few of our very skilled (eye-hand coordination and working under magnification required) members are assembling these beauties.

Green Signal
Yellow Signal
Red Signal

Many signals will be on signal bridges, a few on cantilevers, and we have heard promised S.P. prototype semaphores on two control points.

Our vintage W.P. Centralized Traffic Control (CTC) panels (Union Switch & Signal) will eventually be interfaced into the CMRI system.

First phase will be to have ABS operation. The Absolute Block System (ABS) railway signaling system is based on the principle of dividing a line into sections or blocks. In this fixed block system a train may enter a block section only after the last train ahead has moved and is protected by a stop signal. We hope to have the majority of our W.P. mainline on ABS by the end of April 2006.

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