To paraphrase Vane Jones, "Knowledge is of little value until shared with others."

Sunday, July 8, 2012

Automatic Block Signals on the Chicago & Utopia Railway – Part 1

While working on the layout to correct malfunctioning turnouts and fine tuning the upgraded electrical control system, a couple of non-working block signals were noticed. At the same time a second try was attempted to get the 2 grade crossing warning signals operational.

This caused me to reevaluate the block signals on the layout. Of course, this lead to more work than originally expected to be done on the layout. Here is a written explanation of my layout’s block signals!

An item which catches the eye of the visitor, probably more rapidly than other features on a layout, are the changing lights on track side block signals. Up until recent times I thought the red  and green of block signals were just like traffic signals – red = stop and green = go. Then I found out this was not true. The color of the light controlled the speed of the train. If you ask what speed was each color, you need to look up the speed in the rule section of an employee timetable.

Before going further please recall I am and never have been an employee of a railroad. Therefore my comments are those of a modeler who has taken license to make the “rules and regulations” governing the use of track side signals to enhance the appearance and appeal of my layout.

After reading “All About Signals” by John Armstrong, 1957 Kalmbach Publishing Co., and “The Compendium of Signals” by R.F. Karl, I learned about track circuits, ABS, CTC, and more. However, I was just as confused as ever.

When reading the rules and regulation books for the CA&E, CNS&M, CRT, and CSS&SB; I noticed the section on signals had items common to each railway. But at the same time there were differences between each railway. You may have noticed each railway, besides based in Chicago, had been controlled by Insull at the same time in the 1920’s.

If you recall my layout was to be able to operate both 2-rail as well as trolley (3-rail =both rails grounded) models. Over time electrical gremlins kept coming up and now the layout is trolley operation only.

Trying to have a block signal system which accommodated both 2-rail and trolley operations is difficult. Of the “commercial systems” available, Circuiton’s optical light controlled seemed to be the best for my application. Circuitron's DT-2 boards were used for block controls. At the same time, I wanted to use 2 lights, red and green, instead of 3 lights to indicate block occupancy. Tossed into the mix was a desire to use the old Walthers signals I’ve had for many years. They had been used on a prior layout.

To help “pin down” specific, needed information please allow me to share with you information in the rules and regulation books of a couple of Insull’s railways. Taken from the 1926 "Chicago Aurora & Elgin Rules for the Government of the Operating Department" book are these for single track operation. The signal heads are 2 lights red and green.

BTW – The CA&E used 3 light signal heads for double track plus other signals for special situations.

My layout is a single track with a passing siding. The drawing below shows the “mainline” passing siding plus the sidings for the barn, storage and freight. Also, there is a grade crossing with another mainline railroad.

Either "click on" and/or to print out the drawing above to be able to see all of the parts. An explanation of the signals along with a photo of each signal will follow in the next post along with a copy of a page from an old Walthers catalogue.

The next railway book to be shared is the 1946 "A. A. Sprague and Bernard J. Fallon Trustees for Chicago Rapid Transit Company Rules and Regulations Governing Employees Engaged in Operation". These are the pages for all the block and interlocking signals.

My layout, the Chicago & Utopia Ry. (C&U), has an Automatic Block Signal system. If you look at “Automatic Block Signals”, page 94, of the CRT book you will notice a number plate on each signal. This is an important clue as to the type and operation of the system. The plate can be either vertical, as on the CRT, or horizontal. The number can be either miles or some other unique notation for the location of the signal. Any signal with a number plate is part of an automatic block signal system.

What is important is the meaning of each color light or aspect. For 2 colors, green means proceed. Red means stop for a prescribed length of time and then proceed at a speed with the length of time and speed as written in the rules of the employee timetable. The waiting time may be 5 or 10 minutes with a speed no greater than the distance in which the train can stop upon seeing an obstacle on the track.

Turn to page 92 of the “Interlocking Home Signals”. You should notice there are no number plates which mean the signals are absolute. You need to know what the rules are as posted in the employee timetable. Also, note there are 2 signal heads which on the CRT means diverging routes. The upper signal is for the “main route”; the lower head is for the “diverging route”. The “main route” could be straight ahead or curve off. The meaning of these on the C&U may be slightly different than page 93.

Turn to page 91, Interlocking Home Signals. With the railroad grade crossing on the C&U, interlocking home signals are used to protect this crossing. A signal of red over red indicates a stop and stay. In order to move the motorman must contact the dispatcher for orders.

While I know there are specific AAR rules on signal aspects, my explanations are over simplified to suit my situation – a modeler who wants operating block signals for catching the eye and interest of visitors. The block signals do not control the operation of the model(s) on my layout. The motorman is responsible for the operation.

The next post will show you the block signals on my layout.


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