View Full Version : Ex-C&NW Cab Signal Operation

12-13-2006, 07:16 PM
Could somebody direct me to a site or explain the operation behind the signals on the former C&NW Main Line through Illinois and Iowa? I know that the C&NW used cab signalling, and near my local trainwatching spot in Dixon, Illinois, I often see trains sitting just short of the road crossing. Am I correct in assuming that they are sitting at a spot where a block is located, and marked with the cab signals? I also assume that that explains why there only seem to be signals in the vicinity of crossovers. Thank you to anybody who would be willing to explain this, or even better, have a track diagram!

12-14-2006, 01:31 AM
Cab signals operate via electrical pulses traveling through the rails. Depending on the installation, they are augment wayside fixed signals or may replace them except at control points. As with a standard block signal system the track circuits that operate the cab signals blocks are separated by insulated joints.

It is likely that the stationary trains you have seen are holding back at crossings to allow vehicles to pass and not stopped at a particular place for cab signal operation. Here is a link that will give you a little more information.


12-19-2006, 03:35 PM
As stated on Don Strack's excellent Utahrails site...

Automatic Train Control (ATC) is used between Chicago Passenger Terminal (CPT) and Council Bluffs. It was installed around 1926, and consists of a two-aspect color indication in the locomotive cab (green or "clear" and red-over-yellow or "restrictive")Except at interlockings and their approaches, there are no wayside signals along this route.

See more for yourself at http://utahrails.net/cnw/cnw-roster-notes.php

12-19-2006, 09:46 PM
Thanks Keats!