Canadian Railway Operating Rules

I would like to thank Professor Mark Csele, who used to work for the Canadian Pacific, for the accompanying rulebook scans. I made my single page reference sheet from his rulebook scans. Below is an excerpt from one of his webpages, which is at: http://192.197.62.35/people/mcsele/railroad.htm . While there, you may also want to check out some of his other pages, there's a whole lotta very cool stuff there!!!

Almost all signals in Canada pre-1990 are single-lens searchlight signals and normally you'd find signals arranged as one, two or three aspects (heads) mounted on a single mast. CROR Signals are designed in principle to display speed information only - how fast the engineer may proceed now and approaching the next signal. More complex signals (e.g. three heads) can display a wider variety of speeds. On a high-speed mainline, a single-head signal is sufficient to display all necessary speed information (i.e. full speed or prepare to stop) however where switches are involved such as a crossover to another line, two or more heads may be required to display the fact that the engineer may have to slow to medium or limited speed to pass the switches before continuing.