This complete and illustrated guide to railroad signaling in the U.S. simplifies and presents the utterly bewildering array of mechanisms, procedures, and rules that have evolved since the 1830s to promote safety, impose control, and disseminate information on America's railways. In addition to providing a brief history of North American signaling from the nineteenth century onward, Brian Solomon provides photos of equipment and explanations of not only how it works, but how it is used and what it all means. Solomon also explains how trains on the same route are given "precedence" or placed in pecking orders and how routes are broken down into digestible segments called "blocks" that help dictate the speed and manner in which a train is driven. The result is a fascinating look at the development of communication on the rails, from the days when slips of paper describing an engineer's track orders were held on a metal hook for him to grab on the fly, to today, when instructions are transmitted via computer. Major manufacturers of signaling equipment are represented.