APRIL 2002 INDEX

History Of The Semaphore
by Jim Herron

Lionel's #151 semaphore has been around for a long time. There were pre-war semaphores, including "O" gauge with standard single and double hands. We all know it operates, but what about its history.

Semaphore is derived from the Greek and means, "to bear a sign." Each blade represents a man with a flag. "Stop" is signaled with the arms outstretched horizontally and "proceed" by the arms dropping down to a relaxed position. The semaphore is an example of an Automatic Block System (ABS) operation where the trains moving past a given point activate the signal blades. ABS systems increase train safety and expedite train movements. Semaphores are also used for interlocking at railroad junctions and crossings.

J. P. Coleman and H. Ballet invented the first successful electric semaphore in 1898. After the turn of the century the Union Pacific and Southern Pacific Railroads, both of which were controlled by E. H. Harriman, installed the lower quadrant "B" style semaphores throughout their systems. The Santa Fe, at that time the longest railroad in the country stretching from Chicago to San Diego, pioneered the use of electric lamps in their semaphores in 1900. The success of these semaphores, built by the Union Switch and Signal Company, continued into the early '40s.

With the increase in rail traffic before World War II, railroads began replacing ABS systems with more sophisticated systems in which a dispatcher at one location could control signals and track switches on several hundred miles of railroad. This system was called Central Traffic Control (CTC). By the early 1980's, only a few semaphores were still in operation.