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
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.