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Railroad
Interlocking Towers of Texasby
Jim King |
| Ask
someone to recall railroad buildings from their
childhood memories and they are likely to mention a depot
or perhaps a roundhouse. But there was another railroad
building very common across Texas, in small
towns and large, that few people recall: the railroad tower. Most people
referred to these as "signal towers" or "switch towers", but they
were formally known as "interlocking towers", and their locations and designs
were carefully managed and approved by the Railroad Commission. The purpose of
an interlocking tower was to provide for efficient and safe passage across "at
grade" rail junctions where the rails were owned by different companies.
|
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"The
original Tower 64 around 1930. The track straight ahead is looking toward Commerce,
Texas on the St. Louis Southwestern (Cotton Belt). Track to the left is the Missouri,
Kansas and Texas toward Denison. Structure that can be seen in the distance is
the MKT Hunt Yard office in Greenville,
Texas."
Photo courtesy Katy Railroad Historical Society |
| "The
current structure that still stands at the crossing appears to be the lower half
of the original Tower 64." Photo courtesy Myron Malone. |
| In
1901, a new state law tasked the Railroad Commission with developing rules to
govern safety at all places where two different railroads
crossed, and by 1902, they had produced rules governing such crossings. The basic
rule was very simple - if a crossing was not controlled by an approved interlocking
system, then all trains had to come to a complete stop before crossing the junction.
Stopping and restarting a train was time consuming and inefficient, so the railroads
were motivated to build interlockers at junctions that had frequent traffic. Using
manual or electronic control systems, an interlocker would provide distant signals
to the rail lines to indicate whether the crossing could or could not be occupied
by an oncoming train. If a train had a "clear" signal, it could maintain speed
and cross the junction without stopping. |
Railroad
Interlocking Tower 20 in Bells
1902 photo courtesy George Kimbrough |
| In
the early years, interlocking systems were typically installed in towers staffed
with personnel responsible for controlling the signals. But at rail junctions
where one line was heavily used and the other line was seldom used, this was an
inefficient approach. There was little for a tower staff to do because the signals
would almost always be set to allow passage on the busy line. This problem was
solved through the use of a "cabin interlocker", a small, unmanned hut that contained
the signal controls that could be manually operated by a train crew needing to
get a "clear" signal for permission to cross. The controls were generally left
with the "clear" signal given to the busy line so that the frequent trains on
that line did not need to stop. |
| "A
very old photograph showing Tower 69 in Celeste, TX. Photograph from the Mackie
Don Baber collection, courtesy of Jerry Hunter." |
| The
Railroad Commission assigned a number to every interlocker they approved. The
first three interlockers were authorized on May 21, 1902 to control crossings
at Bowie (Tower 1), San
Antonio (Tower 2) and Flatonia
(Tower 3). By the mid-1960s, advances in electronic control technology had resulted
in the widespread use of automatic interlockers, systems that detected the approach
of trains and automatically issued the proper signals. The Railroad Commission
decided to get out of the business of approving interlockers, and the last interlocker
to receive a number was Tower 215 at Bloomington in 1966. Very few original railroad
towers have survived to this day. Two excellent examples are Tower 3 in Flatonia
and Tower 19 in Dallas http://www.towers.txrrhistory.com/019/019.htm
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| | Railroad
Interlocking Tower 3 in Flatonia
Photo courtesy of Flatonia Chamber of Commerce |
| "Abandoned,
but still standing in November, 1996, Tower 115 in Eagle
Lake sits silently as an eastbound Southern Pacific freight rumbles by on
the Sunset Route headed for Houston. The tower was razed shortly after this photo
was taken." - Photo courtesy Jim
King |
The
Texas Interlocking Tower Home Page http://www.towers.txrrhistory.com/index.htm
is a non-commercial project currently underway to document the history of all
of the interlocking towers in Texas. Historic photos have been found for many
towers, but there are literally dozens of towers for which historic photographs
have not been located. Towers sometimes show up in the background of other photos.
For example, Tower 36 (Bryan)
shows up in the background of a photo postcard, and Tower 4 (Dalhart)
was found in the background of some old photographs of Main Street in Dalhart.
Our only Tower 7 (College
Station) photo is from a 1920s vintage aerial photo of Kyle Field! Perhaps
your collection of old photographs includes a railroad tower. If you find such
a photograph, or if you have personal recollections of a hometown railroad tower
that you wish to share, please visit the Texas Interlocking Tower Home Page http://www.towers.txrrhistory.com/index.htm
and use the email links there to contact the webmaster.
©
Jim
King
They
Shoe Horses Don't They November 10 , 2006 Column | |
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