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The Longest Day-Part 4
By Bob Mintz
The last time that we detrained, I asked about the origins of
the strange looking self-propelled unit
I went to someone more with more expertise in the field than
I, and he gratefully gave me permission to reprint his fine article
A HISTORY OF
By William E. Miller
(Reprinted with permission)
Elmer A. Sperry invented the rail flaw detector car. Born October
12, 1860 in Cortland, NY, Dr. Sperry passed away June 16, 1930.
In his lifetime, he founded eight manufacturing companies and
took out over 400 patents. Having a keen interest in machinery
and electricity from an early age, Sperry developed dynamos and
arc lamps. He established Sperry Electric Mining Machine Company
in 1888 to manufacture electric rotary and chain undercutting
machines he had invented for the mining industry.
In 1890, Sperry began to apply his vast knowledge and skills
to transportation. First he designed an electric industrial locomotive
and motor transmission machinery for streetcars, founding the
Sperry Electric Railway Company in Cleveland, Ohio. He soon sold
this to the General Electric Company. In 1894 he turned his interest
to the building of electric automobiles powered by his patented
Sperry's greatest invention was the gyrocompass. He set up his
Sperry Gyroscope Company in Brooklyn, NY, in 1910. He extended
the gyro principal to the guidance of torpedoes, gyropilots for
steering ships and for stabilizing airplanes.
To railways and railfans, the name Sperry is more likely to be
associated with the Sperry Rail Detector car. Early efforts in
the late 1800's to develop a rail defect-detecting device had
proved unsuccessful while serious train derailments, blamed on
transverse fissures, were on the increase. In addition to previous
derailments, one occurred in Manchester, New York, in 1911, killing
29 and seriously injuring 60, while another killed 21 and injured
over 100 near Victoria, Mississippi in October 1925. It was apparent
that a dependable rail inspection device was needed.
In 1923, Dr. Sperry began work on developing a method of locating
internal rail defects. In 1927, he contracted with the American
Railway Association to build a rail test car. Construction on
this first car, numbered 101, began in June 1927. It consisted
of a metal-faced plywood body mounted on a Kalamazoo motorcar
bed, which was in turn towed by a larger motorcar. Following completion,
it was delivered December 17, 1927 for testing.
An operator, laying flat on his stomach, held a "search unit"
against the rail as he was moved along on a handcar. Fissures
were found during the tests, but serious difficulties were also
encountered. This method also had problems due to uneven rail
Dr. Sperry and his staff worked around the clock for several months,
until in 1928, they discovered a new principal for detecting transverse
fissures, the "induction method". In addition to detecting
transverse fissures, the induction method also found split-heads
and other invisible defects. This system was used until 1960 when
semi-automated ultra-sonic equipment was added to the Sperry fleet.
Ultra-sonic rail testing was first offered in 1949, equipment
being mounted on a motorcar, with hand held inspection made at
It would appear that equipment based on the induction method replaced
the original magnetic equipment on 101. Although it had been completed
almost ten months earlier, the car was not accepted by the Rail
Committee until October 2, 1928 following a test run on September
27, 1928 by Dr. Sperry and H.C. Drake, his research engineer.
It soon began testing on the New York Central under the supervision
of the ARA. So successful was the test with the modified 101 that
construction on SRS 102 was begun almost immediately.
Dr. Sperry's original plan had been to build and sell the rail
detector cars to the railways, as well as selling the testing
service. However, the railways were reluctant to purchase the
cars outright so Sperry decided not to sell the cars but rather
the service only. In this way, testing would be consistent, as
it would be done by skilled, experienced, personnel.
To market the testing service, Sperry Rail Service Corporation
was created. The first commercial testing was done in November
1928, on the Wabash Railway over a 130-mile section of track between
Montpelier, Ohio and Clarke Junction, Indiana, with SRS 102.
The service soon spread and Sperry put two more cars into operation.
At the beginning of 1930 four cars were in service. By the end
of that same year, the fleet had increased to ten cars.
The fleet continued to expand, as did the area served. In addition
to providing service to U.S. railroads, the Sperry rail cars also
traveled to Canada, Mexico, and even overseas. Smaller railways
could not justify the expense of having their own rail detector
car, which would see limited use, unlike the New York Central
and the Union Pacific who did own such cars. Many Sperry cars
were created by rebuilding existing railway cars, in particular,
"Doodlebugs". In most cases, the rebuilt cars bore little
resemblance to the original.