5472 x 3648 px | 46,3 x 30,9 cm | 18,2 x 12,2 inches | 300dpi
Data acquisizione:
25 ottobre 2015
Ubicazione:
Danbury, CT, United States
Altre informazioni:
Dr. Sperry began developing a method of locating internal rail defects in 1911. To build a railway test car he contracted with the American Railway Association in 1927. Construction on this first car began in June 1927. The body was metal-faced plywood, and was mounted on a Kalamazoo motor car bed. This car was towed by a larger motor car. After completion, it was delivered December 17, 1927, for performing tests. An operator, lying flat on his stomach as he was moved along on a hand car, held a 'search unit' against the rail. Both fissures were found, but serious difficulties were encountered during the test. This method also posed problems due to uneven rail surfaces.
