William K. MacCurdy was an American engineer at

SRI International SRI International (SRI) is an American nonprofit scientific research institute and organization headquartered in Menlo Park, California. The trustees of Stanford University established SRI in 1946 as a center of innovation to support economic ...

that developed the Hydra-Cushion

freight car A railroad car, railcar (American and Canadian English), railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck (British English and UIC), also called a train car, train wagon, train carriage or train truck, is a ...

for

Southern Pacific The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...

in 1954. Cushioned rail cars based on his design are still the standard.

Career

MacCurdy joined SRI International in 1952 with a background in shipbuilding; he was previously a naval architect.

Donald J. Russell Donald Joseph McKay Russell (January 3, 1900 – December 13, 1985) was an American railroad executive. He was president of Southern Pacific Railroad from 1952 to 1964 and then chairman from 1964 to 1972. Russell was featured on the cover of Time ...

connected

with SRI in 1954, and asked them to design a new rail coupling; in particular, Southern Pacific was concerned with the

draft gear A coupling (or a coupler) is a mechanism typically placed at each end of a railway vehicle that connects them together to form a train. A variety of coupler types have been developed over the course of railway history. Key issues in their desi ...

, the part that connects the couplings to the rolling stock. In MacCurdy's design, the coupler has an extended connection to the center of the railway car, combined with interleaved fingers at each end of the railway car helping to absorb some of the effects of acceleration. The theory was tested in December 1954 by modifying an existing car with the technology (initially known as the "Hydra-friction") in Sacramento and placing it into relatively difficult service; the car greatly exceeded expectations. The second iteration, bearing the more widely known name of Hydra-Cushion, was introduced in April 1956, and Southern Pacific built and deployed an additional 350 of these cars in summer 1957. The average damage to freight was reduced to 1/25th of previous values. MacCurdy left SRI to be the chief research engineer in the Transportation Equipment Division of

Evans Products Company Robert Beverley Evans, Sr. (March 19, 1906 – August 17, 1998) was an automobile industry executive, a prominent Republican Party (United States), Republican, an Business magnate, industrialist, a socialite, and an avid sportsperson. He foun ...

, which was licensed some of the proprietary information about the Hydra-Cushion from Southern Pacific in 1957.

Legacy

In 1964, MacCurdy and Southern Pacific's William E. Thomford received the

Franklin Institute The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memori ...

's 1964

George R. Henderson Medal The George R. Henderson Medal was an award established by the Franklin Institute in honor of George R. Henderson in 1924, coinciding with a $2,500 fund for the award contributed by his wife. George R. Henderson served on the Franklin Institute's Com ...

for achievements "in the field of railway impact control and associated car design, with resulting benefits in reducing lading and rolling stock damage". In 1967, ''

Railway Age ''Railway Age'' is an American trade magazine for the rail transport industry. It was founded in 1856 in Chicago (the United States' major railroad hub) and is published monthly by Simmons-Boardman Publishing Corporation. History The magazine's ...

'' noted that "The 10th anniversary of the cushion-

underframe An underframe is a framework of wood or metal carrying the main body structure of a railway vehicle, such as a locomotive, carriage or wagon. See also * Chassis * Headstock * Locomotive bed * Locomotive frame A locomotive frame is the struct ...

... has to be one of the most significant anniversaries in the annals of the industry."

References

{{DEFAULTSORT:MacCurdy, William K SRI International people American railroad mechanical engineers Date of death unknown Year of birth missing