Related Resources • Railroads

Special thanks goes to Ian Taggart for providing research for this page.
The following extracts comes from United States Supreme Court decision - Norfolk & Western Railway Co. v. Hiles (95-6), 516 U.S. 400 (1996) and provides historical background and development of the automatic car coupler:

Railroad Car Couplers
Railroad cars in a train are connected by couplers located at both ends of each car. A coupler consists of a knuckle joined to the end of a drawbar, which itself is fastened to a housing mechanism on the car. A knuckle is a clamp that interlocks with its mate, just as two cupped hands--placed palms together with the fingertips pointing in opposite directions--interlock when the fingers are curled. When cars come together, the open knuckle on one car engages a closed knuckle on the other car, automatically coupling the cars. The drawbar extends the knuckle out from the end of the car and is designed to pivot in its housing, allowing the knuckled end some lateral play to prevent moving cars from derailing on a curved track.

For most of the nineteenth century, the link and pin coupler was the standard coupler used to hook together freight cars. It consisted of a tubelike body that received an oblong link. During coupling, a railworker had to stand between the cars as they came together and guide the link into the coupler pocket. Once the cars were joined, the employee inserted a pin into a hole a few inches from the end of the tube to hold the link in place. The link and pin coupler, though widely used, ultimately proved unsatisfactory...

Janney Coupler
In 1873, Eli H. Janney patented a knuckle style coupler that was to become the standard for the freightcar couplers used even today. [*1]. The coupler had a bifurcated drawhead and a revolving hook, which, when brought in contact with another coupler, would automatically interlock with its mate.

The Janney coupler had several advantages over link and pin couplers. Not only did it alleviate the problem of loose parts that plagued the link and pin coupler, [*2] it also allowed railworkers to couple and uncouple cars without having to go between the cars to guide the link and set the pin. [*3] One commentator described the automatic coupling operation as follows:

 While the cars were apart, the brakeman had to make sure the knuckle of the coupler on the waiting car stood in an open position and that the pin had been lifted into its set position. When the opposite coupler was closed and locked in position, the brakeman was able to stand safely out of the way and signal the engineer to move the cars together. When the knuckle of the coupler of the moving car hit the lever arm of the revolving knuckle on the open coupler, it revolved around the locked one, while concurrently the locking pin dropped automatically from its set position into the coupler, locking the knuckle in place. Although the brakeman had to set up the entire situation by hand, the actual locking operation was automatic and did not require the brakeman to stand between the cars."

Though the market was flooded with literally thousands of patented couplers, [*4] Janney's design was clearly among the best and slowly achieved recognition in the industry. In 1888, the Master Car Builders Association Executive Committee obtained a limited waiver of patent rights--placing much of Janney's design in the public domain--and adopted the design as its standard.

In 1875, there were more than 900 car coupler patents. By 1887, the number of coupler patents had topped 4,000, and by 1900 approximately 8,000 coupler patents had been issued.

1 Janney was a dry goods clerk and former Confederate Army officer from Alexandria, Virginia, who used his lunch hours to whittle from wood an alternative to the link and pin coupler. F. Wilner, Safety: "A great investment," Railway Age, Mar. 1993, p. 53.

2 Automatic couplers also made possible the use of power air brakes, which had not been successfully used with link and pin couplers because of excessive slack in the coupling.

3 Ezra Miller is generally credited with creating the first semiautomatic coupling device for passenger cars--known as the Miller Hook--but it was never widely used on freight cars. C. Clark, Development of the Semiautomatic Freight Car Coupler, 1863-1893, 13 Technology and Culture 170, 180-182 (1972).

4 In 1875, there were more than 900 car coupler patents. By 1887, the number of coupler patents had topped 4,000, ibid., and by 1900 approximately 8,000 coupler patents had been issued. Clark 179.

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