The purpose of the couplers is to join the locomotive to the car behind it, and to join each of the cars in the train to each other. Major Eli Janney, a Confederate veteran of the Civil War, invented the knuckle coupler in 1868. This semi-automatic device locks upon the cars closing together without the rail worker getting between the cars. This replaces the "link and pin" coupler, which was a major cause of injuries to railroad workers. A "cut" lever at the corner of the car releases the coupler knuckle making uncoupling safer.
The locking pin is visible in the center of this photo. When the cut lever and pin are raised the coupler is allowed to open, as shown here. The cut lever is on either side of the coupler. In the upper photo the pin is in the lowered position, which keeps the couplers locked together, allowing the locomotive to pull the train.
Have you ever heard the phrase "It was so quiet you could hear a pin drop"? This is a reference to this coupler pin! If the engineer and brakeman work together so that the coupling is accomplished gently, the couplers join together so that the pin drops quietly enough to hear it go "clink". This phrase is one of many that originated on the railroad.
To see daytime hand signals used by brakemen, click here.
To see after dark latern signals used by brakemen, click here.
Videos of coupling and uncoupling at the San Diego Railroad MuseumThanks to engineer Bob Nickles and brakeman Dave Houk.
Approach (1.8 MB) The locomotive approaches the passenger car. The brakeman stops the movement 50' or more from the car for the required safety stop.
Joint #1 (3.6 MB) The brakeman brings the locomotive in for the joint, then once made has the engineer back up to test the joint. This is called a "stretch."
"Going in" (2.0 MB) The brakeman asks for permission to "go between" in order to connect the air hoses. Once given permission by the engineer he kneels down so he can connect the glad hands together.
Uncouple #1 (1.6 MB) The brakeman lifts the cut lever so that the couplers open up. The locomotive now pulls away from the car.
Joint #2 (4.9 MB) The brakeman brings the locomotive in for the joint with a freight car, then once made has the engineer back up to test the joint.
Uncouple #2 (2.4 MB) The brakeman lifts the cut lever so that the couplers open up. The locomotive now pulls away from the freight car, and since the car's air brakes were charged, there is an emergency application.
This page last updated 6-1-2005