The Safety Appliance Act is a United States federal law that made air brakes and automatic couplers mandatory on all trains in the United States. It was enacted on March 2, 1893, and took effect in 1900, after a seven-year grace period. The act is credited with a sharp drop in accidents on American railroads in the early 20th century.
Following the end of the Civil War, railroads expanded rapidly throughout the United States. The increased traffic was accompanied by an increase in accidents among railroad personnel, especially brakemen. Many accidents were associated with coupling and uncoupling of railroad cars, and particularly with the use of link-and-pin couplers, which were widely in use at the time. The operation of manually operated brakes (hand brakes) was also very hazardous. The rise in accidents led to calls for safety legislation, as early as the 1870s. In the 1880s, the number of on-the-job fatalities of railroad workers was second only to those of coal miners. Through that decade, several state legislatures enacted safety laws. However, the specific requirements varied among the states, making implementation difficult for interstate rail carriers, and Congress passed the Safety Appliance Act in 1893 to provide a uniform standard.
The original act was entitled, An Act to Promote the Safety of Employees and Travelers upon Railroads by Compelling Common Carriers Engaged in Interstate Commerce to Equip Their Cars with Automatic Couplers and Continuous Brakes and Their Locomotives with Driving-wheel Brakes, and for Other Purposes. Its first section makes it unlawful, among other things, for a railroad company engaged in interstate commerce to run any train without having a sufficient number of the cars so equipped with train brakes (such as air brakes) that the engineer on the locomotive can control the speed of the train without requiring brakemen to use a hand brake for that purpose.