As part of fleet upgrades in the 1950s, the IRT purchased 250 R21 in 1956/57 and 450 R22 class subway cars in 1957/58 from St. Louis Car Co. for use on New York's Interboro Rapid Transit (IRT).
 
Both classes had drop-sash door windows instead of the round type used on the R17 series. During their service lives, three R22 cars served on the Times Square and Grand Central shuttle in automatic train operation, and three different cars served to demonstrate crewless operation. After retirement, some were converted to work cars. The last revenue run for these cars was in 1987.
 
* 5-Pole Skew-Wound Motor with Dual Flywheels * Close Coupled * Directional Lighting * Interior Lighting * Magnetic Knuckle Couplers