After steam locomotives were banned from operating in the Park Avenue Tunnel in New York City, the New York Central procured the world's first mass-produced electric locomotives. After a derailment, the leading axles were replaced with two-axle bogies. With this rebuild, they were renamed from T-Motors to S-Motors. Until the introduction of the new T-Motors in 1913, they handled all traffic. They were used in commuter service and to switch empty trains until the 1970s.