By the early 1950s, the New Haven Railroad's electric passenger engines were getting a bit long in the tooth, with the newest engines dating from 1938. President F.C. Dumaine, Jr. ordered ten engines from General Electric incorporating a new technology: ignitron rectifier tubes that changed AC power from the overhead catenary into DC, enabling the new engines to use standard DC diesel traction motors.
Before the engines could be delivered, Dumaine was ousted in a shareholder proxy fight led by Patrick McGinnis. While the subsequent McGinnis administration was a disaster in almost every other way, it did leave the New Haven with a memorable paint scheme that originated with the EP-5. Mrs. McGinnis hired famed graphic designer Herbert Matter to create a new look for the railroad. Prior to delivery in 1955, two EP-5s were painted in Matter's "block NH" scheme, one in yellow, white, and black, and the other in red, white, and black. Mrs. McGinnis chose the red version, and the result was a corporate identity that still looks modern more than a half-century later.
Beyond the paint scheme, the EP-5s were famous for their sound. The combination of whining cooling blowers in the rooftop resistor box and high-speed cooling blowers in the body compartment led crews to call them "screaming Marys" or "Jets," and the latter name stuck. After some initial teething problems, the 4000 hp Jets proved dependable and powerful in passenger, mail/express, and nighttime piggyback service between New Haven and Grand Central Station. The EP-5 returns to the RailKing lineup for 2010 in the original McGinnis scheme, a fanciful new M&M'Sr scheme, and decorated for the Great Northern and Milwaukee, which rostered similar-looking electrics.