PRR MP70

The PRR MP70, also known informally as the "double-deckers", was a class of electric multiple units manufactured by the Pennsylvania Railroad for use on the Long Island Rail Road (LIRR). The Pennsylvania Railroad manufactured three prototypes in the 1930s and a full fleet of sixty cars in 1947–1949. They were among the first examples of bilevel rail cars in the United States. The design was unpopular with both LIRR employees and commuters; the last cars were retired in 1972. A single example, the prototype, is preserved at the Railroad Museum of Long Island. The MP70 was an early attempt to increase the capacity of commuter trains without lengthening the train, foreshadowing the successful gallery cars introduced after World War II. The car was not a true bilevel design. It featured a single level with a centerline aisle, and two levels of seats, with the second staggered above the first. Passengers stepped up or down to reach the seats, which were in a facing 2×2 arrangement. This unusual arrangement was devised by Albert E. Hutt in 1928. The original prototype trailer seated 120 passengers, the first prototype motor car 134; all others 132. The Pennsylvania Railroad constructed the cars out of aluminum. This led to significant weight savings in the prototype: compared to an expected had the Pennsylvania used steel. The car was even slightly lighter than the single-level PRR MP54s then in service. Prototype No. 200 was long; all others were . Production motor cars weighed ; trailers weighed . The cars stood tall, short enough for the clearances in Pennsylvania Station and the East River Tunnels. The Pennsylvania Railroad constructed the original prototype No. 200 in 1932. It was an unpowered trailer, with a seating capacity of 120. It entered revenue service on August 13, 1932. Two more prototypes arrived in December 1937: () 201 (another unpowered trailer) and 1347 (a motor car). Because of the scarcity of aluminum, no further cars were built until after World War II. After World War II, the LIRR acquired sixty more double-decker cars.