the b&o had been using rdcs in local baltimore–washington, d.c., commuter service since 1950. pleased with their reliability and lower operating costs compared to heavyweight passenger trains drawn by steam locomotives, the b&o decided in 1955 to replace its money-losing "washingtonian" steam train with rdcs, ordering four rdc-1s with reclining coach seats and two rdc-2s with baggage compartments. the rdc-equipped "daylight speedliner" entered service on october 28, 1956, and reduced the railroad's operating expenses by almost half, compared to the "washingtonian" train it replaced.