Seaboard Air Line 2027 and 2028 were lightweight, streamlinedDiesel-electricrailcars built by the St. Louis Car Company in 1936. Electromotive Corporation supplied the 600 hp (450 kW), eight-cylinder Winton Diesel 201-A prime mover and electric transmission components. The units had a B-2 wheel arrangement, mounted atop a pair of road trucks. The aft section was divided into two separate compartments: one was used to transport baggage and the other served as a small railway post office, or RPO (the forward door, located just behind the radiator louvers, was equipped with a mail hook).
Two units were manufactured for the Seaboard Air Line Railroad (SAL). The last usage of these railcars was in May, 1971.
Unit 2027 was destroyed in a collision with a gas tanker truck at Arcadia, Florida in 1956. Unit 2028 was renumbered 4900 after the Seaboard-Atlantic Coast Line merger in 1967 and was scrapped after Amtrak took over national passenger service in 1971.