of the 1800-series, four cars (01470/01471 and 01480/01481) remain as Red Line work equipment, and 01450 and 01455 are preserved at the Seashore Trolley Museum in Kennebunkport, Maine. Aluminum-bodied cars Three series of older aluminum-bodied cars were built: the 1500 and 1600 series by Pullman-Standard 1969–1970 (known as the "No. 1" fleet), and 1700–57 by UTDC in 1988 ("No. 2" fleet). These cars seat 62 to 64 each and approximately 132 cars are in active service , including some of the oldest cars still in regular revenue service on the MBTA system. All cars are painted white with red trim, with manually operated exterior roll signs. Before their overhauls, the 1500 and 1600 series had a brushed aluminum livery with a thin red stripe and were usually called "Silverbird" cars from their natural metal finish. All these cars use traditional DC traction motors with electromechanical controls manufactured by Westinghouse and can interoperate. The 1500 and 1700 series cars could operate as singles, but in practice are always operated as married pairs. The 1600 series could only operate as married pairs. Originally, the 1500s were double-ended and had two cabs, but were converted to single ended during their midlife overhaul. Headlights are still present on the non-cab ends on the 1500s. The 1700s also have headlights on their non-cab end, but they were built with only one cab. Stainless steel–bodied cars The 1800–85 series of stainless steel–bodied cars was built in 1993–94 by Bombardier from components manufactured in Canada and assembled in Barre, Vermont. (This is known as the "No. 3" fleet.) These cars seat 50, and all 86 cars are in active service. An automated stop announcement system provides station announcements synchronized with visual announcements in red LED signs ceiling-mounted in each car. These cars are stainless steel with red trim, and use yellow LCD exterior signs. These cars originally had red cloth seats (in contrast to the black leather seats of other cars), but in the early 21st century the cloth seats were replaced with black leather seats. More recently the black leather seats were replaced with vandalism-proof reinforced carpet type seats containing multi-colored patterns, as with the other Red Line stock. They have modern AC traction motors with solid state controls manufactured by General Electric, very similar to the Breda A650 for the Los Angeles Metro Rail, the Bombardier R110B prototype for the New York City Subway, and