1258, at the Western Railway Museum In addition, No. 1271 is used as an office trailer in a Bay Area scrapyard. The succeeding Breda LRV2/LRV3 fleet of 151 cars is scheduled to phase into retirement between 2021, when the oldest cars are 25 years old, and completely retire by 2027. 25 years is considered the useful lifespan of light rail vehicles, per the FTA and Muni. Since delivery of the Siemens LRV4 fleet has been ahead of schedule, Muni is considering an earlier retirement for some of the oldest Breda cars. Historic streetcar fleet Historic streetcars are run on the F Market & Wharves and E Embarcadero lines. Introduced as a regular, year-round service in 1995, the F-line heritage streetcar service started out 12 years earlier as a temporary, replacement tourist attraction for the cable carsknown as the San Francisco Historic Trolley Festivalduring an almost two-year suspension (1982–84) of all cable-car service to permit major infrastructure rebuilding to take place. The historic streetcar fleet is composed mostly of PCC cars as well as 1920s-vintage Peter Witt cars from Milan. In addition, Muni operates streetcars from around the world which were bought or donated to the transit agency. The vintage fleet is looked over by the nonprofit Market Street Railway organization, but the vehicles are owned and operated by Muni. PCC fleet Muni's PCC streetcars are divided into one of five classes, sorted by fleet number and original service: Big Ten/Baby Ten/1000s First batch Before 1995, several PCCs were rehabilitated by Morrison–Knudsen (MK) before entering revenue service. These include three of the double-ended "Torpedo" cars or "Big Tens" (1007, 1010, and 1015), which were originally built for Muni; and the single-ended 1050-class (1050–1064), which were originally built for Philadelphia Transportation Company (PTC), the predecessor to today's SEPTA. Both of these sub-classes were built originally in the late 1940s. Car 1054 (original 2121) was damaged beyond repair following an accident on November 16, 2003 and it was stored awaiting scrapping. In 2014, Muni sent 1056, the first from the original batch of sixteen to be overhauled at Brookville Equipment Corporation. The entire first batch of sixteen is scheduled to be rebuilt at Brookville; the next cars to be sent were 1051, 1060, and 1059 in that order; followed (in indeterminate order) by 1055, 1062, and 1063. The first streetcar to re-enter service, 1051, was re-dedicated to Harvey Milk in March 2017, and