Trolley coaches are a cross between streetcars and conventional motor buses. That’s why they were called “trackless trolleys” in some places. They run on electricity from double overhead wires, with one wire supplying the 600-volt DC power, the other serving as a ground to complete the circuit. (For streetcars, the track generally serves as the ground.)
In 1935, San Francisco got its first trolley buses, for the 33-line over Twin Peaks, operated by Muni’s private competitor, Market Street Railway Co. In 1941, Muni countered with its first trolley buses for the R-Howard line.
In 1944, Muni merged with Market Street Railway and by the end of the decade was converting two dozen streetcar lines to rubber tired vehicles – mostly trolley buses. Marmon-Herrington built a majority of the 380 new trolley coaches Muni purchased between 1947 and 1952. They ran reliably all over the city for a quarter-century before being replaced in the mid 1970s. This coach had the distinction (because of its number) of being painted in a patriotic livery for America’s bicentennial in 1976. It was then saved by a small group of preservationists who set up a charitable group for the purpose – today’s Market Street Railway, now Muni’s non-profit preservation partner.
Muni’s shops have kept the bus in operating condition and repainted it into the livery it arrived in — the iconic green and cream “Wings” design. It carries passengers every year during Muni Heritage Weekend. Market Street Railway would like to see it operate once in awhile during the year in regular service around town, as a surprise dose of history to San Franciscans.