Total SF hosts Peter Hartlaub and Heather Knight visit the cable car barn in San Francisco and talk with gripman Val Lupiz and former cable car barn superintendent David Banbury about the history of the transit network, and ask listener questions about the cable car line. Lupiz and Banbury cover the meaning of certain bells, why Muni no longer allows tourists to push cars on the turnaround and what gripmen think about that cable car explosion scene in "The Rock." Produced by Peter Hartlaub. Music from the Sunset Shipwrecks off their album "Community," Castro Theatre organist David Hegarty and cable car bell-ringing by 8-time champion Byron Cobb. Follow Total SF adventures at www.sfchronicle.com/totalsf  Learn more about your ad choices. Visit megaphone.fm/adchoices