Picture it: A car-free trip to Santa Cruz, for an attractive fare, on a train that took you to the beach in the morning, back home that night, and showed you some great scenery along the way. That describes the Sun Tan Special, operated by the Southern Pacific railroad between San Francisco, San Jose and Santa Cruz on summer weekends and holidays for most of the 1930s, ’40s and ’50s. It was more than just a conveyance. “[It’s] a happy train, filled with people in a vacation mood,” says a 1940s Southern Pacific flyer. “It gives you six hours on...