In a scene repeated thousands of times over the years, Caltrain F40 number 901 leads a train south out of San Francisco and around the big curve at the gateway to the 4th and King Station. 901 was built as an F40PH-2 in 1984. In the late 1990s, it was rebuilt by Alstom to have a separate head end power generator, built by Caterpillar, to provide power for the passenger cars as opposed to pulling power directly off the locomotive’s main engine. With this modification, the 901’s model number was c