 The Central California Railway Company, a subsidiary of Southern Pacific, completed the Dumbarton Cut-off in 1910, reducing the rail route distance between Oakland and San Francisco by .Prior to the completion of the Cut-off, transcontinental freight destined for San Francisco was unloaded in Oakland and ferried across the Bay, or trains detoured through San Jose and Santa Clara, using the Peninsula Corridor to San Francisco.The Dumbarton Rail Bridge, a swing through-truss span, was the first structure built across San Francisco Bay.