Dumbarton Rail Bridge, Railway bridge in San Francisco Bay, United States

Dumbarton Rail Bridge is a railway bridge across San Francisco Bay, just south of the Dumbarton Road Bridge. It has dark steel truss spans with X-shaped lattice work on short concrete piers, and a central truss span with a sloped, arched profile. A small rectangular yellow structure with windows and a flat roof sits at the top center of this middle span.

The bridge opened in 1910 as the first railway crossing to span San Francisco Bay. It significantly shortened the rail route between Oakland and San Francisco, transforming regional transportation at the time.

The bridge takes its name from Dumbarton Point, the eastern shore landing where preliminary work began in 1904 with land condemnation. The rail line it carried was called the Dumbarton Cut-off, and the bridge itself was first known as the Dumbarton Point Bridge. Newark marked the start of rail service with a picnic.

The bridge has carried no trains since the last freight run in May 1982, and the western timber trestle approach partly collapsed after the January 1998 fire. It stands beside the Dumbarton road bridge, so it is seen from the road crossing or from the shore rather than walked. The steel truss spans and the yellow cabin atop the middle span are the parts to look for.

The swing bridge that opened for vessels is a separate structure: the Newark Slough bridge, completed by May 1908, east of the Dumbarton Rail Bridge. The main span over the bay is fixed steel truss, with a small yellow cabin at its crown. The 1998 fire burned creosote-treated timber 6 to 9 metres underground.