From Catwalks to I-Beams on the Bay Bridge

The top photograph, set against the backdrop of downtown San Francisco, shows men constructing one of the catwalks that provided necessary platforms for work on the two suspension bridges that make up the western span.

In the bottom left photograph, men are working on the I-beams that make up part of the eastern span of the bridge, while the bottom right photograph provides a look at the saddle carrying the south cable over the center anchorage of the western span. These saddles, made of cast iron and each weighing approximately 46 tons, allowed the cables to flex in response to shifts in load due to construction or regular traffic on the bridge deck. At the time the saddles were built, they were considered to be the largest single-piece cast iron components ever used in bridge construction.

Identification Information: Dept. of Public Works, San Francisco-Oakland Bay Bridge Construction Photographs (F2516:1-93).
Top: North Catwalk, 05/02/1935: Box 13 (C5229), photograph 6-864.
Bottom Left: 288 Ft. Span E-22, 09/06/1934: Box 14 (C5229), photograph 7-67.
Bottom Right: South Cable Center Anchorage, 09/13/1935: Box 10 (C5229), photograph 6-1324.