The steel trusses on each side of the roadway deck structure along its length can be identified by their triangles. The trusses support beams holding up the roadway and stiffen the deck structure against wind. They span 50 feet (15 meters) between the vertical steel suspender ropes that support them. The vertical suspenders pull the weight of the deck, along with its traffic, up to the main cables. When installed, the 250 pairs of suspender ropes looked like strings on a giant harp.
An advantage of a suspension bridge is that once the towers, anchorages, and main cables are installed, no temporary supports are needed under the bridge to build the roadway deck. The deck is built in sections, proceeding out from the towers in a balanced way, each section hung from the suspenders.
The final piece of the overall structure, the roadway deck structure with its paving, was in place by April 19, 1937, about a month before the Bridge opened.
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Solid steel beams across the width of the deck are supported by the steel trusses running the length of the Bridge. Under the deck is the temporary safety net.
Image courtesy of the GGBHTD (Bev Washburn Collection)
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The steel trusses may seem small from a distance, but they are 25 feet (7.6 meters) deep.
Image courtesy of the Bancroft Library, University of California, Berkeley
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Looking north, toward the Marin County end of the Bridge. The suspender ropes are in place, ready for deck installation.
Image courtesy of the Bancroft Library, University of California, Berkeley
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In the foreground at left is a grooved clamp or cable band on the main cable, with steel suspender ropes going over it and attached to the deck to hold it up.
Image courtesy of the Bancroft Library, University of California, Berkeley
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Explore this Topic Further
Construction and Retrofit
Building the Golden Gate Bridge from Bethlehem Steel (all ages)
This promotional film, made by Bethlehem Steel, follows the steel elements of the Bridge from the steel fabrication factory in Bethlehem Pennsylvania through the Panama Canal and arrival in the San Francisco Bay Area. It provides original footage of the cellular construction of the towers, the riveting, and placement of the cable saddle, the construction of the deck, and the spinning of the cables. (26:35 minute video)
Golden Gate Bridge: An American Icon Turns 75 from www.nbcbayarea.com/ (all ages)
This video created for the 75th anniversary of the Golden Gate Bridge uses original footage to highlight aspects of the construction of the Bridge. (5:16 minute video)
Bridge Deck Torsional Resistance Retrofit (all ages)
This exhibit, in the visitor area at the San Francisco end of the Bridge, describes the bracing that was added to the bottom of the Bridge deck to improve its performance when exposed to high winds.