Tall and Strong - The Bridge Towers


The Golden Gate Bridge not only set the record for longest bridge span when completed in 1937, it also had the tallest towers.

HONEYCOMB LEGS – STRONG BUT LIGHT

This innovation introduced by the Golden Gate Bridge provided the strength to withstand the tremendous weight transferred to the tops of the towers by the cables, and also to resist horizontal loads due to wind and earthquakes.

OVER A MILLION RIVETS

Each tower has over a million rivets. A red-hot rivet with a round head on one end was inserted through holes to join pieces of steel. Then while the round-headed end was held securely, a riveter with a power tool hammered (“bucked”) the plain end into another mushroom-shaped head, clamping the pieces together.

More Images

 

Tall and Strong - Tree Trunk A tree trunk is less than solid wood, making it strong but light. Similarly, the Bridge towers, with their cellular construction, provide the needed strength with a minimum amount of steel.
   

Workers inside box-like steel cells.

Source: California Historical Society, Huggins Coll., CHS.Huggins.001

 

Close-up of actual rivet.

Explore this Topic Further

Rivets

Golden Gate’s Golden Rivet from 1937 Sarasota Herald Tribune
This short article from the April 28, 1937 Sarasota Tribune tells the unfortunate story of the gold rivet that was used during the dedication ceremony for the Golden Gate Bridge.

Replacing Corroded Rivets from Golden Gate Bridge Highway and Transportation District (GGBHTD) (all ages)
Find out about the bolts that are used to replace rivets corroded by the fog that rolls through the Golden Gate.

Golden Gate Bridge Rivet Technique from ABC News (all ages)
In this news story developed for the 75th anniversary of the Golden Gate Bridge, Vern Mesler from Lansing Community College demonstrates the now-obsolete technique that was used to install rivets on the Golden Gate Bridge. The video includes a short segment from the 1930s showing ironworkers riveting during the bridge construction. (2:40 minute video)

Bridge Tower Statistics

Golden Gate Bridge Tower Statistics from Golden Gate Bridge Highway and Transportation District (GGBHTD) (grades 3 through adult)
This web site summarizes design and construction statistics for the Golden Gate Bridge towers including height, weight, dimensions, deflections, and foundations.

List of Tallest Suspension Bridges from Wikipedia (all ages)
As of September 2014, the Golden Gate Bridge is the 14th tallest bridge in the world. This Wikipedia page provides a list of 93 of the tallest bridges in the world. Only two others on the list are in the United States: the Verrazano Narrows Bridge and the George Washington Bridge, both in New York City.

Bridge Tower Construction

Building the Golden Gate Bridge from Bethlehem Steel (all ages)
This promotional film, made by Bethlehem Steel, follows the bridge elements from the steel fabrication in Bethlehem Pennsylvania to travels 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 as well as construction of the deck and 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 highlights aspects of the construction of the bridge. (5:16 minute video)

Patent for Bridge Tower Construction from HistoricBridge.org (grade 6-adult)
This links to a copy of patent number 2,054,995 dated September 22, 1936. The patent includes the drawings and documentation that Joseph B. Strauss used to obtain his patent for braces in the towers. The document also refers to patent number 1,967,381 that pertains to the cellular construction technique.

Golden Gate Bridge: Underwater Construction from PBS American Experience (all ages)
This short article summarizes the challenges of building the foundation for the south tower of the Golden Gate Bridge. These include swift and powerful currents, deep water that required divers to work up to 90 feet below the water’s surface, potential impact from ships lost in the fog, and the need to invent new construction practices.

Golden Gate Bridge: Balancing the Forces from PBS American Experience (grades 6-12)
The interactive tutorial allows users to explore the engineering and mathematical principles that govern the forces that act on the towers, cables, suspenders, anchorages, and roadway of a suspension bridge. The towers are in compression while the cables are in tension.

The Golden Gate Bridge – (grades 9-12, College)
This chapter by Thalia Anagnos found in Statics by Sheri Sheppard and Benson Tongue (Wiley, 2007) traces the loads through the elements of the Golden Gate Bridge. Several hands-on activities for exploring the loads on other bridge types are included at the end of the chapter.