Golden Gate Bridge Cable
The Golden Gate Bridge in San Francisco was the longest and tallest suspension bridge in the world when it was completed in 1937. It is lauded as an engineering and architectural marvel and has been named one of the Seven Wonders of the Modern World.
As a suspension bridge, the roadway is hung from two tall masts by steel cables. The roadway spans nearly 1 mile long over the Golden Gate, an especially deep strait carved by glacial runoff during the last Ice Age.
The 36” main cables were the largest ever made and had to be wound on-site. In total, the bridge required 80,000 miles (130,000 km) of galvanized steel wire—enough to circle the globe 3 times.
This piece of cable is a section of the vertical suspension cable that was used on the bridge for about 40 years until its replacement in the 1970s. It is now a collectible artifact of extreme engineering. It may even have some International Orange paint still clinging to its surface.
Note: Full bridge section photos are for reference only. This listing is for a single wire from this section.
Length: ~4"
Vintage photos of bridge during construction courtesy of https://www.goldengate.org/
The original vertical cables, technically called a suspender ropes, of the Golden Gate Bridge consisted of 229 strands of steel wire twisted in 6 bundles around 1 central bundle. The full bundle was 2 11/16" in diameter.
HOW DO WE KNOW THIS CABLE WAS FROM THIS BRIDGE?
Unlike many common construction projects which have features borrowed from similar jobs, an engineering feat as large as the Golden Gate Bridge required everything to be custom designed from scratch, since no suspension bridge had been build to that scale before.
The wires of the suspender ropes were arranged in a specific configuration (fig. 2), unique to the bridge's physical requirements, which acts as an embedded signature. This configuration perfectly matches the section that these strands were taken from (fig. 1). This unique configuration was redesigned again in the 1970s (fig. 3), so we know that our cable was from the original construction.
Here are more interesting statistics about the bridge