Bixby Bridge
This is the Bixby Bridge, built in 1932, and the northernmost part of our trip.
Before this bridge was built, Big Sur residents were particularly isolated in the winter. The Old Coast Road a dozen miles away was often closed. This bridge, the longest concrete arch span in the state and, at the time, the highest single-span in the world, came in under budget.
A person once in charge of the land trust around this area called it “the most spectacular meeting of ocean and land in the entire United States.” That person might have been right.
It’s gorgeous. It’s glorious. How did they build this bridge in the 1930s? Aliens. But how did those 1930s aliens do it?
Construction began on August 24, 1931, and was completed October 15, 1932, beating the two-lane highway, itself an 18-year project, by a half decade. In between, over 300,000 board feet of Douglas fir timber was used to support the arch during construction. It took two months to construct the falsework alone.
They excavated 4,700 cubic yards of earth and rock and more than 300 tons of reinforcing steel were shipped in by train and narrow one-lane roads. They chose cement because it looked better and was more durable in the elements. That decision required 45,000 sacks of cement, zipped across the river canyon on cable and slings.
The arch ribs are five feet thick at the deck and nine feet thick where they join the towers at their base. The arches are four and one-half feet wide. All of this, Wikipedia confidently tells me, means that the bridge was designed to support more than six times its intended load. (Good thing, too, it’s a heavy traffic area these days.)
It turns out that these two large, vertical buttresses on either side of the arch aren’t necessary. It is not clear to me if their addition includes the 6X wiggle-room design tolerance or not.
Before this bridge was built, Big Sur residents were particularly isolated in the winter. The Old Coast Road a dozen miles away was often closed. This bridge, the longest concrete arch span in the state and, at the time, the highest single-span in the world, came in under budget.
A person once in charge of the land trust around this area called it “the most spectacular meeting of ocean and land in the entire United States.” That person might have been right.
It’s gorgeous. It’s glorious. How did they build this bridge in the 1930s? Aliens. But how did those 1930s aliens do it?
Construction began on August 24, 1931, and was completed October 15, 1932, beating the two-lane highway, itself an 18-year project, by a half decade. In between, over 300,000 board feet of Douglas fir timber was used to support the arch during construction. It took two months to construct the falsework alone.
They excavated 4,700 cubic yards of earth and rock and more than 300 tons of reinforcing steel were shipped in by train and narrow one-lane roads. They chose cement because it looked better and was more durable in the elements. That decision required 45,000 sacks of cement, zipped across the river canyon on cable and slings.
The arch ribs are five feet thick at the deck and nine feet thick where they join the towers at their base. The arches are four and one-half feet wide. All of this, Wikipedia confidently tells me, means that the bridge was designed to support more than six times its intended load. (Good thing, too, it’s a heavy traffic area these days.)
It turns out that these two large, vertical buttresses on either side of the arch aren’t necessary. It is not clear to me if their addition includes the 6X wiggle-room design tolerance or not.