In the days leading up to the construction of a new highway between Chicago and Detroit, construction contractors were busy preparing the foundation and foundations for the bridge’s construction.
It would be the first major bridge in U.S. history built by the same team.
But while some of the work was completed, construction crews had to contend with the inevitable construction delays and unexpected problems.
The Chicago Tribune reports that on March 15, 1864, the bridge was expected to open, but then it was delayed by about a month.
The news was not well received, and construction slowed dramatically as workers faced a series of problems with their machinery.
In the meantime, the construction site became a “graveyard,” the Tribune writes.
A construction crane at the Chicago River, built by an architect, is pictured in this March 17, 1872, photo.
(AP Photo/Chicago Tribune, file)The bridge’s first major problem was that the foundation was not complete.
The Tribune reports, “In April 1864 the builders of the Chicago river bridge began to realize the necessity of building a new foundation for it.
A preliminary foundation was laid and an erection of a steel plank was made in the yard, to be raised on the bridge.
The work was continued for two months until the plank was lowered.”
The new foundation would have supported the entire span of the bridge, with a deck extending about 60 feet to its top, the Tribune reports.
But the structural engineers decided to use a concrete slab instead.
The Chicago River was the largest river in the world at the time, and the bridge builders did not anticipate that a new bridge would be needed to replace it, the newspaper reports.
They had planned for a new structure with a similar appearance to that of the existing one, but with a steel frame and steel support columns.
In 1864 it was estimated that the Chicago bridge had a gross weight of 4,000 tons.
But that estimate was reduced to 500 tons in 1867, when the bridge became the most expensive bridge in the country.
The new bridge cost $100 million, but the original design was $200 million.
The steel deck was the most costly part of the project, with the cost of the construction itself estimated at $20 million, the paper reports.
The bridge was completed in 1866, but a major problem arose when construction workers discovered that the concrete slab was not strong enough to hold the bridge together, the report says.
As a result, a crane was needed to lift the bridge from its foundation.
While the crane was lifted, a steel cable came loose, and its length was reduced, which caused the span to break, the Chicago Tribune says.
The engineers had to remove it and replace it with steel.
The newspaper reports that after the bridge finally opened in 1868, the concrete was used again for the support columns and for the foundation.
“The steel structure is still in use for the span,” the newspaper writes.
“There are no other bridges in the United States that are so well built.”