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Building the St. Louis Arch

Construction of the famous Gateway Arch in St. Louis began on February 12, 1963, and was completed in 1965. It was a unique project in scope, design and construction.

Designed to be 630 feet tall and 630 feet wide, the arch is made of sections of stainless-steel equilateral triangles with 54-foot sides at the base, tapering to 17-foot sides at the top. Each section has an inner steel wall that allows for reinforced concrete to be poured between the skin of the arch and the inner steel wall. The north and south bases of the arch rest on concrete supports, with a visitor center built underground between the two legs of the arch. When it was completed, a tram was installed in the hollow chamber inside the arch. Millions of tourists have taken that tram to the top of the arch, where windows afford a wonderful view.

As you may have realized, the Occupational Safety and Health Act of 1970 was not signed into law until five years after the arch was completed. Actuarial tables used for estimating the arch’s construction costs included funds for 13 worker fatalities during construction. As it turned out, there were zero worker fatalities during construction of the arch.

There isn’t much written about why such a daring project was finished without any fatal incidents. The film shown at the arch’s visitor center clearly shows workers hundreds of feet off the ground with no fall protection in sight. There are a few possibilities that may have contributed to this remarkable absence of fatalities.

For one, when promoters were pushing to build the arch, they said it would employ up to 5,000 workers. The project used fewer than 100 workers to do the job. Their job sites were confined to small areas, and there was lots of supervision. We can learn from this. Job-site safety improves when extraneous employees are kept out of the work area. Only those with vital functions should be on-site. A detailed pre-job briefing can then be prepared and given to those who are vital and necessary for the work to be completed. Employees on work sites who don’t have precise duties to perform can be a hazard. They become distracted because there is nothing for them to focus on.

Employ Precision
If you stop to think about the work the Gateway Arch constructors were doing, it is mind-boggling. From the north, using cranes, derricks and a variety of support structures, they raised a series of triangular sections that gradually decreased in size to a point 630 feet off the ground, meeting a mirror-image structure coming from the south base, 630 feet away. If one side of the structure had started an inch out of line, the error would have been magnified as the work progressed, and the two sides would have been impossible to join without ruining structural integrity. At the end of the project, that final wedge was dropped into place with little difficulty, and the monument was complete. 

We can employ precision in dealing with safety every day. We can teach employees that proper PPE must always be worn. We can teach them that proper tools are to be used for the work at hand, and that we should never take chances that a makeshift plan “will probably work out OK.” We can create precise work plans that include work steps, appropriate tools and employees who have been properly trained to do the work. Above all, we can continuously look for errors and be willing to stop work to correct them.

Precision built the Gateway Arch, and precision can help all of us build safe work plans so that employees can leave their jobs they same way they arrived. Those safe work plans should include planning for every person on the job site. When we avoid having workers on the site who aren’t an important part of accomplishing the work, we help to ensure the safety of every employee who does play a critical role in executing the job.

About the Author: Kelly Sparrow, J.D., is a West Coast safety consultant with broad experience supervising safety during construction and maintenance of electrical transmission and distribution facilities in many parts of the U.S. His experience includes working storm response in the Northeast, Puerto Rico and the Gulf Coast. Sparrow has written safety systems that qualified several small companies as contractors for major public utilities and did follow-up field work to ensure employees were part of the company safety system. He currently works as a safety coordinator for a transmission and distribution contractor in Northern California.

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