If we assume a border wall length of 1,954 miles (there are 600 or so miles of existing border barrier, but much of this would not qualify for Trump’s wall), then we can make some estimates as to the volume of concrete needed for the project:
•Foundation: 6 feet deep, 18 inch radius = 42.4 cubic feet
•Column: 4 square feet area by 30 feet tall = 120 cubic feet
•Wall panels: 25 feet tall by 10 feet long by 8 inches thick = 166.7 cubic feet
•Total concrete per 10-foot segment = 329.1 cubic feet
•1,954 miles = 10,300,00 feet = 1,030,000 segments (10-feet long each)
•1,030,000 segments * 329.1 cubic feet per segment = 339,000,000 cubic feet = 12,555,000 cubic yards. (The cubic yard is the standard unit of measure of concrete volume in the United States.)
Twelve million, six hundred thousand cubic yards. In other words, this wall would contain over three times the amount of concrete used to build the Hoover Dam — a project that, unlike Trump’s wall, has qualitative, verifiable economic benefits.
Such a wall would be greater in volume than all six pyramids of the Giza Necropolis — and it is unlikely that a concrete slab in the town of Dead Dog Valley, Texas would inspire the same timeless sense of wonder.
That quantity of concrete could pave a one-lane road from New York to Los Angeles, going the long way around the Earth, which would probably be just as useful.
Concrete, of course, requires reinforcing steel (or rebar). A reasonable estimate for the amount of rebar would be about 3 percent of the total wall size, resulting in a steel volume of 10,190,000 cubic feet, or about 5 billion pounds. We could melt down 4 of our Nimitz-class aircraft carriers and would probably still be a few cruisers short of having enough steel.
But the challenge is far greater than simply collecting the necessary raw materials. All of these hundreds of miles of wall would need to be cast in concrete facilities, probably project-specific ones that have been custom built near the border. Then, the pre-cast wall pieces would need to be shipped by truck through the inhospitable, often roadless desert.
The men and women doing the work of actually installing the wall would have to be provided with food, water, shelter, lavatory facilities, safety equipment, transportation, and medical care, and would sometimes be miles away from a population center of any size. Sure, some people would be willing to do the work, but at what price? Would Trump hire Mexicans?
This analysis also ignores the less sexy aspects of large-scale engineering projects: surveying, land acquisition, environmental review, geological studies, maintenance, excavating for foundations, and so on. Theoretically President Trump may be able to executive-order his way through the laser grid of lawsuits that normally impede this kind of work, but he can’t ignore the physical realities of construction.
Trump’s border wall is not impossible, but it would certainly be a more challenging endeavor than he would ever lead you to believe. Maybe he should stick to 95-story buildings.
