With regard to Mr. Trump’s Border Wall, I am skeptical. Now, I freely concede that I am not an authority on Border Walls. In fact, I have never built a Border Wall. This may surprise readers. Yet it is true. So all that follows is in the nature of speculation. Be warned.
Still, though I may be horrifically wrong, and different numbers can be obtained by assuming different types of wall, I suggest that the following represent the kinds of questions that need to be answered. Further, it should be incumbent on those promoting the Wall to produce prices and times that make sense.
All right, Mr. Trump has eight prototypes, but they run to 30 feet high, made of concrete, and go six feet underground to prevent tunneling. According to rumor among the border authorities, some go considerably deeper, and some prototypes are made of other materials. Here we will assume a hypothetical concrete wall thirty feet high and six feet deep. In other words, thirty-six feet in vertical dimension.
Let us assume a thickness of six inches. Much less would be insecure, one supposes. We will ignore rebar. Actually, a glance at the photograph shows that, of whatever they be made, they are more than six inches thick, but we will ignore this.
The volume of concrete in the entire wall would thus be 2,000 miles x 5280 ft / mile x 36 ft x .5 ft, or 190,080,000 cubic feet.
Now, the wall presumably will have to be built in prefab sections at a remote factory or factories, and trucked to the Wall site on flatbed eighteen-wheelers. Donkeys would seem inadequate, helicopters excessive. Fabricating each section in situ with some sort of traveling factory, requiring the trucking in of phenomenal amounts of concrete (or metal or whatever the Wall was made of), would be crazy even by the standards of federal contracting.
To be carried on a standard semi rig, sections could be no more than 8.5 feet wide. Each section would measure 36 ft. x .5 ft. x 8.5 ft, or or 153 cubic feet. Since concrete weights 145 pounds per cubic foot, the section would weigh 22,185 lbs.
Given that a semi can carry only about 45,000 pounds, each truck could carry only two sections. With special permission, not unusual for outsize loads, a semi might carry a section 10 feet wide. Then a single section would weigh 36 ft x .5 x 10 ft x 145 or 26,100 lbs, but then only one could be carried as two would weigh 52,200 lbs, way over the max weight for a semi load. Some other sort of Wall would weigh something else, but you would need a lot of trucks.
Since I don’t know the weights of the prototypes, the foregoing calculations may be off. Show me how, and by how much for each prototype.
A mile being 5280 feet, each mile of wall would require 5280/8.5, sections, or 621. The entire wall would need 2000 miles x 621 sections per mile, or 1, 242,000 sections. That’s 621,000 truck loads.
Assume that the sections were manufactured exactly in the middle of the 2000 mile border. Each section would then have to be trucked an average of 500 miles to its place of installation. If built in California, an average of 1,000 miles. Buy trucking stocks. Of course more factories would mean fewer miles per section. So I figure Mr. Trump must be asking Congress for money for a bunch of factories. Otherwise I wouldn’t think he was serious.
Now, a concrete sail 30 feet high would presumably require a strong foundation to resist the enormous forces created by, say, a forty knot wind. In fact, a high, heavy wall presumably needs a strong foundation just not to collapse sideways in soft earth. Simply placing it in a six-foot ditch would not work. No?
Let us assume a foundation a foot wide on each side of the wall section and, as noted, six feet deep to force migrants to dig a seven-foot hole. Again, just a guess from one who seldom builds international walls. The required volume of concrete will thus be about 2000 miles x 5280 feet/mile x 6 ft x 2 ft, or 126,720,000 cubic feet.
All of this would have to be trucked to its place of use from its place of mixing, and quickly enough to prevent premature hardening. If some stretches of border are too distant or the terrain not adequate, roads will have to be constructed and concrete mixed nearer to the Wall.
Adding the volume for the wall proper to the volume for the foundation, we get 126,720,000 plus 190,080,000 cubic feet, or 316, 800,000 cubic feet. This will weigh x 145, or 22,968,000 tons, all of which will have to be carried to the site of installation. Buy more truck stocks.
What will the Trump Wall cost? Dunno, but would NBC lie? I find:
” White House officials have suggested that the entire wall project could cost between $8 and $12 billion. And, internal DHS assessments suggest the cost could be higher — as much as $21 billion.“
I can think of no greater authorities on heavy construction than a pack of ideological yoyos in the White House who have probably never seen a shovel. The New York Times says $70 billion, and $150 million a year to maintenance.
So, $8 to $70 billion. The government doesn’t know how much the Wall will cost within a factor of about 9, or else is lying. Both are consistent with federal practice. Note that federal projects typically involve very large overruns. Note also that in federal contracting a common tactic, which I saw often in my years covering the Pentagon, is to low-ball your bid and then, when the project is too far along to be cancelled, to discover that the cost will actually be, heh, rather more.
Over 2,000 miles, the $71 billion figure comes to $35,500,000 per mile, or $57,165 per section. The $21.7 billion figure gives $10,850,000 per mile, or $17,472 per section. At $8 billion, $4,000,000 per mile, or about $6,441 per section. Do you really think the government can buy a 36 by 8.5 by six inch reinforced concrete wall section, truck it a long distance, and erect it for…$6,441? Do you think that even the cheapest of the prototypes would cost so little?
How long will it take to complete this cement F-35? Wall, I mean. Wall. Press reports put time for completion at three years. That’s 660 miles per year. Uh...yeah.
Putting up 621 sections a month, or one mile a month, looks ambitions—over twenty a day. These are hugely heavy concrete slabs requiring a massive crane to set them in place, after which they would have to be tied to neighboring slabs in some manner and, presumably, a foundation poured.
Of course putting up 621 per month requires that the factories manufacture 621 per month. This is certainly not impossible, but will take rather more commitment than we see, which is almost none.
Let us be charitable and assume a mile a month for 2000 months. The Wall will take 167 years. Ten construction crews working at the optimistic rate of a mile a month would take 16.7 years. Mr. Trump has at most 84 months left in office, which would, again at a mile a month, come to 4.2% of the Wall.
Now, I do not know whether Mr. Trump could find the Pacific Ocean on a map of Hawaii. Perhaps so. I have no information on the matter. However, a developer of real estate can reasonably be expected to know something of costing construction.
If I were a cynic, which of course I am not, I might suspect the President of using the Wall to excite his rubes while not actually doing much about immigration, their chief focus. Trump may be a trifle scattered, but he is one hell of a politician. Do we really expect him to send federal marshals to chase away illegals from businesses that depend on them–to shut down agribusiness in California, leave citrus crops to rot, shutter slaughter houses, and put CEOs in slam? Nah. Let’s talk the Wall, a distracting sparkle toy.
Note: I see about as well as a cave fish, so will probably have made arithmetic shiitakes which will bring howling mobs of commenters down on my head. Hey, close enough for government work.