An engineer recently drew up a “quick design” (pictured below) of Donald Trump’s proposed USA-Mexico border wall. (You can read the full technical analysis of what it would take to build such a massive project here.) This particular design consists of I-shaped concrete columns spaced at 10 feet on center, with eight-inch-thick wall panels spanning in between them. In this design, the only concrete that would need to be cast on site would be for the foundations of the wall. The columns of the wall would be anchored to the foundations, and the wall panels would be slipped in place from above.