An Engineer Explains Why Trump’s Wall Is So Implausible
There are very few occasions in American political discourse that require the input of a structural engineer, but when Donald Trump took a question from Univision’s Jorge Ramos regarding his proposed United States-Mexico border wall at a press conference on August 25, I heard the clarion call:
RAMOS: How are you going to build a 1,900-mile wall?
TRUMP: Very easy. I’m a builder. That’s easy. I build buildings that are — can I tell you what’s more complicated? What’s more complicated is building a building that’s 95 stories tall. Okay?
No. Donald Trump is not a builder. Donald Trump could not build a doghouse. Donald Trump is a developer who pays what he would call “very, very smart people” to build things on his behalf. His response to Ramos’ question was meant both to exaggerate his understanding of construction and to downplay the challenges posed by his border wall project.
Though I would never classify the construction of a 95-story building as simple, it is a feat that has been achieved many times before. There are at least 30 buildings that have reached a height of 95 stories or more, according to the obsessively detailed database at SkyscraperPage.com, and there are even more in the design phase or under construction.
On the other hand, human beings have built a 2,000-mile-long frontier wall exactly one time. Once. And it was accomplished only through a centuries-long building campaign that necessitated the forced labor of millions of Chinese peasants.
The challenge of Trump’s border wall is not technical, but logistical. The leap in complexity between “building a wall” and “building a 2,000-mile-long continuous border wall in the desert” is about equal to the gap between “killing a guy” and “waging a protracted land war.” Trump’s border wall, if built as he has described it, would be one of the largest civil works projects in the history of the country and would face an array of challenges not found when constructing 95-story skyscrapers.
In order to adequately answer Mr. Ramos’ question, let’s first make some assumptions on the project’s scope: A successful border wall must be effective, cheap, and easily maintained. It should be built from readily available materials and should take advantage of the capabilities of the existing labor force. The wall should reach about five feet underground to deter tunneling, and should terminate about 20 feet above grade to deter climbing.