A civil engineer’s new critique of Elon Musk’s vaunted Hyperloop project exposes a number of problems with the the futuristic vessel that promises to move humans from LA to San Francisco in 35 minutes.

According to a post by civil engineer Kristen Ray that’s making the rounds on Quora, Hyperloop is a novel concept, but isn’t “even close to feasible” as a project, because of the numerous engineering concerns belying its launch.

Writing in response to Elon Musk’s heralded whitepaper on Hyperloop, published in 2013, which glossed over the gory details of the lightning quick vacuum-powered rail system, Ray methodically hammers out why the engineers have an arduous path ahead of them as Hyperloop construction begins in the coming weeks.

She writes that “the structure is so overly simplified,” noting astutely that Hyperloop is basically an enormous steel tube that lays placidly over concrete pillars:

“To maintain the tolerances needed for the speeds suggested this structure needs to be designed MUCH more carefully. It is not an easy thing to keep such a rigid structure suspended above ground for such long distances.”

Expanding on this sentiment, Ray calls into question the whitepaper’s tepid analysis of Hyperloop’s integrity amid potential seismic activity in California.

Musk's whitepaper claims Hyperloop's concrete pillars can withstand seismic activity. 

Ray calls B.S. on the track’s “dampers,” which are intended to absorb seismic activity:

“Their “structural simulations” are clearly not to scale for the average span (between 20-100ft tall and average of 100ft between spans). A simple damper will not suffice for the major seismic activity potential in the San Francisco and Los Angeles areas with a structure that needs to keep such exact tolerances due to the high speeds.”

Perhaps most glaring in Ray’s findings is that the cost of Hyperloop will most likely mirror projections for the California High-Speed Rail Line that’s currently under construction. Ray says that much of the purported astronomical cost of Hyperloop will hinge on things like system communication, concrete pylons, steel tubing, and perhaps most importantly, dampers.

She writes:

“The Dumbarton Bridge in [the] SF Bay Area recently had 96 bearings installed under the road deck for a seismic retrofit. They cost $90,000 EACH. If one of these bearings was on each pylon, it would add over $2 billion. And there would probably be two bearings per pylon (one for each tube), so we’re probably at $4 billion.”

California’s High Speed Rail Line is expected to cost a whopping $68 billion. Once service begins in 2022, California’s High-Speed Rail is projected to shuttle passengers from Los Angeles to the San Francisco Bay Area in 2 hours and 40 minutes, while Hyperloop intends to do it in 35 minutes.

Passengers will travel in pods — which are being designed right now!

Photos via Space X