SpaceX and Tesla founder Elon Musk has revealed the first design for the hyperloop, a high speed transit system that could take people between San Francisco and Los Angeles in 35 minutes. Aluminum pods enclosed in steel tubes would transport people at up to 800 miles per hour, according to a document published on the SpaceX website and first reported by Bloomberg Businessweek.
Two tubes would run alongside each other and ferry people in opposite directions. At each end, they would connect in a loop. The tubes would be mounted on concrete pylons 150 feet to 300 feet apart. The pods would travel about 5 miles apart, which means 70 pods could be en route between San Francisco and Los Angeles. They could depart every 30 seconds. Additional tubes could branch off to allow stops at stations between the two cities.
“Short of figuring out real teleportation, which would of course be awesome (someone please do this), the only option for super fast travel is to build a tube over or under the ground that contains a special environment,” Musk wrote in the design paper.
Musk proposes two sizes for the tubes. The smaller version, which would have an interior diameter of 7 feet 4 inches, would be large enough to carry people. The larger design would have a diameter of 10 feet 10 inches. That would allow pods large enough to fit a car, which means passengers could drive right onto the hyperloop.
The hyperloop would be solar powered. Panels would be placed along the tubes sporadically, as otherwise they would produce much more energy than the hyperloop would need. They would power linear induction motors, which are designed to power objects traveling in a straight line. Each time a pod passes a motor, it would receive a boost, allowing it to gradually accelerate to and maintain a speed of 800 miles per hour. Energy is recaptured when the pod slows down.
Air pressure inside the tube would be low. An electric compressor on the nose of each pod would transfer built-up air pressure from the front to the rear of the pod. This would make the pod experience very little friction and create a cushion of air that allows the pod to travel like a puck on an air hockey table.
“It’s like getting a ride on Space Mountain at Disneyland,” Musk told Businessweek. “It would have less lateral acceleration — which is what tends to make people feel motion sick — than a subway ride, as the pod banks against the tube like an airplane,” he said. “Unlike an airplane, it is not subject to turbulence, so there are no sudden movements. It would feel super smooth.”
Musk expects the tube would cost several billion dollars, while the pods and motors would cost several hundred million. On a press call, he set the overall price at $6 billion or less.
The light weight of the tubes and pods would mean the pylons would provide ample support for the hyperloop–a contrast to the expensive foundational work needed for the California high speed rail project. Musk said the pylons would have earthquake dampers to protect the structure from earthquakes, but, like a building, it would have its limits.
“If LA falls down, I guess the hyperloop will too,” he said in the press call.
He also clarified that the hyperloop would be extremely difficult to crash, but not impossible, as he had said in the past.
Musk said that while he would love for someone else to work on developing the hyperloop, he is willing to build a prototype himself. If he started right now and made it his main priority, it would take two years. Tesla and SpaceX are his priorities, however, so it would more likely take three or four years. He guesses it would take an additional four or five years to build the line between San Francisco and Los Angeles, putting its opening date at an ambitious seven to 10 years from now. That would beat the completion date of the California high speed rail project.
While Musk said the hyperloop could be prototyped on private land, such as SpaceX’s test facilities in Texas, the builder of the San Francisco to Los Angeles line would need to negotiate for land. Running it along Highway 5 would be ideal because it is mostly straight and built on government land.
Musk first mentioned the hyperloop in July 2012. Before today, he had revealed that it would resemble a cross between a Concorde, railgun and air hockey table. He first started thinking about the project when he read about California’s high speed rail project, which disappointed him because of its slow speed.
“I got to thinking about … what would be the optimal solution in the special case of a city pair that is less than say 1,000 miles and where there is a great deal of traffic between those city pairs?” Musk said in a Google hangout with Sir Richard Branson last week. “You want a transport that is roughly twice as fast as the next best alternative, that costs less, that is safer, that is not subject to weather and is more convenient. If there was such a thing, obviously I think most people would take it. In fact, it would increase travel between city pairs because of the increased convenience.”
Musk tweeted this morning that he stayed up all of last night working on the design. While he started working on the hyperloop 1.5 to 2 years ago, he has since brought in help from more than a dozen people at Tesla and SpaceX. It was a background project until a few weeks ago, when some of them began working full time to complete the design.
Pulled all nighter working on Hyperloop (as did others). Hopefully not too many mistakes. Will publish link at 1:30 PDT.
— Elon Musk (@elonmusk) August 12, 2013
This post was updated several times Monday afternoon as more information become available.