A design for a super-fast transport system dubbed "Hyperloop" -- carrying passengers in pressurized tubes at near-supersonic speeds -- was unveiled Monday by inventor and entrepreneur Elon Musk.

Musk, who heads electric carmaker Tesla Motors and private space exploration firm SpaceX, released a 57-page document describing the project, which he claimed could connect Los Angeles and San Francisco in 35 minutes.

Musk told a conference call this would be a new form of transport, different from traditional rail, and would carry passengers and goods in pods in a contained system elevated on pylons.

"This is designed to be super light and trains are amazingly heavy," he said. "This is designed more like an aircraft."

The system is capable of speeds reaching 1,220 kilometers (760 miles) an hour, or Mach 0.91, according to Musk's document.

The technical paper said Hyperloop "consists of a low pressure tube with capsules that are transported at both low and high speeds throughout the length of the tube."

"The capsules are supported on a cushion of air, featuring pressurized air and aerodynamic lift," it said.

Musk said last week he was merely publicizing the "open source design" and had no plans to actually build the system, but on Monday it appeared he was having second thoughts.

"I'm tempted to make at least a demonstration prototype," he said.

"I'm not trying to make a ton of money on this, but I would like to see it come to fruition and I think it would help if I did a demonstration."

Musk said he and a small team from his two firms came up with the design, drawing on some technology from each.

It envisions some version of the same electric motors used in the Tesla S automobile, creating an electromagnetic field to propel the pod.

"It essentially sends a pulse .. and the tube ends up chasing the pulse," he said.

He maintained that the ride "would feel a lot like being in an airplane .. it would feel smooth, like as if you were riding on air."

Musk has previously called the system a cross between a "Concorde, a rail gun and an air hockey table."

While the system was envisaged to connect the two big California cities, Musk said it would be economical for any link less than about 1,500 kilometers (900 miles).

He estimated the cost of connecting the cities would be $6 billion, which could translate to a fare of about $20 for a one-way ticket.

Musk said he came up with the design because of his opposition to a high-speed rail project in California, which he claimed was more expensive and less efficient.

He said the rail cost has been estimated at "roughly $70 billion" but that "it's probably going to be north of $100 billion and it's going to be less desirable to take that than to take a plane."

California has approved the first phase of construction of a much anticipated yet controversial high-speed rail project linking Los Angeles and San Francisco.

Musk said his system would be less vulnerable to shocks from earthquakes, and less prone to accidents than planes or trains, because "it cannot fall out of the sky nor can it derail like a train."

Besides SpaceX and Tesla, Musk, who was born in South Africa but is a US citizen, heads up SolarCity, a company which makes solar panels for homes and businesses.

He also has a foundation that focuses on education, clean energy and child health.

Musk banked his first millions when he sold Zip2 to US computer maker Compaq for more than $300 million in 1999.

His next company, X.com, eventually merged with PayPal, the online payments firm bought by Internet auction giant eBay for $1.5 billion in 2002.