Vactrain

[1] In 1799, George Medhurst of London conceived of and patented an atmospheric railway that could convey people or cargo through pressurized or evacuated tubes.

[4] In 1909, Russian professor Boris Weinberg [ru] built the world's first model of his proposed version of the vactrain at Tomsk Polytechnic University.

In 1955, Polish science-fiction writer Stanisław Lem in a novel The Magellan Nebula wrote about intercontinental vactrain called "organowiec", which moved in a transparent tube at a speed higher than 1,666 km/h (1,035 mph).

Later in April 1962, the vactrain appears in the story "Mercenary" by Mack Reynolds,[7] where he mentions Vacuum Tube Transport in passing.

This combination of modified (shallow) gravity train and atmospheric railway propulsion would consume little energy but limit the system to subsonic speeds, hence initial routes of tens or hundreds of miles or kilometers rather than transcontinental distances were proposed.

[10] Trains were to require no couplers, each car being directly welded, bolted, or otherwise firmly connected to the next, the route calling for no more bending than the flexibility of steel could easily handle.

[citation needed] A route through the Northeast Megalopolis was laid out, with nine stations, one each in Washington DC, Maryland, Delaware, Pennsylvania, New York, Rhode Island, Massachusetts, and two in Connecticut.

[citation needed] At the time these reports were published, national prestige was an issue as Japan had been operating its showcase shinkansen for several years and maglev train research was hot technology.

The American Planetran would establish a transcontinental subway service in the United States and provide a commute from Los Angeles to New York City in one hour.

[citation needed] Starting in the late 1970s and early 1980s, the Swissmetro was proposed to leverage the invention of the experimental German Transrapid maglev train, and operate in large tunnels reduced to the pressure altitude of 21,000 m (68,000 ft) at which the Concorde SST was certified to fly.

[15] In August 2013 Elon Musk, CEO of Tesla and SpaceX, published the Hyperloop Alpha paper, proposing and examining a route running from the Los Angeles region to the San Francisco Bay Area, roughly following the Interstate 5 corridor.

[17] SpaceX built an approximately 1-mile-long (1.6 km) subscale track for its pod design competition at its headquarters in Hawthorne, California.