Vactrain - Vacuum-tube-train
By: +David Herron; Date: Tue Dec 17 2019 13:08:34 GMT-0800 (Pacific Standard Time)
A Vactrain (or vacuum tube train) is a magnetically levitated, or magnetically powered, train system running in evacuated (air-less) or partly evacuated tubes or tunnels. The lack of air resistance could permit vactrains to use little power and to move at extremely high speeds, up to 4000�5000 mph (6400�8000 km/h, 2 km/s), or 5�6 times the speed of sound (Mach 1) at standard conditions.
On August 12, 2013, Elon Musk proposed the Hyperloop system, which is a kind of Vactrain system. That design reminded me of a system described in one of Robert Heinlein's novels. A bit of googling and I found that the novel in question is Friday, and while I don't remember the name he had for the system, over on Wikipedia they have the word Vactrain and some history of different folks who've developed Vactrain ideas.
There's a lot of big claims on the Wikipedia page
- Vactrain tunnels could permit very rapid intercontinental travel.
- the trip between Beijing and New York would take less than 2 hours, supplanting aircraft as the world's fastest mode of public transportation.
- Travel through evacuated tubes allows supersonic speed without the penalty of sonic boom found with supersonic aircraft
The earliest mention known by Wikipedia is explorations in the 1910s by American engineer Robert Goddard, who designed detailed prototypes with a university student. His train would have traveled from Boston to New York in 12 minutes, averaging 1,000 mph (1,600 km/h). Also, Russian professor Boris Weinberg offered a vactrain concept in 1914 in the book Motion without friction (airless electric ways).
The Very High Speed Transit System was written by Rand Corporation scientist Robert M. Salter, and describes a Vactrain system in great detail.
The idea was also presented in lots of other science fiction works, besides Robert Heinleins novel, Friday, that I mentioned earlier.