The amazing Vactrain.
This has been merely a theoretical model, first proposed 100 years ago. A major proposal was unveiled by a man named Salter in the 1970′s; however, his project was shelved due to huge costs – estimated at $1 trillion. Once it was built out, one could travel from New York to Beijing in 2 hours! Trains would go under the ocean, on the ocean floor or underground. People would be subjected to forces 1.4X gravity, so modifications would have to be made in the model to deal with that.
All of these are theoretical at the moment, but China has unveiled plans to build a Vactrain going 620 mph. It is due to be completed in 2020. Exciting news!
I do not understand engineering well, so if some of you do, you might be interested in the specifics.
