A train ticket to America, please

Last week, the idea of a high-speed rail link between north and south was raised yet again by the Department of Transport as a way of bridging the regional divide in the UK. Journey times of two hours between London and Edinburgh on trains running at 300mph were brandished as if these were somehow the ultimate limit of future rail technology.

But this will cut no ice with Frank Davidson, a pioneer of what is called macroengineering, the art and science of huge engineering projects. For the past two decades, Davidson and a small group of engineers at the Massachusetts Institute of Technology have been advocating a transatlantic rail line, running in a tube under the ocean from, say, Bristol to Boston, using “maglev” trains. The technology involved in both ideas – magnetic levitation – uses the repulsion between magnets on train and rail to create a frictionless cushion for the carriages to ride on, and there is a test track in Japan showing that the system can reach speeds of 300mph.

Davidson’s “Atlantic Tube” would have one extra characteristic: there would be no air in it. This would mean the train would run in a vacuum, saving the energy wasted in a conventional maglev system and making it possible for the trains to travel much faster.

But who would want to set off on a 3,000-mile train journey just to get from Britain to America? Even at 300mph, the journey would take 10 hours, compared with five or six by air. Davidson’s train, however, would beat the plane by a comfortable margin. The technology he advocates means that there would be no limit – apart from public caution – to the speeds that could be achieved, since the resistance would not increase with the speed, as it does in air. Trains could easily reach speeds of 5,000mph and more, he says, meaning that a day trip to the US would be possible, with the journey taking an hour each way.

The Guardian