Neutrally buoyant vacuum tunnel submerged 150 to 300 feet beneath the Atlantic's surface and anchored to the seafloor, through which zips a magnetically levitated train at up to 4,000 mph.Here is a nice render of such a vacuum tube:
Monday, June 23, 2008
Vacuum Tube Train
We've discussed the concept of an intercontinental vacuum maglev train more than once. Some people in Norway have concluded that they are feasible, but very expensive.
I heard about it on Discovery I believe. One of the many problems they faced was G-force during acceleration and braking.
ReplyDeleteBecause they would have accelerate/decelerate gradually for passenger comfort the train would reach top speed for "only" a couple of miles in the center of the Atlantic...
well.. for constant acceleration the equations of final speed and distance travelled are:
ReplyDeletev=v0+a*t
s=s0+v0*t+1/2*a*t^2
v0=s0=0
I think 1g is acceptable, this yields,
t = 166 s ~= 3 min
s = 137780 m ~= 140 km
Even for 0.1g,
t = 1666 s ~= 28 min
s = 555111 m ~= 555 km
I used 6000 km/h as the final speed.
ReplyDeleteLIES!
ReplyDeleteyes, I made one small error :)
ReplyDeletefor 0.1g:
s ~= 1400 km
Yes the g-forces are very much acceptable while still reaching enormous speeds and really short travel times.
ReplyDeleteThey should build it, though it must be really hard if not impossible to recuperate the enormous costs. It would be much more expensive than flying and would have to transport large masses of people to be economical.
But who knows, with new technology it might be much more economical in the future. If superconductors ever function at room temperature then magnetic levitation would be much cheaper.
Quite awesome to imagine to some day being able to take a trip from The Netherlands to New York in just an hour. It will be a windowless trip though, seeing as I doubt it's feasible to put windows in there. And even then, there's not much to see in the ocean while traveling at 6000kph :)