## page was renamed from EvacuatedTubeTransport
#format jsmath

= Evacuated Tube Transport =

[[http://et3.com]] proposes maglev vehicles in long vacuum tubes for intercity transport.   Accelerating vehicles to very high speeds with coil guns is [[MassDriver | expensive ]], so even though a launch loop without energy recovery wastes about 2.4x the kinetic energy of the vehicle, an in-tube loop accelerator will probably be much cheaper than a lot of switching electronics.

Assuming [[http://en.wikipedia.org/wiki/Transrapid|2kW/tonne]] for levitation power P, 8300km between San Francisco and Tokyo, and a maximum acceleration of 10 m/s^2^.  For an acceleration and deceleration time of t,,a,, the maximum velocity is 10t,,a,, and the trip time is t,,a,, + d/10t,,a,,.   The energy used for a trip is E = 2(t,,a,, + d/10t,,a,,)+12t,,a,,^2^ joules per kilogram.   

Assuming 500kg/passenger, and $0.20 per kilowatt hour, the trip looks like so, versus varying acceleration times:

||accel time||vmax||trip time s||trip time hr||  E accel || E lev  || E total  ||$/passgr||
||  20      || 200||41520.00   || 11.53      ||   4800.00||83040.00||  87840.00||   2.44 ||
||  40      || 400||20790.00   ||  5.78      ||  19200.00||41580.00||  60780.00||   1.69 ||
||  41      || 410||20284.90   ||  5.63      ||  20172.00||40569.80||  60741.80||   1.69 ||
||  60      || 600||13893.33   ||  3.86      ||  43200.00||27786.67||  70986.67||   1.97 ||
|| 100      ||1000|| 8400.00   ||  2.33      || 120000.00||16800.00|| 136800.00||   3.80 ||
|| 150      ||1500|| 5683.33   ||  1.58      || 270000.00||11366.67|| 281366.67||   7.82 ||
|| 200      ||2000|| 4350.00   ||  1.21      || 480000.00|| 8700.00|| 488700.00||  13.58 ||
|| 300      ||3000|| 3066.67   ||  0.85      ||1080000.00|| 6133.33||1086133.33||  30.17 ||
|| 400      ||4000|| 2475.00   ||  0.69      ||1920000.00|| 4950.00||1924950.00||  53.47 ||
|| 600      ||6000|| 1983.33   ||  0.55      ||4320000.00|| 3966.67||4323966.67|| 120.11 ||
[[attachment:ETT.ods|libreoffice spreadsheet source]] . . . . [[http://www.libreoffice.org/download/|libreoffice download]]

-----

The pollution cost will vary by the source of grid energy, and ticket costs will include operating expense, amortization of infrastructure, and profits.  Given the $\$\$\$\$\$\$\$\$$ cost of infrastructure, a loop-driven ETT system won't happen soon.