3 ms·

I don't think the tunnel would need to be pressurised. If the air moved at the same speed as the train, no resistance would be met.

• jacquesm 14y ago
  That's what I meant by using the carriages as the impellers, so effectively they push against the air in front of them up to the next carriage, which pulls on this air because it leaves a partial vacuum behind it. So there is no external source of pressure, it's just the carriages moving and 'drafting' in each others wake. There will still be resistance though, both from the walls as well as leakage between the carriage and the walls (there can't be a really good seal there or the friction between the carriage and the wall would become too large, and since the wall is stationary and the carriage is moving very fast this friction is likely sizeable).
  • loceng 14y ago
    Do you know the speed differences that could occur in a tunnel system like this, versus an "open" on-ground maglev system?