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It wouldn't affect those devices because the passenger compartments would have to be pressurized like an airplane. If it lost pressurization, everyone would die from oxygen starvation.

The bigger problem for a system like this would be how expensive, large walled, well anchored, and straight the tunnel would have to be to prevent the passenger compartment from hitting the sides of the tunnel or subjecting the occupants to many times the force of gravity as the train went around curves at thousands of miles an hour.