[panick21_]

I have not done the math on the energy required to create the original low pressure and maintaining it compare to how much you save.

You speak pretty confidently about that, can you actually show any of that?

It also depends on how high the utilization of the tunnel is.

Who says there are no airlocks?

The proposal has been simulated by both SpaceX and Tesla, I don't think they made some basic mistakes about it being impossible to sustain a low pressure tube.