"Andrew Heenan" wrote in message

"Tom Barry" wrote:
Mind you, a 200+km/h underground flying junction is not going to be
the most loony part of the proposal.

The real killer for Boris is a much, much simpler one; it doesn't
have to be a castle in the air; even an airport built on sand will
fail.
The cost of underpinning both (all three?) runways

Four, actually, a pair on each of two separate islands (probably built
in two phases).