Musk shared his ideas for improving tunnelling at a TED Talk last month in Vancouver, while explaining his idea for a 3D network of tunnels that would carry cars on “skates” at speeds up to 200km per hour to mitigate traffic congestion.
When asked about the cost of building tunnels he responded “it's quite difficult to dig tunnels normally. I think we need to have at least a tenfold improvement in the cost per mile of tunnelling.”
Musk said those reductions are possible “if you just do two things.” The first he cited is cutting tunnel diameter by a factor of two or more. Second, he said, is to design a TBM to continuously tunnel and reinforce.
“Tunnelling machines currently tunnel for half the time, then they stop, and then the rest of the time is putting in reinforcements for the tunnel wall.”
He added, “these machines are far from being at their power or thermal limits, so you can jack up the power to the machine substantially. I think you can get at least a factor of two, maybe a factor of four or five improvement on top of that.
So I think there's a fairly straightforward series of steps to get somewhere in excess of an order of magnitude improvement in the cost per mile.”
Musk started The Boring company this year.
