[ncallaway]

> The key cost savings that Musk envisions boils down to "build tunnels that are too small to put existing rolling stock in,"

Do you have a reference for that? My understanding was that over the long term the goal was to develop cost savings through better boring machines themselves, not through just by reducing the cross-sectional area of the tunnel.

I thought they were starting with smaller cross-sectional areas and working their way up as they developed machines, but by understanding of the end-goal of The Boring Company was to be able to build large tunnels at 1/10th the cost of current processes.

[jcranmer]

All of the innovations that are cited on The Boring Company's FAQ are things that are already done (e.g., reusing TBMs, or continually operating TBMs), or related to the "new" transit system and the virtues of narrower tunnels (which are overstated--at the size of tunnels we're talking about, cost tends to scale linearly with diameter, not cross-sectional area).