Could HS3 be built by even smarter machines?

Updated September 2018

The Crossrail tunnelling machines were amazing. I love the idea that, before setting off, each was named after a London role model. They have carved out a huge network connecting station caverns. What if they could have cut out those massive spaces too? How?

Crossrail tunnelling machine by John Sturrock

I've been in touch with the German manufacturers Herrenknecht AG, who were most helpful in referring me to the British Tunnelling Society. There I'll explore my ideas for my next novel, set in the second half of this century. They may seem fanciful now, but so would today's machines 50 years ago.

Existing devices grip on newly bored and lined tunnels, to push forward the rotating cutting head. Would it be possible to include milling arms which could increase the tunnel diameter beyond that of the head?

In turn the gripping mechanisms would need to expand to take hold of the larger tunnel. Lining segments would need careful and variable profile to give strength as the diameter gradually increased. It would take some engineering, but that's already true for today's tunnellers.

Imagine if it was possible. New HS3 or Crossrail 2 stations could be built beneath London without all the traffic jam chaos that occurs now. In fact all kinds of infrastructure could be built beneath us. It is exactly what is envisaged in the third of the Buffalo Future novels, whose storyline is beginning to emerge.