some more here: http://www.businessinsider.com/elon-musk-boring-company-tunnel-project-ted-2017-4 http://www.businessinsider.com/elon-musk-boring-company-tunn..

some more here: http://www.businessinsider.com/elon-musk-boring-company-tunnel-project-ted-2017-4 http://www.businessinsider.com/elon-musk-boring-company-tunn... "Tunnel-boring is a notoriously expensive process. The Boring Company is looking to cut down costs by building a machine that can dig and place reinforcements in the wall at the same time, Musk said. Tunneling machines traditionally dig for half the time and then go back to add reinforcements, a longer and costlier process."