Comments on: Inside the world’s largest tunnel boring machine. https://behindtheblack.com/behind-the-black/points-of-information/inside-the-worlds-largest-tunnel-boring-machine/ Fri, 20 Dec 2013 16:01:25 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: Pzatchok https://behindtheblack.com/behind-the-black/points-of-information/inside-the-worlds-largest-tunnel-boring-machine/#comment-133956 Fri, 20 Dec 2013 16:01:25 +0000 http://behindtheblack.com/?p=24079#comment-133956 I wonder if they hit a huge quartz pocket.

Some quartz is dang close to diamond hardness. And that is all I can think of that would dull those teeth up fast enough to stop one of those.

]]> By: R. Cotour https://behindtheblack.com/behind-the-black/points-of-information/inside-the-worlds-largest-tunnel-boring-machine/#comment-101422 Tue, 23 Jul 2013 20:56:05 +0000 http://behindtheblack.com/?p=24079#comment-101422 Cool.

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