How China Built the World’s Largest Underwater Tunnel in Just 110 Days - Very China Pro - PR - but good and instructive.

Yeah..... the life span of the cutters..... that depends upon what they are made of, how hard or abrasive the material it is that they are cutting, and how much as in volume and how far they have actually cut...... Then there is optimum tooth / edge / sharpness - of the cutters, at their peak rate, then that starts to decline as they dull, and then they do less cutting and more rubbing, so there is a measurable ratio between how much power is required to drive them, the type of material they are cutting, and the amount of material that is being removed...... They are probably keeping them in the top 15% of their cutting ability and then just replacing them / refacing them etc. Below this it's just lots of friction, lots of power, and not much material being removed. Kind of like butchering with really GOOD super sharp knives and then doing meat preparation with average home style knives - that are sharp enough but not brilliantly so.... If your job relies upon breaking down one whole cattle carcass per hour.... Your going to be using the GOOD razor sharp knives and keeping them sharp, every 10 minutes, and not using the kitchen knife from home that gets resharpened every 6 months... Same Same.

From what I could gather most if not all the material they bored through was all the sediment from long gone ancient mountains filling up the valleys... Nothing to bake it or dry it out.... So it's wet sediment. Have you seen the "Fun stuff" called liquifaction? This should thrill you...... https://www.youtube.com/watch?v=gWCtoXsn3dM I think they do it to have a guys day out and to get away from the women... The video is really good - There is a lot of brains, and skill and experience there...... And the ground is absolute shit.

The synthetic diamond cutter teeth, only work on HARD rocks, and the knife type back hoe style cutters, work on wet clays and sands etc... and one does not work well on the other... And despite all the awesomeness of TBM's - the principles have not changed - so the machines get better, but not differently so..... The best in the US or Germany or Japan, is going to be about the same as in China..... Though to be fair - minus the "China is Prestiege" bullshit - their reputation as cost cutting cunts is well earned. I had a friend who is a concrete engineer, and he went on tours of China, and he said they just got dirt and clay and mixed in just enough crap cement to make it gray and then built 10 story apartment blocks out of it.... AND you really could grab a handful of concrete pillar, and it would come away in your hand as powdery, dusty, chunks..... Tofu Dregs.... https://www.mgtow.tv/v/o6F16o

Yeah the friend said almost all of China is built by scum sucking cunts and all their buildings are fucked...... He said that this is going to come back to haunt China as the entire country falls into rubble.......