I work with miners. Most of them are loggers who couldn't find work.
90% of them (and I'm just talking supervisors here) don't even come close to understanding the idea of a pump curve and friction loss, yet that same 90% are the ones who insist we are wrong when we tell them that just because the curve shows that you get 500 gpm at 75 ft of head, does not mean than when that 75 ft is stretched over a 10,000 ft piece of 4" line that you will still get 500 gpm. Then send the pump out to be rebuilt when it doesn't pump as fast as they think it should.
Same goes for ventilation.
