Cutting anything that thick would almost have to be Map or natural gas, could be done with acetylene as long as it was a 6 or 12 pack manifolded system the torch we had in Kuwait had 9 straight line torches on the back 2 planetary & 1 1200 amp Plasma torch . 9 torches cutting strips out of a 40 ft long 10 ft wide 2" plate would suck 3 12 packs dry in a day's time 1 of acetylene 2 of oxygen would have used compressed natural gas but couldn't get a permit for large enough storage
thickest we ever cut was 4 inch on the 2 planet torches and 2 inch on the 9 straight-line the plasma would cut 4 inch but you couldn't get a true vertical cut on all sides