Disks like that are the first thing that I think of when someone says that their 5 or 6 thousand pound tractor pulls a 10 or 12 foot disk. I have seen 8 foot disks with 36" blades that weigh thousands of pounds, I don't think that they pull quite the same as a disk with 18" blades. Turning over 12-14 inches of ground is a bit different than 5-7 inches.