Dozer tracks are designed to handle double the tractors weight. So if a machine weighs 30 tons, the tracks can handle a 60 ton load. You can check this by looking up the pressure on the recoil spring for each track. All that I have had the pleasure of replacing required the weight of the machine for preload before the nut was screwed down on the retaining bolt.
Tank tracks are designed to carry the machines weight and little more. That set up is about what they do with excavators. A recoil spring on an excavator is only pressed to half the weight of the machine.
Tank track is a variation of the flat pad design. Pads are attached to each other, sort of like the old cranes. Dozer track uses a chain link design and the pads are bolted to each link of the chain. I have had the misfortune of working on FMC skidders. There were two type of tracks for them. The tank tracks had open ends and fell apart very quickly when trying to handle the trees we saw in the late sixties and early seventies. The logging tracks were completely closed on the sides. They lasted longer but cost a whole lot more. I remember seeing a bill for one track back then running in at $22,000. There were tricks to working on them and actually they are the lesser of problems. Torsion bars could be replaced weekly and usually exploded inside those tubes under the machine. It could be like sticking your hand into a bucket with 10,000 dull razor blades.
