Tractors and airplanes used to be built with different philosophy's;
one which I still agree with is'
if in doubt build it stout.
an airplane has to balance stout with weight;
Well.... It's not that simple - for any structure. My dad, who was not an Engineer did teach me when I was a kid: "Them that bends don't break", and to a point, its a good philosophy. So I spend a lot of time investigating how things bend under load. As long as it bends back after the load is released, everything is fine. I've even bent some things (expensive things) which stayed bent after the load was released, but - did not release the load!
So if a tractor, or airplane is bending under load, I'm okay with that, as long as bending back to where it came from happens when the load is released. In airplanes (and by FAA requirement) the structure must carry 100% of the design load, proven by actual test, and then return without deformation at all. After that, 150% of the load must be applied. The structure can be permanently deformed, but the load applied must not release (it breaks). Then, the 100% load capacity should be stated somewhere, so the operator knows what to try to carry. Every loader I have ever seen stated a capacity. It's up to the operator to figure out how to measure that!
Though I make no assertions in respect of the broken Kioti, I can imagine a situation where the grapple is heavier than the bucket intended for the loader - okay, but then the capacity should be reduced accordingly. But, maybe, the operator picks up what the loader will lift, Hmmm.... structure tolerates it. But then the operator drives over a bump, and the structure suddenly suffers over load.
Some big loaders I have operated weigh the load, and warn of overload. We were lifting a jet fighter (for pylon display) off a flatbed once. The crane weighed the lift, and said no, by about 300 pounds (1% over) - but no, and would not lift. We all pushed up on the jet, and the crane picked it. The crane operator just held it there, while the truck was pulled out from under, and landing gear extended, so it could be set on the ground. Then he scoped in the boom, and changed the lift angle, and no problem up on the pylon.
The first compact tractor I had was a Kubota. I was a learner, and a little hard on it. I broke the loader. I had it professionally welded to repair it. I began to learn that just because I can lift, does not mean I should. If I can just lift, I need to be really delicate carrying that load. if the front tires are properly inflates, but still bunged right out, I'm asking too much of the tractor....
