I would NEVER go in under that tractor hooked up like that to scrape the deck or anything else. I assume you have people depending on you and you are not thinking of them. Let the deck rust out and get a new one every year, but don't go under that tractor. It would be cheaper than the Dr bills and lost work if it ever breaks. Ed
Ed of all trades,
(And no offense to the OP), but I agree with you (Ed), 100%, on the risks not being worth the "rewards."
But re: any potential "doctor bills"?
No offense, but I think you are rather optimistic--sadly, I don't see doctor bills as being too likely--and personally, I don't know if I'd want to endure what that might mean, phsyically, were things to "go sideways" (or down, in this case).
Now, if the OP wanted to invest in a pair of the large, (screw-type) jackstands you see in marinas, holding up (multi-ton) sailboats, and wrestle the in place every time, that would (in theory) at least give him some
time, to get out from under, before they tipped over, if the chain (or the WOODEN????) beam the hoist is hooked to give way.
But I'm NOT recommending that. I'm recommending NOT being under a chain- (or chainfall)-suspended tractor.
And to the OP: please tell me that is not some non-professional-grade chainfall and chain? Like, NOT Harbor Freight or even Northern Tool? (And, FWIW, I grew up in my father's heavy construction business,
specializing in lattice-boom, and later, hydraulic cranes, which I used to operate, occasionally. The cranes ranged in size from 6 ton to 55 ton. He would not be under that tractor either, if that means anything to you--and he saw combat in WWII, as a Motor Pool Corporal, running cranes and dozers, building roads, bridges, etc..., while being shot at/bombed, etc..., on an Island, far away, at the tender age of 18. He's 90 now.
(EDIT: I read the rest of the replies, and see that it IS a Harbor Freight chain fall. Metallurgical quality issues are running through my mind.)
IF cleaning the deck is that important to you (which I do understand, to a degree, being a bit OCD and cleaning my riding mower decks--but they are of thinner-gauge steel)
have you considered getting a car lift? Or an (illegal, now, I believe) "pit"? But then again, this thread contains success stories of minimal-to-no deck cleaning, of these (relatively) thick, Kubota mower decks. I know, for now, with having certain physical issues, I'm unlikely to be cleaning my deck very often, as Life is Too Short, as it is.
Good luck to all.
My Hoe