http://igor.chudov.com/tmp/Huge-Cart-On-Casters/

This cart is all welded and is about 6-7 ft long. It is Very large
(compare with the hand truck on one picture).

The reason why they junked it is that one wheel was stuck on its hub,
which I fixed by taking it out and doing the usual thing (oiling,
frreeing up, then applying marine grease with a grease gun, etc). It
spins free now.

The kind of stuff that I could do with it is put a lathe on it or
whatever of that size, like a big 8 cylinder inline diesel. It can
probably carry 4k lbs easily.

i