After moving 5 or 6 lathes, a few Bridgeports, two big metal bandsaws, a surface grinder, a 9x16 horizontal saw, etc. I finally realized I need some machine skates. Maybe it's too late, I'm through moving stuff, but that's what I always thought before. I bought 2 of these, my friend bought 2 more, so we're equipped. These are rated 6 tons each, and indeed look very stout...for about $45 each, they are a pretty good eBay deal.
That is a real ball bearing swivel pad, with 4 hard urethane wheels that span the whole width of the skate, or "tank truck" as the manufacturer calls it.
The instructions are a hoot. Here's a sentence, absolutely verbatim: "The use of lifting or lifting equipment will increase the number of objects needed to be transported ( ensure that the small tanks can be smoothly put inThe lower space so far, the carrying of the small tanks according to the intended scheme."
Seems clear enough.