Appears much more likely to ding topsides than jackstands (poppets) are, though the photo is not clear how the frame actually supports the hull. Are there pads/arms at, above, or below the waterline? The photo also shows them still using jackstands to support the bow and stern.
Yep, bow and stern each have one stand each. The keel sets on wood (just like in our own yard). As you can see, the keel supports put the weight of the boat on the frame below making the whole thing really rigid.
The uprights (which adjust in and out) lay against the rubrail, or hull, but it's padded and with the boat more or less balanced, there would be little pressure there. There are no protuberances from the uprights except some rubber padding. The uprights adjust laterally to fit the beam of the boat.
I just thought this makes way more sense when doing a bottom job. the main frames (the part on the ground) are laid out in rows to accommodate many boats. I saw lots of these over there but only took one photo. I suspect the uprights are aluminum for ease of handling.
In areas with no boat present, the uprights are lying on the ground. I suspect they are put in place while the boat is held there by the sling.
Ken
