Don, it is safe to use the mast as leverage - as long as the shrouds are connected and tight, they will take quite a bit of the load.
The boat in this picture was fully loaded with gear and water for 6 days at a Texas 200. John Alesch did not report damage to his mast.
The shrouds connect to the mast some 15' above the deck. To be safe, you could pull on the jib halyard (which is fixed to the mast right there, so all the load would go pretty directly onto the shroud on the side opposite from where you are pulling.
But even if you pulled from the main halyard, while the top section of the mast is unsupported, the lever arm at its bottom is 15+ feet. Meaning the forces are not that much different (and it's the difference that gives rise to a bending moment).
To bend one of our masts you need about 300lbs at 3-6' (a value I know experimentally from straightening mine).
When the boat is on its side (empty), the force at the mast tip required to keep her steady is less than the weight of a standard cinder block.
Hope this helps.
Posted: Tue Nov 12, 2019 8:26 pm