Sea trial breakthrough...

...I think!  Took her out again rigged with the square sail, but this time, I left out the mast retention loop which held the yard-spar against the mast with just enough slack to allow the yard-spar to slide up and down the mast.  

Mast retention loop installed

Mast retention loop uninstalled

Removing this from the rigging equation did a number of things:

1) The yard-spar can now be raised above the level of the spreaders (GOOD)

2) The yard-spar can be lowered below the mast-mounted winch, perhaps all the way down to the level of the lifelines.  This will allow the square sail to be rigged and stowed while also allowing the boat to sail fore-and-aft rigged with the genoa powering the boat; tacking is now possible since the sheets will no longer get hung up on the yard-spar during the maneuver.  This will necessitate the installation of additional rings or U-bolts lower down on the mast to store the crossjacks out of the way, but that is certainly doable. (GOOD)

3) The running backstay can be eliminated since the loads of the sail’s head (top edge) are taken up by the braces (which run to blocks on the transom) and the halyard (which runs to the masthead); no mid-mast loads means no need for the running backstays (GOOD)

4) The yard-spar now becomes a 12.5 pound pendulum that, when hoisted 15 feet above the deck, could possibly start swinging back and forth with enough force to create dynamic loads which might cause the shrouds to fail and the mast to topple over (BAD).

This sea trial was meant to test out #4 above.  Once we out on the water and pointed downwind, the square sail was hoisted and I intentionally rocked the boat back and forth at its resonant frequency to see how the yard-spar behaved.  Thankfully, the braces and shrouds provided enough lateral constraint to keep the movement of the yard-spar dampened.  Of course, this was only with very light wind and the sail was barely inflated.

The true test (yet to come) will be trying this again in moderate wind and seeing how the yard-spar behaves, while hoisting, sailing, and lowering.  If this works, it means I can avoid major surgery on the mast.

Stay tuned....possible rigging disaster pending!