Hi Eric
The early H-21S we sailed in 88 in the Prosail series and Ultimate Yacht Race series were set up with no pole -
Just an extra set of bridal wires off the bows were used and an outhaul to pulley for the spin tack attached to the forward bridals .
Simple and worked well but not as effective as adding a pole and area forard of mast .
The spins were a subject of much experimentation for them ,from very small flat shapes to very full asymetric ones that seemed best on that particular heavy cat design.
The pole of course does add spin area equivalent to the projection forward times the luff --minus raduis aread to spin head --approx one third .
With the spin only to the bow bridal wires the spin were designed with more overlap and aft location lead block sheeting location. On the H-21 this was on the aft end of the ings which placed it outboard more also .
One funny mistake rookies to the 21 would make was not tieing in the wings which simply telescoped the wings alum. tube into a sleave in the hulls .
hen the wind kicked in the force of the spin could pull the wing out and send it thrashing around in mid air at the end of the spin .
If you sail a winged cat with spin ,-tie em in !!
The H-21 is a great cat design ,-just A BIT too heavy -
