My Capri manual advises the following (details deleted). There is no
backstay. Once you have the mast up straight, tighten the upper shrouds
so that there is a 3" forward bend in the mast section at the spreaders,
then tighten the lower shrouds so that the forward mast bend at the
spreaders is reduced to 1-1.5". This dynamic tension reduces "pumping"
of the mast resulting in overall less stress on the rig. The Capri has
similar loads to the P-19. 1350 lbs displacement, 138 sq ft sail area,
22' mast, 1/8 1x19 wire shrouds, etc.
That pumping stress is real. Before, and the reason why, I rerigged my
old P-14, is that a shroud broke, under just conditions. I used to
have the rig just tight enough that I could attach the headstay with a
reasonable amount of manual force. But the leeward shroud, or headstay
on a run, always went a little slack, so there was pumping when going
over swells, wakes, etc, however, I didn't think it was excessive.
Then one day I crossed the wake of a committee power boat that was
warning me to get out of the way of the Polynesian War Canoe Race,
1,000+ pound war canoes with about 20 paddlers each. As I crossed that
wake, the pumping started, the starboard shroud broke, and the whole rig
came down to port. As I cleaned up the mess I noticed the Tongan team
to port and the Samoan team to starboard as they changed course to
paddle past me, with 20 250 lb. paddlers each, all glaring at me like
the Tiki figureheads on Poynesian war canoes.
Talk about feeling sheepish! So, a little mast bend can help avoid
Polynesian war canoes.
:)
Steve Barnes, now a lurker, sailing a Capri-16, #74, in San Diego.
(former WWP-14 skipper)
OLDSURFDUDE