Why slack rigging

There's a fair few threads on here which allude to some classes which favour slack rig tension. I'd like to understand the reason(s) why this is preferred, what's the technical reasoning?


Edited by ColH - 06 Feb 17 at 8:21pm

It seems that on singlehanders like Solo, Streaker and Blaze (and others) the slack shrouds allow the boom forward enough to allow by the lee running. If you want an extreme case just look at a Star bearing away onto a run. If a boat has a spinnaker and/or trapeze(s) a certain amount of rig tension is required to keep the stick in the boat.

On some of these classes (Solo) the rig is essentially unstayed, with the shrouds/forestay used to limit the amount the mast can bend. When these classes were first designed it was probably a much cheaper way of doing it than a bespoke unstayed alloy mast like in the Finn/OK and more robust than the unstayed wooden spars in the same classes. These boats were designed to be built (or at least finished) in your garage/living room/kitchen so the latest hi tech stuff was neither accessible or appropriate and in those days may not have been significantly better.

Edited by Paramedic - 07 Feb 17 at 8:12am

On Firefly Reynolds masts (the ones with the wooden top) diamonds were tight, but shrouds loose. The mast rotated, so tight shrouds would have prevented that happening easily. Once the rotating Proctor mast came out, they were so stiff, even the diamonds became slack.

Edited by Rupert - 07 Feb 17 at 10:16am

Having floppy rigging enables the rig to act a little bit like a racing windsurfer rig, i.e back for upwind and forward for off wind, it also helps in light wind enabling soft sails to heel and keep shape without having to heel the boat on hulls that don't like to be heeled.