3/16 or 5/32 lower shrouds?

[Ryan]

I am looking to replace the lower shrouds on my Catalina 27. They are originally 5/32" 1x19 wire with a marine eye on the upper end that lands between two tangs and is secured with a 5/16" clevis pin. Since all other rigging on the boat is 3/16", I am considering making the switch to 3/16" wire for the lowers as well. In the future, this will allow me to buy one size of wire and fittings (the lower end of all the shrouds are/will be Hayn Hi-MOD mechanical fittings), allow me to use one size Loos gauge, and generally be stronger. The problem that I have run into is that a marine eye for 3/16" wire is not readily available with a 5/16" clevis pin hole. The alternative is aircraft eyes, which are do appear to fit in between the tangs as snugly and frankly, they look a little weak. Would you guys suggest just staying with the 5/32" wire and marine eyes, or upgrading the wire size? The lower ends of the both the 3/16" and 5/32" wire are all 5/16" turnbuckle studs, so there is no issue there. This boat is mostly cruised with some "spirited" club racing mixed in on an inland lake in GA that does tend to get quite windy at times. I just don't want to miss the perfect opportunity to upgrade, if it is feasible. Thanks for any information.

Ryan

[Brion Toss]

Hello,
The upper shrouds on your boat take about 45% of the total shroud load; the lowers share the remainder. So if you have 2 lower shrouds per side, each will take about 30% or so of the total load, once you allow for the load to shift a bit between lowers under way. Therefore the lowers should be smaller than the uppers, and increasing them will make tuning harder, not easier, plus the larger wire and fittings are costlier and heavier than necessary. So if your uppers are the right size -- and that is another subject -- then your lowers are, too.
By the way, your backstay should be smaller than the jibstay, for reasons that will be revealed when I finally get around to posting the winner to this month's Puzzler.
Fair leads,
Brion Toss