Yesterday sailing to my marina from the demarkation line a ferry past in front carrying a steep wake. I was moving down wind in 16-17 kts tws, with full main and some tension on my boom vang. When i met the wake, the bow went up and then down hard, the boom vang ss cable immediately parted. this is the second time this has occurred. My plan is to double the ss wire size to 1/4” and double or triple crimp both ends.
Ha good one ! Maybe right….. first time it occurred the ss cable broke, like this time, but also the vang came away from the mast from the spring compression tube. It was a torque fest to get that all back together. This time the actual tube pieces stayed intact with just the cable breaking- I think by having the vang tension on a bit I saved the strut pieces from flying apart. Don’t know really - just a guess!
Not much help I’m afraid, but I have to comment that with a wishbone boom, the vang is not needed, as the tension in the foot and leech are equal … So eliminating the need for a vang entirely.
Try using synthetic dyneme it is stronger than SS. I have used it for the centerboard lift line in my 33 Cat Ketch along with numerous soft shackles. I like it allot and it is easy to work with.
Erik - thanks for the idea. I bought some 3/16” dynema and will try to double it up on the boom vang for the cable area. Should be there tomorrow to try it. It does advertise as more breaking strength than the similar sized ss. Let you know. On the boom vang down wind thing - I think on this boat going down wind with boom way out more tension on the vang is better - it would prevent the boom from lifting any in the wake conditions described. I do crank on the vang in higher wind conditions down wind keeping the leech in tension, and when over Powered, by blowing the vang clutch, the boom lifts dramatically and spills air. After the puff I crank on the vang again. In this instance a couple days ago, the wind down wind was relatively light and I had only slight tension in the vang. The steep wake gave the vang enough room to move up a bit and then broke on the down motion.
The dynema, if used instead of ss is one compound of the boom vang. The dynema or ss is maybe 1.2 m length and tied into 3/8” Dacron with something like 8:1 purchase leading to cockpit rope clutch. So give is built in. The dynema would have a bit more play in it than the ss cable did. The Dacron will have play.
Today I tried the dynema on the boom vang. I tied a couple of estar knots to try to prevent slipping as the dynema is slippery stuff. I cranked on some tension and everything held - for now- I’ll see how it does but not really thinking it’ll work.
