ASA and PSIA Instructor
Join Date: Apr 2000
Thanked 35 Times in 35 Posts
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Mid boom sheeting does put a big strain on the boom. I've broken two booms with this configuration but on smaller boats. The first was a Rhodes19 with the sheet connected mid-boom via a single bale. This boom broke at the bale beating in 20+ knots, with three adults hiking - just too much load. This is a common Rhodes 19 failure. The replacement boom with two mainsheet blocks attached via eye straps about 18" apart has serviced fine for 6 years. A second time, getting underway on a heavy weather day in a 21' daysailer with mid-boom sheeting, again a single block, as we trimmed the main to closehauled the boom immediately broke - and I realized that we hadn't eased the topping lift after setting in the reef. If the topping lift is tight, trimming the mainsheet hard will break any boom.
I would think having a bale through the center of the boom was not good, and a tightened topping lift also a factor, especially if you gybed the boat so the main had some momentum when the sheet caught it...it's hard to imagine where the force came from in a tack and 15 knots of wind. If this is a model used by some of the yacht charter services and its a common problem with that boom, they would know so. You might try them.