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Old 26-01-2022, 20:52   #16
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Re: moving the boom bale

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Originally Posted by guyrj33 View Post
At those relatively low angles the increase in forward pressure on the mast will be relatively small I dont think it will be a problem.
But you are moving the stress to part of the bone that has been cut away, I dont know if that will be a problem.
Im going to talk to a spar maker about the tapered section. Its tapered and welded and my thoughts were to make large cheek plates welded to a plate at the bottom.
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Old 26-01-2022, 21:08   #17
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Re: moving the boom bale

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Originally Posted by TiPegleg View Post
my concern here is purely about the forces exerted on the boom/goosneck/mast by me moving the bale.
A bunch of fiddling with software isn't necessary, a simple force diagram will tell you everything, (and allay your fears).
You can also just take the sine of the included angle between the new upper block location and the boom and multiply that with the estimated pulling force from the tackle.
You'll see that the forward "thrust" is a quite small percentage of mainsheet load.
As has already been posted, the force from a vang FAR surpasses any increase in compression loading from moving the mainsheet 10in.
And (for all practical purposes,) any change in loading becomes moot as soon as the sheet is cracked-off.
Though it has been noted that fastening the upper block to a section of boom that lacks "full closed-circle" integrity may require some creative engineering.
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Old 26-01-2022, 22:31   #18
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Re: moving the boom bale

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Originally Posted by TiPegleg View Post
TL;DR - I want to move my boom bale about 10" further out, which would make my main sheet no longer parallel to the traveler when sheeted in hard.

My potential worry is that this pushes the boom squarely into the mast when it's all sheeted in. This maybe puts a lot of stress on the goose neck? This maybe creates weird stress on the mast? Is this a bad idea? Maybe this is totally fine? Too many maybes. I also have a rigid vang, for what it's worth.

photos below for illustration and showing just how squishy it is (in my opinion) with the traveler and boom sheets.

The long info:

Hey all, I'm busy refitting and there has been a common thread: the original owner who commissioned the boat was much shorter than myself. Or, was exactly my height and enjoyed a constant feeling of being snug to the ceiling?

Anyway, one of these issues is the dodger. It was a bit short and while it's not a problem to cut and weld on a little more to make it taller, it exposed another thing - literally. The back of the dodger leaves the helm entirely exposed from the top and since this is a center cockpit with end of boom sheeting, entirely exposed from behind since you have your traveler in you back - again, literally. I could kinda see this as a performance thing (helmsman always has a view of the sails and windex if needed), but Nova is a ~16T steel center cockpit cruiser...

So one way that I can see alleviating this by moving the bale and boom blocks further out and welding on a 6-8" rail on the dodger that give me shade and lets me also hang a wind screen if we're going downwind in some weather. I have no issues with welding up whatever I need, my concern here is purely about the forces exerted on the boom/goosneck/mast by me moving the bale. Wanted to get some opinions before I do something crazy like model it in CAD and do a whole finite element analysis...

photos for reference.

Thoughts?
Hi TiPegLeg:
I also have a cc and have a block connected to the boom behind me. However my boom is slightly longer than yours, and your confined space at the helm is very close and may be dangerous to you head if you back up, which can happen in rough seas.
In looking at your pic, I would leave the end of the boom the same, but use the out haul rail and shackel now connected to your out haul, to connect a stainless ring from the shackel around the boom and not drill into the sides. The block will move freely in the ring when going to starboard or port. You can also adjust the size of the ring to the length below the boom.I would not drill into the boom which may reduce the boom strength with holes to mount a connection. The outhaul rail is strong and no reinforcement is needed. I don't think the boom and mast will find an exhorborent amount of stress with such little movement astern on the boom.
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Old 26-01-2022, 23:13   #19
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Re: moving the boom bale

Definitely no problem! If loose-footed, use a strap.
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Old 28-01-2022, 06:29   #20
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Re: moving the boom bale

Just consider what the force on the gooseneck would be compared to the forces exerted on the gooseneck by the mainsheet when the mainsail is let right out...? and that's a sideways force to boot...
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