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Boom Rotating while Reefing

Started by ralay, August 10, 2012, 08:01:06 PM

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ralay

This is my first time to post outside intros - be gentle. 

I share a Westsail 32 with jmwoodring.  The boat has a jiffy reefing system with a tack hook and permanent clew lines lead through cheek blocks to a winch and cleats on the boom.  At the gooseneck, the boom is attached in such a way that it can freely swivel about its long axis.  The reefing gear is on the port side of the boom, and when reefing, the boom will swivel almost 90 degrees.  This leaves the boom winch pointing more or less skyward and the bottom of the boom pointing over the port side.  Not only does the swiveling make use of the winch more difficult, we are concerned that the way the boom curls up to meet the reefing lines is giving the lines a bad lead through the blocks.  The first time we put a reef in the sail (a few days after purchasing the boat), we blew out one of the blocks within minutes.  A picture of the failed block should be found here:

http://4.bp.blogspot.com/-JfQM-70gmWc/T8_d--mqbJI/AAAAAAAAA4k/frz4RSvyvFo/s1600/fort+meyers+031.JPG

The way it is bent makes us wonder if it failed because too great a force was being exerted on the side of the block rather than on the wheel.  We made it home with a swivel block attached to the boom end bail, but this is obviously not ideal.  We'd like to replace it with a new cheek block, but we're worried it may not last long if there is an underlying problem that hasn't been addressed.

Any ideas from folks with swiveling booms?  Should we try to limit the rotation?  Is there another system for leading the lines that would work better than the cheek blocks?  Think the failure was just due to an old block from who knows when and that we should just put a new one on and see how it goes? 

CharlieJ

When will you be back to Mona? I'll be back in the marina on Monday I think.

Maybe we can maybe noodle something out.
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

ralay

I think we're planning to come down next week.  We should be there this Sunday or Monday.  We welcome your noodles.   :P

Captain Smollett

It sounds to me like the boom / gooseneck was originally designed/used for roller reefing (or furling)...wrapping the sail around the boom.

If I had such a set-up, I'd look for a way to limit the rotation, to lock it.  Perhaps drilling a small hole to install a locking screw (which can be removed if someday a roller boom is desired) will work.

S/V Gaelic Sea
Alberg 30
North Carolina

Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.  -Mark Twain

Jim_ME

#4
I was thinking the same thing as John, that the boat was originally setup with roller reefing, which was popular in those days.  I cannot think of any other reason for the boom to rotate. On the boat that I had, the boom was rotated by turning a handle, and the boom was held by a mechanism of gears, so was not free to swivel. Even when a jiffy reefing system was added to the boat much later, the roller reefing mechanism was not used, it held the boom from swiveling.

It may be that when you boat was fitted with jiffy reefing, the roller reefing gear mechanism was removed, but the ability to rotate remained (with nothing to hold it).

I would say that the cheek block is not designed to be loaded against its side plate, so although the fitting is old and this may have been a factor, it is probably the bad lead angle (as you suspect) that is the main issue. If the reefing line is pulling on that side plate, I would expect the line to chafe badly on the edge of that plate even if it did not break the fitting.  

My boat and mainsail was much smaller so were the forces involved. I've never had or needed a reefing winch. I think that my Typhoon's gooseneck fitting allowed the boom to rotate, but the tension from the boom vang was enough to prevent it while reefing.

ralay

I'm not sure that the boom was ever intended for roller reefing.  We have a copy of the Westsail 32 manual and the gooseneck fitting, spars, and jiffy reefing setup all look like what was found on the factory boats.  Our gooseneck fitting looks exactly like the photo posted by Bud Taplin here:

http://westsail.info/index.php?action=posts&thread_id=2371

JW also suggested that installing a vang might help keep the bottom of the boom pointed down. 

CharlieJ

Rachel- isn't there a Westsail 32 just onto B dock? Has a "for sale" sign on it. Might help to take a look at that one. He told me he'd owned it for 30 + years.
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

Captain Smollett

Quote from: ralay on August 11, 2012, 04:48:00 PM

Our gooseneck fitting looks exactly like the photo posted by Bud Taplin here:

http://westsail.info/index.php?action=posts&thread_id=2371


Where exactly is it rotating, at that attachment point?  Seems like it should not be slipping there.  If it's not designed to rotate at that point, and it is, I'd fix it - something is worn or broken and will likely fail worse - at a bad time.

We had a gooseneck failure off the coast of Charleston, SC a few years ago at about 0500.  The boom fell on my knee.  Not fun.

Quote

JW also suggested that installing a vang might help keep the bottom of the boom pointed down. 


Maybe, but you should not need it for that.  That's only fixing the symptom, not the underlying problem (something allowing movement that should not be doing so).
S/V Gaelic Sea
Alberg 30
North Carolina

Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.  -Mark Twain

Jim_ME

#8
When I wrote that the boom vang on my Typhoon helped keep the boom from rotating, I meant that it seemed to be an incidental benefit, not a recommendation that it was solution for your much larger boat. I agree with John that a more direct approach would be a fitting that does not allow it to rotate in the first place--if that is the goal.

Yet when I look at the photo that you referred to, the fitting with the clevis that is connected to the boom itself is [or seems to be] of the type that would create a shaft that the boom could rotate on, so it does seem likely that there was an intention for rotation. There would have been other simpler ways to connect the gooseneck fitting to the boom, if preventing rotation was the goal (such as that in the attached photo).

However, if the intent of this rotation was for roller reefing, it seems like the fitting would be located on the axis of the boom, so that the boom would rotate about that axis. The fitting shown is located considerably above the boom axis, where it would cause the boom to rotate quite eccentrically (especially if rotated fully multiple times). [Also I cannot see anything to suggest that there had ever been a roller reefing crank mechanism] So I have to now [also] doubt that this design is for roller reefing.

Perhaps its purpose is to let the boom rotate as the mainsheet angle on the boom changes from near vertical while close hauled to more horizontal on a broad reach or run, so that the boom does not exert a torque on the gooseneck fitting. Another possible situation that could torque the boom is if on a run the boat rolled and put the lower part of the boom into the water at speed. This might be a feature that [the designer of] a boat such as yours that was intended for passagemaking in heavy weather (with wind vane steering [where there might at times be no one tending the mainsheet or preventer to release them quickly]) would be more concerned about, than say boats in the size that I have owned.

Charlie's idea seems like a good one. If this other Westsail 32 owner has sailed his for 30 years, he may well have been in situations where the design purpose became obvious.    

marujo_sortudo

Like others, I initially suspected roller reefing on your main.  It looks that while your boom was intended to swivel (and I have no idea why,) but doesn't seem to be intended for roller reefing.  More pictures of the hardware at the aft end of your boom could clarify that.

I have a suspicion that the issue may be how you've rove your reefing lines.  In some boats, reefing lines run from the cheek blocks are are simply tied into the clew.  In others, they lead up from the cheek block run free through the clew and go through a small piece of hardware on the opposite side of the boom and have a stopper knot tied in them or otherwise have their end secured.  I have no experience with a swiveling gooseneck, but I imagine that having your reefing lines set up in the later manner could greatly reduce the rotational force and make your leads more fair.  Of course, more pictures of the rig would help us puzzle it out.

CharlieJ

Ya know- on some older, larger boats, the boom was allowed to rotate a bit to let the foot align with the rest of the sail to keep from binding it up at the gooseneck.

Haven't seen this one yet, so I don't know if that's the case. They weren't aboard when I stopped by last evening ;)
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

Jim_ME

Just found this thread of a similar discussion.

CharlieJ

Exactly the point I was making.

And did you ever notice how on some forums, people jump in and answer the question, apparently without ever READING the question?

I notice that a lot.

How did they IMMEDIATELY jump to  roller furling?? He was pretty clear in his question.
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

Jim_ME

#13
Maybe I should have written "a discussion on a similar topic"? I browsed through thread and found some reassurance from some shared views by some of those posting (buffet style)...for example, that some believed that allowing the boom to rotate free would relieve the gooseneck fitting from any torque.

I thought that maybe if I go back and read it carefully there may be a way to reconcile the various views, but that must have seemed too involve too much thinking and so I just posted the link to the thread anyway without doing that...  ;)

CharlieJ

Nothing wrong with your post.

I've just noticed that on many forums, people have answers that don't really fit the original question.

Saw one earlier, asking about the meaning of a boat being "tender" and someone immediately explained that "that was the dinghy"!!!!

Which, while it may be a tender, has nothing whatsoever to do with a boat being "tender"

Just strikes me as funny, to not read before expounding ;D
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

CharlieJ

Quote from: ralay on August 11, 2012, 04:48:00 PM
I'm not sure that the boom was ever intended for roller reefing.  We have a copy of the Westsail 32 manual and the gooseneck fitting, spars, and jiffy reefing setup all look like what was found on the factory boats.  Our gooseneck fitting looks exactly like the photo posted by Bud Taplin here:

http://westsail.info/index.php?action=posts&thread_id=2371

JW also suggested that installing a vang might help keep the bottom of the boom pointed down. 

Went by Mona earlier- no one aboard, but main sail cover was off, so I took a quick look at your blown cheek block. I think I see the  problem- we just have to manage to all be in same place , same time  :D
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

ralay

Please do tell.  I stayed home to work this week and James should be heading back to work tonight.  If it's something obvious, I'll pretend like I'm not embarrassed.  :P Or if it's hard to explain without the visual aid, I suppose it'll have to wait til next time.

CharlieJ

Well, your reefing line appears to be dead ended at the grommet on the sail leech, led down through the block and forward.

It SHOULD dead end at the boom opposite, lead UP through the grommet and back  down to the cheekblock on the OTHER side.

This gives a direct pull DOWN, centered on the boom, instead of only on one side as it is ( or seems to be) now.

Therefore only half the load on the cheek block (it's now a 2-1 purchse) and no twisting forces.

Here's two  pics of the reefing lines on Necessity. First one shows starboard side, lines leading down to cheek blocks and forward. Second shows port side of boom, and lines dead ended in eyestraps
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

ralay

I was just googling pictures of reefing systems and finally noticed this just before reading your last post.

Our screw up stems from the fact that the Aleutka had a funny (crappy) reefing set up.  There was only one reefing line running aft and it had a heavy hook (same as the tack hook) spliced onto the end that you could place through any of the clew grommets.  We hated it because someone had to get out to the end of the boom, put the hook in the grommet, and then try to keep tension on it all the way back to the forward end of the boom (where the cleat was) without letting the grommet spit the hook back out.  Without self-steering this was a miserable one-person job. Terrible as it was, I think it got us in the mindset that the goal was to get the end of the line attached to the grommet and not to run it through the grommet. 

When we got this boat we were thinking, "Oh finally, bigger boom with more blocks!  We'll tie those stupid lines on there permanently and no one will do the hook dance again!" 

I'm confident that running them correctly will solve the problem.  Thanks for lending us your eyes.

Also, if anyone was curious, I asked on the Westsail forum and was told that all the booms rotate and that the rotation is intended to relieve torsional stress on the gooseneck fitting.  I think that was also suggested in the discussion that Jim_ME posted a link for.

marujo_sortudo

I was just reading a sailing book from the 80's today, and I think I figured out how the PO probably had the reefing lines rigged.  With many boats the lines lead out the boom, through a cheek block, through the reefing clew, and then down to a pad eye on the opposite side of the boom where they are secured.  I found it strange that you lacked these pad eyes, like I have.  Well, in reading today, I came across a diagram that instead secured the end of the reefing line to the boom itself, via a loop with a buntline hitch tied in it.  This seems an agreeable arrangement should you want to avoid installing pad eyes for any reason.