My boats rig was being tuned today and the rigger noticed a distinct starboard to port s bend in the mast starting at the mast section between the spreaders. The rigger could not straighten the mast. The boat is an E 36 Ron Holland. Can't Attach an image as I'm posting from iPhone, has anyone seen something like this before and is the only solution to replace the mast?
S bend in mast
- Thread starter jamnet
- Start date
mherrcat
Contributing Partner
I have never seen it but in my reading about rig tuning it seems that condition is not unusual; not being able to tune it out does. Did your rigger start with all the shrouds de-tensioned? Seems like that would be the way to see if it is a permanent condition. And the best starting place for retuning anyway.
mherrcat
Contributing Partner
I'm no expert, but that doesn't look as bad as I thought it would.
I would definitely start by at least de-tensioning your intermediate and upper shrouds to see if the mast straightens out. Before you do that though you should get an idea of how to go about "static tuning" your mast by reading a book like "Sail & Rig Tuning" by Ivar Dedekam or "The Complete Rigger's Apprentice" by Brion Toss or his "Tuning Your Rig" DVD. You want to keep some tension on the shrouds, but only enough to keep the mast up. (I think Toss covers this in his DVD. I have it, but haven't watched it in a while.)
www.briontoss.com
Even if you don't end up doing it yourself, understanding the process is helpful.
I would definitely start by at least de-tensioning your intermediate and upper shrouds to see if the mast straightens out. Before you do that though you should get an idea of how to go about "static tuning" your mast by reading a book like "Sail & Rig Tuning" by Ivar Dedekam or "The Complete Rigger's Apprentice" by Brion Toss or his "Tuning Your Rig" DVD. You want to keep some tension on the shrouds, but only enough to keep the mast up. (I think Toss covers this in his DVD. I have it, but haven't watched it in a while.)
www.briontoss.com
Even if you don't end up doing it yourself, understanding the process is helpful.
markvone
Sustaining Member
Ross,
I agree with Mark, I would loosen the port side uppers and intermediates which are pulling the upper half of the mast to port. Your stbd lower may be a bit tight, causing the slight initial curve to stbd. Doesn't your mast have a slice or repair in the middle of the middle panel? That might be exacerbaiting the "S" by adding a hard or soft point at that spot.
Another thought is to check you don't have too much total tension in the whole rig causing excessive sideways compression bending in the panels that are not exactly lined up vertically (like you try to get by pre-bending the rig fore-aft to flatten the main).
Mark
I agree with Mark, I would loosen the port side uppers and intermediates which are pulling the upper half of the mast to port. Your stbd lower may be a bit tight, causing the slight initial curve to stbd. Doesn't your mast have a slice or repair in the middle of the middle panel? That might be exacerbaiting the "S" by adding a hard or soft point at that spot.
Another thought is to check you don't have too much total tension in the whole rig causing excessive sideways compression bending in the panels that are not exactly lined up vertically (like you try to get by pre-bending the rig fore-aft to flatten the main).
Mark
mherrcat
Contributing Partner
I had the same thought. It looks like there are two bands running across the mast between the upper and lower spreaders but it's hard to tell from the picture. Welding, if that's what was done, can easily deform a thin piece of aluminum like a mast.
If you are talking about the two dark bumps on either side closer to the upper spreader, those may be attachment points for running back stays.
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Rocinante33
Contributing Partner
Did your rigger climb the mast? Is there a visible kink or crease in the mast up there where the bend is visible? If not, I'll bet you can tune the bend out of it.
Go to the links/downloads tab here at EY.org. Go to the E33 documents (I know you got a 36). See the two, "Owners Bulletins for E33-36." Those are the original factory instructions for tuning your fractional rig. Good luck!
Go to the links/downloads tab here at EY.org. Go to the E33 documents (I know you got a 36). See the two, "Owners Bulletins for E33-36." Those are the original factory instructions for tuning your fractional rig. Good luck!
thanks guys for all the help, also, thanks Mark for the tuning guide and email, really appreciate it.
I think my plan is to go up the mast and take a look at the point where the bend starts, there is a welded repair sleeve there. I'm no metal expert, but I will look for obvious signs of metal fatigue, then in the fall, I'll take the mast down and take a good look at it then. The rigger tired to tune it for about 2 hours, he did not go up the mast, he also mentioned that we should not sail in winds over 20knts.
I think my plan is to go up the mast and take a look at the point where the bend starts, there is a welded repair sleeve there. I'm no metal expert, but I will look for obvious signs of metal fatigue, then in the fall, I'll take the mast down and take a good look at it then. The rigger tired to tune it for about 2 hours, he did not go up the mast, he also mentioned that we should not sail in winds over 20knts.
Rig tuning
You need to start over, especially loosening the intermediates. As was mentioned, be sure and check the shrouds are properly seated in the T-ball fittings. Use the guide to dock tune it as well as you can, but this is ONLY the start. Then you need to go sailing, and tune it on each tack until it is straight on both sides. If you do this in 8-12 knots with a 130-150 genoa, there should be no fall off to leeward at the top and the mast should be in column all the way up. If you are sailing in 15+ with big sails, a little tip fall off is OK.
Sailing on starboard tack, sight up the mainsail track and note where the mast is out of column. For example if the mast is falling off to leeward at the lower shroud intersection, you know you need to add a little tension on the lower. To do this, tack over so the side you want to tune is unloaded, make the change and tack back and see what happened. Once everything is good, the lee shrouds should be loose enough to wiggle 1/2" or so but not moving by themselves. In under 10 knots of breeze they shoud still be snug.
It is NOT possible to fully tune a rig at the dock. You get it in the ballpark and finish it while sailing. With 3 people on the boat you should be able to do it in an hour.
There a lot of posts about this in more detail on the site-you may want to look at those as well.
Let us know!
S
You need to start over, especially loosening the intermediates. As was mentioned, be sure and check the shrouds are properly seated in the T-ball fittings. Use the guide to dock tune it as well as you can, but this is ONLY the start. Then you need to go sailing, and tune it on each tack until it is straight on both sides. If you do this in 8-12 knots with a 130-150 genoa, there should be no fall off to leeward at the top and the mast should be in column all the way up. If you are sailing in 15+ with big sails, a little tip fall off is OK.
Sailing on starboard tack, sight up the mainsail track and note where the mast is out of column. For example if the mast is falling off to leeward at the lower shroud intersection, you know you need to add a little tension on the lower. To do this, tack over so the side you want to tune is unloaded, make the change and tack back and see what happened. Once everything is good, the lee shrouds should be loose enough to wiggle 1/2" or so but not moving by themselves. In under 10 knots of breeze they shoud still be snug.
It is NOT possible to fully tune a rig at the dock. You get it in the ballpark and finish it while sailing. With 3 people on the boat you should be able to do it in an hour.
There a lot of posts about this in more detail on the site-you may want to look at those as well.
Let us know!
S
markvone
Sustaining Member
Navtec Rod attachment to mast
Ross,
Here is the Navtec stemball fitting picture to show how the rod atttaches to the mast. On the right is the issue my "expert" rigger could not figure out. Your rod attachments look fine. You will have noticable outward bowing of the rod (vs straight down from the fitting) if the stemball is not seated in the socket washer.
Mark
Ross,
Here is the Navtec stemball fitting picture to show how the rod atttaches to the mast. On the right is the issue my "expert" rigger could not figure out. Your rod attachments look fine. You will have noticable outward bowing of the rod (vs straight down from the fitting) if the stemball is not seated in the socket washer.
Mark
Attachments
pretty tight S bend
This could be a compression bend, but it does seem to be pretty tight radius for a compression bend.
Try slacking the rig so that only enough tension is on everything to hold the mast up. See if the bend goes away or changes position.
Hard to say without looking at the boat, and inspecting the mast from aloft. (Did your rigger go aloft on the boat?). Has the area been inspected for other signs of damage? Do you have any records of the last time the mast was off of the boat? When and how was the boat last transported?
It is hard to say from an phone photo, but the mast head seems to be a little off to port. and there may be signs of a compression bend above the second spreaders?
Always start with slacking everything in a tuning situation.
Keep us posted.
Guy
This could be a compression bend, but it does seem to be pretty tight radius for a compression bend.
Try slacking the rig so that only enough tension is on everything to hold the mast up. See if the bend goes away or changes position.
Hard to say without looking at the boat, and inspecting the mast from aloft. (Did your rigger go aloft on the boat?). Has the area been inspected for other signs of damage? Do you have any records of the last time the mast was off of the boat? When and how was the boat last transported?
It is hard to say from an phone photo, but the mast head seems to be a little off to port. and there may be signs of a compression bend above the second spreaders?
Always start with slacking everything in a tuning situation.
Keep us posted.
Guy
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