SailNet Community - Reply to Topic

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > Skills and Seamanship > Seamanship & Navigation > Dynamic tuning of rig
 Not a Member? 

Seamanship & Navigation Forum devoted to seamanship and navigation topics, including paper and electronic charting tools.


Thread: Dynamic tuning of rig Reply to Thread
Title:
  

By choosing to post the reply below you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Topic Review (Newest First)
04-09-2012 04:36 PM
casey1999
Re: It worked!

Quote:
Originally Posted by L124C View Post
Tuned under sail using the method I mentioned in #97. When I returned, I mesured the tensions in Cap shrouds. Both match (980 lbs) and are just below the initial tensions recommended by Loose for 9/32 rigging (1050). While tuning, I thought that I could have eliminated some more slack with another turn on the turnbuckles, but wanted to verify the tensions first. So...the system seems to work nicely.
Here is a link to the same method for J 22's, suggesting they "lose the gauge". In any case, it's nice to know both methods seem to produce similar results.
Thoughts on Tuning - Lose that Tension Gauge!
When I go to the link some of the number (number of turns and tensioin) show up as a square. Do you know why?
04-09-2012 04:11 PM
L124C
It worked!

Tuned under sail using the method I mentioned in #97. When I returned, I mesured the tensions in Cap shrouds. Both match (980 lbs) and are just below the initial tensions recommended by Loose for 9/32 rigging (1050). While tuning, I thought that I could have eliminated some more slack with another turn on the turnbuckles, but wanted to verify the tensions first. So...the system seems to work nicely.
Here is a link to the same method for J 22's, suggesting they "lose the gauge". In any case, it's nice to know both methods seem to produce similar results.
Thoughts on Tuning - Lose that Tension Gauge!
04-06-2012 02:25 PM
casey1999
Re: The more I learn, the less I know!

Quote:
Originally Posted by L124C View Post
To be fair, he did emphasize SMALL hand tools.


I assume that tightening the rig so that it didn't go slack on Leeward in high wind would require too much constant stress on the rig and boat. The bungee trick certainly wouldn't hurt though. I'm going to tune using the method I suggested in post 97, and will report back on the gage tensions it develops. Should be interesting. Using Dedekam's stretch method worked well as far a boat performance, but read high on the tension Gage. On the other hand, the Leeward shrouds would still go slack in high winds. Do your shrouds never go slack?


As a Union Journeyman Carpenter with over 30 years in the trade , I can assure you that both the Union and Journeyman labels don't mean s**t! Worse yet, I have worked for several licensed Contractors who couldn't frame a wall to save their life, much less know if the job was being performed properly (and many "Inspectors" don't know much more)! So...given that the marine repair industry is less regulated than the building industry......

Do your shrouds never go slack?
In 20 knots or more wind my lee shrouds do go slack, but not by much. I would say they have near 0 load, but they are not swinging around. What I did (at the dock) is tuned my cap shrouds to 12%, lowers at 8% and backstay at 20% (the previous owner had it set to 20% so I just left it at that). On sailing everything looked good so I just left it at that. As others have stated, probably best to keep maximum load below 30% to fend off fatigue failures (most references seem to say go to 15% maximum tension on cap shrouds). I am thinking maybe I should back off the backstay as the forestay tension is probably around 25% at the dock (based on geometry calcs, since I cannot actually measure the tension due to furling jib). I would be concerned if my lee shrouds were swinging around a lot in a stiff breeze. Seems this could lead to fatigue failure very rapidly at the junction of a swaged or mechanical fitting and the wire.

A friend works as a "Rigger" for movie sets and I was talking with him how he got trained- he says basically on the job. Sounds similar to boat riggers. The two jobs have a lot in common. He is even giving me some advice on using a climbing harness to go aloft.
Regards
04-06-2012 05:27 AM
L124C
Re: The more I learn, the less I know!

Quote:
Originally Posted by casey1999 View Post
I have heard of long distance sailors tyeing bungees cord around the leeward shrouds to prevent fatigue failure (from the shroud swinging around for extended periods). Anyone know how say a Volvo 60 is tuned in the around the world Volvo race?
I would be more interested (for my 30 year old Keel Boat) in knowing what cruisers in similar boats do. I think the Volvo boats are high Tech with lots of carbon fiber, and technology light years away from my stout little "yacht".
A guy posted on the Yankee 30 Owners site, asking technical questions about tuning for different conditions and points of sail. Apparently, he came from a racing background with spindly, very tunable rigs. Another owner responded: "Think of the mast on your Yankee as a telephone pole"....
So, while a lot of the concepts are similar, I think it's important to compare
Apples with Apples. Still think the bungee's a good idea for extended distances for any rig. Thanks for that!
04-06-2012 05:14 AM
Patient
Re: The more I learn, the less I know!

Quote:
Originally Posted by Faster View Post
I think most riggers go through a (rather informal) apprenticeship and learn on the job from a (hopefully) skilled experienced person. I don't know of any official accreditation body (like SAMS for surveyors, for instance) but maybe Knothead will weigh in with better information.

I suppose any of us could hang a shingle as you say.. but be sure to have good 'mal-rigging insurance'!
This was my thought on it as well.

I was going to pick up a part time job at a busy seasonal marina last year and one of the job listings was "Rigger's Apprentice". There was a waiting list for it too, but from the description it seemed like working with the master rigger was something that was highly sought after.

As for "Dynamic Rigging" I always thought that pertained to systems aboard racing boats that allowed you to tune just about everything in the standing rigging while actually racing.

My dad raced Etchell 22s for a long time and spent a ton of money on these particular shroud turnbuckles that even under heavy load could be tuned quite dramatically by hand with ease. Everything on that boat could be tinkered with under sail in some fashion.
04-06-2012 04:52 AM
L124C
Re: The more I learn, the less I know!

Quote:
Originally Posted by casey1999 View Post
One thing I think most of us could easily over tighten any rig even with just hand tools, so I would not use that as an indicator.
To be fair, he did emphasize SMALL hand tools.

Quote:
Originally Posted by casey1999 View Post
The other thing I don't understand is why you would want slack on the lee ward shrouds. Would it not be best if all shrouds never went to 0 tension that way the shroud would not see cyclic loads that would potentially lead to fatigue failure? I have heard of long distance sailors tyeing bungees cord around the leeward shrouds to prevent fatigue failure (from the shroud swinging around for extended periods). Anyone know how say a volvo 60 is tuned in the around the world volvo race?
I assume that tightening the rig so that it didn't go slack on Leeward in high wind would require too much constant stress on the rig and boat. The bungee trick certainly wouldn't hurt though. I'm going to tune using the method I suggested in post 97, and will report back on the gage tensions it develops. Should be interesting. Using Dedekam's stretch method worked well as far a boat performance, but read high on the tension Gage. On the other hand, the Leeward shrouds would still go slack in high winds. Do your shrouds never go slack?

Quote:
Originally Posted by casey1999 View Post
Finally, to become a professional rigger /tuner what do you need to do? Go to college? Pass a test? Get a license? Rig and tune 1000 boats and not lose a rig at sea? WTH is a professional rigger? Could any of us hang a shingle and call ourselves a professional rigger?
As a Union Journeyman Carpenter with over 30 years in the trade , I can assure you that both the Union and Journeyman labels don't mean s**t! Worse yet, I have worked for several licensed Contractors who couldn't frame a wall to save their life, much less know if the job was being performed properly (and many "Inspectors" don't know much more)! So...given that the marine repair industry is less regulated than the building industry......
04-05-2012 09:55 PM
davidpm
Re: Dynamic tuning of rig

Quote:
Originally Posted by DougSabbag View Post
This is excellent / valuable information! I can't wait to close on our CT 56 in July and utilize all the great information here!

I sure do want to learn how to properly tune my rig. My previous / haphazard methods, were proven to have a down side....

I used to just pull on the shrouds / stays, at the dock, and adjust them to "feel" equally tight. That was all, and surprise, surprise, considering the ramifications, that was not enough.

Thank you very much gentlemen!
Good luck on your new boat. I'm sure the days are dragging while you wait.
Just to reiterate. It seems unlikely that rig tuning even if not perfect would be the major cause of chain plates failing.
The real lesson is that any stainless chain plate that is over 10 years old and certainly over 20 years old could likely be work hardened and even if it looks perfect and polishes beautifully should be considered for replacement.
04-05-2012 03:22 PM
Faster
Re: The more I learn, the less I know!

Quote:
Originally Posted by casey1999 View Post
WTH is a professional rigger? Could any of us hang a shingle and call ourseves a professional rigger?
I think most riggers go through a (rather informal) apprenticeship and learn on the job from a (hopefully) skilled experienced person. I don't know of any official accreditation body (like SAMS for surveyors, for instance) but maybe Knothead will weigh in with better information.

I suppose any of us could hang a shingle as you say.. but be sure to have good 'mal-rigging insurance'!
04-05-2012 02:46 PM
casey1999
Re: The more I learn, the less I know!

Quote:
Originally Posted by L124C View Post
I've never quoted myself before, but do it now to make a correction. Having done furtherer research on the matter, I think, 3 Riggers might give you 5 opinions!
I'm now a little suspect of Dekekam's stretch method, as older rigging (like mine!)does stretch over time, and therefore, I think the method might not be accurate on older rigs. Dedekam does say that you can't over tighten Keel Boat rigs using small hand tools. On the other hand, another "Author" (admittedly, in a forum) suggested tightening the rig as tight as possible using a 10" wrench AT THE DOCK! Most suggest hand tightening of the Cap Shrouds to the max prior to tunning under sail.
The method that now feels best to me intuitively (and is in contradiction to the PS article I cited above), is maximum hand tightening of the Cap shrouds at the dock, then sailing in 15 Knots and alternatively tightening Leeward shrouds equal amounts until the slack is eliminated. Of course, the the mast should be straight at the dock and while under sail, and the lowers should be adjusted to maintain the Mast alignment under sail. It seems to me that this method would allow some Leeward slack in heavy weather, yet prevent over tightening and shock loads in gusts and while tacking. Thoughts?

Agree this is all good information.

One thing I think most of us could easily over tighten any rig even with just hand tools, so I would not use that as an indicator.

The other thing I don't understand is why you would want slack on the lee ward shrouds. Would it not be best if all shrouds never went to 0 tension that way the shroud would not see cyclic loads that would potentially lead to fatigue failure? I have heard of long distance sailors tieing bunges cord around the leeward shrouds to prevent fatigue failure (from the shroud swinging around for extended periods). Anyone know how say a volvo 60 is tuned in the arond the world volvo race?

Finally, to become a professional rigger /tuner what do you need to do? Go to college? Pass a test? Get a license? Rig and tune 1000 boats and not lose a rig at sea?
WTH is a professional rigger? Could any of us hang a shingle and call ourseves a professional rigger?

Regards
04-05-2012 09:04 AM
DougSabbag
Re: Dynamic tuning of rig

This is excellent / valuable information! I can't wait to close on our CT 56 in July and utilize all the great information here!

I sure do want to learn how to properly tune my rig. My previous / haphazard methods, were proven to have a down side....

I used to just pull on the shrouds / stays, at the dock, and adjust them to "feel" equally tight. That was all, and surprise, surprise, considering the ramifications, that was not enough.

Thank you very much gentlemen!
This thread has more than 10 replies. Click here to review the whole thread.

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


All times are GMT -4. The time now is 05:04 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.