Backstay Adjuster

[Jon Dix]

I've done some research which has not uncovered much in the way of a Back-Stay tension/adjuster recommendations for a Pearson 32. Looking for a replacement for a worn-out "STERN"- hydraulic rig. Back-stay is 3/16" rod and "pin to pin" is distance @ 36 ". Leaning towards mechanical (Cost),

Welcome recommendations! See attached for a Rig I put together. I've been made aware by smarter people than me that this design was not the most "safe or efficient" way to support or "tension" the rig on my boat. It should be a split configuration with cascading blocks?

My first boat, still learning...I know racing J29's, Olsen 30's I  could could put some useful bend in the stick with a rig similar to the one in the attachment, a split back-stay rig and cascading blocks.

Thank-You, JD

80' Pearson 32, w M25 engine, Patuxent River MD

[George Dubose]

I would suggest first ascertaining if your mast wants to be bent at all.

On Skylark, a 1973 Pearson 36-1, the mast is like a telephone pole and isn't bendable.

I heard of another Pearson 36 owner who installed a hydraulic backstay adjuster and when he tried to get a bend to his mast, he pulled the forestay fitting off the bow.

Be careful,

George/Skylark

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[Stephen Craft]

I don't know if the 32 mast can handle it.  My 10M has a hydraulic adjuster.

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[Dan Pfeiffer]

Really like the P32...

I can't see your image right now but I can say a backstay adjuster is great for tweaking the rig and can give you a gear between changing sails.  So rather than changing from genoa to jib and/or reefing at 15 TWS you might get to 18 by the flattening you get from the adjuster.    As has been pointed out they can be very powerful and you need to keep that in mind under use.  But that's manageable. 

The P32 mast is not so big as the P36 or 10M (same mast) which is same as the 424 mast but on the 424 it's shorter.  And the P32 standing rigging is more like the 10M than the P36 with inline and forward lowers and no aft lowers which I think is to enable some mast bend.  The P32 also has intermediate uppers on the single spreader rig (with discontinuous rigging?) which is interesting and implies a lighter mast section that might be more bendable?  But it will not be anything like a J29 or Olson 30 so put that out of your mind.  And most of your backstay tension will likely go to headstay sag control rather than mast bending.  And that's very useful.  

You might consider re-building the hydraulic rig you have.  Might be as simple as seals.  There is a guy who specializes in this.  I'll dig up contact info.  I think he's in RI. 

If you have to replace it, a cascading tackle on a spit backstay is very simple and effective.  You would need to add chainplates at sides of transom.  This would likely involve some reinforcing of the fiberglass.  Basically adding tabbing on the inside at the corner of transom and hull.  Not too difficult.  Mostly prep work.  And chainplate fabrication is not hard either.  Just match size and number of fasteners to what is thee as a single in the center and it will be more than strong enough.  

I am curious how your P32 ended up with a rod backstay.  That is not OEM.  At least I don't think it was.  Is the rest of the rig wire?  And 3/16 seems a bit light for your backstay?  I would think 1/4? 

Dan Pfeiffer

[J D]

Yes forgot the attachment,....

 But it will not be anything like a J29 or Olson 30 so put that out of your mind.  And most of your backstay tension will likely go to headstay sag control rather than mast bending.  And that's very useful.  - Understand and your final point about head-stay tension has been mentioned by others.TY

You might consider re-building the hydraulic rig you have.  Might be as simple as seals.  There is a guy who specializes in this.  I'll dig up contact info.  I think he's in RI.  The hydraulic rig used be re-built every year by the owner, (seal replaced) I finally installed it last year and the fluid was out of it in a few weeks.

.And chain-plate fabrication is not hard either.  Just match size and number of fasteners to what is thee as a single in the center and it will be more than strong enough.   Understand the effort in installing what your referring too, that's why I'm avoiding this option.

I am curious how your P32 ended up with a rod backstay.  That is not OEM,   tt least I don't think it was.  Is the rest of the rig wire?  And 3/16 seems a bit light for your backstay?  I would thick 1/4". I though the same thing when I looked up the value in the boats log. A tuff Luft was added, perhaps the rod rigging was replaced them, don't know. All stays are solid and 3/16".

Very helpful points and considerations, you can see why this has been a challenge deciding on options. I agree the Mast is very rigid, the boat is a Cruiser /racer but don't think the rig was made for bending?

[Dan Pfeiffer]

OK.  So that rig in the photo is a solid NO.  Don't do that.   The only legit backstay adjuster using line will be a split wire with blocks that pull the split together to tighten.   Like this from my old P26:
http://dan.pfeiffer.net/p26/backstay.htm

You can swap out your hydraulic unit with a length of wire with or without a turnbuckle but the rope setup as shown is not good.  The weak point is the blocks.  You could use a dynema lashing with maybe 6 to 10 loops of 3/16 dynema (5400 lbs strength) over some nice fat shackles (like the one at the top of your setup in the photo.  That would also be OK and probably stronger than the wire. Even 1/8 dynema would do with 8 to 10 loops.   take the main halyard and snug down tight to one of those stern cleats when you do the lashing.

Do you have any other spec for the rod rigging?  Like a dash number?  Rod is sized by breaking strength and 3/16" would be about a -4 for 4000 lbs, actually 4700 lbs.  That just seems a bit light for a P32 but I would have to do the whole righting moment calculations to know.  I may have a spreadsheet from my 10M that I can plug the numbers into... Regardless, I would like to find the original rigging specs for the P32 to compare to.   The P26 used 3/16 wire for shrouds (apr. 4000 lbs strength)  and 7/32 for backstay (apr. 5400 lbs).   The P32 should be a size larger at least?  I'll look for my spreadsheet. 

Given the cruser/racer intention of the P32 I would guess the rig was designed for some bending but not like a J29.  Mostly they probably intended backstay to control headsail. 

I like a tuff luff.  Excellent bit of kit.  Hopefully you have two jib halyards so you can do running headsail changes. 


Dan Pfeiffer

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[J D]

Dan,

Again thank-you for the insight and cautions! 

Yes, the blocks are rated @ 2000 & 3700 lbs.... I realize no bueno. I "Mic'd" all the stays, they are 1/4 inch and not 3/16", so some goodness and negates the need for some of the conversation. Very good backstay HW out there, just more of an investment then I wanted to make, welcome to boat ownership...I'll see what Bacons in Annapolis has to offer, maybe a road trip.

Considering a roller-furler rig, with more cruising than racing... Thanks again, a gentleman from an "Ericson" forum sent me the link to this space, glad he did!

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[Dan Pfeiffer]

Excellent.  1/4 makes much more sense.  I plugged the P32 numbers into my rigging spreadsheet.  Se attached results.  Some of this came from list member Mike Robinson and some is from calculations in various books like "The Riggers Apprentice". 

Also check with this place just across the bridge from Annapolis...
https://sailboatparts.com/search?q=backstay&options%5Bprefix%5D=last

I have a nice old mechanical Wichard adjuster that uses a winch handle.  Not so fast as hydraulic but I like it.  Easier to keep from over-tightening.  10 turns per inch.


Dan Pfeiffer

[J D]

Impressive "rig analysis", thank you for sharing your wrok ! Some good options from the site you recommended, I do like the simplicity of the rig your using! Again much appreciated.