Shorter than normal 5/16 turnbuckle?

[Team118]

Hi there guys.
Haven't had to post in awhile, been able to avoid the ever present gremlins that are always stalking my boat!

Till this week that is.

Was out on Lake Ontario Tuesday, enjoying 20-25kt winds and rolling 3-5'. Only had the jib set and probably a 1/3 of that at best. Was a perfect day. 90 degrees out, hot wind in my face, boat doing maximum hull speed with very little heel.

On the way back....BAM!!! Snapped the starboard aft lower chainplate stud! Oh boy, once the shroud snapped, it changed the stress on the mast and loosened the spinnaker halyard (a sail I don't have and a halyard I never use!!!!...lol) and as I tried to furl in the jib, the spinnaker halyard wrapped around the jib furler....Oh yeah.

So about 2 hours later, after getting whipped by flailing jib sheets I got the jib down and headed home.

The sad part is I ordered the Catalina Direct lower shroud chainplate upgrade a few years ago....just sat in my basement.

I installed all the parts over the last few days, no problems...except.

I was almost at the final stops on the 2 aft shroud turnbuckles and the new upgrade adds about 3/4 of an inch in height. I can't get the any more turns.

My only options are to either purchase new shrouds that I can cut and swag myself or....I'm hoping, find 5/15" turnbuckles that are shorter than the standard 5" length.

Any thoughts on if there is such a thing?

Thanks
Chris

 

[jssailem]

Chris, try Hi-Mod swageless fittings by Hayn Marine. Here is a link. http://hayn.com/marine/rigging/index.html
I used their product for all of the deck shroud fittings in my Mast refit. You can get a size to fit your wire. Then make the necessary cut and fit to your need.

 

[Team118]

Thanks John, not sure how this would work for me? It seems that option would require me to cut my current shroud and then install these swageless fittings to marry into the top part of the current turnbuckle?

 

[JimInPB]

If you have 3/4" of extra space between your turnbuckle shackle & the D ring on the deck that it connects to, then maybe you can install a tube with a 3/4" wall around the shackle pin to take up the extra length. I've done this sort of thing before to correct loose & sagging lifelines.

Alternately, can you play with the tuning of the rig? Can you rake the mast forward a little more?

Also, a local machine shop should be able to make you a shorter turnbuckle. They may need to buy a left handed tap to get the job done, so there may be a tooling charge in addition to the normal hourly rate.

 

[Claude L.-Auger]

The threaded part length on both the shroud and the chainplate side is anywhere from 1 & 1/2 to 2''. Since you are needing about 3/4'' to get a proper fit, while it is not an ideal solution you could cut off about 1/2'' each from the threaded part of the shroud and the chainplate end. That would give you about an extra inch. You would also need to drill new holes for the cutter pins or rings. If not able to drill new holes, then install nuts on the outside ends of the turnbuckle. You will need a right and left end nut. Remember I said it is not an ideal solution ! However, I've done it on a previous boat. It worked perfectky and was way cheaper than cutting and re-swaging or having a turnbuckle specially made ! Good luck and keep us posted with your solution.

 

[Team118]

Hi Claude, I'm not sure what you mean. My shrouds are probably original and are cut to length. There isn't anything to cut. I did find a 4" turnbuckle from Jamestown, but I don't know if it's a LH/RH turn...I'll call them on Tuesday. Temporarily I was able to fit a machine screw between the D-Ring and the lower pin of the turnbuckle. It gave me enough room to tighten the shroud.

 

[Claude L.-Auger]

My understanding from your description is that the shroud cannot be adjusted because the new piece makes the entire length of shroud / turnbuckle / chainplate piece too long and that both threaded ends of the shroud and the chainplate now bottom in the turnbuckle preventing tightening of the shroud. Taking a look at the attached pix should help you understand that if you can evenly shorten the threaded end of the shroud and the threaded end of the chainplate by about 1/2'' each or more, you should gain the necessary space. You'll need to either drill a hole near the new ends to put a cutter pin, or if enough threads left outboard of the turnbuckle put a nut and tighten on the turnbuckle to lock it in final position. Finding a lefthanded nut might be tricky so I would drill holes as in the pix. Good luck

 

[Team118]

Ah...I see.
The 'toggle jaw' part of the turnbuckle isn't bottoming out...or rather topping out with the threaded end with the retaining pin hole hitting the middle of the turnbuckle. It's bottoming out when you twist the turnbuckle as far as you can the turnbuckles are hitting the toggle jaw base. So cutting off a length of the threaded part of the toggle jaw wouldn't create more room.

Jim's suggestion of trying to put a piece of metal between the jaw's pin and the newly installed 'D' ring added about 1/4" which was enough to get some good tension on the shroud.

My dilemma is just spending $500-$600 on new lower shrouds next year....on a 1977 boat....I WANT A BIGGER BOAT!!!!!

Thanks guys

 

[kloudie1]

How about putting a 1" spacer under the mast base to get the turnbuckles back to operating range??
Something the other turnbuckles can tolerate in their adjustment range.

 

[jviss]

So far I think the only good solutions offered are from @jssailem and @kloudie1 .

I know there's not a lot you can do, but that clevis pin in the lower toggle against the U-bolt is really not good practice, as it results in point load between the bolt and pin. If you could have a spacer made that's the width of the inside of the lower toggle and fits almost entirely into the U-bolt, would that take up enough shroud length? (I'm guessing not.)

Kloudie's idea is actually quite brilliant, if it can be done. Will require a way of lifting the mast, and must be so that it the mast can't slip out for or aft.

John's is quick and dirty, but will cost something in parts. Hi-mod turnbuckle studs in your size are around $35 to $40 each:
http://www.riggingandhardware.com/c-985-turnbuckle-studs.aspx

 

[jssailem]

putting a 1" spacer under the mast base

That may be where the symptoms of the turnbuckle lead.
The deck under the mast base may be weak and there may be a little compression going on. If the compression post is also a little soft this would show up on the standing rigging ( Needing to tighten until there is no more possible).

 

[jssailem]

on a 1977 boat....I WANT A BIGGER BOAT!!!!!

Given enough time the truth will surface.
So forgo the actions on this boat. Put it up for sale while there is still daylight and tempting weather for a new buyer and wait till winter starts. The prices go down and you get the opportunity to enjoy your dream.

 

[jviss]

That may be where the symptoms of the turnbuckle lead.
The deck under the mast base may be weak and there may be a little compression going on. If the compression post is also a little soft this would show up on the standing rigging ( Needing to tighten until there is no more possible).

That's exactly what I was thinking. Older C30's had wood under the mast step, which rots and softens over time.

 

[Team118]

I thought about that spacer under the mast idea too. It is an older boat, and I am sure there is some compression at the base down in the bilge area. But nothing that is noticeable on the deck in the form of sagging or cracks from a mushy step that is all to common in Mk I's.

I've seen the Hi-Mod turnbuckle studs, but would they work with my current shrouds? Is this the same setup as the Catalina Direct 'Trim to Fit' kits? If so, that would definitely be an answer.

Also, I've seen a number of posts in the past about point loading. What is that? Does it have to do with the clevis pin's surface connection with the D-ring...so because there is little actual surface to surface contact between the pin and the ring (because they're both round) all that weight is focused on a 'millimeter' size contact area?


And yeah, who doesn't want a new...newer boat! Sometimes, when faced with larger than normal expenses (new jib last year, new mainsail this year), it's hard to wonder that if I do move on, just what do I recoup on $2-3,000 in new sails on a 41 years old boat, as opposed to plodding on with those dirty 40 year old rags.

....almost like putting brand new tires on a 15 year old car, just before you sell it.

Thank you very much for all your advice!
Chris

 

[jviss]

I've seen the Hi-Mod turnbuckle studs, but would they work with my current shrouds?

They should work, assuming you order the right parts!

Also, I've seen a number of posts in the past about point loading. What is that? Does it have to do with the clevis pin's surface connection with the D-ring...so because there is little actual surface to surface contact between the pin and the ring (because they're both round) all that weight is focused on a 'millimeter' size contact area?

Yes, that's exactly it. Could bend the clevis pin, too.

 

[JimInPB]

... I've seen a number of posts in the past about point loading. What is that? Does it have to do with the clevis pin's surface connection with the D-ring...so because there is little actual surface to surface contact between the pin and the ring (because they're both round) all that weight is focused on a 'millimeter' size contact area?...

Yea, that's the Cliff's Notes version of it.

If you read a rigger's handbook, you will probably find information that says you are supposed to use a centering spool to distribute load across the shackle pin properly to achieve maximum structural strength, but almost nobody ever does that in actual practice on marine rigs. Most everybody just up-sizes to stuff that is strong enough to take the abuse. Adding the spacer tube around the pin, as I suggested earlier, actually reduces the point load effect. It distributes load & adds support to the pin in addition to increasing the contact area. Aside from the (small amount of) added weight, it's kind of a win-win situation.

 

[jviss]

but almost nobody ever does that in actual practice on marine rigs

I don't agree with that! Almost all boats I've worked on, sailed on, or taken a close look at had this pretty much right. The only thing I find often that's a mistake, or 'wrong,' is lack of toggles where they should be. For example, the mast tangs for the shrouds on Catalinas are usually not bent at exactly the right angle, resulting in a non-straight pull so that there's a bend where the wire exits the swaged terminal. This is a weak/break point. A toggle fixes this.

 

[JimInPB]

I don't agree with that! Almost all boats I've worked on, sailed on, or taken a close look at had this pretty much right. ...

Wow, our experiences are very different. I have never seen a centering spool on a shackle pin on a sailboat. I don't even remember seeing them on the shelf at a marine supply store. I sometimes see them on lifting slings for cranes, but I haven't seen one on a sailboat yet.

 

[jviss]

I have never seen a centering spool on a shackle pin on a sailboat.

Neither have I. I can't recall having seen a U-bolt as a chain plate until this thread. Usually the chainplate is thcik enough that it fills the toggle fork, and the pin holes are the right size.

Maybe I just haven't been paying enough attention.