Soft versus hard shackles

Zanshin · #1 (**permalink**) 08-30-2010

I have a problem with my Genoa clew knots getting stuck while tacking and have now made a soft shackle out of Dyneema and put eye splices on the end of the Genoa sheets so that I have a compact package with little to snag on.

While doing this I thought that I could use soft shackles instead of hard ones for other attachments such as the Genoa travellers (I tripped over one of those hard shackles last year while anchoring and broke my toe) and main outhaul and topping lift attachments. None of these lines have a tendency to flog, so chafe ought not to be a problem.

I'm using 8mm (6800Kg breaking strength) or 10mm (10,500Kg) Dyneema so strength isn't an issue.

Is there any reason not to use these soft shackles for these purposes?

14432 · #2 (**permalink**) 08-30-2010

Many of the soft shackles are designed for halyards on racing boats and use in situations where they are under constant load for a finite period of time. In a situation where there is no constant load, be sure your design will not allow the shackle to undo itself - especially when used on deck and subject to being stepped on. Many of such shackles on the market have velcro retaining straps for this purpose. Nice thing about stainless shackles is they don't come undone.

tdw · #3 (**permalink**) 08-30-2010

Zanshin, (G'day btw, hope you are thriving....

)

We're at the same stage. Just about to replace our headsail clew shackles with soft or as I know them "Dutch" shackles. I'm also wondering about doing the same for other uses.

14432, notes the problem of them coming undone when not under load. Have a look at the Colligo "Softie". It uses a rather ingenious method to keep the eye closed.

Softies XL Large Boat Series Soft Shackles | Colligo Synthetic Systems | Colligo Marine

There is a link to a U-Tube "how to do" video.

Zanshin · #4 (**permalink**) 08-31-2010

TDW - I don't have a problem making shackles (I have a number of smaller ones for my hanked-on staysail) and use the method documented by Colligo. There are easier ways to tie the crown and cap knots than Colligo's method, though.

My question was about potential downsides to using them.

(Although right now I might have some shackles and no boat since the eye of "Earl" (Cat 4) just passed over Anegada, just a few short miles away from where my boat is stored....)
I hope that the new gov't changes the visa rules and I can head back to Oz in the near future.

tdw · #5 (**permalink**) 08-31-2010

Zanshin, I take your point. I thought that perhaps the eye closer that the Colligo method uses would be the key point to expanding the field of opportunity for the soft shackles, preventing them from opeing when not under load. I'm going to use them wherever possible and keep an eye out for those areas where they don't perform. I guess its a case of 'suck it and see'.

Hope that your boat is OK. Keep us informed and remember that anytime you do make it back to Sydney you are due a beer.
Whether we get the Mad Monk or Gillard is still unknown but in either case I wouldn't use the word 'boat' on your application.

cheers and good luck with Earl.
td

Zanshin · #6 (**permalink**) 09-01-2010

I spent some time last night trying to shake open a soft shackle without success. I think that if the shackle is not under load, then the outside sheath somehow gets hooked on something and pulled back and then the shackle flogs it might open up. I think for semi-permanent shackles such as for the travellers and genoa I'll use a thin line to whip the end shut so that it can't open.

I still am amazed at the strength of Dyneema every time I handle it, it is amazing stuff.

zz4gta · #7 (**permalink**) 09-01-2010

No reason not to use it. I'm going to change out my halyard shackles with these. Have already made a pair for the light air spin sheets, and use them for quick attachments at the tack on headsails as fine tune penants. Haven't 'tested' them flogging on the chute yet, but I think that'll be the best test I can come up with.

tdw · #8 (**permalink**) 09-01-2010

Well if you are using 8 and 10mm dyema on Zanshin then I figure 6 or 8mm is going to be plenty for our 34'er.

I'm going to pick up a few metres today, try and get them done over the weekend.

tdw · #9 (**permalink**) 09-01-2010

Quote:

Originally Posted by zz4gta

No reason not to use it. I'm going to change out my halyard shackles with these. Have already made a pair for the light air spin sheets, and use them for quick attachments at the tack on headsails as fine tune penants. Haven't 'tested' them flogging on the chute yet, but I think that'll be the best test I can come up with.

This might make more sense for halyards......

http://www.sailnet.com/forums/genera...yard-knot.html

zz4gta · #10 (**permalink**) 09-02-2010

How does that not slip or load up?