Shackle failure

[garymalmgren]

If we are talking about the spinnaker halyard, why not use a halyard shackle?
Failsafe.

 

[Refueler]

I was a supporter of snap shackles for years until seeing the injury to a guy who got 'clocked' by one ..... flogging genny.

Now I am a Bowline person and sheets separate ! No more tangled sheets where shackle swivel span ...

I accept that even a bowline or clew alone can do some serious injury ... but a lump of metal ??

 

[[194224]]

If we are talking about the spinnaker halyard, why not use a halyard shackle?
Failsafe.

A halyard shackle isn't failsafe. If it fails it fails, there is no safe aspect to the failure. It is perhaps less likely to fail that a snap shackle but it cannot fail is such a way that there is a safe outcome with the system still able to operate.

 

[Roberto]

Consider also your other uses of the spinnaker halyard, if any: for example, sometimes with the sail still in the bag at the bow, I hook it to the sail head grommet at the same time as the upper lifeline (for example while arranging the guy/sheet), or when the sail is lowered and thrown inside the boat and the halyard is removed, it can be useful to quickly make it fast somewhere nearby, etc. All temporary arrangements where a snap shackle is a lot more practical than other means, in particular as it can often be used with only one hand.

 

[garymalmgren]

If it fails it fails, there is no safe aspect to the failure.
Show me a photo of a failed halyard shackle. Or explain how it can fail.

 

[B27]

Probably because of the wrong choice.

I have been using snap shackles for our spinnaker. Crucially, also for the spinnaker head.

Last week, that shackle failed (see attached) - the forces involved bent it. The result was a rather dramatic dunking of the kite in the water, in a large swell, not too far from waves breaking over some submerged rocks (we were not in danger of "touching", but the breaking caps were scary and may have been dangerous). It took a long time to retrieve the large improvised sea anchor. Fortunately, the lines got tangled in the hydrovane rudder rather that the main rudder (or sail drive) and were relatively easy to deal with, eventually.

Some minor tears to the spinnaker caused by snagging against stanchions, on retrieval.

Luckily there were two of us, and we were able to deal with the issue.

Anyhow. Lesson learnt: use a better arrangement at the head. I am going for a halyard shackle. I was wondering if a simple bowline would also be a viable alternative (any views on this?)

That looks like it's been bent by being loaded while not in line with the load?
'Capsized' on a deck eye or something and tensioned up?

Even quite small snap shackles have quite high breaking loads, but if you jam them in a ring and pull at angle, here endeth the warranty.

The actual working load on a kite halyard is what?

I've sailed many small boats tying the kite on with bowlines.
Most big boats have halyards which are fat and stiff from being in the sun for a year of 5, so knots are harder to tie reliably.
Probably OK with stripped dyneema.
I suspect the kite halyard on my boat would not go through the eye in the sail.

 

[B27]

If it fails it fails, there is no safe aspect to the failure.
Show me a photo of a failed halyard shackle. Or explain how it can fail.


View attachment 178718

Send me a couple, I'll get the lads in the club to break them.
As with lifeline tether hooks, jam it in a fitting and give it some twisting tension, that's quite likely to break it.
That split ring looks nasty. Could be replaced by machine screw and nyloc nut

 

[john_morris_uk]

If it fails it fails, there is no safe aspect to the failure.
Show me a photo of a failed halyard shackle. Or explain how it can fail.


View attachment 178718

We use a similar one to that on our main. However I dislike the strip metal ones. All strip metal shackles on our boat were disposed of a long time ago.

Key pin shackle with bar - Dia 8 mm | Wichard Marine

 

[zoidberg]

A bowline is pretty reliable, used for decades.

Jonathan

I and many other climbers used a Bowline to tie on for many years - but with 3-strand laid rope. Then 'kernmantel' or core-and-sheath rope became the norm. This is invariably smoother/less friction than 3-strand, and research in several national labs/industry testing facilities showed that Bowlines could and did slip-untied at well less than the ropes' nominal minimums.

It was found that the Double Figure of Eight was rather more resistant to slipping than the Bowline, and its 'break strength' was markedly higher, too. ( see Marlow diagram et al )

Outdoor Pursuits Centres instructed their staff to use Double-Figure-Of-Eights, for an instructor can also see from a distance if it is properly tied, unlike the Bowline.

Yes, the Bowline has lots of uses - but is not optimum when risk to life and limb is involved.

 

[nevis768]

I and many other climbers used a Bowline to tie on for many years - but with 3-strand laid rope. Then 'kernmantel' or core-and-sheath rope became the norm. This is invariably smoother/less friction than 3-strand, and research in several national labs/industry testing facilities showed that Bowlines could and did slip-untied at well less than the ropes' nominal minimums.

It was found that the Double Figure of Eight was rather more resistant to slipping than the Bowline, and its 'break strength' was markedly higher, too. ( see Marlow diagram et al )

Outdoor Pursuits Centres instructed their staff to use Double-Figure-Of-Eights, for an instructor can also see from a distance if it is properly tied, unlike the Bowline.

Yes, the Bowline has lots of uses - but is not optimum when risk to life and limb is involved.

Actually a lot of climbers don't use the figure of eight because it is hard to untie after loading, unlike a bowline. Also a lot of climbers now use the Yosemite bowline, which is a re threaded version, and a stopper can be added to either version. Also, if your sport climbing, the figure of eight takes ages to re-thread, and locks solid after falls.

 

[flaming]

For about a month a year I sail a 33 metre ketch with soft shackles on the main, mizzen, staysail and jib never had a problem.

I didn't say they were inevitable, just possible with a soft shackle in a way that they are not with a more conventional shackle. And that's still different to a spinnaker halyard, which is not held taught in the same way under use and has more opportunity to snag things.

As I said I'm a big soft shackle fan, but this is not a use I would put them to.

 

[westernman]

Probably because of the wrong choice.

I have been using snap shackles for our spinnaker. Crucially, also for the spinnaker head.

Last week, that shackle failed (see attached) - the forces involved bent it. The result was a rather dramatic dunking of the kite in the water, in a large swell, not too far from waves breaking over some submerged rocks (we were not in danger of "touching", but the breaking caps were scary and may have been dangerous). It took a long time to retrieve the large improvised sea anchor. Fortunately, the lines got tangled in the hydrovane rudder rather that the main rudder (or sail drive) and were relatively easy to deal with, eventually.

Some minor tears to the spinnaker caused by snagging against stanchions, on retrieval.

Luckily there were two of us, and we were able to deal with the issue.

Anyhow. Lesson learnt: use a better arrangement at the head. I am going for a halyard shackle. I was wondering if a simple bowline would also be a viable alternative (any views on this?)

I have always used bowlines for attaching halyards and sheets.
Why would you want to do anything else?

A bowline is less painful than a shackle if you get wacked by one for any reason.

 

[john_morris_uk]

FWIW I use bowlines for sheets and shackles for halyards. There’s not so much room between the head of my main and the masthead sheave for a bowline.

 

[flaming]

I have always used bowlines for attaching halyards and sheets.
Why would you want to do anything else?

Speed.

If you're plugging in a kite and have 5 bowlines to tie that's a lot longer than 5 snap shackles.

 

[westernman]

FWIW I use bowlines for sheets and shackles for halyards. There’s not so much room between the head of my main and the masthead sheave for a bowline.

Your mast is too short!

 

[jamie N]

Shackle types!
Are we witnessing the birth of the new anchor type discussion??
I've never heard of a bowline failing, but it relies on being tied correctly, whereas a shackle can look correct in every way, and still fail.
Unless it's certified and inspected, with the knowledge of only ever having been used in a correct manner, as they are offshore, it's got to be deemed dodgy.
As others have stated, none of the shackles on a boat are certified as suitable for a 'man-riding' application, and 5 bowlines to tie, in preference to 5 snap shackles when rigging a chute in a race, is a no brainer to me.
Choices are hell aren't they!

 

[john_morris_uk]

Your mast is too short!

I’ll water it and hope it grows.

Either that or someone else’s mainsail is too small?

 

[Boathook]

Shackle types!
Are we witnessing the birth of the new anchor type discussion??
I've never heard of a bowline failing, but it relies on being tied correctly, whereas a shackle can look correct in every way, and still fail.
Unless it's certified and inspected, with the knowledge of only ever having been used in a correct manner, as they are offshore, it's got to be deemed dodgy.
As others have stated, none of the shackles on a boat are certified as suitable for a 'man-riding' application, and 5 bowlines to tie, in preference to 5 snap shackles when rigging a chute in a race, is a no brainer to me.
Choices are hell aren't they!

I've seen a bowline fail by coming undone. It was on a mooring line with the boat tugging at the line. I always leave a long tail and some times a half hitch just to make sure.
I used to use lewmar snap shackles for the sheets when the sails were hanked on but sometimes the flogging of the sail would release them. I now use bowlines but make sure that the knot is tight so unlikely to come undone.

Snap shackles are good but the OP''s does look cheap In my view.

 

[Neeves]

Your mast is too short!

Yes - just extend it a little

 

[William_H]

I use bowline on spinnaker sheets and halyard. Just make sure tail is long enough. Bowline omn halyard puts the wear point of halyard on sheavee at top ina different place each time so minimising chafe/wear. ol'will