"soft shackles" and chain hooks

[Neeves]

If you have been following my threads, on fids and what to do with short lengths of braided rope cover you will know I've been making splices in dyneema.

The dyneema are offcuts from useable pieces of rope where the covers has been worn, commonly when a sheet rubs on the lifelines or suffers wear in a clutch. I simply cut off at the damaged portion of the rope, keep the long piece, as is, and make "shackles" from the short pieces. I actually wanted or need the "shackles' that I make for work I am doing on snubbers and bridles. However I have made excess "shackles' as its quite therapeutic.

My splices are not soft shackles in the normal definition as I have eyes at both ends, that's what I wanted. The shackles are simply a bury from both ends, giving me an eye at each end, and because the bury is often not long enough I have sewn the centre of the shackle and then covered it with heat shrink - specifically designed for rope. The heat shrink will shrink in boiling water and a temperature of 100 deg will not impact rope strength (and the device is three thicknesses of dyneema where it is heat shrunk).

As I had made excess I cast around for a use for the shackles that I did not need and one use is for a chain hook to attach to a snubber. If you have a nylon snubber and splice a hook to it you then have a 10m length of rope with a bit of ironmongery on the end. If the chain hook is easily removed the 10m length can be used as a spring when you moor up (or to tie your dinghy to the roof rack).

The shackles are not soft shackles and I have used various sources of dyneema as they are various scrap pieces.


I have not yet tried it but it may be possible to simply offer a lock to eye hooks by cow hitching a silicone band to the eye and stretching it over the mouth of the hook, to stop the chain falling out. I cannot claim to have 'designed' these - they 'happened' but if you wanted a simple chain lock, on passage, or to back up your snubber and keep the tension off the windlass - then if you make something similar of the appropriate length this 'sort of thing' if attached at one end to the rode and at the other end to a strong point (not the windlass) - maybe a horn cleat - would suffice.

To give an idea of scale the hooks are for 8mm or 6mm chain.

Jonathan

 

[thinwater]

In the US those would be called strops, dog bones, or rabbit runners, depending on the context and length. Very handy.

Google "whoopie sling" for another handy variation. They started in the US logging industry, but they have many other uses. I've seen them on some high-end boats (Annapolis Boat Show).

Whoopie Sling Animated Knots

Note that it is easier to splice a short loop than a short dog bone.


A sewn version (Mountain Tools Webolette)

 

[fredrussell]

I’m not sure I understand how you have improved the use of the chain hooks. The way I see it the chain hook has a hole to tie a line to, as does the piece of dyneema you have added. Either way do you not end up tying your snubber line to a hole before use?

 

[Neeves]

I’m not sure I understand how you have improved the use of the chain hooks. The way I see it the chain hook has a hole to tie a line to, as does the piece of dyneema you have added. Either way do you not end up tying your snubber line to a hole before use?

I suspect we misunderstand each other, my apologies, I am sure it is my fault.

How do you attach your snubber to your rode?

To my knowledge you can use a soft shackle, a rolling hitch (there are number of different hitches) you could use a Prussik knot or a steel device, claw a bridle plate (if you use two snubbers) and maybe a hook.

How do you, or anyone attach a hook, with an eye, to a chain and what is the function of the eye.

Jonathan

In the US those would be called strops, dog bones, or rabbit runners, depending on the context and length. Very handy.

Google "whoopie sling" for another handy variation. They started in the US logging industry, but they have many other uses. I've seen them on some high-end boats (Annapolis Boat Show).

Whoopie Sling Animated Knots

Note that it is easier to splice a short loop than a short dog bone.


A sewn version (Mountain Tools Webolette)
View attachment 145625

Separated by a common language.

To me a strop is a short length of rope used to connect in any way two devices. Whoopee sling I know, the name - but note sure why (but I have no background in the timber industry and call only think its from rock climbing). Dog bones always seemed to be but another term for a toggle - but toggles had different meanings - closures on a duffel jacket, a ring through which you ran your neckerchief, and part of the device at the turn buckle, rigging).

Rabbit runners is a new term completely -

No wonder the N Americans with whom I sailed would look askance - often.


Since posting the above I had a quick search on whoopie slings and in Oz the most common usage is for cordage especially for suspending hammock (there was me thinking hammocks were simply suspended with bits of rope (ignorance is bliss). There is mention of use in the timber industry (using dyneema). I don't think the devices I have made would be much use in the lumber industry, too short, I'm trying not to waste short lengths of dyneema.

Jonathan

 

[fredrussell]

I suspect we misunderstand each other, my apologies, I am sure it is my fault.

How do you attach your snubber to your rode?

I tie some 12mm dynamic climbing line to a chainhook with a bowline (with a long tail). This line goes through a fair lead at the bow then down the side deck via a block or two to be cleated off aft.

 

[Neeves]

I tie some 12mm dynamic climbing line to a chainhook with a bowline (with a long tail). This line goes through a fair lead at the bow then down the side deck via a block or two to be cleated off aft.

An excellent practice, cannot fault it. I hope more take notice of your practice.

Many do not follow your practice and attach the snubber at the bow and deploy the snubber forward of the bow roller. They sit at anchor for a day or 3 and as the wind and tide changes their snubber wraps round the chain. The wind picks up and the snubber is sawn away by the chain - a dyneema strop is sacrificial and the dyneema very abrasion resistant.

All I have done is allow you to attach the hook through a different mechanism and allow you to use the short strop, with attached hook, as a means to secure the anchor on passage (should the clutch slip). You can use the short strop, with hook, on a bow horn cleat and then to the chain. If you make 2 such devices you can use one device to attach to the snubber and use another as a chain lock should the snubber fail - and the hook might be the weak link (as Witchard hooks have an eye - and are prone to failure).

I will guarantee some retrieve their anchor until it is tight on the bow roller - leaving the windlass under constant tension. Better to secure the anchor by another mechanism and relieve the stress on the windlass and don't rely on the clutch. I do recall someone, here on PBO, leaving the UK, 10/15 years ago, and as they passed the Needles on their way to more blue waters their clutch slipped and their Spade anchor and all the rode fell into the sea (no securement of the bitter end).... its just an idea.

My whoopee slings or rabbit runners are more a way to reduce wastage of dyneema that to offer revolutionary and novel ideas. I hate waste - what else do you use 2m of dyneema for? but if you decide making rabbit runners might be an idea - what do you use them for (its a bit like - what do you use soft shackles for?). Actually I had, have, a specific use for rabbit runners, specifically short pieces of dyneema with long eyes at both ends (I have not tested the complete idea yet (you will need wait) but I try to be free with my ideas, if successful, so be patient . I hope I have indicated I'm free with my idea - in fact I'm criticised for being too free and using too many words of explanation . I had had no idea my short strops with long eyes at both ends were common place, rabbit runner, whoopee slings, but maybe my application is novel (who knows). Serendipity is part of reality. However I had to make the devices, short strop, long eye, and I ended up with a pile of them - chain hooks seemed an application with some merit - maybe I am wrong (as I use a bridle ).

But I also have a bridle application......

I might add that 12mm climbing rope might be a bit beefy for a sub 45' yacht - 10mm might be better.

Take care, stay safe

Jonathan

 

[yotter]

I have not used my chain hook for a while, favouring a dyneema loop, since this can run over the bow roller. I find the chain hook can be difficult to attach and detach, outboard of the bow roller. Far easier to attach (cow hitch) by dyneema loop inboard of the bow roller, then release some more chain to allow it to roll over the roller to the required position. I use a very stretch line (old climbing rope) on the inboard end of the loop and run this back to a midships cleat. The loop is about 18 inches long and made from something like 5mm D12 dyneema. Hope this helps

 

[thinwater]

I suspect we misunderstand each other, my apologies, I am sure it is my fault.

How do you attach your snubber to your rode?

To my knowledge you can use a soft shackle, a rolling hitch (there are number of different hitches) you could use a Prussik knot or a steel device, claw a bridle plate (if you use two snubbers) and maybe a hook.

How do you, or anyone attach a hook, with an eye, to a chain and what is the function of the eye.

Jonathan



Separated by a common language.

To me a strop is a short length of rope used to connect in any way two devices. Whoopee sling I know, the name - but note sure why (but I have no background in the timber industry and call only think its from rock climbing). Dog bones always seemed to be but another term for a toggle - but toggles had different meanings - closures on a duffel jacket, a ring through which you ran your neckerchief, and part of the device at the turn buckle, rigging).

Rabbit runners is a new term completely -

No wonder the N Americans with whom I sailed would look askance - often.


Since posting the above I had a quick search on whoopie slings and in Oz the most common usage is for cordage especially for suspending hammock (there was me thinking hammocks were simply suspended with bits of rope (ignorance is bliss). There is mention of use in the timber industry (using dyneema). I don't think the devices I have made would be much use in the lumber industry, too short, I'm trying not to waste short lengths of dyneema.

Jonathan

Dog Bone is weird in that it can mean either the double-eye strop or the toggle you might use with it. Yes, it usualy means the toggle, but changes with context ("We splice the rope into dog bones for testing"). Dog Bone | Spliced Goods | DutchWare Gear

A rabbit has two ears. A runner is a sling or strop used by a climber for running belays. Rabbit runner.

See also Davis "line grabber." LineGrabber™

And the Mantus Snubber Pendant. The Spectra cover is a nice touch, adding wear resistance and strength.

and

 

[Mudisox]

Why bother? I have a life to lead.

 

[geem]

Why bother? I have a life to lead.

Why are you here then?

 

[fredrussell]

Why are you here then?

Touché!!

 

[fredrussell]

An excellent practice, cannot fault it. I hope more take notice of your practice.

Many do not follow your practice and attach the snubber at the bow and deploy the snubber forward of the bow roller. They sit at anchor for a day or 3 and as the wind and tide changes their snubber wraps round the chain. The wind picks up and the snubber is sawn away by the chain - a dyneema strop is sacrificial and the dyneema very abrasion resistant.

Ah, I see. Makes sense now, cheers.

 

[thinwater]

Touché!!

 

[Neeves]

Why bother? I have a life to lead.

I said the same of soft shackles and rabbit runners till I needed them.

Dog Bone is weird in that it can mean either the double-eye strop or the toggle you might use with it. Yes, it usualy means the toggle, but changes with context ("We splice the rope into dog bones for testing"). Dog Bone | Spliced Goods | DutchWare Gear

A rabbit has two ears. A runner is a sling or strop used by a climber for running belays. Rabbit runner.

See also Davis "line grabber." LineGrabber™

And the Mantus Snubber Pendant. The Spectra cover is a nice touch, adding wear resistance and strength.

and View attachment 145649

I did like the derivation of rabbit runners, it appealed to me.

I had also thought of the use of one of the ears as a Prussic knot to attach a snubber to the chain, exactly as you illustrate. I actually prefer a hook, quicker/easier to attach detach (but does not come over the bow roller too well - so the hook needs to be disengaged before the roller.

Jonathan

 

[Neeves]

I forget who made the comment, on an earlier thread on a similar subject, but for many application dyneema shackles are OTT, fine if you have offcuts but unnecessary for many applications. Off cuts from conventional polyester would make 'shackles' identical to a dyneema device - and be plenty strong enough.

Making 'shackles' has been immensely popular and then, as I found, what do you do with them.? I was amused by one suggesting that you could use dyneema soft shackles to tidy up the shore power cable by securing it to the stanchions, lifelines - dyneema??. It seems a good location for polyester shackles (made from offcuts).

As I experimented with different lengths and diameters of, scrap, dyneema I have now about 15 rabbit runners. it took me that number to work out what was best for the application I am working on, so I have 13 spares. One application, for dyneema, is for shore lines, to protect the shore line from abrasion. An application for polyester is to hang halyards at the base of the mast on a horn cleat, spinnaker sheets and spare lengths of snubber at the transom when not in use. I do find some uses, contrived, simply to use up the excess shackles

Jonathan

 

[thinwater]

I said the same of soft shackles and rabbit runners till I needed them.


I did like the derivation of rabbit runners, it appealed to me.

I had also thought of the use of one of the ears as a Prussic knot to attach a snubber to the chain, exactly as you illustrate. I actually prefer a hook, quicker/easier to attach detach (but does not come over the bow roller too well - so the hook needs to be disengaged before the roller.

Jonathan

An "ear" does NOT hold rope as well as a sling, unless the eye is long enough for the entire knot. What Davis showed does not hold well on nylon rope, and will slip at ~ 150-500 pounds.

 

[Neeves]

An "ear" does NOT hold rope as well as a sling, unless the eye is long enough for the entire knot. What Davis showed does not hold well on nylon rope, and will slip at ~ 150-500 pounds.

Thanks

Even when sewn?

I started off with only sewing the buries that were short, but still overlapping in the middle of the length - I now sew all of them in the middle of the length where the 2 buries overlap even when the buries are 'long enough'. I lose some of the ability to slide the cover and have a longer ear - but the ears are long anyway, I specially wanted long ears, so its not such a big issue. I'm not using the runners in a critical 'lifting', 'climbing' applications (no mast work).

I'm using braided dyneema fishing line for the securement and sew two lines of stitching at 90 degrees to each other over about 50mm length, multiple stitches using about 2m of fishing line for each runner.

Jonathan

 

[thinwater]

Thanks

Even when sewn?

I started off with only sewing the buries that were short, but still overlapping in the middle of the length - I now sew all of them in the middle of the length where the 2 buries overlap even when the buries are 'long enough'. I lose some of the ability to slide the cover and have a longer ear - but the ears are long anyway, I specially wanted long ears, so its not such a big issue. I'm not using the runners in a critical 'lifting', 'climbing' applications (no mast work).

I'm using braided dyneema fishing line for the securement and sew two lines of stitching at 90 degrees to each other over about 50mm length, multiple stitches using about 2m of fishing line for each runner.

Jonathan

I meant the prusik does not hold on the line you are trying to grip. The splice is a separate question; a lock stitch is very good, stronger than a Brummel if the bury is right.

The lock stiching is only there to keep the splice from shifting under zero load. It is the Chineese finger trap that holds the load. That said, I did some testing with some others that showed that concentrated lock stiching near the eye can add considerable strength in cases where the burry is shorter than ~ 40:1. 70:1 is considered the gold standard, but there is seldom a measurable loss in strength unless less than 40:1. The loss is slippage, and increased lock stitching or a brummel can hold some of the difference, but only to a point, which seems to be around 30:1. All of this depends on the specific line.

 

[Neeves]

I meant the prusik does not hold on the line you are trying to grip. The splice is a separate question; a lock stitch is very good, stronger than a Brummel if the bury is right.

The lock stiching is only there to keep the splice from shifting under zero load. It is the Chineese finger trap that holds the load. That said, I did some testing with some others that showed that concentrated lock stiching near the eye can add considerable strength in cases where the burry is shorter than ~ 40:1. 70:1 is considered the gold standard, but there is seldom a measurable loss in strength unless less than 40:1. The loss is slippage, and increased lock stitching or a brummel can hold some of the difference, but only to a point, which seems to be around 30:1. All of this depends on the specific line.

The 70:1 standard does mean that even with thin rope and if you have two eyes the device turns out to be quite long, so sewing does allow short lengths to be used. I'm not sure that 30:1 with dyneema is a good idea, even when doubled so the 2 buries over lap its not that secure - which is why I sew all the the buries, all of which overlap 100%, in the middle. Its that one time when the slipperiness of dyneema is a disadvantage.

Maybe two eyes, thus 2 buries, is not common practice.

Why does sewing at the eye add additional, considerable, strength over sewing in the centre of 2 buries.

If you sew at the eye you are isolating the buries completely and it is the sewing that effectively provides the strength (non slippage). If you sew at the eye you lose the ability to slide the cover up and make the eye bigger, say for a cow hitch of the eye.

I carry lengths of chain to place round rocks or trees for shorelines - the chains protect the rope from abrasion. I'm thinking of retiring the chain pieces and replacing, made either from polyester or dyneema rabbit runners. I consider these devices as sacrificial - they can be abandoned if we need to leave in an unplanned hurry. Note these runners are only made from cut offs which would be scrap, or fender ropes, otherwise

Jonathan

 

[thinwater]

The 70:1 standard does mean that even with thin rope and if you have two eyes the device turns out to be quite long, so sewing does allow short lengths to be used. I'm not sure that 30:1 with dyneema is a good idea, even when doubled so the 2 buries over lap its not that secure - which is why I sew all the the buries, all of which overlap 100%, in the middle. Its that one time when the slipperiness of dyneema is a disadvantage.

Maybe two eyes, thus 2 buries, is not common practice.

Why does sewing at the eye add additional, considerable, strength over sewing in the centre of 2 buries.

If you sew at the eye you are isolating the buries completely and it is the sewing that effectively provides the strength (non slippage). If you sew at the eye you lose the ability to slide the cover up and make the eye bigger, say for a cow hitch of the eye.

I carry lengths of chain to place round rocks or trees for shorelines - the chains protect the rope from abrasion. I'm thinking of retiring the chain pieces and replacing, made either from polyester or dyneema rabbit runners. I consider these devices as sacrificial - they can be abandoned if we need to leave in an unplanned hurry. Note these runners are only made from cut offs which would be scrap, or fender ropes, otherwise

Jonathan

The reason you sew at the eyes is to prevent shifting. The strength comes from the contraction of the outer against the inner. Thus, sewing at the eye adds strength by serving as additional bury length. But stitching other places (the overlap) might prevent proper contraction and thus probably does not add as much to strength.

Of course, if you stitch enough, the sewing alone can carry the load, and that might not be a terrible idea. There are a number of variables, but as a rule of thumb, if you just multiply the number of stich passes by the strength of the thread, that is about what it will hold (Dyneema and polyester--nylon is different).

Without testing, the strength of overlapping buries is a mystery. I just do not know and have never read anything based on testing. It is not often done. If someone needs something short, they use a loop, a doubled loop (climbers do that all the time) or a lashing. A climber's short rabbit runners, AKA quickdraws, are sewn loops that are also sewn in the center, to create a loop at each end. These can be as short as about 100 mm.

Climbers have long considered runners to be disposable in the event of a retreat, for example in fould weather. I once retreated ~ 12 pitches off Pingora in the Wind Rivers (we were very near the summit when an ice storm started ... in the middle of the summer!). I left quite a few runners. Typically you try to leave the stuff that arguably, was ready for retirement anyway. I got a new rack out of it, which was long overdue.