Soft shackle questions

firstbase · Sep 15, 2019

Don't want to drift the "Snubber" thread off course although it got into soft shackles a bit. Thought I'd just post separately.

This past hurricane was the third one for me that required serious boat prep. Still don't have it down. Need chains/shackles around pilings rather than tying. Good snubber system as I put an anchor off the bow for various reasons. Bought a Mantus snubber system. Too much money and more than a few concerns voiced by others but it is much better than what I had and will give it a try to see how it works for me. Am working on the chains and shackles, pretty easy fix.

My other issue I have to deal with is cleat space. That stopped me from adding more lines, just no place to put them. Not going to add additional cleats as doing that properly with backing plates is beyond my expertise and would be major surgery for someone else to do. I do read about using Dyneema and the like soft shackles or endless loops for extending cleats.

Question is whether or not they are a reasonable solution during a storm or just for less strenuous duty ? What load should I plan on? Which type of line and thickness to use? I see single and double braid. One better than the other for this purpose? In my current slip I need them mostly on the stern and midships cleats more so than the bow. It seems dhays is a resident expert on them and makes his own. Have looked at some of his posts and they are simple enough looking to make. And of course there are 5 varieties of them each with their own pros and cons. Not sure which way to go.

Thanks for any comments.

Rain Dog · Sep 15, 2019

Dyneema is incredibly strong. A soft shackle made of 1/2 inch Dyneema would be strong enough to lift your entire boat out of the water.

If I was making soft shackles to add to cleats, I would use 5/16 Amsteel or similar. That would result in a shackle considerably stronger than a 3/4 inch nylon dock line.

I tie mine like this: https://l-36.com/soft_shackle_9.php

rgano · Sep 15, 2019

A thought about chain bracelets around pilings for storm use: If you are not running a single line to a hard eye through which the chain runs, you are probably running it out to the bracelet itself and back to the boat meaning the line is now in a very short radius bight out there, even if wrapped in anti-chafe gear.

boathealer · Sep 15, 2019

I would be worried about chafe in a severe storm/hurricane situation.

While incredibly strong, Dyneema/Amsteel are not impervious to chafing failure. They excel in a static load situation.

If a "must use", I would up-size 2-3 times based on the breaking strength required ---- to account for some amount of chafe protection.

Comodave · Sep 15, 2019

I think that if I were going to put chain around the piling then I would put an eye splice with a metal thimble in the line and shackle it to the chain. No chaffing.

dhays · Sep 15, 2019

I have been using soft shackles to attach my dock lines to the dock cleats for a couple of years. I spliced a thimble in the dock lines and then shackled those to the base of the cleat. It allows two lines to be attached to the same cleat and avoids any chafing of the mooring line. Yes, the shackles are subject to chafing but I run the shackle through a nylon web tubing where it runs around the cleat. The shackles that I’ve used have been in place for 2 1/2 years. I checked them last a couple months ago and there was no significant chafe of the shackles.

I used 3/16” dyneema on those soft shackles. Based on testing, and my desire to be conservative, I now consider that shackle design to have the same strength at the line it is made of. I used the same design that Rain Dog linked above. 3/16” dyneema has a breaking strength of 5,400 lbs. That is less than the almost 9,000 lbs breaking strength of the 5/8” nylon 3 strand that I used.

When I replace those shackles, I will use the updated design of shackle that I am making now. It has a breaking strength of about 230% of line strength, so I just use 2x as my rule of thumb. So the 3/16” shackle I make has a breaking strength of over 10,000 lbs, stronger than the dock lines I’m using.

So, the shackles are strong and with a bit of nylon webbing, you can guard against chafe. Using a thimble further cuts down on chafe. Here is a picture of the dock end before I put the webbing over the shackle.

What I did on the dock side could be done on the boat side as well. There is a photo of two shackles attaching lines to the base of a cleat on the boat. Finally, there is another way that a spliced loop can be used to provide another attachment point to the cleat. In this way, you could have three different lines attached to the one cleat. Of course, can the cleat take that kind of load?

For the chain around a piling, I might use a soft shackle to connect the ends of the chain and pass it through a spliced eye with a thimble. However, you are wondering about storm prep. If it was me, I’d buy a 600’ spool of three strand and make the lines that I want to use for the storm prep. Have them sized for your dock situation and label each one. That would make prep very quick since all of the thought and work would have been done ahead of time.

If you want stronger shackles, then upsize the dyneema you use. I have made them from 1/4” and 5/16” dyneema. The 5/16 shackles using the stronger design are just ridiculously strong. Minimum breaking strength of over 24,000lbs and average breaking strength of over 27,000 lbs. Definitely overkill. For your purposes, I’d use 1/4” dyneema.

dhays · Sep 15, 2019

rgano said:
A thought about chain bracelets around pilings for storm use: If you are not running a single line to a hard eye through which the chain runs, you are probably running it out to the bracelet itself and back to the boat meaning the line is now in a very short radius bight out there, even if wrapped in anti-chafe gear.

Very true. A 1:1 bend will reduce the line strength by 50%. However, if the line is running from the boat, around the bracelet, and back to the boat the line is doubled. So by reducing the strength at the bend by 50%, you still have 100% of the line strength.

rgano · Sep 15, 2019

dhays said:
Very true. A 1:1 bend will reduce the line strength by 50%. However, if the line is running from the boat, around the bracelet, and back to the boat the line is doubled. So by reducing the strength at the bend by 50%, you still have 100% of the line strength.

Not sure that makes sense at the point of bend. But ok...

dhays · Sep 15, 2019

rgano said:
Not sure that makes sense at the point of bend. But ok...

Yeah, I know. It seems counterintuitive.

firstbase · Sep 15, 2019

rgano said:
A thought about chain bracelets around pilings for storm use: If you are not running a single line to a hard eye through which the chain runs, you are probably running it out to the bracelet itself and back to the boat meaning the line is now in a very short radius bight out there, even if wrapped in anti-chafe gear.

Boat is stern in. 3/8" galvanized chain bracelet with shackle would be on bow pilings, one starboard and one port. 5/8" 3 strand nylon with thimble shackled to to bracelet and led to hawse and cleat a couple of feet aft. Fire hose anti chafe at hawse.

For a second bow line to pilings can I add another thimbled line to the same shackle (assuming it is adequately sized) or should I add a second bracelet on the pilings?

The soft shackle extenders come in to play on the midship cleats. I cannot let the boat go astern as there is a concrete bulkhead behind me. I need two forward spring lines but also need an aft spring as well if not two. Cleats are good size but with three lines I have to start getting inventive. If I had room I would double up the aft as well but four lines isn't going to happen. Hence the discussion on extending.

firstbase · Sep 15, 2019

boathealer said:
I would be worried about chafe in a severe storm/hurricane situation.

While incredibly strong, Dyneema/Amsteel are not impervious to chafing failure. They excel in a static load situation.

If a "must use", I would up-size 2-3 times based on the breaking strength required ---- to account for some amount of chafe protection.

I believe "Aramid" is rated better for heat resistance but thats just reading on my part. No experience whatsoever. Honestly, I read of those who use 5/16" or even smaller but I think that is for day in day out use not storm. My cleats can handle 5/8" or even 3/4" fed through the base. That would leave the cleat free to handle two lines with two more on the extender, one forward and one aft which would break the potential load up in two directions.

firstbase · Sep 15, 2019

Comodave said:
I think that if I were going to put chain around the piling then I would put an eye splice with a metal thimble in the line and shackle it to the chain. No chaffing.

Yes, what I am doing. Also on bulkhead cleats aft. The are attached to a concrete bulkhead. Bracelets on both of them as well with eye splice thimble.

firstbase · Sep 15, 2019

The other issue I have is how to attach the lines coming from piling to the midship cleat extender. I can't adjust the line from the piling so I can't use a thmble on the extender. Can I tie the line to the dyneema or whatever extender? That seems like an open invitation to quick chafe.

Sailor of Fortune · Sep 15, 2019

dhays said:
I have been using soft shackles to attach my dock lines to the dock cleats for a couple of years. I spliced a thimble in the dock lines and then shackled those to the base of the cleat. It allows two lines to be attached to the same cleat and avoids any chafing of the mooring line. Yes, the shackles are subject to chafing but I run the shackle through a nylon web tubing where it runs around the cleat. The shackles that I’ve used have been in place for 2 1/2 years. I checked them last a couple months ago and there was no significant chafe of the shackles.

I used 3/16” dyneema on those soft shackles. Based on testing, and my desire to be conservative, I now consider that shackle design to have the same strength at the line it is made of. I used the same design that Rain Dog linked above. 3/16” dyneema has a breaking strength of 5,400 lbs. That is less than the almost 9,000 lbs breaking strength of the 5/8” nylon 3 strand that I used.

When I replace those shackles, I will use the updated design of shackle that I am making now. It has a breaking strength of about 230% of line strength, so I just use 2x as my rule of thumb. So the 3/16” shackle I make has a breaking strength of over 10,000 lbs, stronger than the dock lines I’m using.

So, the shackles are strong and with a bit of nylon webbing, you can guard against chafe. Using a thimble further cuts down on chafe. Here is a picture of the dock end before I put the webbing over the shackle.

What I did on the dock side could be done on the boat side as well. There is a photo of two shackles attaching lines to the base of a cleat on the boat. Finally, there is another way that a spliced loop can be used to provide another attachment point to the cleat. In this way, you could have three different lines attached to the one cleat. Of course, can the cleat take that kind of load?

For the chain around a piling, I might use a soft shackle to connect the ends of the chain and pass it through a spliced eye with a thimble. However, you are wondering about storm prep. If it was me, I’d buy a 600’ spool of three strand and make the lines that I want to use for the storm prep. Have them sized for your dock situation and label each one. That would make prep very quick since all of the thought and work would have been done ahead of time.

If you want stronger shackles, then upsize the dyneema you use. I have made them from 1/4” and 5/16” dyneema. The 5/16 shackles using the stronger design are just ridiculously strong. Minimum breaking strength of over 24,000lbs and average breaking strength of over 27,000 lbs. Definitely overkill. For your purposes, I’d use 1/4” dyneema.

This makes no sense to me. What are you trying to accomplish? Why not just put mooring line over the cleat? Yes, you have the ultimate strong soft shackle, but there is a flaw here. Those dock and your deck cleats get their strength from a line around both parts. Loading up half a cleat is not what its designed for. Your regular mooring lines are plenty strong for your application here. It seems to me , your coming up with a solution to a problem that you don't have..

dhays · Sep 15, 2019

firstbase said:
The other issue I have is how to attach the lines coming from piling to the midship cleat extender. I can't adjust the line from the piling so I can't use a thmble on the extender. Can I tie the line to the dyneema or whatever extender? That seems like an open invitation to quick chafe.

Yeah, tying your 3 strand to a soft shackle would be an open invitation for chafe of the line. I wouldn’t worry about the shackle but the 3 strand could chafe.

Two options: The first is go ahead and created a line of the proper length with a thimble on either end. Then you can use it when you need to do your storm prep. If the line needs to be tight, then a more fussy way would be to use a metal shackle on the cleat extension and use dyneema lashings to tighten it or even a turnbuckle.

The second option would be to simply use a metal shackle on the cleat extender and then simply tie off the line to the shackle using a halyard hitch. Be aware that one that is tensioned, you will likely have to cut it off.

rgano · Sep 15, 2019

My home boat shed was constructed with eight large diameter pilings, not cleats anywhere. The trawler was secured with all six lines doubled around the pilings with kevlar armor anti-chafe tubes which opened and closed along their length with Velcro. These replaced the original chain bracelets trough which I previously ran the doubled with the aforementioned tight radius turnaround. Being exposed for over a mile to the south, that rig rode out some heavy weather with the 40,000 pound boat bucking and heaving with no chafing of the lines in fifteen years. Large diameter turn around for doubled 5/8 braided nylon lines and good chafing gear at both boat and piling is going to trump cleats with unknown fastenings, Dyneema or not.

Sailor of Fortune · Sep 16, 2019

rgano said:
My home boat shed was constructed with eight large diameter pilings, not cleats anywhere. The trawler was secured with all six lines doubled around the pilings with kevlar armor anti-chafe tubes which opened and closed along their length with Velcro. These replaced the original chain bracelets trough which I previously ran the doubled with the aforementioned tight radius turnaround. Being exposed for over a mile to the south, that rig rode out some heavy weather with the 40,000 pound boat bucking and heaving with no chafing of the lines in fifteen years. Large diameter turn around for doubled 5/8 braided nylon lines and good chafing gear at both boat and piling is going to trump cleats with unknown fastenings, Dyneema or not.

Agreed. Pretty sure DHAYS cleats are going to fail, way before is mooring lines and shackles. I Still don't understand what he is trying to accomplish. Cleats are made to take the strain on both ends.

dhays · Sep 16, 2019

Sailor of Fortune said:
Agreed. Pretty sure DHAYS cleats are going to fail, way before is mooring lines and shackles. I Still don't understand what he is trying to accomplish. Cleats are made to take the strain on both ends.

I agree as well. The bolts or the dock will fail before the lines. No different than what I had before.

I made the switch for three reasons. The first was that I was getting a lot of chafe on my permanent dock lines at my home slip. Now I don’t get any chafe. Secondly, there were two cleats that I needed to attach lines. That created a mess of lines on the dock, which led to the 3rd reason, just to get rid of lines on the dock collecting dirt and holding moisture against the wood.

I certainly could have kept doing what I had been. It worked.

Comodave · Sep 16, 2019

You mentioned using fire hose for chaffing gear. The hose will not let water get to the line to help stop the line from heating up and possibly melting. I have some chaffing gear that is canvas with velcro to fasten it to the line. Water is able to penetrate through it to help cool the line.

firstbase · Sep 16, 2019

dhays said:
Yeah, tying your 3 strand to a soft shackle would be an open invitation for chafe of the line. I wouldn’t worry about the shackle but the 3 strand could chafe.

Two options: The first is go ahead and created a line of the proper length with a thimble on either end. Then you can use it when you need to do your storm prep. If the line needs to be tight, then a more fussy way would be to use a metal shackle on the cleat extension and use dyneema lashings to tighten it or even a turnbuckle.

The second option would be to simply use a metal shackle on the cleat extender and then simply tie off the line to the shackle using a halyard hitch. Be aware that one that is tensioned, you will likely have to cut it off.

Thanks. In working this out I do see a way to change some things and get my extra two lines in place without having to adjust from a far off piling. Still need an extender for my two midship cleats but can use them with eyesplice and thimble lines on board and adjust length from the dock. These are back up backup lines for when all else fails and not the main strains.

Apologies for all the questions. Have a new attitude towards hurricanes due to the acute memory of how I felt when I woke up one morning and saw the eye of Dorian tracking about a mile away from the boat. I had tied up pretty good but I knew I hadn't done everything I could and to the best of my ability. Next time I will know I did what could be done. At least in the slip. Could always put it on land somewhere.

rslifkin · Sep 16, 2019

Personally I don't like the soft shackle on dock cleat thing, just from a practical standpoint. For my home slip dock lines, they're tied at the dock end, so that's where the length adjustment goes. The boat end is an eye splice, so when coming into the dock, each line can simply be dropped onto its cleat. Makes things quick and easy, especially if anyone helping is unfamiliar with my line setup. Nothing gets tied, so nothing can get set to the wrong length.

Now, I do worry a bit about chafe on the slightly rough dock cleats and 1 wooden piling I tie to, but with the time I've been in this slip, it doesn't seem to be a meaningful issue. The lines won't last forever, but even when we've gotten some good winds and movement in the slip the lines don't seem to chafe noticeably, so given periodic inspection and replacement when they look worn, they should hold up fine.

To minimize chafe on the pilings, when I tied the lines, I then slacked off some of my cleat tied lines a little, moved the boat closer to the piling and then gave it a hard shove away, then repeated a few times to let its momentum set the line on the piling. Since doing that, the lines haven't moved against the pilings at all and show just the slightest bit of wear where they contact the piling, so they're probably good for a couple of years before they're worn out. When I do replace them I'll probably add a few foot section of chafe protection to the lines for the first wrap around the piling.

If I manage to chafe the boat end of a line, then we've got bigger problems. They can't touch anything other than the smooth stainless deck cleats and gelcoated fiberglass.

dhays · Sep 16, 2019

rslifkin said:
Personally I don't like the soft shackle on dock cleat thing, just from a practical standpoint. For my home slip dock lines, they're tied at the dock end, so that's where the length adjustment goes. The boat end is an eye splice, so when coming into the dock, each line can simply be dropped onto its cleat. Makes things quick and easy, especially if anyone helping is unfamiliar with my line setup. Nothing gets tied, so nothing can get set to the wrong length.

It sounds like that is what I used to do. At my home slip I looped an eye over the boat cleats and tied the line on the dock cleats. Once the length was set, they didn’t need to be changed. When we came into the slip we just picked up the lines and dropped them over the boat cleats or the hawse holes with ears. We never needed to adjust the lines. When away from our home dock I have a set of double braid lines that I use for dock lines.

That is still what I do now. We come into the slip, pick up the lines and drop the spliced loops over the boat cleats. As you mentioned, it makes securing the boat up properly quick and easy.

So the method hasn’t changed, only the way the lines are attached to the dock.

rgano · Sep 23, 2019

dhays said:
It sounds like that is what I used to do. At my home slip I looped an eye over the boat cleats and tied the line on the dock cleats. Once the length was set, they didn’t need to be changed. When we came into the slip we just picked up the lines and dropped them over the boat cleats or the hawse holes with ears. We never needed to adjust the lines. When away from our home dock I have a set of double braid lines that I use for dock lines.

That is still what I do now. We come into the slip, pick up the lines and drop the spliced loops over the boat cleats. As you mentioned, it makes securing the boat up properly quick and easy.

So the method hasn’t changed, only the way the lines are attached to the dock.

I would like to emulate your method, but all my lines are doubled around pilings with eye and bitter end aboard the boat. It's the best way for me to single-hand out of the slip in a blow. I can hardly wait for the slip and hoist repair to get back up in the air where this boat belongs when not underway! Note to all, this was an early photo, and that crap anchor is now just an aux stern anchor.

dhays · Sep 23, 2019

Great setup there!

timb7734 · Sep 24, 2019

Dyneema line

We have been using this line in recovery on winches for several years to replace steel cable. In addition to its sensitivity to chafe, this type of line is subject to deterioration from UV in sunlight such that we find the exposed sections need replacement annually/ seems sort of expensive for this application given the other limitations.

Nomad Willy · Sep 24, 2019

Dhays wrote;
“It sounds like that is what I used to do. At my home slip I looped an eye over the boat cleats and tied the line on the dock cleats. Once the length was set, they didn’t need to be changed. When we came into the slip we just picked up the lines and dropped them over the boat cleats or the hawse holes with ears. We never needed to adjust the lines. When away from our home dock I have a set of double braid lines that I use for dock lines.”

That’s essentially what I do.
But you can have all ends w an eye .. spliced or w a bowline.
The bow and stern lines don’t need to be extremely tight so w a little muscling they can be attached to the cleats.
The spring lines do need to be fairly tight IMO. I keep one spring line w eyes on both ends. With the other on the dock I take a half turn around the cleat on the float (or dock) and pull it tight. Then holding onto the end I pull up vertically to get lots of tension on this line, pull up the slack quickly and then complete the cleat tie.

I had the marina put in two dedicated spring line cleats (just inboard of the bow and stern cleats) so I wasn’t using more than one line per cleat. If I didn’t employ very tight spring lines all 8 line ends could be with an eye.

When on the go at different tie-ups every night I frequently employ a midship breast line (90 degrees from the boat) as the first tie. Then I attach the stern line ... and the bow line a bit loosely. Then I adjust the fore/aft position of the boat w the springs. When satisfied I tighten all as needed. Much improvising is required as cleats seldom are in the right place. Huge plus for bull rails as lines can be attached anywhere along the rail.

This obviously requires two sets of lines. One for on the fly and one for home port. But on the run I keep all the dock ends w/o loops or eyes. Like a lot of things re boat this system evolved and not from Chapman’s other people.

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