Swivel hoist rings for jacklines instead of pad eyes?

[cristoslc]

I've been reading a bunch of forums/blogs/etc. with an eye to installing jacklines on our '84 Hunter 27. One thing I'm curious about is that the typical hardpoint hardware appears to be padeyes (fixed or swivel). However, there's lots of caveats and concerns about making sure you're loading the padeyes on the right axis, dealing with lateral forces, etc.

Has anyone seen a boat that uses swivel hoist rings, instead? (Actek® Stainless Swivel Hoist Ring, Actek® Sideload Hoist Ring) It seems like the 2-axis rotation would mean you'd never have to worry about your direction of fall w/r/t the anchors because they support their working load limit in almost any direction.

There are some challenges. I've only done a cursory search, but it does seem like they're hard(er) to find in 316 stainless steel, they can be slightly heavier, and they are definitely more expensive than pad eyes. But are there any functional reasons why they wouldn't be a good jackline anchor on a sailboat?

(To be clear, I'm probably going to start with the pad eye route anyway, I'm just pondering ideas here.)

 

[CarlN]

I assume you are using flat webbing jacklines so they don't roll under foot? In that case fixed is better as you'll lay the jackline out flat as you install it. You don't want it then swiveling. As to strength, any properly secured padeye is more than strong enough. Don't use any metal hardware at the end of your jackline. Either feed the sewn loops through the padeye or use several rounds of dyneema cord through the loops.

Be sure your jacklines are near the center of the boat so there's no way you can end up on the wrong side of the lifelines.

 

[Tally Ho]

I've been reading a bunch of forums/blogs/etc. with an eye to installing jacklines on our '84 Hunter 27. One thing I'm curious about is that the typical hardpoint hardware appears to be padeyes (fixed or swivel). However, there's lots of caveats and concerns about making sure you're loading the padeyes on the right axis, dealing with lateral forces, etc.

Has anyone seen a boat that uses swivel hoist rings, instead? (Actek® Stainless Swivel Hoist Ring, Actek® Sideload Hoist Ring) It seems like the 2-axis rotation would mean you'd never have to worry about your direction of fall w/r/t the anchors because they support their working load limit in almost any direction.

There are some challenges. I've only done a cursory search, but it does seem like they're hard(er) to find in 316 stainless steel, they can be slightly heavier, and they are definitely more expensive than pad eyes. But are there any functional reasons why they wouldn't be a good jackline anchor on a sailboat?

(To be clear, I'm probably going to start with the pad eye route anyway, I'm just pondering ideas here.)

How would that ring bolt through the deck?

Greg

 

[thinwater]

I've been reading a bunch of forums/blogs/etc. with an eye to installing jacklines on our '84 Hunter 27. One thing I'm curious about is that the typical hardpoint hardware appears to be padeyes (fixed or swivel). However, there's lots of caveats and concerns about making sure you're loading the padeyes on the right axis, dealing with lateral forces, etc.

Has anyone seen a boat that uses swivel hoist rings, instead? (Actek® Stainless Swivel Hoist Ring, Actek® Sideload Hoist Ring) It seems like the 2-axis rotation would mean you'd never have to worry about your direction of fall w/r/t the anchors because they support their working load limit in almost any direction.

There are some challenges. I've only done a cursory search, but it does seem like they're hard(er) to find in 316 stainless steel, they can be slightly heavier, and they are definitely more expensive than pad eyes. But are there any functional reasons why they wouldn't be a good jackline anchor on a sailboat?

(To be clear, I'm probably going to start with the pad eye route anyway, I'm just pondering ideas here.)

Not a serious concern. The angle of pull on the webbing is very limited, since it is snug. A pad eye is the simplest solution.

 

[jssailem]

I have used he Wichard PadEye for jack lines. The pull is in line with the padeye structure aligned along the center line from bow to mast base. I selected the 10mm because of the space available for the jackline to wrap flat over the padeye.
The specifications for the 10mm padeye:

• Working load (kg) 4080 8994 LB
  
• Breaking load (kg) 9000 19841LB

I know overkill. But definitely not letting go in a fall.

What ever you use be sure you use a proper backing plate. Fender washers are not recommended.

 

[thinwater]

...What ever you use be sure you use a proper backing plate. Fender washers are not recommended.

It's not that they are not recomended. They bend before they spread the load. You can bend them with pliers and very little effort. Every heavily loaded fender washer I have removed was bent into a cone.

You can buy "extra heavy" fender washers that are twice as thick, 4 times as strong, and 8 times as stiff. They work. Stacking regular washers really does not, unless it is quite a stack.

 

[cristoslc]

Thanks for the feedback, all. As I mentioned, I'll be starting with folding padeyes (also Wichards). For my coach roof and [centerline on the] foredeck, I'll be doing either webbing or line covered in webbing to prevent rolling. Those are places where the force directions are probably a little easier to predict, and hopefully any deflection won't move to meaningfully off-axis angles..

For the cockpit, I'm still figuring out the optimal padeye placement, but may wind up mounting on vertical bulkheads (cabin to aft bench) because of the channel running around the sole. It'll create a bit of a tripping hazard to either side of the helm, but I don't see another good, strong way to run the line. (Those may be naked line instead of webbing, since I think it will be more compact if it's up against the passenger benches.)

Had been planning on cutting backing plates out of some structural FRP, but good to know about fender washers distorting into cones Thanks for the tip, @thinwater . Do you think they'd be worse than nothing (or worse than standard washers) between the FRP backing plate and the nuts? Or still worth using in that application?

@Tally Ho -- re: how the swivel hoist rings would bolt through the deck, my impression from some of the diagrams/CAD models was that the fastening bolt could be swapped out for a longer one (on the smaller models). On the larger models, the threaded portion looks like it would be long enough to go through the deck and backing plate without modification.

 

[jssailem]

@cristoslc One of our members is has contributed many articles about boat upkeep. MaineSail is the moderator with year of experience and solid help. He has an article about bedding everything on your deck. Here is the link. Rebedding Deck Hardware With Bed-It Butyl Tape - Marine How To
Go down to step 7 where he talks about backing plates. He shows what can happen if inadequate backing plates are used on a stanchion. The fender washer will fold and become useless. The standard washers will pull through the deck. Doubling up on thick fender washers can help. If your going to be putting strain on the fitting a proper backing plate is your safest approach.

Practical Sailor, to which Thinwater is a contributor has a god article about backing plates and washers. They do a lot of testing. Worth reading.

I have used Fiberglass boards and 1/4" aluminum plates when installing backing plates for say your primary winch or your windlass. Also a good solution for your cleats.

 

[cristoslc]

@jssailem thanks, I'm familiar with the articles you linked -- in fact, ordered my butyl tape from Maine Sail in prep for bolting the padeyes after reading that one. I also reviewed the Practical Sailor article and chose fiberglass backing plates based on their conclusions (specifically, FIBERGLASS SHEETS & PLATES). What I'd like to get a better handle on is whether I need a washer stack or a full-on metal plate behind the fiberglass backing plate. Any suggestions in that regard?

Initially, I'm only installing the cockpit jacklines to see how the whole setup performs, before deciding on a backing plate material for the (higher risk) midship and foredeck. However, I also expect there to be a lot less stress on the cockpit jacklines, as their primary purpose is to restrain our 2 year old's exuberance (though I'm choosing equipment with a 250-lb adult in mind) during coastal daysails.

 

[jssailem]

Cris, for my padeye on the bow used for jack lines, I chose the stainless steel backing plates manufactured by Wichard. You could use fiberglass or even aluminum. All are decent choices.
In used 1/4" aluminum plate to secure my primary winches.
Not it is not just the 250lb adult, it is that weight falling through the air and coming to an abrupt stop when the tether catches the falling body.

John Harries, author

Offers this info regarding jacklines. I have found his information helpful in preparing my boat for the water.
An Efficient Foredeck Centreline Jackline - Attainable Adventure ...

 

[heritage]

I would think a padeye on each side of the cockpit would be better than having a line running the length of the cockpit. The H27 cockpit is fairly short and you could attach the harness to either side depending on the tack. It would be much easier to access the area for backing plates from inside the starboard lazzarette and the port side quarter birth than underneath the cockpit floor.

BTW, I like your companionway doors and hatch. Is that a sheet of plexiglass for the panel below the doors? Any trouble stepping over it to enter the salon?

 

[cristoslc]

@jssailem I appreciate the warning, as I'm sure you've encountered others who were not building sufficient strength into their safety systems. To clarify: I am designing the system for a breaking strength around 4,500-5,000 lbs, being well aware that acceleration of a falling body, shock loading, and lateral stresses all multiply the forces involved. Many components, such as the wichard padeyes, have breaking strengths around 10,000 lbs. If I were just doing this for toddler wrangling, I would probably scale things back by a power of ten

I have also read Harries' set of posts on the topic and was originally planning a similar centerline jackline for our foredeck. However, because the H27's foredeck is so small (a bit over 3' of beam at the midpoint, with a usable length of roughly 7 feet), I think I may need to come up with a system that uses both tether legs on the foredeck to avoid an MOB, instead. Since we'll effectively always be sailing singlehanded (the person watching the toddler is not really available as a deckhand), the foredeck is actually the area I'm most concerned about. In particular, the things that seem riskiest are activities like unjamming the jib furler or dealing with ground tackle during unexpected heavy weather.

@heritage Good idea about using a single padeye on either side. You are correct that the cockpit is quite short, and I'll also be doing an amsteel loop around the base of the pedestal for the helmsman, which should provide enough reach for all areas while minimizing tripping hazards. I was thinking that jacklines would make it easier for more than one child to move around while tethered, but a few soft shackles through the padeyes might do the trick just as well, if not better. I'll have to test the reach and make sure you can still lock a tether from the companionway if I do that.

The starboard lazarette and port berth were my first thought for mounting, but would not align the load very well with the padeyes the way I planned to run the jacklines. That math definitely changes if I skip the jacklines entirely and just use hardpoints. For what it's worth, access for the backing plates around the companionway and through the aft lazarette isn't too bad, but I could definitely fit bigger backing plates on the vertical surfaces you suggested. Now that I look at it from that perspective, it might also be feasible to run a jackline just on the port and starboard benches, while still aligning probable loads in the right orientation for the padeyes.

Re: doors & hatch -- thanks! I can't take credit but it is something we like as well. It was some custom work added 2 previous owners ago. That is indeed plexiglass below the doors, beveled on the sides to encourage drainage towards the cockpit. The plexi is a little higher than I would like for easy movement, but that's partly because the same owner repowered (with a 2YM15) and the new engine box juts farther out into the salon, pushing the companionway steps forward. It's a lot easier to step over the plexi when the sliding hatch is open than when it's fully closed. Of course, we have yet to try any of this underway. Happy to provide you with some more detailed photos if you want, just let me know.

 

[thinwater]

...Had been planning on cutting backing plates out of some structural FRP, but good to know about fender washers distorting into cones Thanks for the tip, @thinwater . Do you think they'd be worse than nothing (or worse than standard washers) between the FRP backing plate and the nuts? Or still worth using in that application?...

There is a lot of misunderstanding on this topic.

• Fender washers are for use mounting fenders on vehicles. They are for spreading force to other thin, weak materials. They are useless for spreading real load and are not recommended by engineers for spreading high loads. You can bend them with pliers. Useless. They have no proper use on a boat and chandleries should not sell them. I have many bent ones, and I have even seen bent ones on new boats.
• Extra heavy fender washers work for spreading loads (yes, there is a spec). They are twice the thickness, 4 times the strength, and 8 times the stiffness (this latter is what matters) and are what you need. Bolt Depot and other industrial suppliers. They are often seen on quality new boats. They work as backing plates for most loads, particularly if the skins are sturdy or solid glass. You still want backing plate for the most severe and serious loads (cleats always, and jackline anchors, winches, and so forth in cored areas).
• You don't use a fender washer or extra heavy fender washer on a FRP (G10) or metal backing plate. You use an SAE bolting washer. They are thicker, stiffer, better transfer force to the plate, and are made for this. If you feel you need a fender washer, what you need is a thicker backing plate.

In summary, there is no actuall marine use for standard fender washers that I have think of off the top of my head. Always double thick or backing plate. Fender washers just bend. Always. If they don't bend, they were not actually spreading the load (were not actually loaded).

 

[cristoslc]

• You don't use a fender washer or extra heavy fender washer on a FRP (G10) or metal backing plate. You use an SAE bolting washer. They are thicker, stiffer, better transfer force to the plate, and are made for this. If you feel you need a fender washer, what you need is a thicker backing plate.

Thanks, that's very helpful and clears up what I was trying to understand.