Kukri
Well-known member
You also need to consider the directions of pull in the other plain to reduce the bending on the chain plate.
I think that will be across the stern, rather than away from it, unless you lose a bridle leg to chafe.
You also need to consider the directions of pull in the other plain to reduce the bending on the chain plate.
I'd rather like to see that, but would probably require to be approved for membership first. And before that, I'd need to get out ocean-sailing again....
I just dragged my bridle out to have a look. Open thimbles with sharp cutty edges. Looks like I'll be replacing them.Good reading.
I'd bet folding money that the thimble cut the eye, rather than the splice pulling out, because I have seen that on JSD bridles.
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Well, yeah, there might be some overthinking going on. But I for one appreciate the time and brainpower that people like Neeves and Thinwater put into this and other subjects. I learn loads, some of which I put into action (I definitely will sort out the shackle and thimble weakness in my system), some of which I'd like to but can't or won't (today I checked the grp layup at my drogue chainplates -8mm hull layup thickening to 12mm before the transom turn, plus 2mm-ish of extra biaxial and some epoxy thickened with silica to bed a 50mm wide x 3mm thick backing plate onto, with four 10mm bolts. Should be wider and a bit thicker) and some of which I appreciate the theory but don't see the actual problem. The latter category will be the risk of the 8mm stainless strap bending or being pulled out if I get hit beam on by a wave that is big enough to do that sort of damage. My JSD either failed to keep my arse into the waves because it broke already or I've encountered a monster rogue wave. Either way, I'm in such a world of trouble that the JSD is way down the list of things to deal with.What strikes me the most about many of these discussions is a distinct lack of a sense of reality.
JSD states that the common loads on gear from his drogue are 10% of the ultimate maximum load while encountering a "survival" wave. The average storm rarely lasts more than five days; less than three of which will likely ever be under survival conditions. I doubt very much that we need to be concerned about stress fatigue.
The concern whether the OP's chainplates might bend under extreme loading, is about as relevant as worrying about whether you might be able to deflate the life raft and restore it to it's container after having had to use it after a sinking.
I just dragged my bridle out to have a look. Open thimbles with sharp cutty edges. Looks like I'll be replacing them.
What's people's thoughts about chainplate to bridle attachment? 16mm octoplait in my case. Shackle, closed thimble and splice? Spliced eye and cowhitch to a shackle? Any other options?
I just dragged my bridle out to have a look. Open thimbles with sharp cutty edges. Looks like I'll be replacing them.
Closed thimbles can be hard to come by....
I think that will be across the stern, rather than away from it, unless you lose a bridle leg to chafe.
The two legs of the bridle are of equal and fixed lengths, because you want the pull of the series drogue to pull the stern back into line with the seas if the boat is knocked askew by a sea, so you want all the pull of the drogue to come on the far corner of the transom.
These sort of screw together LFRs to make the chainplate hole smooth enough to attach the bridle to directly? I didn't even know they existed ?To introduce an idea.
I'd drop the shackle and the thimble.
I'd over size the hole through which I'd attach the bridle and insert a 2 part threaded LFR (or thimble), made from stainless steel. I don't know how big (internal diameter) the thimble needs to be. In fact it will vary (of course) as the JSD will also vary with size of yacht. So its the proportions I'm not sure of. I'd attach dyneema through the LFR, tape or rope - again not sure which. I'd then attach bridle arm to the short strop that is through the LFR. If you use tape it could be a sewn loop.
The short strop proposed can be monitored for chafe but chafe should be minimal because the LFR is highly polished.. The bridle should not suffer from chafe - its a dyneema to dyneema joint.
Don't give me the excuse you cannot get the LFRs - I am using them on my anchor bridle plate. The LFRs can be any size, the 2 unknowns are the internal diameter and how long they need to be. Aluminium 2 part LFRs can be bought off the shelf but mine were specially made to suit the size of the hole in the plate itself.
I run my snubbers through the 2 part thread LFRs (316) and the bridle plate - 2205 duplex. I did do this in 7075 aluminium alloy and a 6xxx for the LFRs but went off the idea - mainly because the anodising on the LFTs wears and I was not sure of longevity in an anchoring environment. My stainless LFRs are a bit long and I'm using Sikaflex to pack out, on a bridle plate (chain hook in mono speak). The Sika is standing up well - but I could make the length of the LFRs shorter so they screw tight. I'm using my bridle plate with climbing rope, kermantle. In fact I'm typing this whilst using the plate at anchor.
If you want to see my bridle plate send me an email address and I send a pdf. I don't know how to post a pdf here
Jonathan