mick
Well-Known Member
I am interested in the type of anchor connector that uses allen screws to hold the parts together. How reliable is this arrangement and can anything be done to ensure that the screws dont come undone?
Anchor connector
- Thread starter mick
- Start date
Richard10002
Well-Known Member
I have a Kong which was fitted in April. So far so good, and I've anchored for about 60 nights over the summer.
There are no forces on the allen key arrangement to undo it, unlike a shackle, so it shouldnt come undone - In fact, I'm a bit worried that mine might not come undone when I change the anchor.
If worried, you could always use some locking compound - Loktite and Wurth do them.
There are no forces on the allen key arrangement to undo it, unlike a shackle, so it shouldnt come undone - In fact, I'm a bit worried that mine might not come undone when I change the anchor.
If worried, you could always use some locking compound - Loktite and Wurth do them.
Krusty
Well-Known Member
I've used two types with Allen screws:
1 : KONG (probably the best) in which the screws hold the two shells together through tubes which share the load and shield the screws from any rotational forces. I coat the screws with white grease, then turn them up 'firm' but not too tight to remove if/when necessary. I have never had one move until intended.
2 : A solid double-fork type, with screwed pins which take all the load and any rotational forces. My feeling is that these need to be taken up very tight to be secure: I've never had one loosen, but I have had to cut one open separate anchor and chain.
1 : KONG (probably the best) in which the screws hold the two shells together through tubes which share the load and shield the screws from any rotational forces. I coat the screws with white grease, then turn them up 'firm' but not too tight to remove if/when necessary. I have never had one move until intended.
2 : A solid double-fork type, with screwed pins which take all the load and any rotational forces. My feeling is that these need to be taken up very tight to be secure: I've never had one loosen, but I have had to cut one open separate anchor and chain.
FAITIRA
Well-Known Member
I too have had to cut/destroy one to take it off.
deep denial
Well-Known Member
I use a simple stainless shackle with allen bolt. I was advised to peen the end of the Allen bolt which protrudes with a hammer to stop it coming undone, which i have done. Very reassuring, and of course also anti-theft. It is simply accepted that you have to grind the shackle off to remove. That will cost about £5 to replace - but how often do you need to disconnect the anchor?
mithril
Well-Known Member
I like Kevin Mac's idea and I use a bow shackle also peened over.
The kong types don't have the full swivel arrangment that tides need and so a bending (potentially breaking) load can be applied to the kong.
The kong types don't have the full swivel arrangment that tides need and so a bending (potentially breaking) load can be applied to the kong.
captainslarty
N/A
B & J, you need to purchase "Infinite Menus".................................... /forums/images/graemlins/wink.gif
vyv_cox
Well-Known Member
There are two types that are held together with Allen screws. In one the screws only hold the body together and are not load-bearing. Kong is one of these, it looks like this
In the other type the Allen screws are load bearing, they are threaded internally for locking and externally for attachment into the opposite fork. This type is known as a 'sex nut' (yes, really). When I tested a selection of these swivels for YM, the sex nut type consistently failed at lower loads. They look like this
This year I have tested a thread locking compound, specifically Loctite bought at my local car parts shop. We spent more than 150 nights at anchor, sometimes up to four nights without hauling the anchor. At the end of the season the screws in my anchor swivel and shackles were perfectly tight, as far as I could tell without deterioration of the Loctite.
In the other type the Allen screws are load bearing, they are threaded internally for locking and externally for attachment into the opposite fork. This type is known as a 'sex nut' (yes, really). When I tested a selection of these swivels for YM, the sex nut type consistently failed at lower loads. They look like this
This year I have tested a thread locking compound, specifically Loctite bought at my local car parts shop. We spent more than 150 nights at anchor, sometimes up to four nights without hauling the anchor. At the end of the season the screws in my anchor swivel and shackles were perfectly tight, as far as I could tell without deterioration of the Loctite.
PeterGibbs
Well-Known Member
Two years ago, whilst wandering around my local chandlery looking for pressies for my lovely, these connectors cought my eye as an elegant additon to my ground tackle. Then I read the label - the breaking strains on these things are discouraging, to say the least.
Went to a shipping chandlery and bought a sturdy "U" shackle with a screw in type pin, as used on trawlers, and the like. Now installed, happiness. And a lot cheaper.
PWG
Went to a shipping chandlery and bought a sturdy "U" shackle with a screw in type pin, as used on trawlers, and the like. Now installed, happiness. And a lot cheaper.
PWG
steve_cronin
N/A
At last \"King\" Kong is recognised....
I have been promoting these on these forums for the last, well, as long as the forum has existed almost. This is our second so we have been using them for nearly fifteen years on two boats. The current one is 5.5 years old and since the boat is Med based, used every day we are on board.
As others have said, it's strength and reliability are centred on the design not using the load bearing pins for holding the device together.
It can get damaged on rocky bottoms gouging out a deep scratch which can cause the swivel to bind so it needs regular, in our case seasonal is sufficient, inspection and the use of a dressing file every so often but that is all.
Steve cronin
I have been promoting these on these forums for the last, well, as long as the forum has existed almost. This is our second so we have been using them for nearly fifteen years on two boats. The current one is 5.5 years old and since the boat is Med based, used every day we are on board.
As others have said, it's strength and reliability are centred on the design not using the load bearing pins for holding the device together.
It can get damaged on rocky bottoms gouging out a deep scratch which can cause the swivel to bind so it needs regular, in our case seasonal is sufficient, inspection and the use of a dressing file every so often but that is all.
Steve cronin
mick
Well-Known Member
Thanks to everyone, especially Vyv for going to the trouble of posting photographs. The lower one is v. scary. Looks like Kong for me, or I may even keep my great big, but safe, s.s. shackle.
A
Anonymous
Guest
You'd be surprised just how unsafe some of those safe-looking big shackles can be. It all depends how they were made. Stainless can be a real problem with crevice corrosion and brittle fracture. Galvanised mild steel is probably safer as the corrosion happens more slowly and visibly and the steel is less brittle. When I buy shackles these days I go for Plastimo's stainless simply because they quote the safe working load. I get the chandler to order them in specially.
mick
Well-Known Member
[ QUOTE ]
When I buy shackles these days I go for Plastimo's stainless simply because they quote the safe working load. I get the chandler to order them in specially.
[/ QUOTE ]
Exactly what I do, for exactly the same reason.
When I buy shackles these days I go for Plastimo's stainless simply because they quote the safe working load. I get the chandler to order them in specially.
[/ QUOTE ]
Exactly what I do, for exactly the same reason.
vyv_cox
Well-Known Member
My personal choice is a Wichard shackle with a countersunk Allen screw fastening. These top-rated fittings are made from 17/4PH stainless, a heat treatable grade that is a level above 316. The shackle itself was one of the best performers in destructive testing, the countersunk fixing allows it to pass through the bow roller.
Galvanised shackles proved to be very variable in the tests. Even some of the ones rated and sold for lifting duties failed to reach the strength of the best stainless steel ones. To quote my article's conclusions: 'with most of the galvanised ones in the bottom half of the range and all of the stainless ones in the top half'. 10 mm shackles were tested but only two out of eleven galvanised ones exceeded the strength of 8 mm chain. Six stainless steel ones were tested, two were slightly below the 8 mm chain strength and the others exceeded it.
Galvanised shackles proved to be very variable in the tests. Even some of the ones rated and sold for lifting duties failed to reach the strength of the best stainless steel ones. To quote my article's conclusions: 'with most of the galvanised ones in the bottom half of the range and all of the stainless ones in the top half'. 10 mm shackles were tested but only two out of eleven galvanised ones exceeded the strength of 8 mm chain. Six stainless steel ones were tested, two were slightly below the 8 mm chain strength and the others exceeded it.
alan_d
Well-Known Member
I don't want to restart the "weakest link" debate, but a shackle slightly less strong than 8mm chain sounds good to me.
In extremis I would expect my deck gear to give way first, but if not I would prefer to lose only the anchor (allowing me to shackle another one on) rather than losing anchor and an unknown length of chain.
In extremis I would expect my deck gear to give way first, but if not I would prefer to lose only the anchor (allowing me to shackle another one on) rather than losing anchor and an unknown length of chain.
Richard10002
Well-Known Member
Kong suggest that their connector is the weakest link in the whole "chain", so that the chain and deck gear are preserved.
steve_cronin
N/A
Right on.
having changed my main halyard shackle for a Wichard last season (In Mast) and seeing how eaily it came apart when removing the sail & halyard for the winter, I've decided to replace all the running rigging shackles for next season. Some of my OE mainsheet shackle pins are already bent out of shape and some of the halyard turners are virtually un-screwable.
Steve cronin
having changed my main halyard shackle for a Wichard last season (In Mast) and seeing how eaily it came apart when removing the sail & halyard for the winter, I've decided to replace all the running rigging shackles for next season. Some of my OE mainsheet shackle pins are already bent out of shape and some of the halyard turners are virtually un-screwable.
Steve cronin
Stoaty
Well-Known Member
Re: Right on.
The trick with anchor connectors is not to connect them straight to the anchor. Put a couple of shackles or a short length of chain between the connector and the anchor. That way you eliminate the damaging sideways forces by always having a straight pull on the connector. Also you have no concerns about the connector seizing up as you only have to tighten it up the once, after that you only have to deal with the shackles or chain.
The trick with anchor connectors is not to connect them straight to the anchor. Put a couple of shackles or a short length of chain between the connector and the anchor. That way you eliminate the damaging sideways forces by always having a straight pull on the connector. Also you have no concerns about the connector seizing up as you only have to tighten it up the once, after that you only have to deal with the shackles or chain.
A
Anonymous
Guest
Re: Anchor connectors
[ QUOTE ]
The trick with anchor connectors is not to connect them straight to the anchor. .........Put a couple of shackles or a short length of chain between the connector and the anchor.
[/ QUOTE ]So why buy a connector at all?
[ QUOTE ]
The trick with anchor connectors is not to connect them straight to the anchor. .........Put a couple of shackles or a short length of chain between the connector and the anchor.
[/ QUOTE ]So why buy a connector at all?
GMac
Well-Known Member
[ QUOTE ]
[ QUOTE ]
When I buy shackles these days I go for Plastimo's stainless simply because they quote the safe working load. I get the chandler to order them in specially.
[/ QUOTE ]
Exactly what I do, for exactly the same reason.
[/ QUOTE ]
Quoted Break Load 10800kg
Quoted proof Load 7200kg
Quoted SWL 3600kg
Actual load applied to this point 4000kg.
All 3 people who know their stuff and were watching were not willing to bet it would go to 4500kg.
Conclusions -
1 - The loads quoted on this swivel were just so wrong.
2 - Even though it implied it had been Proof loaded, obviously they are not.
3 - In many cases the quoted loads, sometime all the loads, are just made up.
[ QUOTE ]
When I buy shackles these days I go for Plastimo's stainless simply because they quote the safe working load. I get the chandler to order them in specially.
[/ QUOTE ]
Exactly what I do, for exactly the same reason.
[/ QUOTE ]
Quoted Break Load 10800kg
Quoted proof Load 7200kg
Quoted SWL 3600kg
Actual load applied to this point 4000kg.
All 3 people who know their stuff and were watching were not willing to bet it would go to 4500kg.
Conclusions -
1 - The loads quoted on this swivel were just so wrong.
2 - Even though it implied it had been Proof loaded, obviously they are not.
3 - In many cases the quoted loads, sometime all the loads, are just made up.
