Cotter pins to secure clevis pins underwater are not to be used. Somebody screwed up by using those swivels. IMHO.
What Anchor Shackle to get? Galvanized anchor shackle with G4 chain and stainless swivel
- Thread starter skunther
- Start date
IMO any underwater connection device, be it a shackle or a swivel, needs to be a type with screw pins with two loops of safety wire. The type of swivel with the cotter pin is not intended for underwater usage where corrosion can destroy the cotter pin. I did not mean to imply that no swivel should be used. Just that a proper part for the application.
Here is a picture of a swivel with screw pins that can be safety wired-
On a side note, I once had a mooring that was assembled with a Chinese shackle. On an inspection I found that the pin was severely eroded along with the threaded portion of the shackle body. The erosion was so bad the pin literally rattled in the shackle. The ONLY thing keeping the pin in the shackle was the two loops of safety wire. I wish I had a picture of this to post.
Needless to say, future shackles were American made, drop forged Crosby shackles.
Here is a picture of a swivel with screw pins that can be safety wired-
On a side note, I once had a mooring that was assembled with a Chinese shackle. On an inspection I found that the pin was severely eroded along with the threaded portion of the shackle body. The erosion was so bad the pin literally rattled in the shackle. The ONLY thing keeping the pin in the shackle was the two loops of safety wire. I wish I had a picture of this to post.
Needless to say, future shackles were American made, drop forged Crosby shackles.
Thanks, Rich. Agree with your thinking. Chinese made products unwelcome on our boat. Quality control suspect and inconsistent specs.
Very informative, I like where the thread went. Thanks for the input. For now I’m going to keep the swivel but add links on the anchor side to eliminate side loading the swivel. Shackle between chain and anchor is American galvanized, screwed pin will be seized with monel. When the time comes I will find a Mantus swivel. SS to galvanized will corrode proximal chain links, as is now clear. I will cut off links as they corrode, which seems will happen at a slow enough pace to not worry about losing too much chain in the process.
Hot dipped galvanized? Important distinction with regard to corrosion resistance. I've seen products that claim galvanized, but are not hot dipped. On our boat I secure the pin with SS lock wire and inspect it regularly while cruising, FWIW.
I know we like to disregard Chinese manufacturing, but if the quality is there, I've found they have greatly improved products in recent years. I've been dealing with Chinese manufactured product that really works. I think this sentiment may need to be revisited.
dj
I read this post a few times and I’m not understanding where the justification for a return came up. Why did you want to return something you used extensively, and it didn’t fail?
@Captain Larry-DH If I'm not mistaken, the 5/16" shackle returned was a mistaken purchase, not the 3/8's long used shackle.
I also had to read that post several times to come to that conclusion. Also helps I've been dealing with Defender and returns and know their policy well at this point...
dj
The best shackle to get for G4 galvanized chain is a Crosby 209A - one size larger than the chain. The 209A is a Hi-test alloy that is considerably stronger than a regular galvanized shackle. Crosby G-209A Series Forged Alloy Anchor Shackle
Before getting a swivel, try the shackle. For many anchor designs using chain and a windlass, the anchor will untwist itself as it comes off the bottom without a swivel. Sometime the shackle actually does a better job than the swivel orienting the anchor at the roller.
Before getting a swivel, try the shackle. For many anchor designs using chain and a windlass, the anchor will untwist itself as it comes off the bottom without a swivel. Sometime the shackle actually does a better job than the swivel orienting the anchor at the roller.
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