Anchor Swivel

[ERTF]

Is this type of swivel with a stainless cotter pin trustworthy for long term anchoring?

 

[Mac2]

Short answer-no. Most people have gone to a Crosby shackle that has a working/break load equal to their chain. Most swivels, even the fancy stainless ones, are not rated. This should tell you something. It's not just the pull strength, but the side force that needs to be considered. The swivel shown has a built in failure point when it comes to side loading.

 

[TJM]

When you use the shackle, do NOT forget to wire tie the shackle pin to prevent it from loosening. This is called "seizing". Use Stainless Steel or Monel (nickle) wire only. The Shackle pin goes thru the slot in the shank of the anchor, just in case people did not know this.

 

[Hook and a screw]

I saw on a YouTube three links of anchor chain prior to the swivel reduces the concern of side loading on the swivel.

 

[Mac2]

When you use the shackle, do NOT forget to wire tie the shackle pin to prevent it from loosening. This is called "seizing". Use Stainless Steel or Monel (nickle) wire only. The Shackle pin goes thru the slot in the shank of the anchor, just in case people did not know this.

Not true. The Shackle pin goes through the rode/chain link. This allows the shackle to rotate on the shank, so the shackle is not side loaded. People will use two shackles if they can't get the shackle pin through the chain.

 

[psneeld]

I saw on a YouTube three links of anchor chain prior to the swivel reduces the concern of side loading on the swivel.

Heard the same and agree..just don't like having to make it more complicated.... but that's just me.

 

[psneeld]

Not true. The Shackle pin goes through the rode/chain link. This allows the shackle to rotate on the shank, so the shackle is not side loaded. People will use two shackles if they can't get the shackle pin through the chain.

Agree....

 

[tozz]

Not true. The Shackle pin goes through the rode/chain link. This allows the shackle to rotate on the shank, so the shackle is not side loaded. People will use two shackles if they can't get the shackle pin through the chain.

I have two shackles back to back reduce pin size to get through the chain but the recommendation I've seen is back to back should be crown to crown. So both shank and chain link have the pins through them. What's the best way to configure back to back shackles?

TIA
-tozz

 

[psneeld]

At some point, it really doesn't matter if you can easily pull the chain past 90 degrees several times after twisting the chain several times on both sides of the shank. You are just trying to see if the chain will unset the anchor by reversing the pull or bend the shank because the shackle is wedged against it.

No matter what the rig, it's possible to bend the shank in some situations...at least that's what the hundreds of bent anchors at the salvage place I worked at suggested to me and the reports from some of their owners.

 

[rgano]

I find the Mantus swivel to be quite acceptable here.

 

[Mac2]

I find the Mantus swivel to be quite acceptable here.View attachment 159013

Mantus would be my choice if I used a swivel-superior design! Do they give working load?

psneeld: great points along with real world experience. It’s rare when anchor companies talk about shank strength. It’s always pull strength. One of the reasons I went with Sarca Excel: they use Bisalloy 80 shanks and add material to the connection point.

tozz: the reason most go with Crosby shackles is that they are the strongest and you can usually just need one that has the same working load as the chain. If I needed two, I would attach pin to pin to avoid side loading the shackle attached to the anchor. They are not designed/rated to be pulled on from the side due to the shackle not being able to rotate at the shank. All that pressure would be transferred directly to the nut/threads.

 

[SteveK]

Thanks for reminder. I have swivel I want to remove as it has caused me concern of being the weak link.

 

[Mac2]

Thanks for reminder. I have swivel I want to remove as it has caused me concern of being the weak link.

My neighbor got his anchor right up to the boat and he watched his swivel fall apart in front of his eyes and he lost his anchor. That was my motivation to switch to crosby shackles.

 

[rgano]

Mantus would be my choice if I used a swivel-superior design! Do they give working load?

The three sizes of Mantus swivels come in 3000, 4340, and 7000 pound working loads. I have the 3000-pound model for my small boat and chain (1/4 inch G43), and the Mantus WLL is about 400 pounds more than the chain's WLL. IRT ultimate breaking strength, the chain is listed at 5200 pound while the Mantus is 15,000. You could hang my whole boat from a crane using the Mantus.

 

[SteveK]

Hang the boat is not the concern. Side pull is.

 

[rgano]

Hang the boat is not the concern. Side pull is.

For sure, and it is of no concern when it is connected to the anchor properly.

 

[Mac2]

The three sizes of Mantus swivels come in 3000, 4340, and 7000 pound working loads. I have the 3000-pound model for my small boat and chain (1/4 inch G43), and the Mantus WLL is about 400 pounds more than the chain's WLL. IRT ultimate breaking strength, the chain is listed at 5200 pound while the Mantus is 15,000. You could hang my whole boat from a crane using the Mantus.

I recall looking at the Mantus and I needed 9000 WLL. My boat is 90t and it likes to swing pretty drastic at anchor, so I didnt want to compromise on anything. Plus the crosby shackle is super ugly, so I know it works.

 

[Mac2]

Has anyone ever added a bigger link (mender ) to the end of their rode, so they could fit a bigger shackle pin? Is this adding the literal “weak link”?

 

[Dougcole]

I find the Mantus swivel to be quite acceptable here.View attachment 159013

Yeah, I love my Mantus. Only thing I worry about is the seizing wire, so I replace it every couple of years.

 

[O C Diver]

Never saw the need for a swivel, but then I don't anchor more than three days in the same spot.

Big fan of Crosby shackles. Replaced the primary rode shackle every 3 years (about 200 anchorings), cheap insurance.

What does Mantus do as far as warranty if it fails below WLL, give you a new one?

Ted

 

[rgano]

I recall looking at the Mantus and I needed 9000 WLL. My boat is 90t and it likes to swing pretty drastic at anchor, so I didnt want to compromise on anything. Plus the crosby shackle is super ugly, so I know it works.

Yeah, Mantus is not in your market at all.

 

[rgano]

What does Mantus do as far as warranty if it fails below WLL, give you a new one?

Ted

Yes they will for upto five years according to the warranty I just read.

 

[more]

Has anyone ever added a bigger link (mender ) to the end of their rode, so they could fit a bigger shackle pin? Is this adding the literal “weak link”?

i do ,possible order with some chain.
but I also use bigger shackle and grind 2 side of pin 1-2 mm.
now I order new 12mm chain in this go 16 mm bolt shackle
chain have breaking point 9170 kg force 16 mm schakle breaking point 20 ton

for paranoid have this shackle

Force 7 Grade 70 Anchor Chain Shackle Link Connector

Force 7 Omega shackle-type anchor to chain connecting links, specially engineered to make the break load compatible with DAMS Grade 70 calibrated anchor chain

jimmygreen.com

 

[NWboater2]

Wow holy thread drift.
OP — No hell no do not put that between your boat and its anchor. The swivels these guys are arguing about are nothing like that, strength, material, design, or price wise. Easy question with a clear answer. Use one or two good shackles. Not that.

 

[Diep]

I don't want to contribute to the thread drift, but wanted to offer a few bits of shackle information based on experience designing rigging for heavy or unique lifts:

Generally speaking, shackles are stacked bow-bow or bow-pin. They can be stacked pin-pin as long as the shackle ears do not interfere.

Crosby provides working load reductions for side loading of shackles based on the angle of loading. For 90 degree side load the reduction is 50%. I still avoid it if at all possible...

"Seizing" (a boat/yacht term it seems) is also called "mousing" (mow-zing) in other applications, so you might see both if you get into a deep dive.

Finally, seizing would be needed for a screw pin shackle. The other primary types are round pin and bolt. Round pin should not be side loaded and I wouldn't recommend one on a boat. Screw pins are really intended for temporary use where you tighten the pin each time you use it and thus the need to sieze the pin for long-term placement. A bolt-type is the best choice for a long-term application. It is also the ugliest...

 

[more]

or bolt type shackle (i use) also have problem and need secure with small bolt with couple nut.
in reality need checking,only when rust seize bolt is secure. in fish cage big shackle is checking daily and exchanging when is loose. i in morning setup big shakle 20-30 ton breaking over 100 tonn secure with sika silicone + extra bolt. last 5-6 year

 

[more]

also possible Self-Locking Bow Shackles but to expensive for mee wichard titanium
like this but need stronger

Wichard Self-Locking Bow Shackles

Wichard Self Locking Shackles, patented locking pin design prevents accidental loosening, forged AISI 316 stainless, exceptional corrosion resistance

jimmygreen.com

 

[Diep]

or bolt type shackle (i use) also have problem and need secure with small bolt with couple nut.
in reality need checking,only when rust seize bolt is secure. in fish cage big shackle is checking daily and exchanging when is loose. i in morning setup big shakle 20-30 ton breaking over 100 tonn secure with sika silicone + extra bolt. last 5-6 year

I agree, the bolt alone is not enough. Typically there is a nut and also a cotter pin as a back up, preventing the nut from coming off. Any solution needs periodic checking. Fortunately the anchor attachment is regularly in view, just need to make a habit of inspecting from time to time.

 

[dhays]

Rather than a swivel, I have considered getting a Flip Links from Ground Tackle Marine. No personal experience, but reports have been good.