Unique Bruce/Claw

I love Walt's bright anchor. I guess it's stainless steel. High carbon steels are usually stronger than stainless so I'm wondering if the pretty SS anchors suffer from lack of strength.

They cost so much money I'd prolly use a trip line if I had one. But speaking of the trip line .... on a Claw many boaters like charter fishing boats in Alaska secure the rode to the trip line attach point, run it along the upper shank to the normal rode attach point and simply use a weak link like wire or small dia line to attach to the end of the shank. So the anchor acts normally until it gets stuck and then the weak link breaks and the rode pulls the Claw out backwards. Fine for some applications (like fishing for an hour) but not for overnight anchoring.

It looks to me like the trip line attach hole is in a good spot.

Fly, those Lewmar's are very popular in SE Alaska. And it looks to me like your Lewmar's shank is considerably longer than Walt's Force. That in itself could be a significant difference in the performance of one Claw over another.

Eric, you're not the first one to tell me that! I have it on good authority that my shank is, in fact, longer than Walt's. I've never done a side-by-side comparison, though. Maybe Walt can add to the discussion.



But not to worry, Walt. Momma always told me it's the angle of the dangle that counts...and I think Eric's previous analysis of catenary proved that.

Next time I'm at the boat, I can measure the length of my claw.

Truth be told, my claw is 15kg and Walt's weighs 5kg more. It might just be a matter of perspective.

manyboats said:

I love Walt's bright anchor. I guess it's stainless steel. High carbon steels are usually stronger than stainless so I'm wondering if the pretty SS anchors suffer from lack of strength.

Click to expand...

It's not so much an issue of strength as it is ductility, the ability of a material to withstand elastic deformation without breaking. Elastic deformation is when a material gets to the point of bending or stretching when the material will no longer go back to its original shape, it has been permanently deformed. Elastic deformation is the range of bending or stretching where the material will return to its original shape.

SS does not like deformation as much as other carbon steels. Something tells me Walt's anchor will serve him well. Putting obvious cost issues aside though, you'll be less likely to find SS used in work boat anchors due to ductility issues.

I'd say this one's been "permanently deformed".

FlyWright said:

I have it on good authority that my shank is, in fact, longer than Walt's.

Click to expand...

I don't know how you could possibly know that from looking at photos.
I ask my wife if my shank was long enough and she just laughed & said she had nothing to compare it to. I also have an old 15kg Bruce in the lazarette whos shank is considerably shorter than my SS. Remember, it's just not the length of the shank, it's the penetration that's important.

manyboats said:

The landing craft's kedging Danforth has weird palms. I've seen it before and don't understand it at all. Most are shaped so as to make the aft end of the anchor rise up to orient the flukes to dig in. But this one (and I've seen others) look like to they are designed to dig in and not particularly to cause the aft end of the anchor to rise at all.
Anybody have any ideas?

Click to expand...

I think the palms are designed to dig into or hook on the seabed as the anchor drags, which will produce a moment or torque around the pivot point and point the flukes into the seabed.

manyboats said:

I'd say this one's been "permanently deformed".

Click to expand...

No, I believe that that is the new BRUSAROC asymmetric anchor.

Half of it was forged in North America and the other half somewhere Down Under. (Rumors of Chinese metalurgy being involved are false).

It was designed by a joint committee, half of whose members came from each region.

Extensive and exhaustive recent tests conclusively show that exactly half the time it sets better than any other anchor heretofore known to man. The other half of the time it just hops across the seafloor making a weird bleating, baahing sound.

I found this spec sheet for the Lewmar Claws. Note that the SS specs vary in all areas from the galvanized specs for same weight anchors. The galv anchors are longer and taller while the SS models are wider. Also, the SS shanks taper toward the tip but the galv shanks are a uniform thickness.

FlyWright said:

I found this spec sheet for the Lewmar Claws. Note that the SS specs vary in all areas from the galvanized specs for same size anchors. The galv anchors are longer and taller while the SS models are wider. Also, the SS shanks taper toward the tip but the galv shanks are a uniform thickness.

Click to expand...

Stop with the straight lines Al and Walt. I'm having a hard time restraining myself.

portager,
I agree w you. A Navy anchor and a Dreadnought have a "palm" that is shaped like a "pad" and causes drag that tends to rotate the flukes into the bottom. This way the fluke tips weigh more than they weigh ...... that is the downward force on the fluke tips in action is more than their own weight.
I noticed the only time I used my Dreadnought that it set so quickly the whole setting process seemed to not even exist. I started to back and instantly the anchor line was very tight.
I saw a Danforth that had the palms reversed so they would dig in rather than slide up and over the bottom. It seemed to be manufactured that way. It looked like the palms would act like a hook and of course the "reaction" from hooking no doubt turned the flukes down toward the bottom.

So it seems there are 2 ways to help the fluke get started penetrating the bottom on anchors of this type.

The pic is for those unfamiliar w the Dreadnought.

Another curious feature of the Claw is the twisted outboard flukes.

Looks to me as the designer did the twist to increase holding power and/or orient the "setting fluke" in such away that it would penetrate the bottom more easily for better setting.

Does the twist do one and not the other?

I've seen only one Claw that didn't have the twist and it was a welded home made Claw. See pic. The owner claimed it worked well but the PO was the home builder.

Hi Eric
Here are some photos for you. Genuine Bruce anchors, big one a 20kg and little one a 2kg for the dinghy..........

Mike your bottom photo shows more twist in the OB flukes. Post # 5, 16, 18, 20, 27, 29 and 36 don't show much twist in the OB flukes. The Claws in post # 25 and 26 show twist in the far side flukes only.

Mike ... in between your 1st and 2nd pic is the place where the twist brings the OB flukes into a position that is more at right angles to the advancing flukes and presents a greater resistance.

While setting the twisted OB flukes present a tip that is more at right angles to the direction of pull making the tips more chisel like do dig better (I think) but perhaps not to penetrate as well. I just don't know. But the anchor has a reputation for setting well so I'm guessing/assuming that the twist is there to help create more holding power.

I'm surprised no one has offered a Claw that departs noticeably in design from the Bruce. My original goal for this thread was to see if the best Claw could be identified. But perhaps there isn't enough difference to boil up.

I think everybody agrees that your type of bottom will dictate the anchor. For us in So Cal we have sandy bottoms and kelp. I see mostly Danforth and CQR here and the Bruce on a few boats but we get Santa Ana winds that can pop up quickly and blow you ashore so the Bruce in sand with 60 kt winds is a bad scenario.

Cap, The Santa Anna Wind is an offshore wind.
So I see no problem w that.

I think the best sand anchor is probably a Danforth.

And yes the bottom is the most important element in anchoring.

It is off shore to the mainland but when you are at Catalina it is blowing you directly on shore. As you know, there is always a windward side and a lee side. Our coast is the windward side. We get surf and seas breaking our shores so we rarely anchor off our coast.

I would love to have it like your area here. We go immediately to unprotected water when we leave our harbors.

Does anybody have any experience w the Sea Dog Line Claw anchors?

If you are not sure use a bigger anchor.
here is a couple of photos of some anchors I found lying around the yard today.
Cheers
Benn

manyboats said:

Does anybody have any experience w the Sea Dog Line Claw anchors?

Click to expand...

We a have 30 Kg Sea Hook by Sea Dog (plow). It sits next to the 33Kg Rocna. We used the Sea Dog as our primary for 5 years but it doesn't set as fast or as well as the Rocna.

Plow. As in CQR, Delta or ??

No big flaws just fair performance. That's how I read your post.

At least compared to a Rocna. What I was more interested in was how the Dog compared w other Claws. It looks like (in photos and in the galvanized flesh) to have a shorter than usual shank and wondered how that would effect performance.

The shank when pulled on rotates the anchor fluke/s vertical enough to allow easy extraction. If one cut a foot off the Claw shank (or even a bit more) and managed to get it set)) you'd probably have a real hard time getting it up (NPI). And if you didn't have real strong ground tackle and winch maybe you woudn't get it up at all.

And if you doubled the length of the shank the anchor may come up easily unless you had 10-1 scope.

The above should apply to all or at least most all other anchors.



Ben,
About the monster anchor. Do you think they are self righting? It looks as like if they were up-side-down they would stay that way. But w that very heavy fluke I would think it would be unlikely to wind up on their side. This is an interesting design and similar to many others except for the two pronged flukes and the double shanks.
I see they are bolted together and it looks like when unbolted they would become a bunch of sheet metal and given their size that would be a nice feature. In a trawler size a storm anchor stowed below?


rochepoint,
Re your post #43 the 2nd pic down I think shows why the holding power of the Claw is limited. Looks like it/they would just glide through a mud bottom like three knives. Of course if you lowered the shank some (much like your 1st pic) the OB flukes (because of their twist) would come closer to right angles to the rode and resist movement much better. The center fluke is attached to the shank at an angle and pulls the anchor down and resists too. I believe it's beneficial that the two OB flukes compress the bottom between eachother with basically no place to go.

manyboats said:

Plow. As in CQR, Delta or ??

It looks like a knock-off Bruce. I should have called it a claw.

No big flaws just fair performance. That's how I read your post.

The Rocna sets quickly in all conditions we have anchored in.

At least compared to a Rocna. What I was more interested in was how the Dog compared w other Claws. It looks like (in photos and in the galvanized flesh) to have a shorter than usual shank and wondered how that would effect performance.

Click to expand...

Eric: We used a genuine CQR for 10 years and the only time we dragged was when we caught an abandoned net in AK. My fault for not adequately checking the set. The Sea Dog didn't always set easily or quickly in all bottom types where the Rocna does. If I had to rate the anchors we have used. Rocna #1, CQR #2 and the Sea Dog #3.

Eric,
Yeah , anchors like that are usually lowered into position and then set.
These units have been used on small drilling platforms etc.
Cheers
Benn

Cyclone said:

The Bruce was developed to secure oil and gas rigs in the North Sea. A tug would deploy anchors with weights of many tons, sometimes setting three per corner and one or two mid ships of the rig. Once dropped the tug would use its power to set. Once set they were never recovered.
Yes the Bruce is a fine anchor but should never be used in on a Stoney bottom. I have witnessed boats dragging with Bruce and when the anchor was recovered the throat was full of a rock.
My favourite all round anchor is a trusty Northill, and it like the dean forth was developed for anchoring aircraft. Bill

Click to expand...

Actually Bruce is still making anchors, just not for us.

Marty......................

Isn't "Bruce" a brand name?

My boat came with an unbranded claw anchor. It never let me down but it was slightly bent and a size smaller than the maximum for my pulpit so I replaced it with a larger Lewmar claw anchor.