Choosing the Right Anchor for Your Trawler

AllanY,That was a breath of fresh air. There's so much hype about these "next generation" anchors*it seems to good to be true. And we all know what that means. On what seemed to be the biggest and best anchor test about 5 next generation anchors tested with 20 times the holding power of most all the old standby anchors like CQR, Danforth and Bruce. TWENTY TIMES. How could these old anchors have kept the boats of the world off the beach and rocks if that were true? And at the bottom there was an advertisement by guru Peter Smith about his next gen anchor. What does that say about Practical Sailor Magazine? I've never seen a copy of PS mag but I'll bet there's full page adds for next gen anchors. I do think many of the comparisons are probably valid though. I was hoping on this thread more would tell of their experiences anchoring and build a basement of knowledge to get one through all the hype and old wives tales. Probably 25% of our members have the Bruce anchor and feel it needs replacement now and that may not be justified. Interesting how the Plough has driven or influenced most of the NG designs.
Thanks again for your post Allan.


Eric

I love all this anchor talk. I had no idea so many trawlermen were doing that much anchoring. It would seem with all this debate that a "best" anchor would "surface."
I have a 20kg SS Force on my bow and I have no idea how well it performs. It's purely for "looks." I use a Danforth on the bow and a Bruce for my stern when needed. (Which is almost never. )* The Force looks great..Doesn't it?

I found this interesting.
The CQR.
Legend has it that in 1933, Cambridge professor Geoffrey Taylor conceived the first plow anchor, the CQR ( the name being a faux acronyme for SECURE ). I always wondered what it stood for. Sort of like the band NXS. for in excess. anyway it was to outfit World War II hot air balloon missions.

SD

Peter

Often small ships up to about 150 ft carried a plough (CQR)

It depends on where they carried their anchor if on a bow roller then it was a plough and if through a hawse pipe then a dreadnaught or danforth type anchor

Whilst working around the islands we used ploughs in the main but it depended on the type of vessel with landing barges using dreadnaught or similar and these anchors were holding large vessels with no issues.

Allan

nomadwilly wrote:


Interesting how the Plough has driven or influenced most of the NG designs.

Click to expand...

The design of the three roll-bar anchors--- Rocna, Sarca, and Manson Supreme--- is the exact opposite of the plow design.* Where the plow is shaped to facilitate forward movement through the bottom (like a plow being pullled by a horse or*tractor, a concept that has never made sense to me from an anchoring point of view), the Rocna/Sarca/Manson are spade designs.* The*fluke, when buried, resists forward movement just like*a shovel blade.

There may be other NG anchors that got their inspiration from the plow anchors like the CQR, but the roll-bar anchors aren't among them.*

All anchors are "shaped to facilitate fwd movement through the bottom". How else are they to penetrate the bottom so they can resist movement mostly in the other direction and hold a boat in place. Anchors that don't penetrate don't anchor. The CQR has the outward and upward shaped fluke much like the Delta. Peter Smith, Manson and others learned from Spade that a concave surface seemed to be better for holding while CQR, Delta, Hydrobubble and SARCA perhaps tried to optimize for penetration. Both obviously are needed. The CQR was the original. It was unique. It was not a descendant of any other.*I don't even think at that time there any other single fluke anchors but ??? I would say the Spade is a closer relative to the Rocna than CQR but most all modern anchors descended from the CQR. The Rocna just traded the tip ballast for the roll bar and I'm not sure that was a 100% positive trade. The Spade and Delta have weak short scope performance too. I think the next "next generation" anchors will perhaps incorporate the advantages of the independent shank movement of the Danforth types w the Spade like fluke. I know it's kinda like having to admit you descended from Neanderthals but*that's fact too.


Eric

Marin, Eric made a good point there.* That is one area where Sarca diverges from the Manson and Rocna, in that the fluke is convex, rather than concave.* The reason is exactly the point re the way a plough works, by digging in and furrowing/burrowing down, then if its resistance to foward motion is overcome, it slices forwards under the surface still, and in a controlled manor, without dosturbing the surface very much until it takes up again, so there is no sudden lurch free, and it brings up a lot less bottom on retrieval.* By contrast, there is the potential for those like Spade, Rocna, Manson Supreme, filling up with bottom until they can hold no more then popping out, or gouging a huge trench behind them, depending on the nature of that bottom.* The Sarca inventor experimented with a concave fluke and in the end gave it away, because of that feature.* The real issue with the CQR/plough is the tendency to not dig in, and if it does not, the hinged shank lets it just bounce its way across the bottom.* Once they do set, they hold quite well.* Delta, Ultra, and the Sarca Excel solve this by variations on a clever design of the edge of the fluke, and doing away with that hinged shank.* My off-putting experience was all to often where we cruise having the 'bounce-over-the-bottom' happen, thank goodness noticed before dark and we retired for the night.
Note convex fluke in pic below....

You two are missing the point. There is a difference between moving forward to penetrate the bottom and moving forward once the anchor is IN the bottom. The plow anchor (CQR etc) is still aligned to move forward through the bottom once it's set. Just like a farmer's plow. The only thing keeping it from acting like a farmer's plow and slicing smoothly forward through the bottom (and thus not holding the boat) is the fact there is a second blade welded or cast onto the other side opposing the the opposite blade. So the theory is that as the plow moves forward after setting, which it will, the two blades together force the blade deeper into the bottom to the point where the resistance against the blades is such that they won't move forward anymore.

The concave spade-configuration, on the other hand, is shaped like a shovel blade. So when it's set, it's entire shape resists forward movement though the bottom. If you stick a shovel into the dirt and then tie a rope on the handle at the top of the blade and then pull forward parallel to the ground, you're pulling against the whole flat of the blade which, with its concave shape, resists any movement forward and it won't move forward unless the dirt gives way in front of it.

The plow, on the other hand, is sitting there with its blades streamlined to move*in the forward direction. The only thing preventing it from simply "plowing" through the bottom is the downward force created by the curvature of the two opposing flukes. This works, obviously, and most of the time works quite well. But I believe it is still not as inherently resistive to forward movement through the bottom as a spade-shaped fluke.

This is a whole different deal than setting the anchor, where, yes, the shape obviously has to be designed to penetrate and dig in. But that's only half the story. The other half is how the blade or fluke shape behaves once it's in the bottom and is being pulled on. This is where I believe that anchors like the Rocna, Sarca, and Manson Supreme outperorm all the other designs.

-- Edited by Marin on Thursday 19th of August 2010 01:37:08 PM

Marin,

You've been reading too much PS.


Not one of your super hot roll bar anchors can even outperform a Fortress, an old Danforth design.


I understand what your'e saying and Iv'e heard it from PS. Fact is the roll bars PREVENT the anchors from burring completely. As soon as the roll bar goes under penetration stops.I don't know how the RB anchors perform as well as they do but they do very well. The Plow anchor is not designed to plow despite what PS says. It's designed to go down like a spade (as you say) and then (because of the geometry of the shank, rode and bottom it acts like a deadman to the boat and rode. All anchors do that. The Rocna, Spade and others have a concave fluke that gives them a 5% edge on holding power, perhaps a tad more but it's not as stable as the convex form. So your'e correct when you say,


"But I believe it is still not as inherently resistive to forward movement through the bottom as a spade-shaped fluke."


Your roll bar anchors are excellent in most situations but the're only fair in at least two
situations that are important and even your favorite claw anchor does better.


Eric

nomadwilly wrote:

Marin,


You've been reading too much PS.


Fact is the roll bars PREVENT the anchors from burring completely.

Click to expand...

Eric---

I have no idea what PS is.* And the roll bar does not prevent the anchor from burying completely.* I've seen footage, of above-water*tests*as well as underwater footage of Rocnas burying themselves so deep that in the case of the above water sets someone had to dig down with a shovel*to find the rollbar and then use that to horse the anchor up out of the bottom.

I daresay it won't do this in every kind of bottom and it won't do it at all unless it really gets hauled on, but neither will any other anchor.

Peter,I think what we're both trying to say is that the convex fluke is more stable * *.. kinda like a wing w lots of dihedral * *..Pigeons not Gulls. They said in the tests the SARCA lacked a bit of strength but made up for it in consistency and dependability. In another airplane analogy the interplane drag on the SARCA must be much less as the roll bar is skinnyer and larger in diameter.
Marin,
Well I'm glad you didn't think it was partially disguised BS. Very similar but no I was referring to you're guru Peter Smith. OK I take that back. All the pics I've seen of the Rocna being dragged on a beach looked like a mole was under there make'in like a rabbit. On our trip to Alaska on our Albin we had a small Bruce and it buried itself so deep it was hard to get out. Did that on several occasions.


Eric

Eric,* you said you wondered if I would post in the anchor thread, so here goes.*

My experience is mostly with Bruce anchors, mostly in WA, BC, and SE AK.* Some 700-750 nights at anchor so far.*

I've also used a Fortress, which is great for sand bottoms like Lake Powell.* It's my backup now, and a stern anchor in narrow canyons at Lake Powell.

In the PNW the Bruce has never dragged, except immediately after setting in soft mud (rare) and very kelpy bottoms.* When we test the set and it drags, we reset until it holds, and it has never dragged after a successful test.* For my 26' boat I have a 16.5lb Bruce, with 40 feet of 1/4' HT chain and 300" of 1/2" rope.

P.S.* I'm tied up at the transient moorage in Thorne Bay tonight.

-- Edited by RCook on Friday 27th of August 2010 08:07:38 PM

Richard,It was fun to meet you last night. Now I've met all our the members from Utah! Got a few members and states to go.
Another thought for cruising is Tongas Is. east of cape Fox. It's sort of an alt to Brundage Inlet. And if you need a bombproof anchorage go up the canal to Winter Inlet. I've always tried to make it to Port Simpson but haven't done it. When we go to Ketchikan we go to the yacht club in Thomas Basin use their shower and eat at the New York Cafe.
Picture is of the YC in Thomas Basin.

Hi Eric,* Sure was fun to visit!* Thanks for the cruising ideas.* I'll definitely come by to visit again in the future.

Anybody using a SUPERMAX anchor?

http://tinyurl.com/34dn2w9


R.

Ralph,Yes. I don't remember who but they really liked it. I found an anchor test that included the
SuperMax.


http://www.xyzanchor.com/pdf/PracticalSailor-April06.pdf


Sorry it's not a hyperlink.
This is the only test I've seen the SuperMax in so it may be considered a mud anchor.


Ralph,
I found the guy w the SUPERMAX anchor. It's wingspar. He has a big sundeck in Seattle.


-- Edited by nomadwilly on Friday 3rd of September 2010 01:15:33 PM

At the risk of stirring this topic up again I thought I would post the link to this article I came across as someone might be interested

http://www.mysailing.com.au/news/anchors-the-never-ending-story

Allan

Allan,
I have at last been getting to test my new anchor. The SARCA Excel.
Must admit so far really impressed with the holding power.
4 different anchorages so far.
Pelican Point , Kauri Creek, Garrys Anchorage, Kingfisher Bay and tonight the SW corner of Big Woody Is. and this is a bit rocky.
Ventured north past Moon Point today for a bit of whale watching and saw some great performances from Cows and calves.
weather change commin thru so back down here and into Susan River tomorrow for a couple of days until the westerly component of the wind dissipates.
Head up to Rooneys along the beach hopefully Monday.

Benn

AllanY wrote:

At the risk of stirring this topic up again I thought I would post the link to this article I came across as someone might be interested

http://www.mysailing.com.au/news/anchors-the-never-ending-story

Allan

Click to expand...

Interesting and well-balanced article Allan.* Confirms my feelings and experience re anchors pretty much.* I'm still sold on my Sarca as a quick-setting great all-rounder.* Has the article prompted you to consider relegating your present anchor to back-up duty by any chance?* Looks like Benn's pretty happy with his too.

*

I haven't yet as I am happy with the plough I have ATM but maybe one day.
I'll see what Benn says in six months time

Allan

I bet he'll still be lovin' it....