What happened to Bruce almighty?

[Andrew Troup]

Another interesting question, apart from the "dimensions and build quality" you mentioned, Kettlewell, is material spec.

Unless the knockoff material is as strong as the heat-treated, monolithic manganese-steel casting - which is a BIG ask when affordability is a problem, given the limited appeal of the Bruce concept* - it may not be possible to provide the frontal area slimness, particularly for the 'wings', which might be essential to reliable setting and more particularly resetting.


* by which I mean a focus on reliability in difficult bottoms, particularly but not exclusively kelp and rock, rather than high holding power in good bottoms...

[Andrew Troup]

A notion just occurred to me which I'd like to float:

Like many, I've been puzzling for many years over the increasing disparity between the actual performance of Bruce and CQR anchors vs the test results.

Particularly, testers describing behaviours by both anchors which were not hitherto evident in the field. (CQRs are said to weave horizontally, Bruces to bob vertically, both to the point where they cannot hold a moderate load in good holding)

Up til now I've assumed that it was something to do with the way the loads were applied or the bottom selected.

But this thought just occurred to me: I wonder if there's an elephant in the room, namely the radical downsizing of chain in recent years, undertaken on purely theoretical grounds, explained in terms of 2D statics, promoted primarily by new gen anchor designers (which grounds - as a separate topic - I still find unconvincing)

what if 'old school' anchors do not work well with 'new school' chain weights?

- either in regards to how they set, or how they hold once set, or both.

(and having regards to subtle, 3D dynamics as well as simple 2D statics)

? ? ? ? ? ? ? ?

[noelex 77]

Originally Posted by Andrew Troup

Up til now I've assumed that it was something to do with the way the loads were applied or the bottom selected.

Anchor tests are just a minor piece in the jigsaw of selecting the best anchor.

Modern anchor tests have (mostly) selected firm substrates for their testing. This is no coincidence, it is the best sort of bottom structure to differentiate anchor designs.

It does, however, have real world application. New cruising sailors are often shocked that their trusted CQR design that worked so reliably, for so many years, in their home waters, fails miserably when confronted with some hard sand, or thick weed.

[Andrew Troup]

Noelex

I'm not talking about problem bottoms (where an "old schooler" would probably pull out a heavy pick): I'm talking about a large number of tests which have suggested that the genuine CQR and Bruce will each malfunction in specific ways at relatively low loads in good holding.

This is contrary to real world findings, and I'm wondering if one major "missing term" in the polynomial is chain weight.

[noelex 77]

Originally Posted by Andrew Troup

Noelex

I'm not talking about problem bottoms (where an "old schooler" would probably pull out a heavy pick): I'm talking about tests which suggest a CQR or Bruce will drag at relatively low loads in good holding.

This is contrary to real world findings, and I'm wondering if one major "missing term" in the polynomial is chain weight.

Chain weight is hotly debated topic. My belief is that the modern view that the benefit of chain weight disappears in stronger winds, is correct, but I have met some experience cruising sailors with alternative views.

Part of the problem is that chain weight plays a signifficant role at lower windspeeds. A poorly set anchor will drag at 25k with light chain but perhaps 35k with heavy chain. The extra holding power at these lower, but common, windspeeds promotes the belief of the benefits. People assume, incorrectly in my view, that this extends to a well set anchor in stronger winds.

However once the windspeed is above 40k I think the benefits of heavier chain are lost. Any well set anchor should hold, even with little chain, at these windspeeds. The difficulty is too extend the reliable holding up to storm force winds.

In hard substrates CQR anchors will not set. There are all sort of tricks, such as leaving the anchor to settle, setting with a short 3:1, or long 10:1 scope, doing a naked war dance on the foredeck ( OK I made that one up ) but at best in the wrong substrate this will generally achieve a marginal set (occasionally you will get lucky).

A poorly set anchor will start dragging around 30k wind, which is consistent with the anchor tests.

People that have anchored for many years in soft, medium, or even medium hard, substrates find these results very difficult to believe. They often blame the results on a lack of anchoring skill, lack of scope, poor technique, inadequate chain, bias etc.

In fact, anything that explains how their reliable CQR could be performing so poorly.

My belief based on many years diving is that the CQR rarely sets in Hard substrates. I have reached the stage where in hard sand I amazed to see a CQR more than very marginally set. Most of the time the owner is unaware. An anchor like this will not drag until the mean wind is around 30k

The anchor tests do reflect real life in hard sand.

[Kettlewell]

Is hard sand the typical bottom in the Med, or only in certain areas?

[noelex 77]

It's only certain areas, but they are often the areas that are nice to cruise. Hard sand is associated with clear water.
New generation anchor anchors are opening up areas that have a traditional reputation for poor holding.
Some of these are rock, or rock with fine layer of sand where new generation anchors offer little extra benefit, and a safe overnight anchorage is not advisable, but many are just hard sand where old generation anchors will not set, but modern anchors manage fine.

Some of these anchorages are popular day anchorage spots, because they are so beautiful, but all the boats disappear late in day in search of better safety overnight.
An oversize modern anchor can allow you to safely stay in these spots. It means you get to enjoy the sunset, morning coffee, and skinny dip without another boat in sight.

[Cheechako]

Originally Posted by Andrew Troup

A notion just occurred to me which I'd like to float:

Like many, I've been puzzling for many years over the increasing disparity between the actual performance of Bruce and CQR anchors vs the test results.

Particularly, testers describing behaviours by both anchors which were not hitherto evident in the field. (CQRs are said to weave horizontally, Bruces to bob vertically, both to the point where they cannot hold a moderate load in good holding)

Up til now I've assumed that it was something to do with the way the loads were applied or the bottom selected.

But this thought just occurred to me: I wonder if there's an elephant in the room, namely the radical downsizing of chain in recent years, undertaken on purely theoretical grounds, explained in terms of 2D statics, promoted primarily by new gen anchor designers (which grounds - as a separate topic - I still find unconvincing)

what if 'old school' anchors do not work well with 'new school' chain weights?

- either in regards to how they set, or how they hold once set, or both.

(and having regards to subtle, 3D dynamics as well as simple 2D statics)

? ? ? ? ? ? ? ?

Alot of things in play I suppose, but the CQR has that heavy shank and knuckle, my thinking says, that more often then not the CQR lays on it's side due to this imbalance and tries to drag one fluke in first. In a perfect situation and rode angle it then may turn up more as it digs in, but more often then not just sets mostly one fluke.
The similar looking Delta lands sitting upright and digs in most every time because the ballast is in the bottom of the anchor between the flukes.
However, once tipped over from a windshift, the tension on the rode keeps the Delta from standing back up and setting. The CQR seems to do a little better in reversing wind.
The Bruce simply doesnt present enough surface area against the pull. Just look at a pic of it and think it through.... only the suface area of the very tips of the flukes are presented against the sand.
Why does the Danforth style receive such high marks in tests? Simply look at the huge surface area presented against the pull of the rode.
Getting an anchor to hold well once set isnt rocket science..... it's all about surface area restraining the pull. What is tough is making an anchor dig in and reset after a shift!

[Andrew Troup]

Originally Posted by Cheechako

...
The Bruce simply doesnt present enough surface area against the pull. Just look at a pic of it and think it through.... only the suface area of the very tips of the flukes are presented against the sand.....
.

Hmm.... Unless I'm completely misunderstanding your point, the same can surely be said of any anchor, if you look at the flukes edge on.

Maybe you're looking at a photo rather than a real anchor.

In simple terms, what's most important is the angle of the palm of the flukes relative to a line through the chain attachment point.

The attached diagram shows the angle of the flukes, at the tip.

The other line (A-C) shows an angle which becomes relevant once the anchor has dug in: it's the fluke angle at the centre of pressure (roughly the same as centre of area)

This diagram does not show something which is different about the Bruce, and difficult to see in a 2D drawing or photo:

When you take an actual (genuine) Bruce and look at the flukes along line A-B, the small side flukes are twisted so that they present more perpendicularly to this line. In other words, the leading edges shown in blue on the diagram are further apart, and the trailing edges shown in red closer together, than if the side flukes were part of the vaguely cylindrical form of the main (palm) fluke.

Consequently they will provide a significant drag force when the anchor is buried, despite their 'fluke angle' in the 2D view shown suggesting they would have little effect. This, at least in theory, could be expected to help prevent the anchor from resurfacing, particularly on short scope.
(ON EDIT By providing a correcting, anticlockwise moment in the diagram, because the drag they supply is displaced significantly above the main palm)

The angle ACD is significantly closer to 90 degrees for the Bruce than the newGen anchor, once again favouring shorter scope, but potentially threatening to behave strangely when it does drag.
Which it can certainly be persuaded to do, particularly in artificial situations.

[s/v Jedi]

Okay, let me describe our experiences with our Bruce:

1. We have a very light chain compared to the anchor. The Dashew way is to put the weight where it counts: in the anchor.

2. We always drop the anchor by gravity; loosening the windlass clutch, never by electric down. This results in the anchor putting a crater in the seabed, breaking it up in case of hard sand. This is very important and gives us a 100% success rate in setting the anchor. Electric down is always trouble.

3. We try to keep the bow to the wind while reversing while I let out chain to a 5:1 scope. Not less and not more. I then slowly tension the clutch to let the anchor start digging in. When I feel it setting hard, which it always does, I lock the clutch so that we really pull it hard; hard enough for guests to be warned to hold themselves.

4. After setting we adjust scope to anywhere between 7:1 and 3:1 depending on swinging room and weather. We have had 50 knot squalls on 3:1 scope without trouble.

5. The Bruce starts on it's side. When that side's fluke digs in, it forces the next, center fluke into the seabed, which turns the anchor more. When we have good sand, this is as far as we can set the anchor; we just can't pull harder for it to dig in it's 3rd fluke. In softer bottoms it digs in immediately and in hard sand after a squall it is also completely dug in.

6. When the wind reverses the Bruce does not break free. It turns while in the seabed. I never found more that a foot between where it first dig in and where it ends up after a squall with 180 degree reversal. I know that exactly because I put markers around the anchor using rocks, bottles etc. that I find on the bottom

7. During big storms the anchor digs down further and further. We have had it 10 feet down the seabed once, taking 5 hours to get it back up. This is very different from the tests where you see it just crawl through the sand a bit.

8. I suspect that small Bruce anchors do not hold well. I once salvaged a 55lb. (25kg) original Bruce and it did not hold well at all. It did not feel like a smaller version of our 176lb. Bruce at all; it never set hard when I tested it.

Point 2, 3 and 4 above are the key to our Bruce.

cheers,
Nick.

[Greggegner]

I have a 42# Bruce that has worked well. Once while working on the alternator belt I was reving the engine to test the belt tension the boat was in gear. It took a couple of adjustments to get the tension how I wanted so the anchor was really set. All I can say was I finally got the anchor back up after repeatedly using the weight of the boat 20k to brake it lose. The bottom was soft and we didn't drag. I am in the process of mounting a similar Delta, but the Bruce always sets and when we were in the tides of Charleston it reset ever time. I think the 30' of 3/8 chain I have helps.

[Andrew Troup]

Jedi: thanks for the detailed and interesting info. For those unfamiliar with your setup, perhaps you could mention the weight of the anchor, and of the chain.

As regards the popular belief that Bruce (even the real thing) don't work in small sizes, I'm a bit puzzled, given my contrary experience.

I have anchored many times in many situations using a small genuine Bruce (7.5kg) on a 7m sailing boat with a tall rig. That's not particularly big for the boat, which weighs about 1900 kg in light cruising trim.

The owner has anchored with complete success in sustained 50+ knots a couple of times I know of; I've not been in an anchorage in that boat with that much wind, but 40 knots maybe half a dozen times, with a variety of bottom qualities and conditions.

The thing I have to say about this setup is that the chain is, by modern standards, massive overkill in relation to the anchor and the boat: 10m of 10mm chain next to the anchor, followed by 20m of 8mm chain.

It is never necessary to rig a snubbing line, except in shallow water or very extreme conditions.

The combination of moderate anchor weight and heavy chain was selected to keep weight off the bow (the chain locker is low and well aft) and has been entirely satisfactory. The only time I've ever dragged was in greasy mud in water so shallow the keel had to be retracted. And that was a rate of something like 2 - 3m per 24 hours IIRC - hardly life threatening.

As far as I'm aware, the owner has never dragged, even in the conditions mentioned above, nor had difficulty setting (outside the usual chance encounters with foreign objects). That's in well over twenty years, all in NZ waters, often in locations where anchoring is challenging.

In several small bouldery coves I've taken the opportunity to pull hard on the anchor from all angles, in situations where accurate transits would show any repositioning: I've been very impressed by the ability of the anchor to hold station.

I also have a 1kg Bruce I use for a dinghy anchor.
Works OK, very well considering its weight.
Makes a great 'throwing anchor' for climbing steep banks in heavily wooded coves to set up shorelines, too....

I didn't expect to use it when I bought it - I thought it was just cute and ornamental. Back then, it was exciting new tech ....
:-)

[Panope]

For 10 years (1990's), we used a 33 pound Bruce on Panope out here on the west coast between Washington and Baja Mexico). Always set right away and no dragging. We cruised in good weather months only - we never saw more than about 40kts (we do not get Thunder Storms of any significance).

We have very few "hard sand" bottoms. Mostly mud and soft sand. Bruce anchors are very common on cruising boats here.

Never used any special setting technique. Just drop and reverse power.

I have set it while sailing downwind (light conditions) by doing nothing more than dropping anchor and quickly setting the chain stopper. Boat would just stop and turn into the wind as I douse sail.

I would still be using the Bruce as the primary anchor if it was a bit larger. My future cruising area will be the inside passage where even during Summer one will encounter strong winds.

The Bruce is enjoying its retirement under the V-berth.

Steve

[Tx J]

"What happened to Bruce almighty? "

IIRC: PI Honey West put Bruce, her growley pet ocelot, into the AC Cobra and zoomed off down 'Route 66' when the series ended...

Honey West (TV series) - Wikipedia, the free encyclopedia

[noelex 77]

Originally Posted by s/v Jedi

6. When the wind reverses the Bruce does not break free. It turns while in the seabed. I never found more that a foot between where it first dig in and where it ends up after a squall with 180 degree reversal. I know that exactly because I put markers around the anchor using rocks, bottles etc. that I find on the bottom
.

I do the same trick with the rocks ( when their are no suitable existing landmarks) For some reason I always feel slightly stupid doing it. So it nice to know someone else does the same thing.

My Rocna always spins around without any apparent movement (other than rotation).

I am puzzled why some beach tests model this behaviour so poorly, suggesting well set anchors break out and reset to the new direction, when confronted with a large change in the direction of pull.

As the anchor rotates it typically develops a slight list and if set very poorly, or completely un set, it can break out at this point, but then it almost always simply drags.

Some yachtsmen believe that with a 180 degree shift their well set anchor routinely breaks out and then resets to the new direction, this is not how a good anchor responds from my observation (Danforth type anchors excluded).

People who don't dive also believe the anchor rotates more often than it does. It is variable with bottom type, size of anchor, scope etc, but a well set anchor will typically stay set in the same direction until the windspeed reaches around 25k.