Manual versus windlass anchors

[NormanS]

SRM - The implication is that for the last 40 years you have been anchoring as you describe, that's since 1980 and limits you to CQR, Bruce and Danforth, I am most impressed.

You carefully lay your anchor in anchorages subject to the full fury of 60 knots, I'm even more impressed

Jonathan

AntarcticPilot - the hold of the anchor is determined by the tension in the rode and that tension is contingent on the power of the engine or the windage of the yacht. It does not matter how big, or small, the anchor is (as long as it is 'big enough') the hold will be identical (unless you magically increase the size of the yacht). Now science might have changed - but no-one has illustrated this change in science, yet

and yes, AP

I think the point you make

A larger anchor will be more shallow set than a smaller one. If the tension is maintained in a straight line pull - possibly not an issue - but if the tension veers//

Jonathan, we've been over this before. In the waters of NW Scotland, winds of over 60 knots are a fact of life. Not all the time obviously, but one has to be prepared, and equipped for the eventuality. We are well blessed with anchorages, many with excellent holding, and perfect shelter from waves. The force of the wind however, is much more difficult to avoid. The further N and W that one goes, the sparser the vegetation, and in many of the further out areas, there are no trees at all, just bare and often rocky windswept hillsides. There is nothing remarkable about laying an anchor in these sort of places. If you want to go there, there is no alternative.

 

[Neeves]

Norman,

I did say I was impressed. Anyone who has been anchoring for 40 years in NW Scotland, or anywhere, where winds of 60 knots are a regular occurrence has an impressive background. Not many can claim that depth of expertise.

'Your' weather, and landscape, is little different to SW Tasmania where there is a Storm warning somewhere in Tasmania in the summer every month. We do have trees, but they are sometimes only about 1' high. The difference possibly being the fronts are well forecast, or they are now, as they are accurately tracked as they rush across the Southern Ocean and if you listen to the forecast you can anchor in fairly benign conditions, call it shelter. If you get it wrong - wave heights can be 11m, there is a waverider buoy halfway down the west coast.

Jonathan

 

[noelex]

Jonathan, we've been over this before. In the waters of NW Scotland, winds of over 60 knots are a fact of life. Not all the time obviously, but one has to be prepared, and equipped for the eventuality. We are well blessed with anchorages, many with excellent holding, and perfect shelter from waves. The force of the wind however, is much more difficult to avoid.

+1. This photo was taken in January this year.
Don’t believe the tales that you will never see more than 30 knots at anchor. There are some great cruising grounds that can be much windier than this on occasions.

 

[geem]

I guess this must be a key factor with a windlass. Bikedaft has a SL. they ceased trading 25+ years ago . Modern electric motors must be a lot more powerfull for their size today.
I need to measure the m/min on my manual windlass out of curiosity. The seatigers still command a great used price and are sought after.

Yes, I am sure you are correct. We replaced our old Lofran Falcon with a new one six years ago. The old unit was circa 30 years old it had a 2kw motor. The new model has a 1.7kw motor and actually seems more powerful than the old unit

 

[AntarcticPilot]

Norman,

I did say I was impressed. Anyone who has been anchoring for 40 years in NW Scotland, or anywhere, where winds of 60 knots are a regular occurrence has an impressive background. Not many can claim that depth of expertise.

'Your' weather, and landscape, is little different to SW Tasmania where there is a Storm warning somewhere in Tasmania in the summer every month. We do have trees, but they are sometimes only about 1' high. The difference possibly being the fronts are well forecast, or they are now, as they are accurately tracked as they rush across the Southern Ocean and if you listen to the forecast you can anchor in fairly benign conditions, call it shelter. If you get it wrong - wave heights can be 11m, there is a waverider buoy halfway down the west coast.

Jonathan

I obviously don't know Tasmania well, but I have visited it. I remember hacking on poorly defined paths through a temperate rain forest in SW Tasmania (NE or Hobart), with trees well over 100' high around me! This was inland; coastal conditions are probably different, but SW Tasmania certainly has some very impressive trees. Woodcarving was one of the common local crafts; I've still got a few items made from woods like swamp gum.

 

[geem]

Depends where you sail and how often you are willing to drag and 'reset' your anchor. We carefully lay our anchor, set it, and on all but a handful of occasions over 40 plus years of cruising stay put until its time to leave.
I have been told my anchor is too big when in marinas. However, I like to able to sleep securely in a reasonably sheltered anchorage when winds are gusting to 50 knots . At mean wind speeds of 60 knots plus the wind noise keeps me awake and I will have laid a second 'oversized' anchor. All these conditions have been experienced in northern UK waters.

We have experienced winds over 50kts recently when anchored in Falmouth harbour, Antigua. Not sustained but lasting a few minutes. Nobody in the anchorage dragged. Most people like ourselves were using anchors of a size recommended by the manufacturer. Why do you need a bigger one? Seems to me that carrying the extra weight over the bow for no reason just costs you more, reduces sailing performance and stresses the boat more

 

[Rappey]

using anchors of a size recommended by the manufacturer.

Interestingly, viking anchors website says going oversize could mean the boat has not got enough weight to dig the anchor in properly in the first place, leading it to pull out, dig in, pull out etc.
That info is for their modern hybrid type.

 

[srm]

Oh dear, I seem to have had a 'wooden spoon' effect. I won't answer individual comments above but just add my personal thoughts.

I would start by saying that the nice thing about sailing is that we are all free to make our own choices and decisions. There are no right an wrong answers other than loosing the boat.

I started my cruising career in 1974 by taking a 26 ft catamaran to Shetland as I was working there. Choice for anchors then was CQR and danforth. The boat came with a danforth and I added two 35 lb CQRs as I expected she would be on her own ground tackle most of the time. Yes 35lb appeared overweight.

My thinking is that anchoring is an act of faith, we do not know what the sea bed is in the spot the lump of iron lands and holding can vary greatly over an anchorage . As a diver I had seen lighter CQRs sliding happily along the sea bed with horizontal pull on the rode; being dragged by an inflatable in a light breeze. An anchor needs weight at the tip to make the initial penetration of the sea bed. After that what happens depends on design of the anchor and load on the rode.

I was an early adopter of the Bruce Patent anchor and still carry two on my current boat. The difference in initial holding compared to the CQR was remarkable - there is no way I would use a CQR or plough type now. However I ignored bruce's claim that I could reduce the weight and had main anchors of 15 kg on my 29 ft sloop and 30 kg on my 42 ft sloop with ten ton displacement. Often just the side tip of the anchor had penetrated after backing up with the engine (observed by diving). However, when the load increased they would dig in further. Incidentally, I found the big Bruce quite good at hooking rock on the west coast of Norway, though always felt more comfortable with a line ashore as well.

My current boat has a 25kg Rocna as main anchor. Stowed low down below are 20kg and 10 kg Bruce patent anchors (not copies), as I already had them, plus rodes for both.

I understand the concerns about excess weight, especially in the ends of the boat. I sold my Prout catamaran after four years following a brutal passage from Lerwick to Fair Isle via the middle of the North Sea because I was concerned that the weight I had accumulated was effecting the seaworthiness (we were heading to Norway). I prefer heavy displacement boats, so my solutions may well smack of 'brute force and ignorance'. They will be different to those I would use should I ever have to fit out a modern lightweight cruiser racer, but then I have had sleepless nights when being paid to skipper such boats.

Hope this may be of help. Remember no wrong answers, as long as you keep the boat afloat and clear of the shore.

 

[NormanS]

Interestingly, viking anchors website says going oversize could mean the boat has not got enough weight to dig the anchor in properly in the first place, leading it to pull out, dig in, pull out etc.
That info is for their modern hybrid type.

So they are trying to suggest that the same boat will drag a heavier anchor more readily, than a lighter anchor of the same design? Pull the other one. ?

 

[srm]

Indeed new gen. anchor designs are meant to set deeper, burying also their shank and part of their chain, if the size is too big for the boat size and power one will not be able to set the new generation, oversized anchor properly.

Really? What type of bottom material are they supposed to do this in?

Sea beds vary greatly in composition all the way from fine silt through muds and sands to clays of varying density on to soft shales and hard rocks. Also, the depths of differing substrata vary so a layer of soft mud or sand often overlies other materials at varying depths. As a hydrographic surveyor I have measures such features. For instance the harbour of North Haven in Fair Isle has a nice sandy bottom and looks like a good anchorage through the clear water. However, when I did a survey for new pier works (way back in the 70's) the sand layer was generally only 20 to 30 cm deep over beach pebbles and boulders.

I have seen an anchor that was totally buried pull through fine sand with little resistance, possibly skipping along a denser substrata.

Personally, I will always go one size up from manufacturer's recomendations on anchor size to allow for all the variations that were not in the maufacturer's test model. Also, I am not worried if the anchor does not fully dig in when setting it, provided of course that it is holding the boat. This gives me an added holding reserve as wind and wave loading on the boat can become far greater than that developed when running the engine astern for a minute or two and the anchor will then dig in as designed to take the increased load.

However, that is just my way of keeping my boat and crew safe. By all means follow manufacturer's recomendations if you feel it is safe to do so.

 

[Neeves]

There is no evidence that a large anchor penetrates a difficult seabed more easily that a small one of the same design. Given that the bigger one will have larger cross sectional area then it will in fact have greater difficulty (under the same tension) to penetrate. It is much easier to drive a small garden spade into hard soil than a large one. It is also much easier to drive a thinner blade into hard soli that a big beefy bladed spade (or anchor).

A 15kg anchor has a hold in clean sand of around 2,000kg - there is no way that the yacht for which this size of anchor is recommended is ever going to experience 2,000kg of tension. In some seabeds this 2,000kg will be reduced, say thin mud, and will drag - but you are then using the wrong anchor and a big one (of the same inadequate style), would possibly need to be 2 to 3 times the size to have any security. No anchor is perfect - you should be carrying more than one anchor - and if needs be change the anchor. If your anchors are so large that changing anchors is not possible then,. really, you should have twin bow rollers (as Kukri appears to be planning).

People will jump all over what I am saying - I'd be interested in actual data and experience where people have actually used a small anchor (but of a size recommended for the yacht) and found it wanting and changed to a bigger one of the same design and found that it worked in the same seabed. I am the first to agree that if you take a small CQR then a big Rocna will work better - so what, it proves - not a thing

For hard seabeds the US Navy, RN and oil rigs do not use bigger anchors but anchors with sharp toes and low fluke/seabed angles - they change design, not anchors (in the same way a Fortress returns better data than a Danforth of the same size and also allows alteration of fluke angle for different seabeds). In fact a Fortress outperforms a Danforth in almost every test - the heavy weight of the Danforth appears to offer no advantage. The comparison is not entirely fair as the Fortress is, arguably, better designed - with thinner fluke blades ((which goes back to Vikings claims of better performance). Viking's use of HT steel allows a thinner fluke blade, compared to a similarly designed anchor with a mild steel blade, and thin flukes penetrate more easily than beefy flukes (confirmed by research at a variety of Universities - including in Houston, the home of Mantus).

We carried both a steel Excel and an aluminium Excel of identical size but one weighs 15kg and the other 8kg. We can detect no difference in performance between the 2 and carry the aluminium version in preference to the steel one (the latter sits unloved collecting dust in storage). Panope in his videos tested, I think the most recent 2 vids in his series, a small Excel and a larger Mantus and in the same seabed the small Excel returns a, much, higher hold. Its design that matters - not weight. Mantus looks, with a quick glance, like a Rocna - but quick looks, and ignorance, are deceptive. Mantus is a variation of a Bugel (which itself is a welded Danforth with roll bar) and all are unballasted fluke anchors. Rocna is a BALLASTED fluke anchor. Unfortunately Mantus have the crown in the wrong location - halving its potential hold. So a 15kg Mantus has half the hold of a Rocna and a similar hold to a Delta - of the same weight - another perfect illustration, backed up by Panope's vids - its design NOT weight.

Obviously if the anchor is ridiculously small then it will not have the ability to hold a vessel - too large. But if the anchor is of the recommended size and is chosen appropriately for the seabed (which covers most seabeds described in most cruising guides) it will be adequate.

We do use 2 anchors when we expect winds to exceed 35 knots - not because we doubt the hold of our primary (aluminium) anchor but because deploying 2 anchors in a 'V' reduces veering and I, and some others, think veering is a major cause for anchors to drag. But then we carry spare anchors, they are all aluminium, they are all easy to deploy. This is another benefit of the Viking - because they chose to use high tensile steel throughout the anchor they can save weight for a given area or volume or hold. Now whether there are downsides - testing will tell. I'm not aware that anyone has bought a Viking - and it may be all talk (and no trousers) - time will tell.

Jonathan

 

[NormanS]

Yes but, Jonathan you're not addressing the point. You are comparing all sorts of anchors. What about the question that I raised in #50? Is there any evidence to suggest that a boat will drag a heavy anchor, when a lighter anchor of the same design, would hold? And if so, what is the mechanics of such an unlikely phenomenon?

 

[Neeves]

Norman,

People have voted with their wallets. There are no end of Bruce, CQRs and many more almost new Deltas all languishing - you could buy, sorry recycle, one of these as big as you want (relative to the size of your yacht) no-one moves these anchors (which you are implying will be superb because they can be (given the choice) much larger than recommended - but no-one wants them. People would rather spend good money on an oversize Rocna for which there is no evidence that a smaller Rocna would not be as safe.

So - come up with the data that an oversized Bruce, or Delta is safer than one of the recommended size, or come up with the data that an oversized Rocna is safer than one of the recommended size. I know the bigger Rocna, or Supreme, or Spade or Excel costs more - but does anyone get a return on their investment.

I can confirm, it is obvious, that a larger Rocna will not be set so deeply as a small one, in the same seabed and with the same tension. I'm not sure that with a 5kg difference in weight it makes much difference (to performance) but when you get excessively large and Dashew put no limits on how big to oversize and some have gone to twice the size) but if you offer me a deeply set anchor of the recommended size and one that is lightly set and bigger - with veering and chop - I know which we would choose, and have chosen. I also note that the Classification Societies allow a 30% reduction in size of Supreme, Spade, Excel, Ultra (and in the past Rocna) over a CQR, Delta, Bruce (which is roughly what we have done). Obviously LLoyds, Norsk Veritas, ABS et al - don't know what they are talking about - best to rely on internet chatter.

I know my small anchors are safe, because we use them, and I suspect there are thousands using one of these anchor, Rocna etc etc - of the recommnended size who are all alive and kicking and have not lost their yachts through drragging - so why this need to suggest people shore up the pension funds of anchor makers. If I'd known it was so easy to sell a more expensive product - I'd have gone into the anchor making business.

Certainly anchor makers do not need salesmen - they have internet forum to replace salesmen. You can sell anchors now without hold data - who would have believed that in, say, 2009. People obviously like gin and tonic because they buy lemons, sorry anchors, on the flimsiest of evidence. The same people who recommend lemons, sorry specific anchors, also heavily sell the idea of 'buy big'. Lacks credibility - they sell lemons and know about big anchors...??? If you press the lemon salesman - they soon run for cover.

Sorry if I'm a sceptic.

Just come up with the data that buying big, and spending big, offers a return to the customer. Find me evidence that people who have bought an anchor of the recommended size, Rocna et al drag more frequently, or even drag at all, compared with those with big anchors.

Jonathan

 

[geem]

Norman,

People have voted with their wallets. There are no end of Bruce, CQRs and many more almost new Deltas all languishing - you could buy, sorry recycle, one of these as big as you want (relative to the size of your yacht) no-one moves these anchors (which you are implying will be superb because they can be (given the choice) much larger than recommended - but no-one wants them. People would rather spend good money on an oversize Rocna for which there is no evidence that a smaller Rocna would not be as safe.

So - come up with the data that an oversized Bruce, or Delta is safer than one of the recommended size, or come up with the data that an oversized Rocna is safer than one of the recommended size. I know the bigger Rocna, or Supreme, or Spade or Excel costs more - but does anyone get a return on their investment.

I can confirm, it is obvious, that a larger Rocna will not be set so deeply as a small one, in the same seabed and with the same tension. I'm not sure that with a 5kg difference in weight it makes much difference (to performance) but when you get excessively large and Dashew put no limits on how big to oversize and some have gone to twice the size) but if you offer me a deeply set anchor of the recommended size and one that is lightly set and bigger - with veering and chop - I know which we would choose, and have chosen. I also note that the Classification Societies allow a 30% reduction in size of Supreme, Spade, Excel, Ultra (and in the past Rocna) over a CQR, Delta, Bruce (which is roughly what we have done). Obviously LLoyds, Norsk Veritas, ABS et al - don't know what they are talking about - best to rely on internet chatter.

I know my small anchors are safe, because we use them, and I suspect there are thousands using one of these anchor, Rocna etc etc - of the recommnended size who are all alive and kicking and have not lost their yachts through drragging - so why this need to suggest people shore up the pension funds of anchor makers. If I'd known it was so easy to sell a more expensive product - I'd have gone into the anchor making business.

Certainly anchor makers do not need salesmen - they have internet forum to replace salesmen. You can sell anchors now without hold data - who would have believed that in, say, 2009. People obviously like gin and tonic because they buy lemons, sorry anchors, on the flimsiest of evidence. The same people who recommend lemons, sorry specific anchors, also heavily sell the idea of 'buy big'. Lacks credibility - they sell lemons and know about big anchors...??? If you press the lemon salesman - they soon run for cover.

Sorry if I'm a sceptic.

Just come up with the data that buying big, and spending big, offers a return to the customer. Find me evidence that people who have bought an anchor of the recommended size, Rocna et al drag more frequently, or even drag at all, compared with those with big anchors.

Jonathan

We are currently anchored in Horta, Azores. We had three days of windy weather with gusts/squalls in the high 30s everyday.
The vast majority didnt have any real problems and the anchorage has a reputation for sketchy holding.
A friend with a 28ft boat had trouble setting his Rocna. He has a 25kg Rocna on a 28ft boat!! I suspect he didnt have enough power to set it. It dragged. Took three attempts to get it to hold. When the wind blew it dragged then held. I suspect it took some some strong wind to actually get his anchor to set.
A French guy came in with a Bongo 9.6. Superlightweight boat. They go pretty beaten up onroute to Horta from the Caribbean. Light boat, headwinds and big seas. Not much fun. When they arrived tired they had terrible trouble setting their tiny anchor on some chain but mainly rope. It was blowing 35/38kts. Eventually they gave up and marina let them go on the fuel dock. I guess on a small racing boat you dont want to carry heavy ground gear but a good example of two different situations where too small or too big just doesnt work

 

[srm]

Oh what fun!!
I have yet to meet three skippers that can all agree on a choice of anchor.

Incidentally, I have anchored a small yacht with a ship's anchor chain shackle (around 5 kg) tied on the end of a length of rope. I don't recommend it but it worked on that day on that sea bed.

It's also worth noting that Bruce eventually stopped making their anchors, driven out of the market by cheaper (probably inferior) copies. People voted with their wallets.

 

[NormanS]

Norman,

People have voted with their wallets. There are no end of Bruce, CQRs and many more almost new Deltas all languishing - you could buy, sorry recycle, one of these as big as you want (relative to the size of your yacht) no-one moves these anchors (which you are implying will be superb because they can be (given the choice) much larger than recommended - but no-one wants them. People would rather spend good money on an oversize Rocna for which there is no evidence that a smaller Rocna would not be as safe.

So - come up with the data that an oversized Bruce, or Delta is safer than one of the recommended size, or come up with the data that an oversized Rocna is safer than one of the recommended size. I know the bigger Rocna, or Supreme, or Spade or Excel costs more - but does anyone get a return on their investment.

I can confirm, it is obvious, that a larger Rocna will not be set so deeply as a small one, in the same seabed and with the same tension. I'm not sure that with a 5kg difference in weight it makes much difference (to performance) but when you get excessively large and Dashew put no limits on how big to oversize and some have gone to twice the size) but if you offer me a deeply set anchor of the recommended size and one that is lightly set and bigger - with veering and chop - I know which we would choose, and have chosen. I also note that the Classification Societies allow a 30% reduction in size of Supreme, Spade, Excel, Ultra (and in the past Rocna) over a CQR, Delta, Bruce (which is roughly what we have done). Obviously LLoyds, Norsk Veritas, ABS et al - don't know what they are talking about - best to rely on internet chatter.

I know my small anchors are safe, because we use them, and I suspect there are thousands using one of these anchor, Rocna etc etc - of the recommnended size who are all alive and kicking and have not lost their yachts through drragging - so why this need to suggest people shore up the pension funds of anchor makers. If I'd known it was so easy to sell a more expensive product - I'd have gone into the anchor making business.

Certainly anchor makers do not need salesmen - they have internet forum to replace salesmen. You can sell anchors now without hold data - who would have believed that in, say, 2009. People obviously like gin and tonic because they buy lemons, sorry anchors, on the flimsiest of evidence. The same people who recommend lemons, sorry specific anchors, also heavily sell the idea of 'buy big'. Lacks credibility - they sell lemons and know about big anchors...??? If you press the lemon salesman - they soon run for cover.

Sorry if I'm a sceptic.

Just come up with the data that buying big, and spending big, offers a return to the customer. Find me evidence that people who have bought an anchor of the recommended size, Rocna et al drag more frequently, or even drag at all, compared with those with big anchors.

Jonathan

Jonathan, I really don't need a lecture about fashionable anchors versus presently unfashionable anchors. What I was responding to was the suggestion that a heavy anchor would get a lesser grip than a lighter one, of PRECISELY THE SAME MAKE, in use by the same boat. That suggestion was made in this thread in #47. If this, to my mind, highly unlikely scenario, is a fact, I would be interested in the mechanics of it. (Please note, a second hand tale of one boat dragging somewhere doesn't prove anything).

 

[LadyInBed]

A friend with a 28ft boat had trouble setting his Rocna. He has a 25kg Rocna on a 28ft boat!! I suspect he didnt have enough power to set it. It dragged. Took three attempts to get it to hold.

You did say that the anchorage has a reputation for sketchy holding.

When the wind blew it dragged then held.

Isn't that the the whole principle of setting an anchor? - You drag it until it sets.

I suspect it took some some strong wind to actually get his anchor to set.

OK, it wasn't completely set, but set well enough for the conditions at the time of dropping it.
Maybe it was a case that he didn't run his engine hard enough for it to completely set and he stopped pulling when he observed that he wasn't moving, isn't that what we all do? Then the wind came along and finished the job for him.

 

[Neeves]

Norman,

No-one is lecturing you.

People who upgrade their anchors would currently have a CQR, Bruce or Delta or copies of same. If using a big anchor was the panacea you are suggesting then instead of going off and buying the latest fashion in anchors they would sensible take possession of a larger model of the self same anchor that they already use. You seem to be suggesting that a bigger anchor, of the same design will be better. People do not take up the option of a very cheap (think free) larger anchors - they go off and buy one of the more fashionable ones.

Geem seems to offer an example? I hope their comment is not considered a 'second hand account' My guess is that amongst the yachts anchored in the anchorage some will be using Rocnas - it would be most unusual for there to be no Rocnas.

I would be interested in which small anchor the Bongo was using - normally it would be a Fortress - but it is wise not to guess.

But to correct your last post - if you set 2 anchors, one large and one small of the same design, in the same seabed then the hold of each of them will be identical - hold is the measure of the tension developed either by wind or engine. Because they have the same hold, they have as you put it - the same grip. Why you would think the big anchor would have a lessor grip I don't understand - it was never mentioned as such. The large anchor will be more shallow set than the small one - hold is usually a function of surface area (and design - but as design is the same that becomes of less importance). As the bigger anchor will have the same surface area (or volume) buried (approximately) as the smaller one - it will be more shallow set - or perhaps more accurately will have more anchor above the seabed. If the smaller anchor is buried the larger anchor will have some of the shank protruding and maybe some of the fluke (commonly the heel).

Having more anchor above the seabed possibly allows the chain to get under the shank or the unburied heel of the anchor. In a change of tension direction the large anchor that has a large amount of shank protruding is more likely to capsize (because it has a big unsupported lever sticking up above the seabed) - and need to reset itself whilst the small anchor may simply turn round without breaking free, because it will have more, or all, of its shank buried and a buried shank acts like a vertical fluke and will resist acting as a lever (because the seabed within which it is buried will need to be 'moved' for it to capsize the fluke. If you think this does not happen - I can assure you anchors are tripped because chain gets under the shank or under the heel of the fluke (and for Fortress under the stock). I can also assure you that the shank does act as a vertical fluke.

We have changed our Fortress from a FX23 to a FX16 for exactly this reason. We have found that setting the FX23 leaves the stock protruding and we also know that Fortress have a reputation of tripping in a change of tide or wind. We have reduced the risk of tripping our Fortress by using a smaller model - whose stock is more easily buried. This is not second hand and we have done it on the basis of viewing hundreds of our own FX23 performance and comparing it with that of the FX 16. The downside is that we also now carry a FX37, set at 45 degrees, because in thin mud the FX16 its simply too small - it maybe will not develop sufficient hold.

Modern anchors are excellent at developing additional hold, over and above that from the engine or the wind when the anchor is set, if the tension direction is maintained in the set direction. If the tension directing changes - bets are off. Normally they will reset, and quickly, but worse case scenario they catch a beer can in the toe - unless of course they remain buried.

Jonathan

 

[Neeves]

You did say that the anchorage has a reputation for sketchy holding.

Isn't that the the whole principle of setting an anchor? - You drag it until it sets.

OK, it wasn't completely set, but set well enough for the conditions at the time of dropping it.
Maybe it was a case that he didn't run his engine hard enough for it to completely set and he stopped pulling when he observed that he wasn't moving, isn't that what we all do? Then the wind came along and finished the job for him.

You should not need to 'drag' an anchor until it sets - most modern anchors engage virtually immediately and set (lock up) in their own shank length You can tell if the anchor is 'dragging' and not engaged as if you simply rest your fingers on the chain just forward of the bow roller you can feel the anchor bouncing along the surface of the seabed. An all chain rode transits vibrations exceptionally well - mixed rodes, and snubber/bridle lack the sensitivity. Of course you can also tell if the anchor has not engaged as all the other yachts in the anchorage are moving closer or further way or....

Jonathan

 

[NormanS]

Jonathan, I again refer you back to #47. Please desist from saying that I am claiming that bigger and bigger anchors are the answer. I am saying no such thing. I am trying to get to the bottom of the claim in #47, that a bigger anchor of the same design will get less of a grip, and will even drag, when the smaller anchor of the same design will hold.
I am not making any claims or comments about different varieties of anchors.
In the unlikely event of the claim in #47 has any truth, I would like to try to understand the science behind it.