Rappey
Well-known member
Yes.
An Anchor Thread! Grab your beers and popcorn.
- Thread starter KeelsonGraham
- Start date
Quandary
Well-known member
After I sold my last yacht I tried to do a clear out by advertising a number of items on here, because there was more than one ad. I was accused of being a scammer and permanently banned from the 'for sale' columns of YBW. Among the items I have was a 15k. galv. Spade anchor which I wanted to offer about 1/2 price. I support the provision of school lunches to hungry kids in Malawi through a local charity called 'Mary's meals' and the money I hoped to raise would have gone to them.
Of course as a disgraced outcast I can not offer it here but since the O.P. might benefit from one (it was a superb anchor, rust free, never dragged in the 2 years we were using it) he might be interested to learn that with other useful stuff it is available on the more exclusive but less commercially restricted Blue Moment yachting forum which serves those who sail around Scotland.
Of course as a disgraced outcast I can not offer it here but since the O.P. might benefit from one (it was a superb anchor, rust free, never dragged in the 2 years we were using it) he might be interested to learn that with other useful stuff it is available on the more exclusive but less commercially restricted Blue Moment yachting forum which serves those who sail around Scotland.
Graham376
Well-known member
No idea which is best but our Manson Supreme has never let us down. We never use the slot though, I suspect there's a slight risk of tripping at change of tide.
Zagato
Well-known member
Having also read many threads I went with a Spade anchor, and yes when it arrived from Jimmey Green it had rust on it from new!! I treated the rust and am very happy with it.
newtothis
Well-known member
Everyone knows that all you need is a chain. It's the catenary effect that holds the boat. Anchors are just a conspiracy dreamed up by evil Big Anchor to extract your cash.
Tranona
Well-known member
See post#11. A Delta 20kg is recommended for boats 42' up, and the boat quoted here is 37' which is right in the middle of the 16kg range (and still just in the "top" of the 10kg). If we take the data from the Rocna guide which takes into account displacement, a 20kg would not be recommended unless the boat had a displacement of 12 tonnes - inordinately heavy for a 37' sailing yacht.
Weight per se is not a good measure of effectiveness although physical size is, in the sense that a bigger anchor of the same design will have higher ultimate holding power because of the greater area of the flukes. The real question is how do you best access the holding power of the anchor and this is a function of how well it penetrates the seabed and how much pull you can apply to it. The former is a design issue but the latter is dependent on the size of the boat and the power of the engine or strength of the wind. Many tests (Neeves will give you chapter and verse) have shown that it is very difficult to achieve sufficient pull to gain the maximum holding power of the "recommended" size anchor. So a typical 37' may not be able to achieve the maximum holding power of a 16kg anchor. If this is the case going up to a 20kg has no value because you simply don't have the power to use the extra potential holding.
Your "experienced long distance cruiser" may therefore be kidding himself (or herself) by thinking an oversized anchor is going to "save" them any more than a more appropriate size. Better to look to identifying a higher holding power anchor of the same size. Surprisingly manufacturers (particularly Lewmar) do not reflect differences in holding power in their sizing charts. The Epsilon is demonstrably higher holding power than a Delta but their sizing charts are virtually identical!
FWB
N/A
The chain is probably more important than the anchor, unless in a severe blow.
I have 10mm chain with a 10kg Delta on my 28 ft 9 ton gaffer. The boat tends to ride around the chain in most conditions and doesn’t bother the anchor unless the wind starts to howl.
I have 10mm chain with a 10kg Delta on my 28 ft 9 ton gaffer. The boat tends to ride around the chain in most conditions and doesn’t bother the anchor unless the wind starts to howl.
Tranona
Well-known member
The chain only serves to connect the boat to the anchor, so only needs to be strong/big enough to not break before the anchor exceeds its holding power. The only advantage of heavy chain is the catenary damping the movement of the boat and this can easily be achieved by using smaller lighter chain and a nylon snubber. Once the wind speed reaches around 25 knots the chain is straight independent of its size. 8mm chain is more than adequate for a 10kg Delta and 6mm exceeds the holding power of the anchor.
Neeves
Well-known member
I do love this.
Take 50 of 8mm chain and lay it in straight line on a beach such that it just under water. You can go deeper if you like but you will become wetter. Now, imagine you are a yacht with the wind in your face and put all your weight into it - and Wow! you will be able to pull the chain along the seabed, You might need some help, one other person, but once you get the 50m moving you should be able to keep it moving by yourself - that is the hold of chain, its friction effect - maybe 70kg of tension. Now that is 50m of chain laying flat on the seabed.
Take 30m of 8mm chain and devise a means to lift all of the chain, except for the last link off the seabed which you will secure, with say an anchor. The tension will be around 85kg. That's roughly the windage on a 45' yacht using the same chain 5:1 scope - there is now no friction (because all of the chain is off the seabed, and 75kg of tension is roughly the tension developed by a 45' yacht in 18 knots of wind.
The trouble with the 'written' word is that some people believe it - but some of the written word is rubbish.
Now you will possibly find it difficult to set up my little experiment - so I did it for you.
This is 30m of 8mm chain with the last link, the one furthest away, secured to the fence. The tension is increased on the chain winch till that faraway link, or the one next to it, is just lifted off the ground, you can slide a sheet of paper underneath, just.
This is the displayed tension. The tension to achieve the same under water will be less.
I have similarly measured the tension in the rode in a developing seabreeze and a tension of about 75kg is the tension in the, identical, rode, deployed from a 45' AWB with a wind of 17 knots, well secured using an anchor.
At snatch loads, short scope, in 35 knots the tensions were 650kg - do you really think chain alone can hold your yacht.
The hold of a modern, efficient anchor, as listed in previous. posts, is around 2,000kg for a 15kg anchor in good holding sand. If you experience tensions of 650kg your anchor will be secure, it can hold 2,000kg - but your wife will be busy (talking to her divorce lawyer). You will be unable to think clearly - a 650kg snatch will be checked feed to your anchor but its a bit like driving your yacht into a brick wall at 5 knots. The children will be screaming and dog parking at all the uproar.
Now the holding may not be clean sand it might be soupy mud - but then you deployed the wrong anchor and should have used your Fortress.
But with a 15kg anchor and a potential of 2,000kg of hold - you have a good safety factor.
The maximum hold actually developed by your yacht is its windage and at 35 knots the maximum is about 650kg of hold for a 45' yacht. Your 15kg anchor will hold 2,000kg - how exactly are you going to develop the potential of that anchor. If you have a bigger anchor it will develop the self same hold as the 15kg anchor, no more no less - but the bigger anchor will not be set so deeply.
Deep set anchors will hold more if the wind is yawing or veering
You can reduce the tension in the rode by using a snubber.
If you read accounts of yachts in strong wind events.....the people that listened to forecasts and found the best shelter survived the best.
Storm tactics at anchor: Surviving gales in Scilly - Yachting Monthly
Take care, stay safe
Jonathan
Frogmogman
Well-known member
FWIW, I have an AWB of the same length and displacement (Sun Odyssey 349) as you. I am delighted with our 15kg spade. It sets straight away and holds well. it is also a thing of beauty (I bought the stainless one, because I am a tart and like shiny things).
GHA
Well-known member
Anyone else see the massive philosophical switch there? ? Pretty well aligned with the differences in East/West philosophy.
Went from being alone in an unpredictable universe pushing the odds in our favour to controlling everything & ticking boxes thinking all will be well. Might work day sailing in the solent..
It's not like that out there.
Plenty reason why cruisers like a good anchor then maybe go up a size.
Outfitting a world girdling boat there really is no down side.
Tranona
Well-known member
Perhaps you could list the reasons with the science behind them.
GHA
Well-known member
Been done so many times before. Very basic, 2 anchors, same design, the bigger one will hold more force than the smaller one. That's why bigger boats have bigger anchors.
So when the thunderstorm comes in with 70Kt gusts you might not loose your home. This seems to happen every year in the Med.
Same when you end up in bad holding.
Same when you've less scope than you would like.
Can you really not figure that out on your own?
And gotta ask -
Did you not even consider for a moment that a cruising boat might not be in such perfect holding to get such results? The real world isn;t like that. Sometimes the hold ain't great and it's all there is.
Neeves
Well-known member
I find the idea that somehow world girdling cruisers justify their anchor choice by underlining the simple factoid (that is not valid) that they suffer more severe weather than people who need to work. That article on the storm in the Med, or the one in the Scilly Islands was a day trip or a weekend out and maybe even part of a 2 week holiday cruise for many. Storms, with a capital 'S' are not restricted to world cruisers - there is a Storm warning once a month in Tasmania in the summer. I met a delivery skipper in Port Stephens (70nm north off Sydney - a good weekend destination from Sydney) who was delivering a 50' Benny to Sydney - we were confined to the same anchorage - he told me the weather from which we were anchoring was the worst he had had since leaving France.
Day trippers, weekend sailing warriors and those that use 2 weeks to sail a bit further afield from 'home waters' need exactly the same anchors as world cruisers. The storm in the Med and Scilly Islands was not put on especially when there were only real sailors (sorry world cruisers) and none of us weekend warriors at anchor.
Bajansailor had a comment on bad weather - forecasts are now sufficiently good that when bad weather is forecast - move. The Scilly Isle storm was well forecast - the yachts that took heed and moved, for example Geem (on his way to cross the Atlantic) had a relatively quiet night. If the holding is bad - you chose the wrong location and/or the wrong anchor and/or you took no notice of bad weather brewing. You carry 2 anchors - deploying the second anchor will offer more benefit than the illusory benefit of the bigger anchor. Why carry, at least, 2 anchors - if you do not use them.
If you back up your poor scope with a decent snubber - scope is of less importance. The elasticty of the snubber replaces your inability to rely on catenary.
Its a really simple graph but you can replace catenary with elasticity. I gotta ask - you obviously have not figured it out on your own?? - you obviously have not embraced nylon? Just think you could use a 30m snubber )and have only 10m beyond the bow - extrapolate the data......
Reduce the impact of variations in tension, gusts, seas and your anchor will not be under stress (and will be more reliable in poor holding). Your catenary, your better scope, is all about absorbing energy - nylon does it much better than chain.
Your answer is throw money at it and carry unnecessary ironmongery. - We rely on the science and buy cheap nylon (and carry an aluminium Excel 8kg, an aluminium Spade 8kg and an aluminium Fortress 8kg - we have the windage of a Bav 45 we use 6mm chain (75m) and spare rode of 15m of 6mm chain and 40m of 3 ply nylon. We are a bit overweight at 7t but can still cover 100nm in 10 hours - now define your ground tackle, yacht and performance.
Our cruising ground is the Roaring Forties and the next land east or west is Patagonia - where do you go?
Jonathan
Day trippers, weekend sailing warriors and those that use 2 weeks to sail a bit further afield from 'home waters' need exactly the same anchors as world cruisers. The storm in the Med and Scilly Islands was not put on especially when there were only real sailors (sorry world cruisers) and none of us weekend warriors at anchor.
Bajansailor had a comment on bad weather - forecasts are now sufficiently good that when bad weather is forecast - move. The Scilly Isle storm was well forecast - the yachts that took heed and moved, for example Geem (on his way to cross the Atlantic) had a relatively quiet night. If the holding is bad - you chose the wrong location and/or the wrong anchor and/or you took no notice of bad weather brewing. You carry 2 anchors - deploying the second anchor will offer more benefit than the illusory benefit of the bigger anchor. Why carry, at least, 2 anchors - if you do not use them.
If you back up your poor scope with a decent snubber - scope is of less importance. The elasticty of the snubber replaces your inability to rely on catenary.
Its a really simple graph but you can replace catenary with elasticity. I gotta ask - you obviously have not figured it out on your own?? - you obviously have not embraced nylon? Just think you could use a 30m snubber )and have only 10m beyond the bow - extrapolate the data......
Reduce the impact of variations in tension, gusts, seas and your anchor will not be under stress (and will be more reliable in poor holding). Your catenary, your better scope, is all about absorbing energy - nylon does it much better than chain.
Your answer is throw money at it and carry unnecessary ironmongery. - We rely on the science and buy cheap nylon (and carry an aluminium Excel 8kg, an aluminium Spade 8kg and an aluminium Fortress 8kg - we have the windage of a Bav 45 we use 6mm chain (75m) and spare rode of 15m of 6mm chain and 40m of 3 ply nylon. We are a bit overweight at 7t but can still cover 100nm in 10 hours - now define your ground tackle, yacht and performance.
Our cruising ground is the Roaring Forties and the next land east or west is Patagonia - where do you go?
Jonathan
Tranona
Well-known member
Sounds very unscientific to me. .
No dispute that the bigger anchor of the same design will POTENTIALLY have higher ultimate holding power - indeed I made that point myself!. The question is whether the boat in a particular set of circumstances actually access that additional holding power. Everything says not necessarily, from the tests carried in post#29 to the recommendations given in the Rocna guide you posted (look at the huge difference potential between for example a 15kg and 20kg anchor in terms of boat size and displacement).
Yes, I have figured it out and just come to a different conclusion from you which is why I suggested you might like to give some science to support your claims. This blind belief is that "bigger is better" is just not supported by the evidence. Yes I did consider that holding ground may not be as perfect as you would like, and could find no evidence that a bigger anchor would provide greater holding power - indeed as Neeves suggests, maybe even inferior because the boat cannot apply enough power to set the larger anchor. (Read post#29 again).
GHA
Well-known member
What evidence shows that a bigger anchor won't hold more than it's smaller brother? Dig deep in google maybe one time somewhere but lets face it. it's a ridiculous hypothesis.
So bigger anchors only hold more in perfect holding? Doubt it......
And do you really think pure engine power is the only way to dig in a hook? It's really not that hard!! So with that argument, anchor size should be linked to engine size.
Back in the real world cruisers know better...
Same old crazy arguments on a web forum....
geem
Well-known member
I would suggest not buying a Spade. They are excellent anchors but they rust for fun. My Spade has done 12 month service as a live aboard and looks like its 25 years old. Very very disappointed with the galvanising. Spade don't acknowledge they have a problem.
A Viking anchor would be worth adding to the list
Frogmogman
Well-known member
TBH, that’s one of the reasons I went for stainless, not just because I like shiny things. ?
newtothis
Well-known member
Them's an awful lot of words and effort to say what I said in one line, albeit through the medium of ironic anchor thread humour.
Tranona
Well-known member
You really do have a talent for twisting what is said seemingly in an attempt to ignore the obvious! When did I ever say that engine power is the only way of setting an anchor? or that bigger anchors only hold in perfect holding? Just figments of your imagination!
Once again read Neeves' posts particularly the bit about the amount of load a boat can exert on the anchor - from whatever means. Pleased you eventually fall back on the good old ""cruisers know better" - the perfect way of avoiding providing any evidence to back up what you say!