The Anchor is Just Decoration

[Greenheart]

...an increasing number of cruising sailors use Grade 70 chain a size down from the Grade 30 they would otherwise have used, to save weight in the bow locker. Paul Chandler followed this route when refitting Lorne Rival, 8 mm Grade 70 instead of 10 mm Grade 30.

That is interesting. Presumably, eventually a rope cable looks more usable, if weight is more of a burden than a benefit?

 

[vyv_cox]

That is interesting. Presumably, eventually a rope cable looks more usable, if weight is more of a burden than a benefit?

Substituting 100 metres of 8 mm Grade 70 for 10 mm Grade 30 saves 90 kg in the chain locker and almost doubles the strength.

 

[Greenheart]

That's extremely encouraging. Although it certainly seems to sew-up the old idea that the chain's weight was an important virtue.

I know it isn't realistic, but I wonder how much weight-reduction and strength-increase one might gain, if the rode was all-Dyneema?

 

[Chris_Robb]

I feel certain you have already consulted the Alain Fraysse website. I believe that he and Alain Poireaud worked closely together. Despite the theoretical benefits of all-, or nearly-all rope rodes not all that many people use them for some of the reasons I have already given. Multihull sailors differ of course and many use rope to save weight.

However, there is an increasing number of cruising sailors who use Grade 70 chain a size down from the Grade 30 they would otherwise have used to save weight in the bow locker. Paul Chandler followed this route when refitting Lorne Rival, 8 mm Grade 70 instead of 10 mm Grade 30. Interestingly, I received an email flyer from Jimmy Green advocating that practice only yesterday.

Vyv - I bought from Bradney chain 8mm dia x 24mm inside pitch Grade 30 chain test 12.7KN. I didn't know much about chain then (or now!) and might have bought 10mm chain if the existing gypsea was not already 8mm. It would seem ok to me, and I presume 12.7KN is something to do with tested strenght? In your view is this set up strong enough? I always use a nylon snubber in heavy weather to avoid snatch loads.

 

[AngusMcDoon]

Wear, longevity, stowing, windlass grip, not wrapping around underwater parts, preventing the boat from dancing all around the anchorage, are the first few that come to mind.

I use virtually all rope to save weight on a multihull. Not had any wear or longevity problems or the rope getting caught round underwater bits as it still sinks. No windlass so that's not a problem. I have also not noticed too much swinging around, not more than a similar sized fin keel mono.

An advantage not mentioned so far is that without a windlass rope is a lot less effort to pull up in deep water. Two disadvantages are caused by the higher scope:depth ratio though, which are

1) more space is needed in a tight anchorage and I often get other boats anchoring too close not realizing that I have 50m of rope out.

2) I have found in Scotland where the shallow water suitable for anchoring is close to the shore and quickly deepens that the slope of the seabed is steeper than the slope of my anchor line. This makes anchorages untenable if there is a risk of swinging towards the shore for any reason as the scope required will be more than the distance from the shore at the point where it is possible to anchor. The anchorages in Tobermory are like this, for example.

 

[Downsman]

was that on the East Coast

Most probably Greece.
Noelex ain't fool enough to try and take photos in the cold and murky N Sea.

You're sacked Sailorman, get your gear ashore...

 

[charles_reed]

Hopefully. I read on here, late last year, that even a long chain lifts right off the bottom in surprisingly light conditions, thereby relying wholly on the hook at the end, for holding.

That seemed to fly entirely in the face of all the lessons I'd ever heard about the importance of catenary, and the point of carrying a huge weight of chain and handling gear.

I'd like to believe an anchor is all that's needed (aside from chafe-proofing the lower end of the rode) but if that really is the case, why do the majority still carry an all-chain rode?

Many, perfectly competent sailors, in the US use only textile rode with their anchors. Admittedly on a 12:1 scope, I'd suspect that, over there, more use just textile rode than purely chain.

 

[charles_reed]

Recently we were anchored in 10 knots in a bay (Sporades). We dragged even in that wind. I dived on the anchor to watch what was happening. The anchor was completely buried in very loose sand and was dragging along under the surface leaving a cloud of suspended sand. The anchor was a Manson and 30 meters chain out in 5 meters depth.

So even at 10 knots of wind the anchor chain made little or no difference.

No doubt the chain only brigade will be along shortly!

Superfluid white mica sand. Northern Sporades was it?

I doubt any anchor would have held in that, just as it's a waste of time anchoring on the W side of Portopalo di Passero.

We have to face the fact that there are some places, however inviting, where it's impossible to anchor safely.

 

[Chris_Robb]

Superfluid white mica sand. Northern Sporades was it?

I doubt any anchor would have held in that, just as it's a waste of time anchoring on the W side of Portopalo di Passero.

We have to face the fact that there are some places, however inviting, where it's impossible to anchor safely.

Yes - The southern bay off south end of N Peristera near Alonnisos. We moved 10 meters over and all was fine. Not heard of this superfluid MICA sand before.
I am used to mud and weed types where you just abandon - having removed half a ton of bottom from the anchor with clouds of mud all around the boat.

 

[[3889]]

What a shame all that lovely yellow paint has been damaged.......

Didn't they change to a lower spec paint when they moved production to China

 

[Storyline]

As Vyv touched on, another great benefit of an all chain rode is that it self stows, stays unknotted and comes out of the chain locker smoothly !

Like others on here it was a bit of a Damascus moment when I first realised the heavy chain concept was a myth. It was during a thread on here featuring (among others) Vyv and Neeves. I started contributing to the thread with tales of how our anchor stayed put with 3/8th chain whilst our friends with 5/16th used to drag. During the course of the thread I sudzdenly saw the light - will never forget it

 

[vyv_cox]

I use virtually all rope to save weight on a multihull. Not had any wear or longevity problems or the rope getting caught round underwater bits as it still sinks. No windlass so that's not a problem. I have also not noticed too much swinging around, not more than a similar sized fin keel mono.

An advantage not mentioned so far is that without a windlass rope is a lot less effort to pull up in deep water. Two disadvantages are caused by the higher scope:depth ratio though, which are

1) more space is needed in a tight anchorage and I often get other boats anchoring too close not realizing that I have 50m of rope out.

2) I have found in Scotland where the shallow water suitable for anchoring is close to the shore and quickly deepens that the slope of the seabed is steeper than the slope of my anchor line. This makes anchorages untenable if there is a risk of swinging towards the shore for any reason as the scope required will be more than the distance from the shore at the point where it is possible to anchor. The anchorages in Tobermory are like this, for example.

I knew you used mostly rope and almost mentioned it but thought you would like to comment yourself. The catching on keel and rudder problem has been reported by several forumites, particularly with tide direction changes. I have watched many monohulls on rope moving considerably by comparison with those on chain, especially in relatively sheltered bays in light winds. One situation where an angel could be useful.

 

[KristiferColumbus]

There have been a number of anchor threads on YBW where posters have expressed the surprising view that it is the chain that really holds the boat. Such discussion has cropped up repeatedly in many anchor threads. Someone even suggested doing a trial and anchoring without the anchor.

I came across this example that proves that the chain on its own, or even with a weight attached to the end has very little holding power. Hopefully the photos prove the point.

It was a Kobra, but the skipper left out the bolt holding the fluke at the correct angle. This made the anchor little more than a dead weight. Of course if the chain was doing all the holding of the boat, the anchor being defective would make no difference and the boat would be held quite nicely.

As most of would expect this was not the case. The skipper re anchored three times and dragged slowly each time in the light wind. As he became more frustrated he laid out more chain with each attempt.

My wife explained the problem to the skipper and he subsequently fixed the anchor.

This was the photo of the anchor dragging. You can see it was lost in the disturbed sand. On each of the three occasions the boat dragged over 100m due to the ineffectual anchor.

This makes the missing bolt clearer. The anchor would not sit still.

I am afraid these are not good quality photos because of all the disturbed sand. I have been trying to take some better photos of anchors underwater to show what is going on. Here is a Rocna doing what an anchor should do which is a lot more that just decoration. (OK, this is really included just because it nice picture )

I'm stunned.Now I know why just tying a pair of old trainers on the end of my anchor line never worked.

 

[AngusMcDoon]

I have watched many monohulls on rope moving considerably by comparison with those on chain, especially in relatively sheltered bays in light winds. One situation where an angel could be useful.

In light winds I agree that there is more wandering around on rope only, but as soon as there's enough breeze that all the boats are sitting the same way then the wanderings diminish. I use less scope in light conditions if the wandering around is a problem.

 

[noelex]

I saw another example today that proves the anchor is responsible for most of the holding power.

This boat dragged 60m. I can dive and see the anchor is not working, (see the photo, not even the tip is engaging) but why isn't the chain on its own holding the boat if the chain is responsible for most of the holding?

If the chain is normally holding the boat what has stopped the chain holding the boat on this occasion?. There was plenty of scope. The chain was an appropriate size. What else is there?