Anchor chain or chain, warp combination ?

[tsekul]

Thanks for all the responses.

Another question regarding the scillies in particular. In some of the small anchorages do you ever see people taking a stern line or two ashore ?

Also any thoughts experiences of Bread and Cheese cove on St. Martins or a snug anchorage between Little Arthur and Authur head on the Eastern Isles. I am sure we will be starting in the usual spots but I do love studying charts !

Thanks
T

 

[mjcoon]

It's what works that is in fashion on my boat.

- W

Well, I suppose 20/20 hindsight has its uses...

Mike.

 

[jdc]

Thanks for all the responses.

Another question regarding the scillies in particular. In some of the small anchorages do you ever see people taking a stern line or two ashore ?

Also any thoughts experiences of Bread and Cheese cove on St. Martins or a snug anchorage between Little Arthur and Authur head on the Eastern Isles. I am sure we will be starting in the usual spots but I do love studying charts !

Thanks
T

I have never seen anyone using a line ashore in the Isles of Scilly, but I have used two anchors to restrict swinging.

Bread and Cheese cove, and the adjacent Stony Porth both have rather poor holding because they're stony, and are in my opinion not that attractive. But on the N side of St Martin's I do like Little Bay or Great Bay, or anywhere inshore of Mackerel Rocks, where there's sand. One will usually be quite alone and (but not in a NE'ly!) very peaceful in good holding and sheltered from swell.

I have anchored in sand between Great Ganilly and Little Arthur a few times and it's very pleasant. The tide does run through, and so do some inter-island tourist boats. However on a calm evening it's a magical place. But I think you are referring to Arthur Porth which is nearer Little/Great Arthur (they, and middle Arthur, are hillocks on the one island). This is rather stonier and weedy so with our slightly larger boat we've kept out but I have seen yachts anchored there.

 

[G12]

Well, as someone who goes to Scilly with a similar sized boat I can tell you that I used to have a genuine CQR on chain/warp and it was ok there. However, Scilly isn't noted for the quality of its holding ground and I did drag a bit there a couple of times despite having plenty of scope out. The way I got around that at the time was to use an anchor chum (mine is a big lump of lead with a shackle at the top) at the chain to warp splice and this seemed to make a large difference when a blow went through.
I now have a Spade anchor with chain/warp and it hasn't moved an inch every time I've used it. I'm not saying go and buy a Spade but I'm saying you might find one of the modern anchors a bit better there especially as they nearly all reset better than a CQR which can be a pain sometimes.
One of the nice things about having a decent anchor in Scilly is that you can avoid rolling like a pig in St Mary's harbour in bad weather with all the other yachts. Just go and find your own safe spot and you'll be much comfier.

 

[lw395]

Since I am converting to rope, as described above, having previously always used chain, what are people's thoughts on using a kellet to provide a little drag on the bottom and avoid drifting around too much in light conditions?

Pete

I tend to keep the kellet off the bottom.
It works for me, especially in light swell where the boat otherwise seems to wander about.
In moderate breeze it damps the motion better than rope alone.
In strong breeze I tend to go somewhere secure, haven't really pushed the limits TBH.

 

[prv]

I tend to keep the kellet off the bottom.

Interesting - so the warp hangs more or less straight down to the kellet, then you have a loose length of warp floating about until it gets to the chain? I'm surprised that has any effect on drift as the drag of a bit of nylon across most seabeds must be minimal.

Pete

 

[mjcoon]

Interesting - so the warp hangs more or less straight down to the kellet, then you have a loose length of warp floating about until it gets to the chain? I'm surprised that has any effect on drift as the drag of a bit of nylon across most seabeds must be minimal.

Pete

Surely the kellet (never heard that name before, except for a surname!) would not be dropped until the warp had been stretched out by a bit of reverse and digging-in. Thus it would be in a straight line rather than "a loose length of warp floating about"?

Mike.

 

[tsekul]

Excuse my ignorance but what's a Kellet ?
I assume it's a weight to keep the chain / warp on the sea bed ?

If so what's to stop you, in a blow, having two anchors on on a length of chain with the warp coming off one

 

[vyv_cox]

Excuse my ignorance but what's a Kellet ?
I assume it's a weight to keep the chain / warp on the sea bed ?

If so what's to stop you, in a blow, having two anchors on on a length of chain with the warp coming off one

A Kellet, Chum, Angel, is an additional weight that can be slid down the anchor rode, on a big shackle or something similar. It used to be thought that this would improve holding in strong winds but we now know that it does no such thing. It is useful as suggested above, to reduce the tendency of the boat to wander all over the anchorage in light winds when the rode is mostly rope.

Your second question describes 'tandem anchoring'. The technique seems to be quite popular in USA but it has many problems, especially recovery. Personally I doubt if it works at all but that has yet to be proved. Far better to have one good anchor that is sufficient for the conditions.

 

[NormanS]

A Kellet, Chum, Angel, is an additional weight that can be slid down the anchor rode, on a big shackle or something similar. It used to be thought that this would improve holding in strong winds but we now know that it does no such thing. It is useful as suggested above, to reduce the tendency of the boat to wander all over the anchorage in light winds when the rode is mostly rope.

Please don't include me in your "we" above. I still believe in the benefits of catenary. This is normally achieved by using heavy chain, but can be augmented with the use of a "chum".

 

[prv]

Surely the kellet (never heard that name before, except for a surname!) would not be dropped until the warp had been stretched out by a bit of reverse and digging-in. Thus it would be in a straight line rather than "a loose length of warp floating about"?

I'm specifically talking about the case where conditions are very light, a calm windless evening say. So the warp was initially stretched out when I set the anchor, but what is going to hold it there? Chain will stay put of its own accord in light conditions, but nylon in water weighs practically nothing. So although when the wind fills in I'll hang back on the anchor, in the meantime I'm essentially drifting around on a very long leash.

(This is all kind of theoretical, as I always anchored on all-chain before)

Pete

 

[tsekul]

A Kellet, Chum, Angel, is an additional weight that can be slid down the anchor rode, on a big shackle or something similar. It used to be thought that this would improve holding in strong winds but we now know that it does no such thing. It is useful as suggested above, to reduce the tendency of the boat to wander all over the anchorage in light winds when the rode is mostly rope.

Your second question describes 'tandem anchoring'. The technique seems to be quite popular in USA but it has many problems, especially recovery. Personally I doubt if it works at all but that has yet to be proved. Far better to have one good anchor that is sufficient for the conditions.

thanks

 

[mjcoon]

I'm specifically talking about the case where conditions are very light, a calm windless evening say. So the warp was initially stretched out when I set the anchor, but what is going to hold it there? Chain will stay put of its own accord in light conditions, but nylon in water weighs practically nothing. So although when the wind fills in I'll hang back on the anchor, in the meantime I'm essentially drifting around on a very long leash.

(This is all kind of theoretical, as I always anchored on all-chain before)

Pete

Yes, I agree with all of that. (I am also more used to all-chain, except for a kedge kept mostly in a cockpit locker!)

But I am guessing that the weight, called chum, kellet, angel or whatever, acts like a single large link in the middle of the warp. Thus it can restrain the leash so long as the conditions are so light that it does not get lifted or at least not slid far from its initial location. A bit of a half-way house...

Mike.

 

[30boat]

When I had a GK29, which does not have an opening anchor locker, I felt that feeding rope down the hawse pipe was very tedious. For that reason I preferred all chain. Presumably you are used to the current rode configuration and are happy with it?

That's what's been keping my from changing to rope.The Fulmar doesn't have a locker which ,to me, was a very bad idea from Westerly.I may start using rope and keep it coiled attached to the pulpit when not in use.

 

[prv]

But I am guessing that the weight, called chum, kellet, angel or whatever, acts like a single large link in the middle of the warp. Thus it can restrain the leash so long as the conditions are so light that it does not get lifted or at least not slid far from its initial location. A bit of a half-way house...

Exactly - I see it acting kind of like a ditch-crawler's "mud weight", holding the boat on a near-1:1 scope in the lulls, occasionally being shifted a little in the puffs, and becoming completely irrelevant when wind or tide comes back properly.

However, lw395 says he doesn't let his touch the bottom, so the above wouldn't apply. Hence my query, which he hasn't responded to.

Pete

 

[Birdseye]

Since I am converting to rope, as described above, having previously always used chain, what are people's thoughts on using a kellet to provide a little drag on the bottom and avoid drifting around too much in light conditions?

Pete

I wouldnt be too keen. In a strong breeze, the weight would rub and weaken the rope unless you can find a way of attaching it that I am not aware of. In any case provided you have sufficient scope of rope to allow the pull on the anchor to be at the angle it is designed to take, there is nothing much to be achieved by lengthening the scope unlike with chain.

There are two issues with anchor rodes. The first one is the angle of pull. The anchor is designed to take some upward pull and still to try and dig itself downwards into the muck. The second issue is shock absorption and here chain and rope work differently. The catenary in chain absorbs shock and since bar tauat chain will jerk horrendously, the worse the weather the bigger the catenary you need. With rope you absorb shock much better with elasticity so you dont need to lengthen in the same way. So you start off with a longer scope on rope than chain to get the angle right - the catenary helps in this respect. But as the wind rises you have to let out more chain than you do rope.

Or thats the way I see it.

Incidently, use the thinnest stretchiest rope that will hold and give some abrasion resistance.

 

[noelex]

In any case provided you have sufficient scope of rope to allow the pull on the anchor to be at the angle it is designed to take, there is nothing much to be achieved by lengthening the scope unlike with chain.

There are two issues with anchor rodes. The first one is the angle of pull. The anchor is designed to take some upward pull and still to try and dig itself downwards into the muck.

Rather than a "designed angle" an anchors holding ability increases as the pull becomes lower in other words more parallel to seabed.

Good anchors will still dig in and hold as the rode angle rises above the seabed to quite a remarkable degree, but the depth of bury and the holding ability will be greater if the pull is is more horizontal.

There are some very rare exceptions such as initially setting a Fortress anchor in an extremly soft substrate, or the very unusual mark 1 XYZ anchor, but in most cases as the scope goes up so does the anchors holding ability.

The law of diminishing returns starts to set in about 10:1-14:1 where the angle of pull is so shallow there is little extra benifit of more scope.

Fortress produce a table showing the relative holding power of their anchor at different scopes. Although the results vary from design to design this table provides a rough rule of thumb for many anchor models:

2:1 10%
3:1 40%
5:1 70%
7:1 85%
10:1 100%

 

[Storyline]

..... In any case provided you have sufficient scope of rope to allow the pull on the anchor to be at the angle it is designed to take, there is nothing much to be achieved by lengthening the scope unlike with chain.
..... So you start off with a longer scope on rope than chain to get the angle right - the catenary helps in this respect. But as the wind rises you have to let out more chain than you do rope.
.....

Agree with you think you are maybe putting too much emphasis on the snubbing effect of the rode. The rode (chain or rope) has only two significant functions, providing the correct angle of attack onto the anchor and being strong enough not to break. Now we (except NormanS) know that the affects of the catenary dissappear in anything over modest winds the rode could even be wire if it was strong enough. The way to snub the anchor is to use a snubber.

Also cannot see the purpose of a chum that is not on the bottom.

 

[snowleopard]

I have 20m of chain and 80m of rope. When I started I would just use the chain when anchoring in shallow water. Now I always run out all the chain, it's so ****** noisy if the chain is in the roller.

 

[vyv_cox]

Agree with you think you are maybe putting too much emphasis on the snubbing effect of the rode. The rode (chain or rope) has only two significant functions, providing the correct angle of attack onto the anchor and being strong enough not to break. Now we (except NormanS) know that the affects of the catenary dissappear in anything over modest winds the rode could even be wire if it was strong enough.

This photo was taken by 'Noelex's mermaid' and shows nicely how catenary does nothing once the pull on the rode is over a relatively modest amount. 16 kg Rocna, 8 mm chain, scope about 4:1. The engine is pulling astern at about 2500 engine revs. We know from many other observations that this level of pull corresponds with a wind strength of about force 6, certainly more than force 5. Alain Fraysse's calculations show that the effect of going to 10 mm chain, or adding weight in the form of a Chum, is very limited.

Several well-known long distance sailors (e.g. Paul and Rachel Chandler) have changed from 10 mm Grade 30/40 chain to 8 mm Grade 70, taking advantage of a significant weight reduction, almost doubling of strength, and after understanding that catenary is valueless.

Note also, harking back to previous discussions about swivels, how twisted my chain is.