JumbleDuck
Well-Known Member
The CCC book (and conventional wisom) have said for decades that one should carry a big fisherman's anchor for anchoring in seaweed. I have never heard of anyone actually doing so, though. Anyone here use one?
8mm Anchor chain?
- Thread starter Niander
- Start date
The CCC book (and conventional wisom) have said for decades that one should carry a big fisherman's anchor for anchoring in seaweed. I have never heard of anyone actually doing so, though. Anyone here use one?
vyv_cox
Well-Known Member
Assuming a reasonably sheltered anchorage with a fetch of no more than a couple of hundred meters I find from observations that it's the yawing of the boat, rather than waves, that seem to cause the biggest pull. My longest period of observation was at Cala di Lupe, just south of Porto Cervo in Sardinia, where we spent several days of fresh to strong winds anchored with a scope of more than 10:1 in very shallow water. The chain was lifting totally off the bottom at about the end of every swing, corresponding with heavy jerking of the boat. I carried out quite a few trials of methods of reducing these snatch loads, using a long snubber and, eventually, two anchors. The snubber was very effective, the Delta, which we had then, seemingly unconcerned and unmoving. However the two anchors were far more comfortable for us on board and snatch loads, although still there, were much reduced.
lw395
Well-Known Member
Good info, thanks.
57knots (from your earlier post) is not my idea of a 'reasonably sheltered anchorage', that's 'check insurance' territory on my permanent mooring.
lw395
Well-Known Member
I have a modest one, use it for laying racing marks sometimes, FWIW.
Not very good in mud, as you might guess.
vyv_cox
Well-Known Member
No significance in the 57, was just the bottom of the screen when scrolling the cells down in the spreadsheet
Maximum we saw during our Cala Lupe period was 45 knots, quite tiring when on anchor (but better than at sea).
noelex
Well-Known Member
This is some video I took earlier in the year. The beginning shows some of the yawing of the boat that occurs in stronger conditions.
NormanS
Well-Known Member
Thanks for that, Vyv. I didn't think that there would be any problem with my 10mm chain, in the winds that I can reasonably expect, and have experienced. My reason for having chain of a size which you, and many others here, consider to be too heavy, is that even in strong winds, my set-up still benefits from good old fashioned catenary.
My present boat is a deck-saloon ketch, so probably has more than average windage, so I tend to have gear which is "robust".
Someone mentions yawing. I am having good results with a double-winged anchor-sail, hoisted on the mizzen, and sheeted back to each quarter. It seems to cut down yawing a lot.
NormanS
Well-Known Member
I carry a 20kg fisherman anchor, but to be honest, I think I've only used it once on my present boat. My main anchor is a genuine 20kg Bruce, and my second is now a 8 or 9?kg Fortress, which has satisfactorily replaced my genuine 20kg Danforth, (which is now looking for a home, - any takers?).
As to anchoring in weed. I try never to do that, and as you may know, I advocate having a fishfinder to find good clean holding.
JumbleDuck
Well-Known Member
Thanks. I have a CQR as my main anchor and some dubious looking Danforth thing - may well be a real Danforth - as backup, though I have never used it.
One of the things I miss about the Seafarer whirlie in my last boat is the ability to assess the bottom by the hardness of the echo. However, as I only draw 3' I normally anchor close enough in to have a good look!
NormanS
Well-Known Member
Yes, you are quite correct, the old Seafarer whirly things were far and away superior to something which just gives a number.
That video is an example IMO as how it should be done, at least it follows what my ancestors taught me, and has served me very well indeed. With respect to those who prefer all rode, I would not have wished to be on board, anchored in the conditions shown on the video, with just rode only, for me there is no substitute for heavy tackle. The trim arguement does not hold to much water, it is entirely possible to have heavy tackle and a good trim.
+1 Sounds similar to mine, 10mm chain and I use my mizzen sheeted midships, keeps me nose on and very comfortable.
vyv_cox
Well-Known Member
That's pretty much exactly what we do, although I think his snubber is a bit too heavy. Have to say though, I have seen photos and text of Alain Poireaud anchored in the Magellan Strait on his Hylas 48 in a great deal more wind than that on almost all rope (just a few metres of chain for wear resistance). He was a great advocate of mixed rodes and backed up his writing with real world experience.
JumbleDuck
Well-Known Member
Erm, isn't whatever joins the boat to the anchor called "rode", regardless whether it's made of cable, chain or rope?
I understand rode to mean anything other than chain, but I see your point, although most speak in terms of an x amount of chain with a y amount of rode, meaning rope of one sort or another, could me mistaken.
We work with all chain and snubbers 10m long set up as a bridle (10m each side). Our bridles are 12mm but we would replace with 16mm if the winds were actually to be over 35 knots.
I like the idea of a mixed rode but never quite worked out how you decided on what length of each. If you have say 20m of chain and 40m of rope you would always need to deploy 30m in order to benefit from the elasticity of the nylon - and that might be too much for the anchorage. In coral 20m of chain might be too little.
What to do?
Jonathan
I like the idea of a mixed rode but never quite worked out how you decided on what length of each. If you have say 20m of chain and 40m of rope you would always need to deploy 30m in order to benefit from the elasticity of the nylon - and that might be too much for the anchorage. In coral 20m of chain might be too little.
What to do?
Jonathan
If the SWL is 1,275kg then the chain should have been proof tested to 2,550 kg. Yield will be at about 2,700kg and break at about a min of 5100kg min, and it should stretch between 15% and 20% between yield and break. My testing of G40 suggests that actual break will not be much more than min break. However if you ever load beyond yield you will start to notice the chain will no longer fit the gypsy.
Basically newish chain should never break (including G30) - unless grossly undersized, something else will fail first - and stories of chains breaking are non existent.
I am with Vyv: on the assumption the anchorage is sheltered from 'seas' and swell its all about yawing, caused by wind sheer (and those previously mentioned bullets). Snubbers must be a first line of defense and we would be deploying a second anchor if winds are expected to be over 30 knots (in the anchorage) as 2 anchors set in a 'V' steady veering. As we anticipate setting two anchors (to enjoy the dampening of the 'V' we do not carry oversize models (as deploying an oversize anchor, unless it is alloy) means you must deploy and retrieve from the yacht and retrieving an oversized anchor by hand simply does not appeal (especially as it is unnecessary).
Jonathan
PS, edit We find that at about 30 knots the load, or tension, on the snubber, is less than 100kg. Note this is the load on one snubber of the 2 that make up the bridle. We find each side of the bridle takes the full load, but for half the number of times, as the yacht (cat) veers. There is some friction in our bridle (which will reduce bridle life) and we use climbing rope (rather than 3 strand or octaplait). We have never used a load cell over 35 knots, it takes too long to set up and we are usually wondering about other things.
Further edit - I like the idea of a riding sail, for a cat, but cannot work out how to deploy.
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Storyline
Well-Known Member
That is a similar dilemma we had when I was considering of going to mixed rode. If you always anchored in the same depth it would be easy but to get the benefit from the rope part it would mean always having to veer a certain amount which might be too much if in shallow water with other boats on all chain. The only way round it is to have a very short length of chain which just does not sit right with me. Another reason (for us) to continue with well snubbed all chain is that I prefer to have chain going over the bow roller albeit just sitting there under no load. Understand that chain then rope gives the potential for limitless scope in a storm/survival situation and I would be acutely aware of chafe but for routine use I would fret that the rope would chafe through. There are no doubt ways to overcome the chafe but it just adds unnecessary complication and surely 10m of snubber has a similar effect as 10m of rope rode.
JumbleDuck
Well-Known Member
My last 8mm chain snapped in 40 - 50kt gusts on the Firth of Clyde. Offshore wind, smooth water, 25lb CQR, 26' boat, remaining chain looks fine.
Chain from a reputable supplier is marked. The markings are simple but can usually be used to define the manufacturer. At the least - in your case they will include something that defines 'quality' or Grade, a 3 or a 4. Chain cannot be sold in America unless it is marked. If its is not marked - you have no idea off the quality, Grade, nor manufacturer. What are the marks on the chain you had that broke?
Jonathan
