How much anchor cable for North Brittany?

[Chalker]

"There is no force however great will stretch a twine however fine into a truly horizontal line."
You will ALWAYS have a catenary, sometimes it is only a small dip but it is never staight (OK, before someone leaps in - it will be in zero gravity)

 

[LadyInBed]

In areas with a big range and stronger currents you may need to be concerned about the rope part snagging your prop or even your keel when the tide turns. This is one of the few occasions where you may find an angel to be useful, holding the rope on the bottom.

An anchor chum (Angel, Sentinel, Buddy, Kellet) on the rope part can be helpful in this situation to keep the rope vertical on the tide turn.
I carry one of 14 kg (equivalent to 10 mtrs of 8mm chain), I wouldn't go less than 10 kgs.

 

[Poignard]

You only anchor in places that dry at LAT, then?

Pete

Not intentionally . But I should have said my 5 metres includes an allowance for draft and for clearance under the keel. It's only a rough calculation FGS

 

[Babylon]

An anchor chum (Angel, Sentinel, Buddy, Kellet) on the rope part can be helpful in this situation to keep the rope vertical on the tide turn.
I carry one of 14 kg (equivalent to 10 mtrs of 8mm chain), I wouldn't go less than 10 kgs.

What's your setup in terms of shackle to Chum/Angel and line to bow roller - and how far down the cable do you set it?

 

[Pleiades]

How much anchor?

Scope ok by me but anchor a bit skimpy methinks.
My highly unscientific( but well tested by me!) working formula for anchor weights is that a lb of anchor per foot of boat length is the absolute minimum - irrespective of the type of anchor and I use the lb per foot ratio only for my kedge and spare anchors. So my 35 footer dangles contentedly on a 44lb hook. The Vancouver 27 is not a lightweight vessel by any means so I would not sleep content unless I had a 35 lb main anchor on her - and although I will be flamed for drifting the thread too much - I would relegate that CQR to spare duty and get something with more staying put power.

Robin
Pleiades of Birdham
MXWQ5

 

[Babylon]

Scope ok by me but anchor a bit skimpy methinks.
My highly unscientific( but well tested by me!) working formula for anchor weights is that a lb of anchor per foot of boat length is the absolute minimum - irrespective of the type of anchor and I use the lb per foot ratio only for my kedge and spare anchors. So my 35 footer dangles contentedly on a 44lb hook. The Vancouver 27 is not a lightweight vessel by any means so I would not sleep content unless I had a 35 lb main anchor on her - and although I will be flamed for drifting the thread too much - I would relegate that CQR to spare duty and get something with more staying put power.

Robin

Pleiades of Birdham
MXWQ5

Hi Robin, I'm an open-minded sort of fellow and appreciate your input. What anchor with more staying power would you - or the veritable panel - recommend?

 

[Roberto]

What anchor with more staying power would you - or the veritable panel - recommend?

that is the sort of question where usually one half of registered users is answering and one half of registered users walks away and will never look at this thread again

 

[Babylon]

that is the sort of question where usually one half of registered users is answering and one half of registered users walks away and will never look at this thread again

 

[Pleiades]

Staying put power.

Many different opinions about what is the best of the new anchor designs but I think it is fair to say that the balance of opinion is that the CQR is definitely inferior to more modern anchors. If you look at the various anchor comparison tests then the failings of the CQR are hard to dispute. If money is tight a Delta is imho significantly better for modest outlay. They are cheap enough to buy comfortably oversized. The Vancouver will obviously carry the weight fine on the bow but a windlass will be necessary unless you have arms and a back like a gorilla. I have recovered my 120m of 10 mm chain and 44 lb anchor by hand but once only was enough of that labour!
If you can take the hit on the wallet then a Spade or a Manson will be better again. The Kobra 2 also gets a good write up although I have no experience of them myself. The Rocna design suffered from disgracefully slovenly manufacturing process a year or two back when they decided to downgrade the steel without telling anyone but the latest ones should be fine - hopefully - and the basic design is very good.

Robin
Pleiades of Birdham
MXWQ5

 

[LadyInBed]

What's your setup in terms of shackle to Chum/Angel and line to bow roller - and how far down the cable do you set it?

Chum attached to anchor rope with large shackle around rope.
Control line attached to small shackle on Chum.
Chum lowered down anchor rope to a depth just less than depth at LW measured on control line.

 

[Iliade]

pinga...

Should be no problem.

I have got by with 45mts of chain on a similar boat. I generally scuttle to somewhere more secure/comfortable if the weather is rotten.

But what to do if the blow lasts longer than your air tanks?



I'll get my coat...

 

[vyv_cox]

Many different opinions about what is the best of the new anchor designs but I think it is fair to say that the balance of opinion is that the CQR is definitely inferior to more modern anchors. If you look at the various anchor comparison tests then the failings of the CQR are hard to dispute. If money is tight a Delta is imho significantly better for modest outlay. They are cheap enough to buy comfortably oversized. The Vancouver will obviously carry the weight fine on the bow but a windlass will be necessary unless you have arms and a back like a gorilla. I have recovered my 120m of 10 mm chain and 44 lb anchor by hand but once only was enough of that labour!
If you can take the hit on the wallet then a Spade or a Manson will be better again. The Kobra 2 also gets a good write up although I have no experience of them myself. The Rocna design suffered from disgracefully slovenly manufacturing process a year or two back when they decided to downgrade the steel without telling anyone but the latest ones should be fine - hopefully - and the basic design is very good.

Robin
Pleiades of Birdham
MXWQ5

An excellent summary of informed thinking.

I changed the CQR that my original boat came with for a Delta in about 1990. It gave a significant improvement in setting and holding, both anchors 25 lb. The Sadler came with a 25 lb CQR that I upgraded to a 35 lb Delta and used successfully for the next 15 years, between the Baltic and Greece. The only negative experience with it came when we dragged on a soft mud bottom in a horrendous amount of wind in Vliho, other than a failure to set once on a very hard sand bottom. Incidentally the Kobra 2 appears to be a Delta fluke on a Spade shank. I have heard no bad and plenty of good about it. Like the Delta I would expect it to perform very well in typical Atlantic coasts that have a good proportion of sand in their bottoms, but where the bottom is mostly fine mud it will tend to drag like the Delta in a lot of wind.

I replaced the Delta with a Rocna, fortunately one made in NZ with the original shank. It sets about the same as the Delta but should hold better in the bottoms that the Delta does not like, although I have read that it can be problematic in extremely soft mud. But what anchor would work in that?

For general use around most of the UK coast a Delta, or Kobra 2, would be hard to beat. Indeed, when I bought my motorsailer I sold the CQR it came with and bought a Delta.

 

[TimBennet]

. . . it can be problematic in extremely soft mud. But what anchor would work in that

Fortress with the blades set at the larger angle.

 

[doug748]

Hi Robin, I'm an open-minded sort of fellow and appreciate your input. What anchor with more staying power would you - or the veritable panel - recommend?

Babylon is being a little imp.

He knows full well that if his CQR does not drag in the UK it will not drag in France. I just might suggest that an extra 15 or 30 fathoms of chain is added to the rest, to complete the picture.

I am not a big fan of routinely throwing out miles of stuff at anchor (esp rope), in snug Brittany anchorages. They often have nearby rocks, seafood larders and boats; with a healthy, inponderable, tidal flow.

 

[vyv_cox]

Fortress with the blades set at the larger angle.

I have one for that very reason On the occasion of the major blow in Vliho I would have used it but during our efforts to set and reset our Delta I managed to trap my little finger between chain and windlass and was unable to do so. We reversed upwind into the mud until the rudder felt the bottom and tied the boat back to trees, always a great solution to tricky anchoring.

 

[chrisclin]

Babylon is being a little imp.

I am not a big fan of routinely throwing out miles of stuff at anchor (esp rope), in snug Brittany anchorages. They often have nearby rocks, seafood larders and boats; with a healthy, inponderable, tidal flow.

I agree with this. In most Brittany anchorages, I ended up adjusting the anchor chain every couple of hours. With a Spring tide you will have 60 metres more slack in your anchor cable at low tide than at high and there always seem to be oyster farms exactly where you would end up!

 

[jimbaerselman]

Quite happy to justify the figures with details of the various forces involved - vertical, tensional and horizontal. They're based on a standard shaped 8m monohull, 30m of 8mm chain and 50m of warp, with up to 30° of yaw, and do not include snatching forces.

Of course, snatching forces as the boat reverses from side to due to yawing in stronger winds (in areas where there is little current) by far exceed any steady state forces.

'no catenary whatsoever' is an interesting comment. Perhaps your chain was 'bar tight', but it would have been in a curve unless the chain was made of a very light metal

I would have said "no detectable catenary", ie, less than a couple of degrees. Quite a common condition in the Med when the big winds blow offshore in many anchorages. Less common in Brittany's steep sided estuaries where tidal currents dominate, but something to think about when the "Vent Solaire" blows up at 0300 in some of the popular more open anchorages in S Brittany; places like Glenans, and Ile Houat. Or Port Blanc for big W or SW winds.

Plenty of moorings and marinas around the area, though, if the forecast is bad, so stronger wind anchoring is less of an issue in the Channel or Brittany.

 

[Tintin]

Babylon, I know what they say about Chinese chain, but I don't reckon you can go wrong really.

 

[Babylon]

Babylon, I know what they say about Chinese chain, but I don't reckon you can go wrong really.

Red,

I'm so grateful to all those who've contributed their expertise to this thread, and have now come up with a cunning plan!

I'm going to defer the cockpit enclosure for another year and spend the money instead on 80m of 8mm calibrated chain with a 16kg Lewmar Delta anchor or a Kobra 2 equivalent (the Rocna or Manson are way too expensive), and so can fit a windlass either now or later.

Don't forget, she's a heavy old bird for her size - and I've been warned by a Frenchman to only use all-chain on that rocky coast!

I can of course keep (and stow low down) the old 25lb CQR with its 30m chain and 50m rode as spare ground tackle, and practice Bahamian and V-moorings in Southampton Water... instead of chasing wealthy widows!

Babs

 

[Uricanejack]

I have 30m of chain (8mm) plus 50m of rode (16mm if I recall correctly), a total cable of 80m. Will this be sufficient scope for a month's cruise on the N Brittany coast?

For rope use
Divide x 5.
=Max Depth of water to anchor in good conditions. stormy use 7x depth

For all chain use x3 or x 5 for stormy.

Drop you 30m of chain in 10m plus some rope and you should be good for most summer conditions.
PS for scope use high water depth. For location at least 20% more than draft at low water.