Cruising Anchor Chain Length

[wingssail]

Originally Posted by Montanan

Now I have never seen or heard this being done, but just imagine if one was able to rig a system wherein the barrel of chain was transported to a hollow in the keel of the boat so as to add weight for stabilization when sailing and to store it out of the bow while sailing. It would require some kind of a conduit or puller to gently get it to travel from the primary lifting windlass towards the inner keel storage space, a low powered drum with a few wraps of chain around it would seem to avail enough friction to draw chain from the bow to the keel in a metal tube. A barrel's weight of chain being used for righting the boat and providing for long length of rode for deep anchorages.

At least two boats owned by commenters on the forum have an arrangement that works:

The windlass is mounted far from the bow.
A board or rubber mat is attached to the deck for the chain to run along from the roller to the windlass.
The chain locker is directly below the windlass (in my case not quite). No drum or tube or puller is needed.
The chain drops into the locker. We don't drop the chain into the keel void but into a locker on or below the level of the cabin sole near the top of the keel.

One disadvantage of this are that the chain is then in the cabin and must be clean or it stinks. We have a powerful washdown system and the length of chain running on deck give us an opportunity to brush it if needed.

Besides having the weight back in the center of the boat and low where it reduces pitching and can increase righting moment instead of in the bow, it allows the chain to dry out and stay dry, rusting less and lasting longer. Our chain has been in continuous use since 1993.

[charliehows]

Originally Posted by roverhi

We carried 70m/230' of 3/8" high test chain on a 20,000# boat with a 45# CQR in French Polynesia and only used the full length once. That was a forecast tropical depression with 50 mph plus winds. We were in 30' feet of water and let out the entire length just because we could. Always used a 30' 5/8" three strand nylon snubber.

The problem with rope rode is abrasion where it passes through chocks on the boat. Stretch under a heavy load will pull the line past the chafing gear leaving the line unprotected. From experience it is no fun trying to add chafing gear to a line where it passes through a chock in 40k winds. If you chose to slowly pay out rode to vary the chafe point be very careful. In high winds the force on the line is tremendous and it can get away from you.

I was wondering if anyone has experimented with chain-rope-chain combination? chain on the seabed is obvious, rope for weight advantage and deep anchorage also obvious, chain at ship end for antichafe, damage from boats over-running etc also obvious, but I havent heard anyone discussing incorporating rope into a 2 ended chain rode.

[GRIT]

Touchy subject, interesting reading.

As far as sleeping in 25 knots of wind... We only stay up if there are boats upwind of us, where we question their ability to stay put. Usually, if possible, we'll move if there are those types upwind of us. 25 knots isn't much of a blow, the Christmas winds in the Caribbean are 25 knots.

We always had an oversized Bruce (both previous boats). 15kg on our Hughes 35 (5 tonne boat) 30kg on our Corbin 39 (12 tonne boat). We were always happy using 3:1 scope, up to about 25 knots, we'd then increase the scope to 4:1 or 5:1. We sat out Hurricane Juan, in Halifax, with 90 knot winds. We had out 10:1 scope, which was all we had. I wasn't trying to prove anything to anyone, that's a survival situation! It held.

Our boats weren't named Jedi, but we seemed to have similar missions, when it comes to helping dragging boats, and ill-equipped boats. We were, perhaps, "padawan"?

Our new boat has our old 30kg Bruce as "second chair", we'll test it out, but I don't know if it'll hold, with all the windage. The primary is now an S 200, Spade anchor. It's a beaut, at 55kg, and 2000 cm2. It's attached to the boat with 10mm chain, 75m long, and will have another 100m of line attached to the end of the chain.

I can't, yet, accurately comment on our scope, as it's not yet marked. But I'm timing my chainfall, and am letting out about 3:1. It seems to hold fine. I set it with around 5:1 a couple of days ago, while expecting 35 knots gusting to 50 knots, with very good protection from wave action, and little protection from the wind. I was monitoring closely, as this was a good test for the new gear. We got the promised gale, with 45 knot gusts, and she never budged. I'm pleased with the anchor so far. I never thought I'd be happy with a "non Bruce" anchor, but so far, so good. It looks as though I can keep anchoring with similar scopes, as that used on my previous boats. Kudos to large Spade anchors.

The chain stows just ahead of the mast, 5.5 metres from the bows.


The boat is a 15m, Kurt Hughes Catamaran. We had him modify it quite a lot, to fit our thoughts on what our "perfect" boat would be. Fully loaded and fuelled (750l), but without mast and sails, she tips the scales at 8 tonne, but with lots of windage. Again... so far, so good.

For those with raised eyebrows, regards the 750l fuel, most of that is used for heating. The two "day tanks" are 100l each, we only plan to use the larger tanks for offshore work, or wintering in interesting places. This year, it's Halifax.

Cheers all.
Paul.

[wingssail]

Originally Posted by charliehows

I was wondering if anyone has experimented with chain-rope-chain combination? chain on the seabed is obvious, rope for weight advantage and deep anchorage also obvious, chain at ship end for antichafe, damage from boats over-running etc also obvious, but I havent heard anyone discussing incorporating rope into a 2 ended chain rode.

The method we've used in really tough conditions, where chafe on the snubber is bad and the anti chafe gear is melting due to the heat of the nylon stretching over the roller, is put on a length of non stretchy line, double braid polyester for example, through the chafe gear and over the roller, then tie on the nylon snubber, at least 20 feet, and chain hook to the chain.

[noelex 77]

Originally Posted by Canderes

i'm not talking about chain angle! I'm talking about anchor (shank) angle!
Handbreit

That is my point. You have to have a extremely short scope, much less than 3:1 before the anchor shank angle reaches 8° when the anchor is set properly in a typical substrate.

[Dockhead]

Originally Posted by noelex 77

That is my point. You have to have a extremely short scope, much less than 3:1 before the anchor shank angle reaches 8° when the anchor is set properly in a typical substrate.

Alain talks about it here:




"[M]ost anchors are somewhat tolerant to moderate positive angulations . . . because the resistance of the soil on the fluke(s) creates a torque that tends to pin the shank to the bottom (fig. 4.5). Hence, as long as the anchor holds, the angle between its shank and the bottom is significantly lower than the rode angulation ."





Anchor

[At Peace]

Originally Posted by CAVOK

Is there any consensus about what is the ideal anchor chain length to carry on a cruising yacht. We intend to cruise the Med then over to the Caribbean and possibly further, so there isn’t any specific cruising area. I intend to have only chain as I will be anchoring out as much as possible. Ideally the more the better, but cost, weight and it’s distribution also have some bearing. Thought there might be some long-term cruisers that may have an opinion based on experience.

100 m minimum of ALL chain paid out as needed to provide the anchor with horizontal pull. If you don’t have it, you can’t use it. There are many heavyweight items that can be debated weather to carry aboard, the anchor and chain should not be one of them. Your ground tackle is your primary insurance policy and probably the only one that will pay for itself.

[wingssail]

Originally Posted by CAVOK

Is there any consensus about what is the ideal anchor chain length to carry on a cruising yacht. We intend to cruise the Med then over to the Caribbean and possibly further, so there isn’t any specific cruising area. I intend to have only chain as I will be anchoring out as much as possible. Ideally the more the better, but cost, weight and it’s distribution also have some bearing. Thought there might be some long-term cruisers that may have an opinion based on experience.

Already answered, but for reiteration, 100m, in my opinion, is not needed.

We have been cruising since 1996. We have 85mt of 5/16 high test chain (275 ft). We have rarely used all of this. We have 100mt of 5/8 nylon rode, which we have never used. We have a 44lb Bruce anchor. It has always held. We have a 66lb Bruce anchor which we have deployed twice, (and at each instance the 44 was holding, but we were nervous). Of course the 66 held as well.

To deal with the weight of the ground tackle we have it stowed in a locker below the cabin sole well aft, near the mast, and only one anchor, the 44, is on the bow.

We set our anchor well, we never drag, and we sleep well at night (and we use an electronic anchor watch).

We have a 43 ft boat with high freeboard.

People who advocate insanely large anchors are foolish, in my opinion.

[slug]

Originally Posted by CAVOK

Is there any consensus about what is the ideal anchor chain length to carry on a cruising yacht. We intend to cruise the Med then over to the Caribbean and possibly further, so there isn’t any specific cruising area. I intend to have only chain as I will be anchoring out as much as possible. Ideally the more the better, but cost, weight and it’s distribution also have some bearing. Thought there might be some long-term cruisers that may have an opinion based on experience.

In regions like the Med you are plagued by posidonia grass

This grass is photo synthetic.... it needs sunlight

As s result the 5 to 15 meter depth range is unusable

Dense posidonia grass beds



You will be anchoring in 15 to 30 meters of water

100 meters of chain is a good compromise

Be alert , some anchor chain lockers are poorly designed and can’t handle the physical bulk of s long chain

It this is your situation , shift down one size diameter and shift up from normal anchor chain to high strength G 70

[Jenneau Owner]

Some good advice above.
I have been in the Med and now Greece for some time and are virtually always at anchor either stern to or swinging. Anchoring in 10-15 meters is normal even when going stern to. The Agean can be very windy but we have only ever dragged once and that was in a 8/9 and probably weed.
I carry 80 meter of 10 mil chain plus warp. I concur 80-100 is sensible.

[Montanan]

Originally Posted by slug

In regions like the Med you are plagued by posidonia grass

This grass is photo synthetic.... it needs sunlight

As s result the 5 to 15 meter depth range is unusable

Dense posidonia grass beds



You will be anchoring in 15 to 30 meters of water

100 meters of chain is a good compromise

Be alert , some anchor chain lockers are poorly designed and can’t handle the physical bulk of s long chain

It this is your situation , shift down one size diameter and shift up from normal anchor chain to high strength G 70

I have an alternative perspective, a Green Sailing perspective. The areas are not plagued by posidonia grass, they are blessed by posidonia grass,

Please anchor in areas designated by the buoy markers or where clear sand is visible from the surface. Do not damage natures sea meadows by dropping anchors and dragging chain rode in vast circles on the fauna. Minimize your impact to the environment, or better yet utilize enviro-friendly floating rode, permanent moorings and dispense with using temporary shipboard anchor mooring.

https://theibizan.com/keep-off-the-g...our-posidonia/

Keep off the grass. Protect our posidonia.
By The Ibizan -15th July 2016

The Consell of Ibiza, in association with the office of tourism, has launched a campaign intended to educate those who work and participate in nautical tourism in Ibiza and Formentera. The initiative sets out a list of ‘best practices’ to ensure the natural environment is protected and respected.

Miquel Vericad, minister of the environment, said “it is important to educate our visitors of the island’s underwater heritage. We must seek a cultural and social change so that these best practices become normal procedure.”

Neil Wood of Boats Ibiza "Posidonia is a magnificent feature of our marine environment"
We asked Neil Woods, owner of Ibiza pleasure craft business Boats Ibiza, for his take on the initiative. After taking a look at the information on the Consell website and the Green Sail documents, Neil sent us his reply:

“Posidonia is a magnificent feature of the Ibiza and Formentera marine environment. We support any initiative about protecting it and respecting its ancient fragility. It’s in everyone’s interest to look after our beautiful island and for this reason we only ever anchor on sand.

Either you are part of the solution or a part of the problem. Which do you wish to be?

[slug]

Originally Posted by Montanan

I have an alternative perspective, a Green Sailing perspective. The areas are not plagued by posidonia grass, they are blessed by posidonia grass,

Please anchor in areas designated by the buoy markers or where clear sand is visible from the surface. Do not damage natures sea meadows by dropping anchors and dragging chain rode in vast circles on the fauna. Minimize your impact to the environment, or better yet utilize enviro-friendly floating rode, permanent moorings and dispense with using temporary shipboard anchor mooring.

https://theibizan.com/keep-off-the-g...our-posidonia/

Keep off the grass. Protect our posidonia.
By The Ibizan -15th July 2016

The Consell of Ibiza, in association with the office of tourism, has launched a campaign intended to educate those who work and participate in nautical tourism in Ibiza and Formentera. The initiative sets out a list of ‘best practices’ to ensure the natural environment is protected and respected.

Miquel Vericad, minister of the environment, said “it is important to educate our visitors of the island’s underwater heritage. We must seek a cultural and social change so that these best practices become normal procedure.”

Neil Wood of Boats Ibiza "Posidonia is a magnificent feature of our marine environment"
We asked Neil Woods, owner of Ibiza pleasure craft business Boats Ibiza, for his take on the initiative. After taking a look at the information on the Consell website and the Green Sail documents, Neil sent us his reply:

“Posidonia is a magnificent feature of the Ibiza and Formentera marine environment. We support any initiative about protecting it and respecting its ancient fragility. It’s in everyone’s interest to look after our beautiful island and for this reason we only ever anchor on sand.

Either you are part of the solution or a part of the problem. Which do you wish to be?

Local pilot books identify grass beds

In areas with no grass mapping avoid anchoring in shallow water

[kas_1611]

Originally Posted by Montanan

I have an alternative perspective, a Green Sailing perspective. The areas are not plagued by posidonia grass, they are blessed by posidonia grass,

I agree, Sea Grass is to be preserved and encouraged. Sea Grass absorbs and fixes 4x more CO2 per square meter than Amazonian Rain Forest.

Whenever I come into an anchorage and see dark green below me I try to avoid dropping my anchor in it as much as possible. Mostly because anchors never hold great in weed but also to protect this vital ecosystem. Yes sometimes my chain may swing about through or over it but as I generally anchor with between 3 and 4:1 scope the damage is minimal from chain sweep. It doesn't take much to stand at the bow and view the sea bed to find a clean area to drop your hook and if you can anchor stern to shore that helps as it minimises chain drag even further.

[slug]

posidonia Is critical for beach formation and erosion control

Once the offshore bed dies the beach disappears

More and more regions are laying moorings and prohibiting anchoring