All Chain versus Chain/Rope?

[Gypsyjoss]

I currently have 30m chain + 60m 16mm rope and a windlass that isn't particularly happy pulling in the rope. I was going to buy 45m chain (45m being a regularly used length) but all the arguments point to having less chain say 10m and the rest rope. I quote Alain Hyles below.

"The main and ONLY advantage of the chain is that it is the only and perfect means to avoid chafing of the anchoring rode on agressive sea beds...

Except for this point, chain has all the disadvantages..:
Stored in the bow chain locker, it adds a heavy weight in the last place you want one. When deployed, chain is actually working in the the opposite way to the way it should work:

with light wind, it gives a perfect horizontal pull to the anchor and the best holding.

with moderate wind, its weight and catenary effect give a perfect shock absorbing effect.

As the wind builds up, the chain will become straighter (and this with as little as 25/30 knots of wind). The pulling angle will increase and as a consequence, the holding of the anchor will decrease.

When the shock absorbing effect is most necessary, the "bar tight" chain will not allow this to happen."

I do use a snubber - which is about 5m to a centre deck cleat, but the gurus (also Anchorwatch) say this is inadequate to stop shocks to the anchor with an all chain rode.
Has anyone here used less chain and more rope? I'm used to seeing charter boats putting out 65m chain! Comments?

 

[fireball]

Our last boat had 3m of chain and 35m of rope when we got her - no good except for a lunch stop - as we didn't have a windlass and didn't anchor too much we increased to 10m of chain and still the 35m of rope ...
It was very apparent that our anchor line went out at a greater angle than the all chain vessels - creating a greater trip hazard to anyone (usually dinghies) passing too close to our bow.

As for the quote above .. yes Chain has the disadvantage of weight in the locker, however if you're anchoring it has the advantage of weight - and if your chain is bartight to the anchor then you're in too deep or not enough chain out - probably due to extreeme winds ...

 

[William_H]

Chain versus rope

Certainly with rope you need a longer scope so the boat will need more room to turn to different tides and wind. However if you only anchor in shallow water this is not so much of a problem.
Here in West Australia all chain is almost unheard of until you get to ships. This may in part be due to very little tide movement so no need usually to anchor in deep water.
So yes I would advocate use of 5 or 10 metres of chain followed by lots of rope. You may be able to stow a slightly larger anchor which will give better holding for similar weight on the lift and much less weight in the bow. The decision must be yours considering your anchoring habits and needs. good luck olewill

 

[kacecar]

For what its worth, I was recently told by a supplier of anchors that the reason my anchor was now bent was the fact that I had extended the chain in a chain/rope rode from 5m of 10mm chain plus 50m of 16mm octoplait to 25m of 8mm chain and the 50m octoplait. The view was that as I had often been anchoring in relatively shallow water there wasn't enough shock absorption in what was, effectively an all chain rode. He suggested the solution was a chain hook on at least 10m of suitably strong and stretchy rope.

In fact I suspect that, in my case, the lack of damping / shock-absorption in the anchor rode only became a problem when the anchor came to a sudden stop in rock while I was going astern with gusto trying to dig it in - somehow the shock (significant)was at an angle so the shank became bent (and cracked). A rope rode would have absorbed some of the shock but. even then, I suspect the shock-loadings would still have bent the shank.

Me? I'm sticking with the longer chain as it decreases the swinging space I require in quiet anchorages, reduces the sheering in moderate winds, doesn't get wrapped around the keel on change of tide and is likely to improve the direction of pull on the anchor. I'll probably get a chain hook and a long stretchy line as well - and be a bit more circumspect with the throttle when digging the anchor in!

 

[PeterGibbs]

I currently have 30m chain + 60m 16mm rope and a windlass that isn't particularly happy pulling in the rope. I was going to buy 45m chain (45m being a regularly used length) but all the arguments point to having less chain say 10m and the rest rope. I quote Alain Hyles below.

Comments?

The arguments about weight forward in the boat are much overdone. Even if you took a little more water over the bow in a blow, could you measure it, so what is this in the scheme of things?

When you anchor you need digging in power and resiliance - that's down to anchor design and weight, plus length of chain. String plays no part in this dynamic, only ease of handling.

30m of chain is somewhat minimal, especially for deeper waters off western parts. Laid out with a rope extender in spacious conditions and a decent anchor, ok. But to limit swing it has to be all chain. I have 50m on my boat (E coast) and have never been pinched for scope although I'm sure I would use the full length more often in deeper water.

If you land your chain and just retain a nominal length at the anchor, you have limited your options and therefore your peace of mind.

I suspect you knew all that anyway....

PWG

 

[Bosun Higgs]

From the point of view of the physics involved Alain is quite right - the ideal combination is enough chain to avoid abrasion on the sea bed and then lots of stretchy rope to absorb shock loads. But in the real world of British anchorages, there often isnt sufficient swinging room to accommodate that approach and there is no doubt that less room is needed with chain until you get to extreme weather.

As for weight in the bow, then again Alain is right but if you arent racing ( and if not, why not? ) the practical effect is likely to be small.

Plus its no good at all if your windlass wont pull rope - getting the anchor in against 20kn is much more likely to be your problem than survival in 60 kn when you can always bend some more rope onto the end of the chain anyway.

 

[Pye_End]

I guess your choice depends a little on what size boat you have, and what sort of anchoring you do - eg. what is the typical depth; do you use it most of the year or a few times a year; how often do you rely on it in nasty conditions etc.

 

[Robin]

It doesn't say what size of boat the OP has or what depths are usually encountered when anchoring.

However I am a fan of all chain for all normal situations. We had chain + rope on one boat many moons back and in strong wind against tide one night wrapped the rope around the keel so tight it was humming with the boat then side on to the loads.... then it snapped, chafed through on the back edge of the keel. Since then I have avoided wind over tide anchoring and rope rodes wherever possible.

We went up from 90ft of 8mm chain on a W33 to 180ft of 10mm and 45lb CQR when we fitted an electric windlass. That set up held us in some really bad winds and we never had to add more scope although we had extra in rope form if needed..

Our most recent boat at 41ft had pretty much the same set up except the anchor was a Delta. Again very successful.

We have always used a form of chain snubber. In early years and small boats we made them up with lengths of bungy whipped together and set into a nylon line. On later boats we have made them up with rubber mooring snubbers wound into nylon lines and chain hooked to the anchor rode. Leaving chain with the possible snatch loads straight onto a windlass is a sure way to an expensive repair bill! However IMO, it is snatch loads that break out anchors rather than steady wind loads and snubbers remove that and as a real bonus make for a peaceful non-jerky stay. We had two, one regular and one heavier 'storm' snubber.

The downside is the extra weight in the bows. That said most boats have too much weight aft as well (also bad) but at least now the fore/aft trim is right. It is always better to keep heavy weights away from the ends to minimise pitching, but in normal cruising with normal size boats that gets difficult to arrange, on race boats it is easier.

 

[doug748]

"The main and ONLY advantage of the chain is that it is the only and perfect means to avoid chafing of the anchoring rode on agressive sea beds...

Too strident for me. When someone kicks off with such a an odd statement it always puts me off taking them seriously.

 

[lw395]

I think Robin has it about right, but in some boats the extra weight in the bows is very noticeable when beating into chop. Taking the anchor and chain below could be worth several places in a race.
In terms of providing 'spring' to an anchor rode, a heavy weight in the middle of the catenary is far more effective than evenly weighted chain, but of course it's trouble to set up and does not go well with an electric windlass.
Both my own yachts were ex-racers, so a bit minimal on the chain, a 10kg lump of lead on the rode transformed the holding power of the undersized anchors and improved the way the boat sat anchored in a bit of chop.
For a 'proper cruising boat' I'd want a chain locker down near the keel.

 

[Quandary]

If you ever share tight anchorages with other boats rope rodes can encourage a lot more dancing around the anchor. When we raced we went for min. weight forward but I once had to leave Caladh Harbour in embarassment. I use more chain now but have made a low timber bulkhead which keeps it in the back third of the anchor locker.

 

[Chris_Robb]

In terms of providing 'spring' to an anchor rode, a heavy weight in the middle of the catenary is far more effective than evenly weighted chain, but of course it's trouble to set up and does not go well with an electric windlass.

I am not sure I agree with you about the effectiveness of an anchor chumb. Once the wind is really blowing and the chain is effectively straight to the anchor, what possible anti snub effect can it have? Far better to have a 20 meter nylon rode to chain hook to take out the snubbing.

I agree about a chumb on all warp rode, as it keeps it down below the surface and stops it wrapping around the fin and skeg.

 

[Gypsyjoss]

It doesn't say what size of boat the OP has or what depths are usually encountered when anchoring.

Thanks for all your replies. Should've given more info - must update my profile! Boat is a Sadler 32 out in the Aegean (into 2nd season, didn't have a windlass on previous boat)-
So no tides, rarely crowded anchorages. Racing is rare out here!
Typical depths 2 to 8 metres.
Anchor is a 35lb CQR (might buy a Rocna next year).

Is part of the reason for having all chain the positive drive given by the windlass?

 

[Ricd]

Thanks for all your replies. Should've given more info - must update my profile! Boat is a Sadler 32 out in the Aegean (into 2nd season, didn't have a windlass on previous boat)-
So no tides, rarely crowded anchorages. Racing is rare out here!
Typical depths 2 to 8 metres.
Anchor is a 35lb CQR (might buy a Rocna next year).

Is part of the reason for having all chain the positive drive given by the windlass?

If your max anchoring depth is only 8m then 30m chain (100% chain) should cover almost all situations without using any string and a 35lb CQR is man enough for the boat.

 

[Robin]

Thanks for all your replies. Should've given more info - must update my profile! Boat is a Sadler 32 out in the Aegean (into 2nd season, didn't have a windlass on previous boat)-
So no tides, rarely crowded anchorages. Racing is rare out here!
Typical depths 2 to 8 metres.
Anchor is a 35lb CQR (might buy a Rocna next year).

Is part of the reason for having all chain the positive drive given by the windlass?

All chain is much better IMO, it handles and stows better on a windlass system and you swing around much less in a crowded anchorage. Shouldn't be a problem on a Sadler 32 used for cruising and 50m would mean you would rarely if ever use extra rope rode, even with 5 x depth as scope.

 

[Chris_Robb]

If your max anchoring depth is only 8m then 30m chain (100% chain) should cover almost all situations without using any string and a 35lb CQR is man enough for the boat.

My calculation for 8 meters depth would be - add the freeboard first - so say 9 meters X 4 = 36 meters. And don't discourage the OP from getting a proper anchor!

I still think that I would carry a minumum of around 60mtr. I would be surprised if he never had to anchor in more than 8 mtrs.

 

[Monique]

I use 75 M chain. If I need extra shock absorbing power, I shackle a 18 mm line to it for a further ... up to 100 M.

My boat stays where I anchor her!!! (swings a lot...) But what cost

 

[theguerns]

Anchors

We live aboard our colvic watson 32 which is special build for the north atlantic which means that in full cruissing trim with all tanks full 3 months food aboard and 2 crew we weigh 18 tons. We have 4 anchors, 2 forward each on 100mts chain and 2 aft on the same. We use spade anchors all the same weight 35lbs. we have anchored in winds up to 65 knots and never moved mainly because we had all the chain out. We always use a snubber which is fully covered with rubber pipe and 4mts long of 25mm anchor plait. We have no snatching and sleep well knowing that we wont move. In the stronger winds we deploy 2 anchors at 45drg angle to eachother. Rope is fine but as already said no good near rocks. With all the weight of the chain we have it makes no difference to the motion of the yacht what so ever. Happy sailing to you all

 

[Bosun Higgs]

I am not sure I agree with you about the effectiveness of an anchor chumb. Once the wind is really blowing and the chain is effectively straight to the anchor, what possible anti snub effect can it have? Far better to have a 20 meter nylon rode to chain hook to take out the snubbing.

I agree about a chumb on all warp rode, as it keeps it down below the surface and stops it wrapping around the fin and skeg.

Whilst in strong winds the chain rode may get close to being straight, it wont stay permanently like that cos as the wind varies so the boat moves. But in the end, all you are doing is changing the boats kinetic energy into potential energy by raising the chain and chum hopefully before the chain rode becomes bar tight.

Just been playing with some numbers. Ignoring the water resistance as the chain is straightened, the kinetic energy of a 5 tonne boat moving at 1 kn ( and I would have thought that the movement under wind would be a lot less quick) is easily absorbed by lifting 100lbs of chain about 12ft. Which is to say that the rode you put out for your 5 tonnes boat in a depth of 8m at a 4 to 1 scope will absorb the 1 knot sheer.

Interestingly, adding a chum mid way down the rode is approximately twice as effective as adding the same extra weight of chain to the length of the rode.

 

[Chris_Robb]

Whilst in strong winds the chain rode may get close to being straight, it wont stay permanently like that cos as the wind varies so the boat moves. But in the end, all you are doing is changing the boats kinetic energy into potential energy by raising the chain and chum hopefully before the chain rode becomes bar tight.

Just been playing with some numbers. Ignoring the water resistance as the chain is straightened, the kinetic energy of a 5 tonne boat moving at 1 kn ( and I would have thought that the movement under wind would be a lot less quick) is easily absorbed by lifting 100lbs of chain about 12ft. Which is to say that the rode you put out for your 5 tonnes boat in a depth of 8m at a 4 to 1 scope will absorb the 1 knot sheer.

Interestingly, adding a chum mid way down the rode is approximately twice as effective as adding the same extra weight of chain to the length of the rode.

I think I prefer to go the route of a 20 mtr Nylon snubber with chain hook. You can then drop a bight of chain to the seabed in between the hook and the bow roller, to allow it to drag across the seabed slowing down the sheering - and of course killing off any seahorses that get in the way.

Certainly the chum is essential when on all nylon rode - just to stop it getting caught in the keel!