First trip out with my new anchor - but did I drag?

MagicalArmchair said:
I like option 2 quite a lot from GHA! My pathetic stab of 2k revs astern pales in comparison. How long do you run it in astern? And how much 'welly' (rpm) do you give it?
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Usually dunno, 20/30 seconds 3/4 revs maybe? That's where a good transit really helps, you can see an inch or 2 of movement, move your head left right to confirm :cool:

Muddy bottom maybe less.

While ago in a known anchorage with a decent bottom it was dragging about half revs but I was just nipping to the shops so left it, hook came up with an ancient life ring round the fluke :)
 
I would be interested to know what sort of anchor needs 8:1 chain in benign conditions. I'm guessing "Supermarket carrier bag full of gravel" but I'm not sure that counts as new generation.
 
It didn't need 8:1 (note, conclusion was I didn't drag) - I just missed the chain marker at 35 meters when I was shooting for 7:1. Honestly, when I didn't have a windlass on the old boat I would sleep easy on 5:1 with the Rocna and (shhh, don't tell the anchor police) 3:1 on quiet nights. The new boat has an electric windlass - my quads will never be the same... feels a bit like cheating...

Roger, so about 2500 RPM astern, 20/30 seconds, check transits, go ashore, dig holes in sand, eat lunch, got it.
 
MagicalArmchair said:
It didn't need 8:1 (note, conclusion was I didn't drag) - I just missed the chain marker at 35 meters when I was shooting for 7:1.
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Sorry - I really am not aiming for an anchor war or a personal attack, but 7:1 seems an extraordinary amount of chain for any anchor, let alone a new generation one. Gales apart, and even then ...
 
JumbleDuck said:
Sorry - I really am not aiming for an anchor war or a personal attack, but 7:1 seems an extraordinary amount of chain for any anchor, let alone a new generation one. Gales apart, and even then ...
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I would have thought too, and my father never put out much more that 3:1 in his sailing, however, the dudes at Rocna, when I purchased my last anchor, were pretty firm about it.

Rocna anchoring solution - Triola - Albin Ballad #50

Important bit being below, all their suggestions, and news to me at the time.

  • The bottom is more important than the anchor, rode or boat! If there the bottom does not have good holding, no matter how good your gear is, you will still drag.
  • If anchoring for lunch, a scope of 3:1 is sufficient.
  • If anchoring overnight, a scope of 5:1 is preferable.
  • If anchoring and a blow is expected, 7:1 is better.
  • If the rode is all chain, let out all your required scope and let the anchor set. Once the anchor is set, bring back in 10 meters of chain, tie on the end of the 10mm snubbing line, and let the 10 meters back out, leaving the chain slack and taking the load on the snubber. This will make the boat sit better at anchor and will cut down on snatching loads.
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I ventured forth again to Brownsea, the kids had their buckets, spades and a picnic ready. The wind was up, however, I was content with this, as I wanted to gain some faith in my new hook. When I arrived at our anchoring location, there was more south in the wind that I had accounted for, meaning Brownsea was now our lee shore. I considered that so long as I tested the anchor and was happy with its set, the wind was due to die off over the afternoon, so we would be safe enough.

We got to our anchoring location, there was between 3 and 4 meters of the wet stuff under us as we got into position and started to drift back. I dropped the anchor and the anchor chain went slack as it hit the mud, I gave stab of astern to give us a little backward motion to make sure the chain didn't all pile up on top of the anchor. My goal was to go for 7:1 again, for security with a lee shore and a bit of wind, so I dropped 30 meters of chain and would dig in at that, and then, once dug in, I'd release another 5 meters with the snubber on it. We drifted back on the 30 meters of chain, I checked my transits, and all looked well. I figured at this point, the chain would not be taught, so I thought now was the perfect time to set the anchor.

I gunned the big 50hp engine on Mirage in astern to 2000rpm, and checked my transits. They started to move a bit, then they started to move a lot as we shot backwards :ROFLMAO: towards some moorings - I let us go for a while, hoping the anchor would dig in as it dragged across the sea floor, it didn't. Hmm, so up came the 30 meters of chain - along with a whole bunch of fishing tackle, weed and junk! I struggled to release the junk, tried to get it on board to stop it fouling someone else's anchor, failed, as it splashed back into the depths. Tired and muddy, we went back to our starting position, and dropped the hook a second time.

This time, I only let out 25 meters of chain, I figured 4:1 / 5:1 should dig in fine. Same MO, I started dropping back, dropped the hook, stab of astern, let out the chain. I let it settle as the hefty wind dragged us back, transits looked good, then out came the 2,000 rpm again in astern... checked the transits and boom, back we went again...!

I repeated this process one more time - With the same depressing outcome, although I feel on the final set it might have dug in as it was harder to recover. Even if it was harder to recover, it was not set enough to weather the 2,000 rpm of the engine in astern.

Much as I was keen to continue chugging back and forth and testing different locations, the kiddies were frowning and lunchtime was approaching, so I called it a day and picked up a PHC mooring bouy and paid my £10 over the phone, and went and dug some holes in the sand, bloodied, stinking of mud and defeated.

Weedy bottom? However, the anchor did come up with mud on it? Or is it Plowing? The shape of this anchor did have me worried it might...
 
There is mud and mud and even more and different mud.

I have no idea what sort of seabed in which you were trying to anchor.

But:

When we anchor we deploy to about 3:1 and if it does not set immediately, by this is I mean hold - we move. Invariably it holds and we then deploy for whatever the conditions are likely to be. The 3;1 is chosen because in the worst case there is less chain to retrieve.

Moving on

Most anchors require a firms seabed on which to set, whether this is a roll bar anchor, like your Rocna or a ballasted anchor like a Spade (or our Excel). If the seabed is 'firmish' the anchor rolls on the roll bar or on the shank plus the ballast falling one way of the other. All of them fall and lie on their side - tension then allows the toe to engage, catch, and the toe buries and drags the fluke down with it. Simple stuff. If the seabed is very soft, and this can be soft mud or soft sand, the roll bar can simply sink into the seabed, or in the case of the ballasted anchor, the shank can sink into the seabed, and the anchor can drag inverted upside down - for a long, long way. This is why its a good idea to power set, even a little bit - as if the anchor engages - it will invariably set (and lock up)

If you look at the Chesapeake/Fortress tests it looks as if this is what many of the anchors did - because they never achieved any hold at all. Fortress chose their seabed for testing with skill (what do you expect?).

So a very soft seabed can be an issue.

So I can conjure up a reason why your anchor did not set - its nothing to worry about - in very soft mud this is what you expect (and you should use a Fortress).

Now if you tell me the mud is 'firm' then it should have set.

Recall also - you picked up rubbish - you may have been very unlucky and chose somewhere that had been used to jettison all and anything. Something might have stopped your anchor engaging - and fallen off before it arrived at your bow roller - common enough.

Persevere.

I personally don't like Rocna and all it stands for, bendy shanks, and I can maintain this holier than thou attitude as a roll bar anchor does not fit on our cat and there are other options, Excel, Spade (both of which we carry) - but the forum members here generally or wholeheartedly seem to use a Rocna without any issues (no-one complains). It would be perverse, of me, to argue with the views of so many - so try again.

Jonathan

Now - why did I think you had a Rocna? I've just re-read your Opening Post and note you did not declare your anchor. It does not alter what I said, so I'm not going to correct my misapprehension - but I'd add Vulcan, Supreme and Kobra to the list of anchors that might drag upside down - they all have similar issues in very soft seabeds.

Interestingly a Mantus M1 is hydro-dynamic and if the yacht moves aft then the anchor aligns itself 'correctly', caused by the water flow such that when it arrives at the seabed it 'plonks' down such that they fluke sits flat on the seabed. It develops poor hold - but it will engage. If you are moving forward when you deploy - the opposite will occur (but most people deploy going backwards).

Now if you have bought the Mantus M2 - they have had issues with it not setting in mud - and are sending new shanks out to everyone who bought one. One would think they would have sorted this out before releasing the anchor but this is characteristic of their product releases. They did the same with the M1, mild steel shank (replaced FOC with a HT shank), withdrew their chain hook, now the M2 and have a swivel that is too big and detracts from anchor performance. You will note they have never released hold data on the M1 (nor the M2) - I wonder why?

I don't receive products from Mantus to test anymore - I wonder why for that as well!@ :)

Surely you did not buy the M2? :( It would be valuable for the forum members if you did buy the M2 if you can fess up - saves anyone else making the same mistake. But hey - you might get a new shank.

I have little faith in their ability to design an anchor that competes with Spade, Rocna, Supreme, Excel etc so........

J
 
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The RYA suggests 4:1 chain and 6:1 rope..

I'm starting to like the Spanish approach; They come in at about 3 or 4 knots, and start dropping the anchor, when the boat stops they're done.
I cannot argue with the speed of it, and if it's stopped the boat at that speed it'll likely hold for lunch. They also only have as much chain out as they need.
 
JumbleDuck said:
I would be interested to know what sort of anchor needs 8:1 chain in benign conditions. I'm guessing "Supermarket carrier bag full of gravel" but I'm not sure that counts as new generation.
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Scope as a simple ratio isn't the whole picture.
With the RIB, I've found that 6ft of rode is not enough in 1ft of water.....
 
TernVI said:
Scope as a simple ratio isn't the whole picture.
With the RIB, I've found that 6ft of rode is not enough in 1ft of water.....
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Perhaps, but 35m of chain in 3-4m of water - "there was between 3 and 4 meters of the wet stuff under us a ... I dropped 30 meters of chain and would dig in at that, and then, once dug in, I'd release another 5 meters with the snubber on it." is both absurd and also selfish behaviour which is likely to make the OP very, very unpopular in many anchorages.
 
Neeves said:
There is mud and mud and even more and different mud.

I have no idea what sort of seabed in which you were trying to anchor.

But:

When we anchor we deploy to about 3:1 and if it does not set immediately, by this is I mean hold - we move. Invariably it holds and we then deploy for whatever the conditions are likely to be. The 3;1 is chosen because in the worst case there is less chain to retrieve.

Moving on

Most anchors require a firms seabed on which to set, whether this is a roll bar anchor, like your Rocna or a ballasted anchor like a Spade (or our Excel). If the seabed is 'firmish' the anchor rolls on the roll bar or on the shank plus the ballast falling one way of the other. All of them fall and lie on their side - tension then allows the toe to engage, catch, and the toe buries and drags the fluke down with it. Simple stuff. If the seabed is very soft, and this can be soft mud or soft sand, the roll bar can simply sink into the seabed, or in the case of the ballasted anchor, the shank can sink into the seabed, and the anchor can drag inverted upside down - for a long, long way. This is why its a good idea to power set, even a little bit - as if the anchor engages - it will invariably set (and lock up)

If you look at the Chesapeake/Fortress tests it looks as if this is what many of the anchors did - because they never achieved any hold at all. Fortress chose their seabed for testing with skill (what do you expect?).

So a very soft seabed can be an issue.

So I can conjure up a reason why your anchor did not set - its nothing to worry about - in very soft mud this is what you expect (and you should use a Fortress).

Now if you tell me the mud is 'firm' then it should have set.

Recall also - you picked up rubbish - you may have been very unlucky and chose somewhere that had been used to jettison all and anything. Something might have stopped your anchor engaging - and fallen off before it arrived at your bow roller - common enough.

Persevere.

I personally don't like Rocna and all it stands for, bendy shanks, and I can maintain this holier than thou attitude as a roll bar anchor does not fit on our cat and there are other options, Excel, Spade (both of which we carry) - but the forum members here generally or wholeheartedly seem to use a Rocna without any issues (no-one complains). It would be perverse, of me, to argue with the views of so many - so try again.

Jonathan

Now - why did I think you had a Rocna? I've just re-read your Opening Post and note you did not declare your anchor. It does not alter what I said, so I'm not going to correct my misapprehension - but I'd add Vulcan, Supreme and Kobra to the list of anchors that might drag upside down - they all have similar issues in very soft seabeds.

Interestingly a Mantus M1 is hydro-dynamic and if the yacht moves aft then the anchor aligns itself 'correctly', caused by the water flow such that when it arrives at the seabed it 'plonks' down such that they fluke sits flat on the seabed. It develops poor hold - but it will engage. If you are moving forward when you deploy - the opposite will occur (but most people deploy going backwards).

Now if you have bought the Mantus M2 - they have had issues with it not setting in mud - and are sending new shanks out to everyone who bought one. One would think they would have sorted this out before releasing the anchor but this is characteristic of their product releases. They did the same with the M1, mild steel shank (replaced FOC with a HT shank), withdrew their chain hook, now the M2 and have a swivel that is too big and detracts from anchor performance. You will note they have never released hold data on the M1 (nor the M2) - I wonder why?

I don't receive products from Mantus to test anymore - I wonder why for that as well!@ :)

Surely you did not buy the M2? :( It would be valuable for the forum members if you did buy the M2 if you can fess up - saves anyone else making the same mistake. But hey - you might get a new shank.

I have little faith in their ability to design an anchor that competes with Spade, Rocna, Supreme, Excel etc so........

J
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Thank you for that full and useful write up. The anchor is, in fact, a Knox anchor, so very similar to the Rocna in design, and comes with a good technical write up. Scottish steel, the science behind it and UK design appealed to me.

The mud that came up, with a fair bit of weed, was quite soft, but then nothing I am not used to on the East Coast - I would have expected solid holding. I will persevere when I don't have the troops about to mutiny on the skipper for failing to deliver the promised picnic - hard being scientific when your two year old is frowning at you. In future I'll go to 3:1 first, see if it holds and digs in at that and go from there.

JumbleDuck said:
Perhaps, but 35m of chain in 3-4m of water - "there was between 3 and 4 meters of the wet stuff under us a ... I dropped 30 meters of chain and would dig in at that, and then, once dug in, I'd release another 5 meters with the snubber on it." is both absurd and also selfish behaviour which is likely to make the OP very, very unpopular in many anchorages.
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Yes, yes, if there were space concerns I wouldn't have put out so much rode, however the anchorage was empty, zero boats for miles around (the closest were the PHC moorings some way off, the ones I ended up on) and I wanted to be sure the anchor would have the best chance to set and hold. The fact the anchorage was empty could have been telling in itself (lee shore, blowing hard plus poor holding?) - although there was another boat anchored around the East side of the island inshore.

This was one test case on one bottom, that has shaken my confidence in the hardware a little if I'm frank, however, I'll try again another day, in a different anchorage. In a few weeks I'll be back on the Medway and I can test the anchor on mud I know extremely well indeed
 
MagicalArmchair said:
Yes, yes, if there were space concerns I wouldn't have put out so much rode, however the anchorage was empty, zero boats for miles around (the closest were the PHC moorings some way off, the ones I ended up on) and I wanted to be sure the anchor would have the best chance to set and hold.
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If you want the anchor to set you need to give it a good, hard pull. You had the best part of 30m of chain lying on the sea bed, absorbing at least some of the force you apply to the boat end. I really think it would be worth trying with a more moderate amount of chain. Good luck.
 
GHA said:
Well researched kindle from one of our own. :cool:
Not often actual data creeps into anything to do with anchors ;)

Rigging Modern Anchors eBook: Frye, Drew: Amazon.co.uk: Kindle Store
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This is interesting, thank you for posting. "In anchoring in very soft mud, allow the anchor to settle for ten to fifteen minutes", he also talks about slowly increasing the revs, not smashing it into astern as I did - this guy also talks about 7 to 10 times scope (!!). My approach, on soft mud, of laying out a bunch of chain and then motoring hard astern against it on soft mud was likely always doomed to fail. There is some very sound advice in the book, I'll be sure to buy that and cover to cover it. You can preview the first few pages of it on Amazon, and there is some good stuff in there too.
 
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We had friends way back we cruised in company with once. Wifey only knew 2 options full throttle or neutral. Hubby routinely dropped the anchor whilst she took the wheel, so when he said 'go astern', she did so at full throttle. they always had trouble anchoring however good the bottom holding was to the point where I once swam over and did it for them, having anchored up ourselves first.
 
Magic....

There is no perfect anchor, they all have compromises.

We have a 13kg Knox, we were given it and brought it back within our luggage allowance, which we have tested in a variety of seabeds. In a soft seabed the big issue we had was it set so deeply we could not see it! Part of the idea being to see at what orientation it locks up at as this is a function of performance - lesson learnt. We like it, except having a roll bar means we cannot use it other then deploying it from the foredeck rather than hanging from the bow roller. It sets quickly and reliably and develops excellent hold. It is very robust, to my mind over engineered (but that's what you want - the alternative being the bendy shank). Our 2 gripes - the pockets 'under' the fluke can fill with mud and care needs to be taken to keep them clean (some muds will destroy the gal and if you leave the mud it will harden and modify the balance - impacting performance) Its not a big deal to wash it clean with a deck wash. We don't like the split toe as the slot collects debris (which you may have found with your first described deployment). If we were to use it as a primary we would close that slot, somehow - pan headed nut and bolt?, weld it closed would be the ideal but I'd then worry about the lack of galvanising.....but as the gal wears off the toe of well used anchors - why worry.

We commend your choice

Persevere.

On setting - we have found that most modern anchors engage quickly and lock up abruptly (including a Knox) and if you are standing on the foredeck with an enthusiastic reverse you will spill the chardonnay (or worse - lose the single malt). We slowly increase power to 3/4 max cruising revs (at our standard 3:1 scope). When the anchor has locked up, deploy a more appropriate amount of chain, add snubber (bridle in our case) - and relax. In thin mud I can think of better things to do (that malt beckons) than wait in the pouring rain, after a 36 hour passage for an anchor to 'settle'. If we know its thin soupy mud we deploy a Fortress from the outset - that's why we carry it. HMS Rattlesnake, Bramble and their successors accurately defined virtually every anchorage round Australia (and some of our near neighbours) and these anchorages have remained largely unchanged. - it would be unusual for us not to know what our seabeds are.

Jonathan
 
There are a couple of soft mud places locally that I use, and they give good holding if you do it by allowing the anchor(Delta) to settle on the bottom before putting any pull on it. lay the chain out at a reasonable scope. 5:1 at least.
Then gently increase the pull on it. I often use the main to do this as the Ballad runs in circles at tickover in astern.

Once gently set you can then increase the pull and it won't move. A couple of minutes is all it takes.

If you rush then it will drag along the bottom quite happily. I think this is one occasion where throw it over the side, and put the kettle on works better than a "proper " technique.

I have spent many nights in strong winds once set.

If I had a Fortress, then I would probably use it, though it does have a split toe.
 
MagicalArmchair said:
This is interesting, thank you for posting. "In anchoring in very soft mud, allow the anchor to settle for ten to fifteen minutes", he also talks about slowly increasing the revs, not smashing it into astern as I did - this guy also talks about 7 to 10 times scope (!!). My approach, on soft mud, of laying out a bunch of chain and then motoring hard astern against it on soft mud was likely always doomed to fail. There is some very sound advice in the book, I'll be sure to buy that and cover to cover it. You can preview the first few pages of it on Amazon, and there is some good stuff in there too.
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Same author but you need to pay, which is well worth it for a year then download all the back issues, lots of good anchoring articles often with data to back up, a rare thing in an anchoring discussion :)
Mud Anchoring Wisdom - Practical Sailor
 
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