Photos of Anchors Setting

[kas_1611]

Originally Posted by Fortress

Why do you think that two sharp and thinner flukes, which are likely to take up a comparable amount of surface area as a single narrow fluke (at least initially), would have a disadvantage in weeds, particularly if there was some serious weight (from a larger model) behind those two sharp and thinner flukes?

Additionally, the resistance from penetrating the weeds comes much sooner from the shank of your anchor, which is bolted on only a matter of a few centimeters from the tip of the fluke.

I sense a new test coming up

Not being an engineer but a geologist my thought would be to use a sharp point to cut through weeds and weed roots. 2 sharp points would be better but the gap between the Fortress flukes, to my untrained eye, looks perfect for clogging up with weed and preventing further digging in. The single blade of the Mantus and my Vulcan should cut through without getting clogged, although yes the shank can affect the entry ability. As we all know weed is the anchorholics nightmare and no single design has really been great in thick weed.

I'm not knocking the Fortress in any way shape or form and I for one would love to see a series of tests done with various anchors in sea grass, weed and other difficult vegetation to get a formal, scientific result.

Keiron

ps still think it's great Fortress are actively involved in this thread, wish we could get more manufacturers involved

[noelex 77]

Originally Posted by Fortress

Why do you think that two sharp and thinner flukes, which are likely to take up a comparable amount of surface area as a single narrow fluke (at least initially), would have a disadvantage in weeds, particularly if there was some serious weight (from a larger model) behind those two sharp and thinner flukes?

Brian, perhaps I am misunderstanding your meaning, but you seem to have said the opposite on another forum just recently:
"There is no question that there are bottom conditions where the two large flukes of the Danforth-type will have difficulty penetrating, such as in grass, weeds, or rocks, and that an anchor with a single narrow fluke with a lot more weight behind it will have a better chance of penetrating and getting a grip."(See post #43: Fortress Anchor)

Fortress anchors are excellent kedge or secondary anchors. I have one and strongly recommend it for this purpose. But lately I detect a push on this forum to recommend the Fortress as a general purpose bower anchor. I think this is a mistake.

I don't think I am alone in the view that the Fortress does poorly in thick weed.

Once again, a recent quote of yours:
"The Fortress is going to have setting and holding challenges in grass, weeds, and rocks."
(See post # 83: Deep Breath - anchor thread - Page 9)

I stand by the comment that I don't think a Fortress anchor, of any size, would have performed as well in the thick weed shown in the photo.

[Fortress]

Originally Posted by noelex 77

I stand by the comment that I don't think a Fortress anchor, of any size, would have performed as well in the thick weed shown in the photo.

Noelex, I will certainly stand by my prior comments about Fortress anchors having difficulty in grass, weeds or rocks.

However, I cannot agree with your 100% certainty that a very heavy Fortress, such as our FX-85 (about 50 lbs / 23 kg) or the larger FX-125 (70 lbs / 32 kg) would not have the weight behind them to drive the two sharpened and thinner flukes through the weed as shown in your images.

That's all.

For the record, I have heard conflicting reports from owners on how well a Fortress performs in weeds. Some will say that they are sharp enough to slice through some types of weeds and reach firmer ground below, while others have said that in thick weeds they don't have the weight to push through them, hence my point about anchor weight and a larger model size being a factor.

Brian

[noelex 77]

I have just been sorting out and backing up my older underwater photos and I came across this one from a little while ago.

It does not show an anchor, rather just the chain disappearing into the sand. I sometimes see this even in the hard sand in this area. It is easy to conclude that the anchor is completely buried, especially if the water visibility is poor. But in fact the anchor was a considerable distance away and was not very well set.

It is another reason why an under water float on the anchor is helpful. If you fit a float and it cannot be seen it is likely that the anchor is elsewhere (I have had one instance when the Mantus was so deeply buried it also buried the underwater float, but this is very rare and will only happen in soft substrates).

In most cases the presence of the float sticking up above the substrate proves you have located the anchor. The float is especially helpful on a non-rollbar anchor that will disappear as soon as the shank is buried. If you have a rollbar anchor the rollbar will be the last part of the anchor to bury so acts like a mini float, but in strong wind even this can disappear especially the less tall rollbars such as fitted on the Bugel.



If you dive to inspect the anchor don't be fooled by this common "illusion".

[kas_1611]

A quick lunchtime stop off of Otocic Katina located between the Kornati chain and Luka Telascica on Dugi Otok

3:1 in 8m water, 30m out. Set with 1500rpm reverse for 30 seconds in lovely sticky sandy clay with shells. Took a little wiggling to break her out again.



Can't promise many more this season as the water is getting a tad chilly unless someone wants to buy me a nice, heated dry suit for Christmas

Keiron

[kas_1611]

OK so maybe not the last swim of the season last time

This was from our lunch stop today near Otok Molat. Large bay on the eastern side of Molat Town. 3:1 in about 6m. When setting the anchor and chain gave such a tug against the initial reverse I nearly went over the pulpit!
As we weren't staying long we didn't bother setting any further and this is the result. Think with more reverse for longer she'd have dug herself in deeper and levelled off. As it was it took a bit of work to get it back with a noticeable "ping"



Cheers

Keiron

[kas_1611]

We stopped off overnight in Luka Kosirana on Murter. It is a large sheltered bay surrounded by a campsite with a majority sand base. That said we have had problems with rocky areas ourselves and seen many boats struggle to get a set first time (even those with good technique).

So it wasn't much of a surprise to find our Vulcan looking like this after dropping 4:1 in 6m (7.5m to bow roller) and giving it a good reverse set.



You can see where she landed, started to dig in then continued digging in while swinging. The bow fell off the wind rapidly so we ended up reversing at an angle to the wind rather than straight back. Gave it a good 30secs at 1500rpm+ in reverse.



Swimming down and getting a closer look you can see it has dug in well, if on the piss, along with the roots from sea grass and what I think might be gravel in the setting mark. I suspect we may have hit a hard patch with gravel or stones under the sand. Would it have dug in further and straightened with more reverse? Possibly but as she held us securely all night through a full 180º wind shift that rotated us through our full swing circle (not just around the vertical chain) I'm not overly worried.

I was however concerned about this:-





This example belonged to a charter boat that would end upwind of us with the forecasted shift. They actually moved and re dropped later but watching their technique I didn't exactly relax. It was a drop the anchor, let out the bare minimum of chain, turn the engine off and get stuck into the wine. No reverse, no snubber, nothing but blind faith. How they didn't drag is beyond me.

Keiron

[double u]

"How they didn't drag is beyond me" -
this is the trouble: far too often conditions are so clement, that "chuck-it-in-&-lets-go-swilling" has no negative consequences & so no learning-curve is possible...

[kas_1611]

Here's another 2 drops. Amazingly the water hasn't been that cold with the shorty on but getting out again is a different kettle of bananas

1st: Drvenik Veli,
Dropped in 6m (9.5m to bow roller) and let out 4:1. Landed in dead sea grass which was thicker than I realised but the Vulcan dug through the grass quickly and held the full reverse set perfectly.



On swimming down it wasn't totally clear if it had dug into the sand below or just built up the grass. Given it had held 1500-1800rpm reverse I wasn't overly concerned. When we lifted it up in the morning I could clearly see sand washing off the blade so it had done a good job of digging in.

2nd: Rogac on Solta for lunch



3:1 in 6m (9.5m to bow roller) for lunch in good sand. As we'd "deliberately" anchored towards a lee shore we gave it a good long reverse set with 1800rpm, just to be sure. You can see the short setting mark and the Vulcan has dug in clean and level. I'd be happy to remain where we were overnight with 4:1 out on this set.

Cheers

Keiron

[sanibel sailor]

Not sure I understand the extra 3.5 meters for the bow roller...

[kas_1611]

D'OH! My bad, it's 6m water depth plus 1.5m to the bow roller so 7.5m

Believe me mathematics was never my strong point which is why I became a Geologist, +/- 1 million years is close enough for me

Many thanks for pointing out the glaring error. I shall find a quiet corner and wear the dunce's cap

Keiron

[thinwater]

Originally Posted by noelex 77

These pictures shows better what is happening. The skipper deployed a tandem anchor arrangement. They have not used the correct hole in the Rocna to attach the the second anchor (it should be the lower hole in the shank just above the fluke) but I doubt it would have made much difference in this case.

When tandem anchoring, it is tough to get both anchors to set. It helps to use the same design of anchor, or at least one with a similar setting distance, but the risk is just one anchor will bury. If the end anchor sets, as in this case, the anchor closer to boat will might not even be on the seabed most of the time, as illustrated here. Even when it touches down it is not in any position to dig in. Even a heavy unset anchor will be off the bottom continuously in strong wind in this situation.

The Rocna is therefore just acting as a dead weight or kellet (sometimes called an Angel or Chum). Most experts agree a kellet does little to improve the rode angle and here is the proof. This was only 25 knots but the Kellet (the Rocna) was lifting well off the bottom in the gusts. If you look at the rode angle the weight of the Rocna is helping very little during the gusts. Any slight benefit will disappear when the wind strengthens.

The other lesson here is how such a tiny amount of fluke that the Brittany has buried in the rock can hold the whole boat. It looked very precarious, but did not move the whole time we watched and they had already been anchored for a couple of hours.

It was a charter boat and I think the skipper had just attached the stern anchor to the primary, using the wrong hole and with a very dubious snap shackle. We sometimes see these sort of weird tactics by charter boats. A common one is to deploy a second anchor in a crowded anchorage when everyone else is just using one. The different swing pattern creates mayhem, usually at 2 am .

In this case, the second anchor was hindering the performance of the Rocna, although in the rock where they dropped no anchor can work correctly.

We had a word to skipper, pointed out where the sand substrate lay and suggested they ditch the Brittany. They did not speak much English, but they did reanchor a bit later. They still used both anchors. It is hard for some people to imagine one anchor could be better than two.

They held overnight.

I know this is a ways back, but I think it merits discussion. I think our take-aways were either incomplete or wrong. Let's also ignore the lame cababiner and string and pretend that was done right.

This is rock. No anchor could have buried and any anchor could come lose on a shift (that he should move somewhere else is valid but is a separate point--let's assume there is no other option). This is one of the very few times in-line tandems do make sense. But he did it all wrong.

a. The scope is way to short. For an in-line tandem to work, and to have both anchors working, the chain needs to STAY on the bottom. The only way that happens is to use ~ 20:1 scope, which is a problem of course. Since the forward anchor feels 100% of the up lift but perhaps none of the hooking force, there can be zero uplift on the lead anchor. Unlike buried anchors, the fluke angle cannot be relied upon to provide any hold-down. In fact, the anchors may just be scraping for friction on cobbles. The chain must lie on the bottom, not even lifting in the gusts and surges.

b. The secondary attachment point is wrong. Up high it will just pull the primary on it's back and keep it there, which we see. The Rocna tandem hole is workable (don't know why he didn't use it), the back of the fluke is even better. Over the roll bar is just sad.

c. Being hooked by a tip is not unusual on rock. It can work IF the second anchor is also ready to hook, not up in the air and on its back. That is where the the resistance to shifts comes from; keeping 2 hooks on the bottom. Strangely, sizes is not quite as important as a good hooking design (that pivoting fluke anchor seems like a poor choice, but...).

It's not difficult to get in-line tandems to bury properly... it's impossible if there is any shift. I tested this repeatedly with Manson and Mantus under conditions where both set very well. The lead anchor will roll out every time, because the secondary anchor changes the forces. You might like to try it and see if you can get real world pictures over a few days. You might be the first to succeed, with NG anchors in the real world! The only way it will work is if the load is not high enough to tax the lead anchor and the secondary rode tension is light, in which case you obviously didn't need it.

(this is from Wemar's site--they didn't even have proper sets there!)

[kas_1611]

And now for the last photo of the season



Lunchtime stop in a nice bay on the mainland. Dropped in good clean sand at 4.2m (5.7m to the bow roller) and let out 3+:1. Gave it our usual 1500rpm reverse to set.

You can see the short setting mark and although the Vulcan is still listing slightly it has dug in deeply. A wee bit more reverse and it would have levelled out nicely. Managed to swim down and look under the blade to check how it was digging in but couldn't hold my breath long enough to grab the camera and set up the shot.

Big storm due in this weekend so with all the cold rain due the sea temp will drop below the 20ºC threshold for comfortable swimming.

Keiron

[GMac]

Originally Posted by kas_1611

This example belonged to a charter boat that would end upwind of us with the forecasted shift. They actually moved and re dropped later but watching their technique I didn't exactly relax. It was a drop the anchor, let out the bare minimum of chain, turn the engine off and get stuck into the wine. No reverse, no snubber, nothing but blind faith. How they didn't drag is beyond me.

Keiron

I always 'chuck and swill' without 'setting'.

There is no reason most boaters have to set their system if the system is well set up, if it is the anchor will set itself and continue to do so as the loads increase.

But then I have spent the last couple of decades specifying anchoring systems and advising others on how to sort out their anchoring issues. As a FYI, one of the biggest issues in anchoring worries we have increasingly starts with 'I was reading a internet forum and ......'. It's amazing what people take from forums like this so write carefully and qualify what you say.

[kas_1611]

Originally Posted by GMac

I always 'chuck and swill' without 'setting'.

There is no reason most boaters have to set their system if the system is well set up, if it is the anchor will set itself and continue to do so as the loads increase.

But then I have spent the last couple of decades specifying anchoring systems and advising others on how to sort out their anchoring issues. As a FYI, one of the biggest issues in anchoring worries we have increasingly starts with 'I was reading a internet forum and ......'. It's amazing what people take from forums like this so write carefully and qualify what you say.

I think I did qualify what I said with the picture of an unset CQR lying on its side. I agree with you there are many an armchair "admiral" who only know what they have read on a forum but I think you'll find most of us on this one only speak from what we have physically seen with our own eyes. What I described as their technique was exactly what they did as seen by me, at the time and not any speculation, hearsay or circumstantial evidence.

Could you help us by explaining how, in your opinion, the example I posted of the CQR lying on its side, on the surface of the seabed, with no setting force applied to it initially could be a "well set up system in which the anchor will set itself and continue to do so as loads increase"

Cheers

Keiron