Extending anchor chain with warp

[RupertW]

These pics aren't a great example but they do highlight the point.

This is my old Delta anchor starting to plough its way through the sand.
View attachment 191203

And this is our Rocna after about 3 days
View attachment 191204

You can see where the chain has been spinning round the anchor which hasn't moved.

Here they are, side by side - the Rocna IS bigger but the difference in performance is significant.
View attachment 191205

There is a massive difference between ploughing to set then stopping, and continuing to plough. I often dive over my anchor in crowded anchorages and have a look at other anchor types too. There is no doubt that Rocnas set really fast with minimal travel, compared to our Delta which takes 1-2 metres drag to dig itself in. But there it stops if it sets, and will remain stopped for days and in high winds and gusts many times.

So I think your photo shows a set and not a continuous plough.

 

[benjenbav]

Here is a better photo of the two side by side
View attachment 191225

The shank joins the blade much closer to the pointy end (in relative terms) on the Rocna. That might help the ‘bucket’ get a purchase.

My last boat came with a Delta and, as I never had a problem, I didn’t change it. But, if I had had an issue I’m sure I would have looked more closely at alternatives.

 

[MapisM]

Deleted User had a Bruce not a Delta, and switched to Rocna. His boat, Ferretti 630, came OEM supplied with a 30kg Bruce, which is a joke, so when he switched to a bigger Rocna it isn't much surprise that it worked better but that forms no basis to say that Rocna is meaningfully better than Delta AOTBE.

This forum engine that automatically converts old forum names now deleted into "Deleted User" is laughable!

Anyway, I believe that MikëF (with the umlaut just for sake of cheating the software! ) did buy his F630 with the OEM small Bruce, which Ferretti used to fit for reasons only known to them, but asked the seller (SL) to replace it with a bigger Delta as part of the deal.
Can't recall the size, but i think somewhere in between the original Bruce and the Rocna that he installed afterwards.

So, I think that our two Mikes did follow a very similar path - but your point ref. being pointless to compare different sizes still stands, of course.
Otherwise we should draw the conclusion that the archaic anchors below are the best thing since sliced bread, because they worked perfectly for 17 years...
...Forgetting the fact that they were actually sized for boats 20+ feet larger than my 53 footer!

 

[Sticky Fingers]

This forum engine that automatically converts old forum names now deleted into "Deleted User" is laughable!…

In our mutual friend’s case IIRC it was part of his exit agreement

 

[jfm]

This brings us back to the reviews from SV Panope, which are the only good like-for-like tests conducted on equal terms . But as you said, there are bound to be user input differences, so the same anchor will likely perform differently across different operators/locations. I think you also mentioned in your build thread that, at the anchor weight of your Sanlorenzo, the anchor type doesn’t matter - and I imagine that’s probably true at lower weights as well, so the comparison of anchors is maybe only really relevant up to c.50kg?

When people report anchor dragging incidents online, it seems to me that if often stem from being stuck in overcrowded anchorages where they can't put out as much chain as they would like. SV Panope generally conducts his tests at a 5:1 scope (5x water depth), and perhaps you guys differ when it comes to the amount of chain set when anchoring conservatively?

@jfm: I also wanted to ask whether you think your stabilizers significantly reduce jerking on the anchor or if any effect from that is offset by the chain catenary?

I'd somewhat question the "good like for like" description. Not criticising the guy, and getting like for like is very difficult, but we need simply to identify what is truly like for like and what isn't.

As regards scope, most like-for-like testers use the same scope, which is a reasonable approach but is far from scientific. Imagine anchor A has a holding force of 2 at 6x scope and 0.8 at 5x scope, while anchor B has holding power of 1.2 at 6x and 1 at 5x. If the tester (arbitrarily) chooses 5x for his scope then anchor B wins with 25% margin, whoopee doo, yet I would much rather own anchor A. And so on.

For sure I only do lunch stops at 5x, and perhaps 4x if calm. For overnighting I'm 6x +, perhaps 8x. The chain isn't any use in the locker, plus you tend to anchor with more space at night.

Then as you say weight matters differently at different weights, meaning that 40kg vs 55kg "comparisons" must be viewed accordingly. I mean, if you compare a 55kg with an otherwise identical 40kg, the weight has increased 1.375x but the surface dig area only 1.23x. So you gotta think about whether weight or shape makes an anchor work - answer is both of course, to differing degrees in differing substrates. Nothing's simple.

Anecdotes are interesting and I'm only giving mine to counter those who insist matter-of-factly that XYZ anchor is rubbish. Hurricane says 40kg Delta on Princess 67 is rubbish, and it might be, but does that mean Delta's are all rubbish or was something else going on? I had 50kg Deltas on 2x squadron 78s for a decade and they never slipped even in howling winds where we wouldn't choose to be but had to because of circumstances. How do we weigh up such opposite anecdotes? There's plenty of confirmation bias typically with anchors (me included )

Stabiliser fins can help and hinder but mostly have no meaningful effect imho. A rolling boat puts no more load on the anchor than a non rolling boat. Fins can swim the boat forward, which can do two things: (a) simple reduction in anchor load, or (b) forward movement of boat makes the chain go slack then the wind catches the bow so the boat goes beam on to the wind and blows back, with increased anchor load as the chain tightens and the boat goes head-to-wind again. But in strong winds when you care/worry about your anchor you only get (a), which therefore helps, but so slightly that it hardly matters.

 

[Hooligan]

Personally I am with @Hurricane re the ROCNA. But I do agree re @jfm that it is not all about the anchor. Sea bed conditions, weight of chain, amount of chain deployed. Personally it shocks me at times how little chain people put out. Sure there are times when there may be space issues but I usually subscribe to the view that more is better than less. Personally I would always have chain and given that the cost of chain is likely to be less than the cost of the boat ….

 

[Sticky Fingers]

… I would always have chain and given that the cost of chain is likely to be less than the cost of the boat ….

That’s definitely true for sure! I’ve pretty much decided to go all-chain rather than extending, not least because the cost of the warp, splicing and whatever isn’t a lot less than the new chain.

 

[boomerangben]

In my view and from what I have seen, Panope seems to be very dynamic whe. Setting the anchors, ie uses significant power when initially setting the anchor. I was taught to set the anchor gently. Technique (and that includes choosing not only how you anchor but also where you anchor) is more important than which modern anchor you choose.

Weight is less important than the area of the fluke as aluminium anchors demonstrate.

Whilst weight in the bow might be a benefit for trim at speed, a heavy boat is slower than than the same boat with a lower displacement

Mixed warp/chain rodes have significant benefits in terms of comfort and ease of recovery and cost.

The ultimate test though is how well you trust what you have - having a super efficient well designed and optimised anchor rode may be light and cheap but it is no good if you don’t have confidence in it.