Mystery useless anchor – can you identify it?

[GreyWolf_359]

Hello everyone,

I would really appreciate your help identifying this anchor. It was fitted to the 36 foot Bavaria we had in Greece last summer and it was utterly useless!!
On one occasion we were anchored in 7-10 meters of water with 50 feet of chain out with our stern 15-20 feet from the quay (to be well clear of some underwater rocks) and no wind.

I had driven astern on the anchor to check it was dug in and all was well the first night. But, the next morning the wind suddenly came up and we were being hit with gusts of 25-30 knots on our port beam and the next thing we knew we had dragged so far that we almost hit the rocks!

This was not the only incident we had with this anchor, and having had very few problems in 35 years of sailing in the med using either a delta or occasionally a danforth, I’m keen to know exactly what sort of anchor this is.

Any help would be much appreciated!

BM.

[rslifkin]

It's a Rocna Vulcan. If you only had 50 feet of chain out in 7 - 10 meters of water, that's not even 2:1 scope once freeboard is factored in, which is probably the biggest cause of your issues. It's also possible that it was undersized and couldn't handle the load of being sideways to the wind, particularly at short scope.

[GreyWolf_359]

Hi rslifkin,

Thank you for your quick response! That was a typo on my part, I meant 50 metres of chain, not feet. Sorry about that.

One thing I will do in future having read lots of the other posts in this forum is to give it 2000-2500 RPM in reverse for way longer. Some say a couple of mins which seems a lot but the experience I described above scared us both so I think I will er on the side of caution in future.

Thanks again for identifying the anchor!

[rslifkin]

There are multiple thoughts on how to best set an anchor. Personally, I usually drift back on the anchor slowly once all of the scope is out and let the boat give a gentle tug. Do that with the boat moving at an angle (let the wind blow the bow around a bit) and when the anchor bites, you'll feel it snap the bow around when it grabs. Once it grabs and the boat settles, I gently bring up tension on the rode and then once it's tight, hold idle reverse for a bit and then gradually bring the power up a bit. I don't power set it for as long as some do.

Wind from the side when anchored bow and stern or anchored and stern tied is always a bit tough, as you have far more windage from the side. Generally if there's a good bit of wind and you won't be bow or stern to the wind, I'd rather be free-swinging so the boat can point to the wind.

[GreyWolf_359]

Thanks, I think that's a good procedure. And you are right, I'm pretty sure the free-swinging boats were fine during this episode, and that would usually be my preference.

I'm now going to read more about the Rocna Vulcan.

Thanks again.

[slug]

I pay out 3 to 1
Dog off
Give the boat a click of reverse to test anchor set , bottom condition
If it feels good I drop to 5 to 1
Then back the anchor in

Greece is plagued with posidonia

Anchors don’t bite in this weed

Best to anchor in deep water , 15 to 20 meters , , posidonia needs sunlight to live

[Riddle]

There is nothing wrong with this anchor. Rockna is supposed to be in the top league. The trick is in the correct procedure in setting and than preloading the anchor with some strong reversing. Sometimes the bottom itself is the problem, gravel, rocks etc. That will show up during the reverse thrust.

[SV__Grace]

We are full time cruisers and this is our second boat with the Vulcan as our primary bower. It's a great anchor that has held firm, without dragging an inch, through multiple gales topping 65 knots one time.

But I have two big issues with it that caused us to recently replace it with a Sarca Excel-

1. It's finicky to set. Requires careful technique, minimum 5:1 scope, and won't set reliably if dragged before the scope is deployed (discovered this the hard way after 6 tries in a familiar anchorage with sticky mud bottom, then finally looked up the manufacturers guidelines for setting this anchor which clearly state the above).

But my experience has been that once it's set, it holds very strong. It's never dragged on us.

2. Recent tests by sources I trust show that it can pull out and resist resetting because its scoop can get clogged with mud. Seems more likely to do this with strong 180 degree shifts. While my Vulcan has always stayed in place and pivoted, it does not provide me peace of mind to know this weakness.

For more info see https://www.cruisersforum.com/forums...rs-230603.html

[uhu]

check if your anchor is at least within the recommended sizing specs.
https://rocna.com/wp-content/uploads...art_metric.gif

[Robert E]

We use a Rocna Vulcan #15, 33 lb anchor on our Nonsuch 33 with 5/16" chain. We follow the Rocna recommended procedure to deploy. Drift astern with 5-1 scope. The anchor sets quickly. Then gradually apply reverse 1000-1500 RPM. Shorten scope to 3-1 if needed. Holding power is 90% of 5-1 scope. A solid, reliable anchor.

[SV__Grace]

Originally Posted by rslifkin

There are multiple thoughts on how to best set an anchor. Personally, I usually drift back on the anchor slowly once all of the scope is out and let the boat give a gentle tug. Do that with the boat moving at an angle (let the wind blow the bow around a bit) and when the anchor bites, you'll feel it snap the bow around when it grabs. Once it grabs and the boat settles, I gently bring up tension on the rode and then once it's tight, hold idle reverse for a bit and then gradually bring the power up a bit. I don't power set it for as long as some do.

This is a good description of what I call "finessing" the anchor set, and has worked well for me with the Vulcan, given a minimum of 5:1 scope and decent bottom.

The Rocna Vulcan is very different from the roll bar Rocna. When I had a boat with the roll bar Rocna it was not necessary to finesse the anchor at all- just throw it overboard and it bites and holds immediately, every time (in my experience with that boat).

When we moved up to a larger boat with a bowsprit, the roll bar Rocna wouldn't fit, so we got a Vulcan. It's a great anchor that holds strong but requires finesse to set.

After a few years of full time cruising I got nostalgic for how easy it was to set the original Rocna and after some research and correspondence became convinced that my current anchor (Excel) would do that and more, and so far so good!

[sailjumanji]

I've used both the traditional Rocna with the roll bar, and now the Vulcan. The roll bar model set easier. Once set, I don't think there is any difference in holding power. From the looks of your bow, why don't you go to the roll bar model? Only reason I have the Vulcan vs roll bar model is self launch setup on catamaran doesn't allow roll bar.

[hpeer]

The difficulty I have with these “finicky” anchor setting techniques is when you need to deploy in an emergency in sub-par conditions.

I advocate an anchor you can throw over the side and go below. Of course no such anchor exists but it is the ideal to strive for.

There is no substitute for weight. Your anchor provides the weight every time you set it. So in the heavier anchor or heavier chain income down on heavy anchor side. How heavy? I wing it at 6pound/to, not liner, heavy boats can go lighter, light boats heavier. Eventually that weight WILL break through the weeds, the heavier the sooner.

I personally like the Mantus if you can accommodate the HUGE roll bar. I think you can. They are very effective, relatively inexpensive to buy, and if you need to ship it break down flat for low cost shipping. All reviews give them high marks

[kas_1611]

Like any anchor the Rocna Vulcan needs to be set well and yes there is a finesse to doing this with the Vulcan. However once you get the hang of it you find it sets really quickly and holds really well (even upside down in one instance with ours!!!).

I have a 33kg Vulcan on the bow of my 40ft Bavaria Cruiser, having replaced the what I considered undersize 16kg Delta after if repeatedly dragged in sand. The Vulcan is connected to the 8mm G70 chain by a Mantus Swivel to give it excellent articulation.

I drop at least 2:1 and let the boat drift back and as the chain starts to tighten up I slowly let out to 3:1 (at least) before the Admiral starts to apply the reverse, slowly building up to around 1800 to 2000 rpm. As the chain tightens we both watch our marks for any signs of dragging and frequently find the boat getting hauled foreward, even against the 1800rpm reverse. Finally once we are happy it has set I let it out to 4:1 if there is space and if the winds are predicted to be above 12kts. And I always try to swim over it to check like any good paranoid anchorholic does.

Only time it has ever dragged was during the Medicane, Storm Zorba, when we'd rotated through nearly 270deg and the chain had wrapped around the shaft. Once we'd got the anchor up and found another space to drop it held for the rest of the blow without a problem. In fact it took quite an effort to break it out a couple of days later from the clay.

[barnakiel]

Look at your scope ratio again.


Once the hook is in, then you may, if conditions are light and you are keeping watch, shorten to maybe 1:3 with some anchors. But when you dig in it takes plenty more.


Next time give it 1:7 or more scope. See if it changes anything. It might.



Cheers,

b.