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-   -   Rocna Vulcan anchor size for Grand Banks 42? (http://www.trawlerforum.com/forums/s15/rocna-vulcan-anchor-size-grand-banks-42-a-33080.html)

FBoykin 07-19-2017 05:44 PM

Rocna Vulcan anchor size for Grand Banks 42?
 
New to me Grand Banks 42 Classic has a 45# CQR as primary anchor. Shank is bent and I'm thinking of replacing it with a Rocna Vulcan anchor (research says that style fits my bow roller best). Wondering if anyone on a GB 42 is using a Vulcan and has advice about the size they're using?

On a Vulcan sizing chart, a GB42 in size & weight is between a size 25 (55#) and a 33 (73#).

Any GB42 folks using a Vulcan with advice? Thanks.

hmason 07-19-2017 06:19 PM

We have a GB 46 and use a 75# Rocna (not a Vulcan model) with the roll bar. The size is more than adequate and would likely be overkill for your boat. We anchor several 100 times/year as we are full time cruisers. The 55# should be more than enough.

djmarchand 07-19-2017 07:26 PM

I suspect the 55# Rocna Vulcan will be plenty big. OTOH I would never discourage someone from getting a bigger anchor. But check the bow roller to anchor windlass length and make sure it can accomodate the long shaft of the Rocna.

David

HiDHo 07-19-2017 08:05 PM

1 Attachment(s)
We replaced our old friend our 45 lb CQR with a 44 Lb Rocna Vulcan. The Rocna web site has plans for each size anchor that you can down load and print. We did that before ordering and the plans are true to size.
We have anchored several times with the Rocna Vulcan and it truely is a better setting anchor than the trusty CQR. Best example was anchoring in 10-12', sand bottom, 1 1/2 knot current, dropped the Rocna and used the current to lay out about 50' of 5/16" chain, I snubbed the chain and let the current set the Rocna. When it set the chain straightened and the Rocna set so solidly it was hard to keep your footing on the bow. :)

Bigsfish 07-19-2017 08:33 PM

We have a 43' GB between 40k to 50k pounds and use a Manson Boss (similar but not exact) and it is 60 pounds with chain ride. Best anchor I've ever had but it has a large fluke.

Nomad Willy 07-19-2017 09:31 PM

Anchor manufacturers and other experts often say holding power is proportional to fluke area. Of course it's not true but lt's a very good indication. Anchors w small fluke area most often have low performance. However the details can make a big difference.

Bigsfish 07-19-2017 09:35 PM

Eric

This damn anchor has the biggest fluke area I've seen, it looks like a 747 wingspan. :b

Anchor Brian 07-20-2017 03:27 PM

Quote:

Originally Posted by Nomad Willy (Post 574980)
Anchor manufacturers and other experts often say holding power is proportional to fluke area. Of course it's not true but lt's a very good indication. Anchors w small fluke area most often have low performance. However the details can make a big difference.

Eric, good points. This fluke area comparison with anchors of similar weights might be of interest.

https://s19.postimg.org/j3d8susyr/Fo...Comparison.jpg

Bigsfish 07-23-2017 10:12 AM

If fluke area was the only determine factor the Boss would win hands down but fluke area is only one part of the equation which makes rating anchors a very difficult practice.

hmason 07-23-2017 10:20 AM

Fboykin, did you receive my reply to your PM?

Group9 07-23-2017 10:38 AM

Once, you've been in a 75 mph squall on a lee shore, there is no such thing as too much anchor.

On our 42 foot motor yacht (40,000 lbs), our primary anchor is a Mantus 85 pounder.

It may look silly, but it feels good!

Nomad Willy 07-23-2017 10:45 AM

Quote:

Originally Posted by Bigsfish (Post 574983)
Eric

This damn anchor has the biggest fluke area I've seen, it looks like a 747 wingspan. :b

Bigfish,
I've seen them on boats and they always look BIG.
Handled one at a boat show and it seemed lightweight. But if the fluke to shank geometry is correct (no reason to belive otherwise) it should serve you well. Perhaps you should change your username to "BigBoss".

Nomad Willy 07-23-2017 10:48 AM

Brian,
Yes indeed the holding power king is .. in a word .. Fortress.

Nomad Willy 07-23-2017 11:10 AM

Bigfish,
Surface area is a big factor to be sure.

But surface area is easy and even idea fluke shape is more or less a given. The tricky part is setting. Steve (Panope) was brilliant to pick setting to analyze in his anchor tests. And the thing that made Bruce and roll bar anchors a smash hit on the anchor market was setting. And setting is what opens the door to more basic performance factors like holding power.

I think I've said as much in the past but if I was heading to SE Alaska tomorrow I'd pick an anchor first for excellent setting performance. Then bottom compatability (rocks, sand mud, weed ect) holding power and other secondary considerations like fitting on the bow can be considered. But your sunk if you can't hook up.

Bigsfish 07-23-2017 11:23 AM

Eric

BigBoss. LMAO.

I agree about the fortress being a holding power champ and I used one for years but had problems getting them to set and if you can't set them they won't hold. I'm no expert but I felt that being lightweight they were hard to penetrate grass bottoms and lost confidence in the anchor. I always thought the best use for the Fortress was as an extra, stored in the bilge anchor and not as a primary.

Just my SSO!

Group9 07-23-2017 11:27 AM

Quote:

Originally Posted by Bigsfish (Post 575948)
Eric

BigBoss. LMAO.

I agree about the fortress being a holding power champ and I used one for years but had problems getting them to set and if you can't set them they won't hold. I'm no expert but I felt that being lightweight they were hard to penetrate grass bottoms and lost confidence in the anchor. I always thought the best use for the Fortress was as an extra, stored in the bilge anchor and not as a primary.

Just my SSO!

We had an F-37 Fortress as a backup/kedge anchor and that was our experience as well. With the right bottom, it would set quickly, and a D-7 tractor couldn't pull it out. On the wrong bottom, you could try and set it all day without any luck.

Bigsfish 07-23-2017 11:54 AM

Agreed.

Nomad Willy 07-23-2017 12:20 PM

Bigfish and all,
To delegate the Fortress to a backup status may be a mistake.

Many things on TF get repeated over and over again because people don't know what to say so they repeat what so many others have said that they assume that is bullet proof. Kinda like bigger is better. Talk about bullet proof! But if it's said enough times most will belive it.

If I was to try an anchor that I've not had any experience with they would be the Fortress and the Super Max. One heavy and one light. Always liked extremes. Even have an anchor called the "Extreme". HaHa

I'd say see Steve's Anchor Setting Videos but Max is not there.

Bigsfish 07-23-2017 12:27 PM

Eric

My reason to have the Fortress as a back up is that it can be stored in sections and it is light weight but my experience using the Fortress as a primary has not been good.

Just my SSO!

Nomad Willy 07-23-2017 03:30 PM

Big,
Weed, rock, operatir variables or?
Many think anchors are to be hucked over the side and forgot about.
Oh sorry.
However some are said to have the ability to find the bottom, orient themselves toward the mothership and dig down into the seafloor. Oh, and stay put.
So either you're not the great anchor whisperer I thought or you said the wrong thing while sending the anchor on his way.


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