Is my Rocna to big?

[sebathon]

Have purchased a 25kg ronca on a B 40' oceanis and unsure if I have gone to big. Boat has light displacement of 8,500kg so probably around 9,500kg now as it's a live-aboard.Attachment 1

Currently living and cruising in Norway and plan on heading towards Australia in the long term so due to this I followed advice and took the size up from the recommended.

I have 70m of 12mm chain and 1000w quick windlass.

As there is some mounting difficulties and quite a hassle to launch without swinging into hull I am considering downsizing to 20kg. Is this a good idea?

Or should I alternatively have the roller rebuilt to better house and launch the rocna ?

Thanks in advance for any advice.

[s/v Moondancer]

I have a 122lb Rocna, initially I thought it was too big but I had cheeks welded onto the anchor roller to aid launching. After 1,000 nights at anchor it is the best decision I ever made on a boat.

[UNCIVILIZED]

No, it's not too big by any means. Though your chain may be. That stuff is HUGE (12mm). Were it me, I'd go down to 8mm G43 & perhaps go a size bigger on the anchor, & it'd still pull a ton of weight out of the bow. Well, okay, 150kg or so (I think).

That said, regardless of your anchor choice, you'll need a roller thats a lot more stout, & that's better connected to the boat. As that one looks like a recipe for getting bent into "modern art" the first time it blows 40kts & there's any fetch.

One other thing that you can do, & it's in relation to your anchor banging into the topsides when retrieving it, is to put a "skid plate" on the bow. Some type of wrap around guard that prevents a flailing anchor from doing any harm to the boat. Whether it's metal, like stainless or aluminum, or something synthetic. And with the latter, it's pretty easy to find a solution which is color matched to your topsides as well. Like the one which Ann (JPA Cate) & Jim Cate have on their boat. As they've a fairly plumb stem as well.

And to leave you with a thought. The fact that you're asking this question, to me, says that it's not obvious that your anchor's too big, so leave it be. Also there's a thread on this exact topic by a64pilot, & his Rocna's much bigger than yours, on a similar sized boat. But the thread's worth a read, if you're not convinced.

[GordMay]

Greetings and welcome aboard the CF, Sam.

[Gdog6]

Don't go smaller. When you get to the pacific, and you are anchored upwind from a coral reef, and it starts to blow, you will be happy you have the extra weight !

[sebathon]

Originally Posted by UNCIVILIZED

No, it's not too big by any means. Though your chain may be. That stuff is HUGE (12mm). Were it me, I'd go down to 8mm G43 & perhaps go a size bigger on the anchor, & it'd still pull a ton of weight out of the bow. Well, okay, 150kg or so (I think).

That said, regardless of your anchor choice, you'll need a roller thats a lot more stout, & that's better connected to the boat. As that one looks like a recipe for getting bent into "modern art" the first time it blows 40kts & there's any fetch.

One other thing that you can do, & it's in relation to your anchor banging into the topsides when retrieving it, is to put a "skid plate" on the bow. Some type of wrap around guard that prevents a flailing anchor from doing any harm to the boat. Whether it's metal, like stainless or aluminum, or something synthetic. And with the latter, it's pretty easy to find a solution which is color matched to your topsides as well. Like the one which Ann (JPA Cate) & Jim Cate have on their boat. As they've a fairly plumb stem as well.

And to leave you with a thought. The fact that you're asking this question, to me, says that it's not obvious that your anchor's too big, so leave it be. Also there's a thread on this exact topic by a64pilot, & his Rocna's much bigger than yours, on a similar sized boat. But the thread's worth a read, if you're not convinced.

Thank you all kindly for the quick response.

Apologies, I just double checked and the chain is actually din766 10mm x 70m of chain my mistake.

Thanks for the info and I will surely check out the relevant threads.

I have had a few nights in 35kn exposed anchorage of sand where I was indeed very happy with the choice although now on the west coast of Norway soft bottom anchorages are few and far between so usually I am in rock with the lines ashore and use of small Bruce stern anchor.

Ok, I will definitely look into finding a fabricator to extend and adjust the roller to give it more clearance from the bow and also beef it up a little. With regard to that is it at all possible to include some sort of bowsprit arrangement into this modification in order to fly a gennaker and provide a step (of much use here in Scandinavia)???

I have seen a few stainless bow protectors but I will look into synthetic also.

Cheers

[GordMay]

See also ➥ Bow roller assembly design (Rocna Knowledge Base)

And ➥ Category:Rocna bow compatibility (Rocna Knowledge Base)

[oslokid]

I have a 15kg Rocna on my Beneteau 373 and although it is correct size according to their website I have it not set a couple of times and I don't always sleep well at night when on the hook. Sometimes bigger is better. Stay with the 25kg.

[UNCIVILIZED]

Originally Posted by sam_hawk

Thank you all kindly for the quick response.

Apologies, I just double checked and the chain is actually din766 10mm x 70m of chain my mistake.

Thanks for the info and I will surely check out the relevant threads.

I have had a few nights in 35kn exposed anchorage of sand where I was indeed very happy with the choice although now on the west coast of Norway soft bottom anchorages are few and far between so usually I am in rock with the lines ashore and use of small Bruce stern anchor.

Ok, I will definitely look into finding a fabricator to extend and adjust the roller to give it more clearance from the bow and also beef it up a little. With regard to that is it at all possible to include some sort of bowsprit arrangement into this modification in order to fly a gennaker and provide a step (of much use here in Scandinavia)???

I have seen a few stainless bow protectors but I will look into synthetic also.

Cheers

It's quite common for folks to use their bow rollers to attach asymmetrical kites to. You just need to be sure that it's designed for that type of loading, as well as that exerted by anchoring, as it's in a different direction, with a lot of force. And a rollers have been torn off by spinnakers. But there's even a picture or three of this in the Dashew's Offshore Cruising Encyclopedia, vol. II In the section on anchor rollers (I think). The books are available for free download at www.setsail.com/free-books.com
And of course there's plenty of anchoring wisdom in them, along with a couple of thousand pages of other sailing knowledge.

On the roller, one thing which is pictured in the book, & that you see on some boats, is a metal pipe supporting the roller from underneath, & it's connected to a fitting on the stem.
I'm terrible at uploading pics, or I'd post a couple of such setups. But the design, when well done, adds a lot of strength to things.

Given the comment about a step, I gather that you mean something that might be useul in a situation akin to a Med Moor? Regardless, if you're going to have the roller rebuilt, it might make sense to consider anything you're currently only entertaining as wanting to incorporate, & doing some sketching/designs on paper. So that even if you don't build it now, there's room on the stem/bow for it later. For example a deck mounted sprit (custom designed, or a kit), a 2nd roller, etc. That perhaps, as well as starting a thread to ask folks to show their bow roller setups, & such.

[SVTwilight]

Originally Posted by sam_hawk

Have purchased a 25kg ronca on a B 40' oceanis and unsure if I have gone to big. Boat has light displacement of 8,500kg so probably around 9,500kg now as it's a live-aboard.Attachment 151726Attachment 1

Currently living and cruising in Norway and plan on heading towards Australia in the long term so due to this I followed advice and took the size up from the recommended.

I have 70m of 12mm chain and 1000w quick windlass.

As there is some mounting difficulties and quite a hassle to launch without swinging into hull I am considering downsizing to 20kg. Is this a good idea?

Or should I alternatively have the roller rebuilt to better house and launch the rocna ?

Thanks in advance for any advice.

Stay with the 25! We have a 36 foot heavy cruiser and it is perfect. While you boat may be lighter, it is also presents a much larger wind target than ours. We chose 25kg over 20 and I am so glad we did. Whatever you need to do to modify and upgrade you bow roller assembly, do yourself a favor and do that now as well.

[fatherchronica]

We have a 25 kg Rocna on Mana and love it.

[S/V Alchemy]

Most sailors think their anchor is too big. Most sailors' wives will tell you otherwise.

[SeaBreeze-1]

If you wish, you can google a sizing guide for Rocna anchors online. You will likely find that your approaching the upper limit of the 20Kg capacity. My wife and I have a 40 foot steel boat that weighs in at 25,000lbs and are at the very upper limit of the 20Kg. We opted for the 25Kg as it put us "smack dab" in the middle of its performance window.

[DMCantor]

My rule of thumb is that your anchor is the right size when your neighbors in the marina are laughing at you for how big it is.

Just for fun, a fellow we know, on a charter boat with a French flag, went merrily through the anchorage (in the Caribbean), with a 3kg dinghy anchor on his bow roller. Lots of people hoping desperately he didn't stop near them!

[Wallaby]

I have a 33 Rocna on a 50ft 36K pound sailboat. It is an excellent anchor, though I depend on an oversized Fortress for really bad weather.

The issue of the bow roller is a big one. As the anchor comes up to the bow, you are dragging a 25kg load over 90 degrees with a two inch lever (initially). A bigger diameter roller is obviously better. That small single roller causes huge and unnecessary loads on the windlass, the roller itself, etc.

I made my own double roller, swiveling on the same bolt as the original roller. Problem vanished, retrieving the anchor is a breeze.

The basic design is a 1/4" thick stainless channel, 12 inches long, about 3" inside width, and about 2+ inches high. I had one welded up. Next, drill two sets of holes near the ends, and one set of holes in the middle. Insert new rollers and bolts in the end holes, and a bolt through the bowsprit and center hole. Total cost about $100 including the welding.

I'd send a photo but it is too damned hot to go outside.