Catalina 34

General Activities => Main Message Board => Topic started by: Dave Dawe on July 28, 2008, 12:09:31 PM

Title: Roll bar anchors on bow roller Rocna Flix
Post by: Dave Dawe on July 28, 2008, 12:09:31 PM
I am looking at a new anchor to replace my Bruce 22 and the roll bar anchors - Manson Supreme and Rocna are looking good. Does anyone know how well these fit on a C34 1991 stock bow roller?
Title: Re: Roll bar anchors on bow roller
Post by: Craig Illman on July 28, 2008, 12:30:39 PM
Dave - I just put on a Manson Supreme on my '91 #1150. I replaced the bow roller with the longer one from Catalina Direct. http://www.catalinadirect.com/index.cfm?fuseaction=product.display&Product_ID=927  I also needed to replace the bail with a longer one (BB-2) from Garhauer. http://garhauermarine.com/catalog_process.cfm?cid=73 The Manson shank is very thick. Even the 33# Bruce was a tight fit on the old roller and the bow gelcoat was nicked a few times while in charter.

There's a thread about replacing the bow roller with a tip about using DeBond and using the spare jib halyard to apply upward pressure. The supplied backing plate from Catalina Direct was too wide and needed to be trimmed. You could use the existing backing plate. I also had to drill the head off the most forward fastener on the old roller. It was more expedient than trying to remove the nut.

Craig
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on July 28, 2008, 12:32:35 PM
Here's a 22# Rocna coming up (for it's first overnight stint on the bottom) and how it fits on the old toy bow rollers.

Our old Bruce 16.5# is on the port side and "protects" the hull from the new longer Rocna.  I've since removed the old Bruce and use it for a stern anchor, and moved the Rocna to port.  We added a port cleat, but still kept the middle factory cleat, so a port side anchor works best for us with the two cleats we do have.  I'm considering either what Craig did, or just biting the bullet and adding a small stainless plate to the bow.

We bought this at the suggestion of Maine Sail who did a terrific writeup - search for "Rocna" and read his contribution (#33 page 3 at: http://c34.org/bbs/index.php/topic,2705.0.html) .  I wrote him offline:

"I bought the 22# having experienced over 25 years sailing here that I would not require anything larger.  Long story, doesn't involve windlasses or bad backs, but just the places I choose to anchor and the way the weather works here - we just don't get those afternoon thunderstorms, etc. 
 
"Well, you were spot on right about the anchor.  I haven't felt an "I gotcha bottom" like that since [forever]..."


We have 30 feet of 1/4 chain, I bought an anchor connector between the chain and anchor, but still have a shackle on the rode chain joint, but will do a splice there to get rid of the big shackle.  I used 3/8 chain in these pictures, but it's too much for the "system" and having Calder's "Cruising Handbook" I designed the system with the appropriately sized components - only the 3/8 rode chain shackle is overkill.  42 knot wind design with anchor, chain, connector and shackle.

A big advantage of the longer bow roller is keeping the beast on the bow.  We use a line tied to the stanchion and the roll bar of the Rocna.  While I don't have a picture of the latest final install, the shank does come back a teeny bit aft of the anchor locker doors, but the shackle hole is a short slit, not just a hole, so the connector ends up dropping straight down into the locker with the chain.  Interesting and great physical serendipity.
Title: Re: Roll bar anchors on bow roller
Post by: Craig Illman on July 28, 2008, 12:52:12 PM
Dave - A picture of the Manson, cropped out of a vacation picture.

Title: Re: Roll bar anchors on bow roller
Post by: Dave Dawe on July 29, 2008, 07:33:52 PM
Thanks for the info and the pics!
Craig - did you put on the longer bow roller because you had to for the Manson to fit or was it an upgrade you were doing anyway? Did the holes match the other one like they say at Catalina Direct?
Title: Re: Roll bar anchors on bow roller
Post by: Craig Illman on July 29, 2008, 07:48:37 PM
Dave - I felt the Bruce 33 was pretty tight for the existing roller, the newer MKII's have the longer roller. I had my doubts whether the Manson would fit, so I did both at the same time. You can print out a template from Catalina Direct. The newer roller had a second rear hole, I just drilled another hole through the quite thin, solid deck. I used new fasteners. The replacement roller was punched with square holes for carridge bolts. The old roller had been fastened with pan head bolts. I recommend taking a ratching box end wrench. I had some interesting bruises on my bicep from reaching through the Beckson plate. Even though it comes with a backing plate, you can use the existing one after retrieving it from under your V-berth when it falls off.

Craig
Title: Re: Roll bar anchors on bow roller
Post by: Dave Dawe on July 29, 2008, 07:52:07 PM
Thanks Craig - what size manson do you have?
Title: Re: Roll bar anchors on bow roller
Post by: Craig Illman on July 29, 2008, 07:59:01 PM
Dave - a 35#. It's only been on the bottom four times, too early to comment on it's effectiveness. It seems to set quicker than my Bruce, but it might be my wallet's optimism. The first time I tested, it was in eelgrass, and it seemed to set right in. I was by myself, quite a distance from shore, hard to tell how much the boat moved.

Craig
Title: Re: Roll bar anchors on bow roller
Post by: Marshall Tonner on July 31, 2008, 05:34:42 PM
Dave, This is my second season with a Rocna 15kg anchor.I have yet to be able to retrieve it without assistance from the engine or oncoming waves.I also installed a self launching anchor roller in place of the original and moved the original to the port side. This required modifying the the anchor locker closure to accommodate the anchor shank. You asked earlier about an anchor windlass and it is the Rocna that has me looking for help in that area because it sets so well. If you drop by to see the factory windlass maybe the anchor rollers will be of some help too.
                                  Marsh
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on August 08, 2008, 08:29:54 AM
Finally got the anchor set on the port side.  Good news is that because of the design of the shank, and how it sits on the toy bow roller, the blade doesn't dig into the gelcoat on the bow.  Also, the slot at the connection to the connector to the chain makes the connector a bit flexible and drops right into the anchor locker - I was originally concerned that I'd have to do some work on the door.  Next step is to address the lines holding the roll bar, I've got some ideas to clean them up.  The anchor balances very well, but won't stay there without being "leashed."
Title: Re: Roll bar anchors on bow roller
Post by: Dave Dawe on August 16, 2008, 06:17:00 AM
Thanks Stu
I just bought the Rocna 15 and it seems to fit fine on my original bow roller. Just had to change the bail. I have tied a small line through the hole on the top bend of the shank and it goes through the holes at the bottom of my roller furling. So far it is holding well but I haven't given it a good test yet.

Dave
Title: Re: Roll bar anchors on bow roller
Post by: Ancora Latina on August 23, 2008, 08:36:22 PM
A big advantage of the longer bow roller is keeping the beast on the bow. 

Beware of  "longer" bow rollers!.

During a gale, the forces of the anchor and the anchor line on the bow roller are quite high!!.

Long bow rollers need to be oversized!

AL
Title: Re: Roll bar anchors on bow roller
Post by: pjcomeau on August 25, 2008, 10:57:14 AM
I have the same anchor roller (double) with the forestay in the center as Stu does. It's one solid piece. Has anyone replaced this to put a longer roller? If so, what did you do for the forestay? The roller at Catalina Direct must be for newer boats.
Title: Re: Roll bar anchors on bow roller
Post by: Ken Juul on August 25, 2008, 11:43:02 AM
I have the long single model shown on the Catalina Direct site.  I think it was standard issue on my 1990 model because I have most of the upgrade receipts from previous owners and its not listed.  It passes to the right of the forestay at a slight angle.  I like the longer "U" groove on it, protects more of the foredeck from banging chain and anchor stock.


Here is the best picture I could find on Yachtworld.  Note that all the long bow rollers have dual forward cleats on the side and at least in my case the anchor cleat has been moved into the anchor locker.  The long bow roller may interfere with the use of the single center cleat just behind the forestay
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 15, 2009, 11:05:54 PM
For sake of completeness, I thought I would include a shot of what a proper anchor looks like on the bow.   This is my new Rocna 20.   Possibly the best sleeping aid one can find for rolly swell off the surf line.   Oh, and the "toy" anchor rollers work just fine and I don't need to worry about ripping them off with a shock load.   The arch gives me nice access to the cleat and makes it self launching.   

I had Tracey wind her up to about 3 knots in reverse.   I let it roll with a short scope and put a turn on the cleat.  Stunning.   Absolutely stunning.   We used to think we were pretty cool dragging a claw around getting a good set and backing down.    This is an anchor for idiots.   

I have for sale a geniune 10 kG Bruce.   What the heck, I'll offer a package deal with my 15 kG claw...   
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 16, 2009, 12:31:40 PM
See, see, see!!!!

All done with the original TOY bow rollers!

Yipee!

Now I KNOW I don't have to install a new BIG bow roller.

Thanks, Steve
Title: Re: Roll bar anchors on bow roller
Post by: badams on April 16, 2009, 12:41:19 PM
I have the Rocna 15 on the toy roller.  Works well.  Steve, what are you using as a back up, and where is it?
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 16, 2009, 12:46:30 PM
Who needs a backup with a Rocna or a Manson Supreme?   :D :D :D

A stern anchor choice is usually a Fortress or Danforth.
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 16, 2009, 01:23:08 PM
I have the Rocna 15 on the toy roller.  Works well.  Steve, what are you using as a back up, and where is it?

A backup? :shock:

From the way you phrased the question, it sounded like you expected it on the bows?   Interesting.   I've never carried a backup forward.   I keep it in the aft locker.   Currently a 15 kg claw type anchor with a couple hundred feet of chain / nylon combo.   My thinking for backup is it's used in one of two modes:  1) primary is hoplessly snagged, float it, call the diver and use the backup for the rest of the weekend or 2) holy crap we're dragging and there's the rocks!   

In 1) there is plenty of time to drag the rode forward and lay it in the anchor locker.   For 2) I want it available right now for deployment in any conditions.   That means it's in the cockpit right by my wheel, engine controls etc.    I'm not going forward.   

The backup to my backup is a danforth.   This is going on the end of a couple hundred feet of a series drogue.    Serves two functions - keeps the drogue in the water for those days we feel like surfing down 40 foot seas and fondling our EPIRB (ie hopefully never) and it can be used as a conventional anchor for those days when the other two just aren't enough.   I haven't started sewing the drogue yet - upholstery and spinnaker first to get the crew excited.   No need to scare them away at the outset!

The backup to the backup to the backup is a folding grapple type anchor that hangs on the end of a nylon tube with a shockcord in the middle.   This is our dingy anchor.    If the other 3 anchors are gone, it means the boat probably sank and we are in a liferaft, maybe towing the dingy.   Come to think of it.  In this mode, we never would have had time to load an anchor in the dingy.    There is no backup to the backup to the backup!  But if you haven't seen these anchors they're amazing.    You toss it over as your dingy is approaching shore, hit the beach and get out, then you let the shockcord pull the dingy back out to sea while you hold the painter.   You're dingy is anchored with a shore tie and you don't have to drag it down the beach when you come back and the tide is out.   Useless for a lake sailor but great for tides!   I digress.  I'll take a picture and post separately some other time...

 
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 16, 2009, 01:33:35 PM
See, see, see!!!!

All done with the original TOY bow rollers!

Yipee!

Now I KNOW I don't have to install a new BIG bow roller.

Thanks, Steve

Stu, I lived for a year and half thinking I need to put a proper bow roller on the boat.    But the more I think about it the more I'm convinced the boat already has a proper bow roller.   Ever get caught in an anchorage where the sea started running?   Big loads on that bow roller.   You want a short lever arm.    Sailing performance?   You want weight as close to the center of the boat as possible - not hanging out forward.   We don't have plumb bows so the anchor isn't dragging up the gelcoat on retrieval.   The only reason I can think of for an extended bow roller is to protect the gelcoat from the anchor when it sits in the roller.    That's best done with a little patch of stainless applied for protection.   Don't need a long roller.

So that's the extensive rationale for not doing anything.   In other words, I'm cheap and lazy and that's not always a bad thing!   Now where is Jon to tell me that I'm cheap and lazy?
Title: Re: Roll bar anchors on bow roller
Post by: Braxton on April 16, 2009, 02:44:26 PM
So does a 15 KG claw fit on the stubby double roller?     I'm trolling the local BoatersWorlds for liquidation deals and I have my eye on a 15KG claw.   It would be nice to know that its going to fit.

Also...

What's the preferred method for anchors in place if you have them up on the roller?   I can imagine all sorts of shock cord setups but they all seem prone to failure.
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 16, 2009, 04:04:50 PM
So does a 15 KG claw fit on the stubby double roller?     I'm trolling the local BoatersWorlds for liquidation deals and I have my eye on a 15KG claw.   It would be nice to know that its going to fit.

Claw what?  Some specifics would be in order.  Bruce, Delta, Rocna, Manson Supreme, nope, the last two are too new for your description.  After the discussion about anchors (see: http://c34.org/bbs/index.php/topic,2705.0.html, reply #33, page 3, search on anchor, mainesail), I would think that anybody who had any $ would spend the extra few bucks for something that would save their $50K+++ boat without hesitation.  35# of "something" on the bow is NOT half as worthwhile as 20# of Rocna or Manson Supreme.  Period.  Of course, your selected anchor weight may vary based on the sizing of YOUR particular anchoring SYSTEM.  I saved all sortsa $$ when I bought our old Bruce at a nautical swap meet eight years ago, but when I learned about these new anchors, that's what I bought and the ONLY thing I considered was a choice between a Rocna and a Manson Supreme.  When the anchor, when it bites, pulls you off the bow, you've got the right anchor.  This is truly one of those times when it is NOT a "Your boat, your choice" issue.  While we all say anchors are like choices in (you pick it, women, whiskey, wine, etc.), I disagree strongly NOW, and posit that this is no longer one of 'em.  If you re-read the Anchor link, some folks still swear by what they have.  Their boat, their choice, but if you're buyin' somethin' else?....

The Rocna has a very, very long main fluke.  If it fits (my Rocna 10 and Steve's 20 and my old Bruce), yours will, too.

What's the preferred method for anchors in place if you have them up on the roller?   I can imagine all sorts of shock cord setups but they all seem prone to failure.

I've already reported that we tie our Rocna 10 roll bar off on the pulpit with line.  It appears that Steve has a similar line, but I'll let him answer for himself.  Shock cord is NOT right for holding anchors.  My Secretary reports in Mainsheet magazine discussed this a few issues ago.
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 16, 2009, 04:27:30 PM
I think Braxton means a Lewmar claw.   It's a Bruce knockoff.   And the answer is yes it does fit on the stubby quite nicely.  That was my solution up to a few weeks ago.   And to hold it in, I actually drilled a hole through the shank and used the stock factory pin straight through.   

I also agree with Stu and appreciate the unambiguous advice.    I read every post on anchors when I bought the boat and kind of felt that the electronic consensus was a 15 kg Bruce type was the way to go.   In my opinion, I made a mistake and wish I had invested in a Rocna up front.   I don't often anchor in places exposed to gale force winds, but last summer I had wind veer and hit me side on with a stern tie and the claw dragged despite being set hard with a ten to one scope.   Twice.   So now I don't sleep well when I hear a shriek in the rigging with a claw anchor down. 

You don't want an anchor to work well 95% of the time unless you always stay on your boat, awake, standing watch.   Then you can afford to drag...   
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 16, 2009, 05:19:33 PM
Steve, you DID invest in "a Rocna up front!"  :D

Here's that Nov. 2008 Secretary report I mentioned in my last post.  For those of you who are still contemplating joining the C34IA, please note that many of the reports from others of your C34IA officers include technical information not only what's in the Tech Notes section.  Some of the older Mainsheet magazines included that technical information, 'cuz they hadn't yet invented the separate "Tech Notes" section.  Plus, we continue to recommend reading all of the quarterly  Mainsheet magazine, 'cuz the information from other boats sizes with similar systems, both in their officers reports, fleet activities and Tech Notes for items that apply to our boats as well as theirs, is invaluable.  There's still lots to learn out there.  Join the C34IA, support this website and read Mainsheet, a very good investment in your safety and pleasure while boating.

Just for grins & giggles, I added my anchor to my signature!   8)

The Napa Cruise was the first time I used our new Rocna 10 (22#) anchor.  It sits well on our old “toy” bow roller, but requires a line be tied onto it and back to the pulpit.  A few weeks later we were heading out the Gate after anchoring the night before.  About two miles out, I was down below on the phone, when I heard this horrible noise, thinking we’d hit something, something really big!  I popped up and, well, I’ll let Dave tell “the rest of the story-“

“Suddenly I hear a rumbling sound - never heard on board before. The engine is off, so I know its not bearings or prop shaft related. Stu climbs (flies up!!!) the companion steps and we think together for 30 seconds before it dawns on us - that was an anchor chain sound. Up until now we had been riding the swells powerfully, with many a wave washing over the bow of the boat sluicing the entire front of the craft up to the dodger with salt spray and wash. One of these waves, or a series of them, had loosened the knot (that Dave tied!!!) holding the anchor to the bow pulpit, and the anchor had left fly toward the bottom.  As luck would have it, a tangle in the anchor rode at the aft end of the big center cleat stopped the entire line from unreeling and scrolling overboard. Somehow we were still sailing. The anchor had not hit bottom. Instead of dropping the sails, we just hove to. Then I went forward to assist Stu at the anchor locker.  Stu thought perhaps we were indeed "anchored" in a patch of very bumpy water just off Point Bonita. Surreal upon reflection.  I sat down on the bow, anchored my feet against the stanchions, and with the best body mechanics I could muster, began the long and arduous job of hauling in the anchor. Indeed upon a few hard tugs, it seemed like we were not actually dug into the bottom, but simply dragging the long chain and anchor like a heavy fishing line. Pull by pull the line came in.  I kept looking up at the rocks off point Bonita, concerned we might drift that way, but Stu was keeping a careful eye out, and the current plus wind were driving us parallel to, and not up upon the rocky point. I stopped often to brace the line against a bow cleat to catch my breath. What seemed like forever transpired in just a few minutes. Before I knew it there was wet chain in my hand and I knew we had only 30 more feet to go. With one more mighty effort the anchor was back aboard where it belonged, and Stu came forward with a very stout rope of sufficient length to tie a bombproof set of knots to hold it in place for the remainder of our journey. Phew!!”


So, I had replaced the shock cord that we earlier used on our old smaller Bruce anchor, and had used line with the new heavier Rocna.  Now we know how to tie useful knots, too!   Oh, and Dave's a mountaineer, the climbing kind -- he was mortified, but eventually happy we got everything back on board.   :cry4`

Added 9/15/12:  I later added a Johnson cleat on the pulp[it to hold the anchor "restrainer."
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 16, 2009, 06:35:34 PM
Braxton & Dave,

You might also be interested in this: http://forums.catalina.sailboatowners.com/showthread.php?t=106915
Title: Re: Roll bar anchors on bow roller
Post by: Braxton on April 16, 2009, 07:54:06 PM
I think Braxton means a Lewmar claw.   It's a Bruce knockoff. 

Yes, that's what I meant.  Thank you for translating.

OK, I'm looking at the Ranco and Mason Supreme.   Right now we only have the original Danforth so almost anythng would be an upgrade.
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 17, 2009, 07:57:57 AM
Braxton, thanks for listening, because when it comes to the safety of your boat I sometimes use "the soapbox."  BTW, it's ROCNA.  If you use the links I provided to co.com, and do some comparative shopping, I think you'll find that you can get a reasonably good price on either one of them now.  They've been out a few years, have obtained rave reviews, are selling more and the prices have dropped.  I bought mine at a good price through the generosity of the local C36 Fleet here during a group purchase some time ago.

Last item: Anchoring Systems: you should size your entire system for conditions you think you'll experience.  Why is my anchor a Rocna 10 and Steve's is a 20, and others are 15s?  Here's why:

As I mentioned in earlier anchoring threads, I've sized our anchoring system for 42 kts. That's the anchor, chain, rode and all shackles. That's because we're somewhat between other posters. We rarely have thunderstorms here, and the places we do traditionally anchor do not have winds anywhere near that strength. I also noted, for newbies and new readers, that our brethren in other parts of the country experience what others have mentioned: fronts moving through can easily have winds well in excess of the 42 kts we're sized for. I also noted that if I was going elsewhere I'd require and would install a heavier ground tackle system. We sized our system based on Calder's Cruising Handbook, anchoring sizing tables and information. We have a 22# Rocna with 1/4" chain and 1/2" line. Our friends back east and in the PNW have 35# equivalent anchors with either 1/4 or 5/16 chain and 5/8 line.

This comes from http://forums.catalina.sailboatowners.com/showthread.php?p=604459
Title: Re: Roll bar anchors on bow roller
Post by: Braxton on April 17, 2009, 11:00:08 AM
I already have the stock Danforth for the regular conditions and a smaller Danforth as a backup and lunch hook.   I wasn't planning on getting rid of anything so I was planning on making the next anchor a bit oversized so it can handle the rough stuff that we may see.  So I suspect that I'll be looking at a #25 Rocna.   I'm also not sure where I want to store it.   I don't want all the weight on the bow (especially as I'd like to move to having more chain then I presently do) but the thought of not having the good anchor on the roller in an emergency is not appealing either.   

Any thoughts on Stainless vs. galvanized? 
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 17, 2009, 12:20:12 PM
Braxton, I gotta go out for my wife's birthday celebration.  Will get back to you later.  SS is worthless in anchoring gear.
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 17, 2009, 07:03:02 PM
But Stu, tonight is my wife's birthday.   I've told her we can't have a focussed celebration because the Canucks are in a playoff hockey game.   If she finds out that you are celebrating, it will make me look bad.   

Wait a minute.   Is she out celebrating with you?   Are we married to the same woman?
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 17, 2009, 08:16:29 PM
Braxton,

Emergencies are what you make them when it comes to anchoring.  Weather forecasting is a very able tool to understand what's ahead of you.  In your cruising grounds you have a wide variety of conditions, and if you stretch your legs to the Gulf Islands and further north, you have even more.  I will rely on our experienced northern brethren to explain anything you need to know about "local knowledge."   :D  I'm glad to explain what it is I don't know, which exhibits itself on a regular basis.

The general consensus is simple:  deploy your "main" anchor all the time unless you actually believe the weather reports, and even more important, your own eyes and ears.  If you're ever gonna stop your boat, stop it right, the same way every time, as if you're gonna be sleeping all night even for a lunch break.

There is no such thing as "oversized," because that means you selected the wrong anchor!  And you already have recommendations about what Rocna to buy from those in your neck of the woods and planning to go further afield.

YOU have to balance your back, your windlass (?), your conditions and your expectations.

And design an anchoring system, not just some cobbled together arrangement.  Think it through:  anchor size, chain not too big, chain length [longer to make shallow anchoring all chain OR 50 feet and nylon or new 8 strand???], and things like that.

Your selection of the 25 KG Rocna makes sense for a "maximum" storm anchor, and given Steve's design, appears to be overkill for your intentions and should be reconsidered.  Size the anchor for your cruising needs on a daily "I'm-gonna-use-THIS-anchor-ALL-THE-TIME" and save something else for your 100-year event.  Re-read Steve's discussion.  Mine's half his size, I'm designed for my use as defined above, his is twice the size of mine because he designed his anchoring system for something different than ours.

We want you to be happy raising it regularly, because we KNOW you'll just LOVE dropping it - don't let yourself get pulled off the bow - stand back!  :D

Once you buy into this concept, you'll find our toy bow rollers work just fine, like all the pictures on page 1 of this thread prove.

1/4 to 5/16 chain will be ALL you'll ever need - 3/8 is way overdoing it --- for me.  Check your calculations for your own system.

"Store" it on the bow, where it belongs.   :D :D :D


PS to Steve:  Happy Birthday to Tracy.  Yup, she's right here with us!
Thanks, Stu
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 17, 2009, 08:49:24 PM
I wouldn't suggest that anybody read too much into my anchor system design decisions.   Rocna doesn't recommend the 20 kg anchor for our boats.   They told me the 15 kg would be overkill.   My decision was based on excess.   I really don't want to be lying in bed at night wondering if the anchor manufacturer had the particular conditions in mind that I'm experiencing.  I want to sleep.   And at times on a long voyage, enough sleep will be a safety factor.    This is not an engineered solution.  It's an emotional one.   


Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 17, 2009, 09:13:18 PM
Rocna doesn't recommend the 20 kg anchor for our boats.   They told me the 15 kg would be overkill.   My decision was based on excess.  ...  I want to sleep.   And at times on a long voyage, enough sleep will be a safety factor.    This is not an engineered solution.  It's an emotional one.  

That's a great DESIGN CRITERIA all in itself, and a very well engineered one.  

Sleep, gently sleep... :sleepy:

So, Braxton, given that, please reconsider your 25 KG selection.
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 18, 2009, 12:24:37 AM
For those with data driven view...   

Rocna bases their sizing chart on 50 knot wind and marginal silt type holding.   For our boats, they recommend a 15 kg for 50 knots stuck in baby poo.   A 10 kg would probably be fine for just about anything most of us regularly encounter.   My 20 kg anchor they would recommend for a 39 foot boat weighing 10 metric tonnes (or a 30 foot boat weighing 16 tonnes - I'd like to know if those actually float).   

However, in spite of their well articulated and conservative sizing philosophy, I still went bigger.   A sizing chart is just a chart.   It doesn't howl in your rigging.     
Title: Re: Roll bar anchors on bow roller
Post by: Braxton on April 18, 2009, 03:17:50 PM
I guess I'm miss reading the chart.   Looking at the chart it seems like their recommendations for us range from the 10 all the way up to the 25.   Am I reading this wrong?

BTW:  for those of you who want to follow along here is a link to the chart:
http://www.rocna.com/main.php?section=best&chapter=sizing&page=1
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 18, 2009, 04:21:31 PM
Braxton, thanks for the link, but ya gotta go deeper than just the chart.  Try this:  http://www.rocna.com/kb/Rocna_sizing_recommendations.  It's from a "continuation link" right below the basic main website chart.

It, in part, says:

Over-sizing

Many Rocna customers, in improving their anchor type by switching to a Rocna from an older anchor which they have learned to be unreliable, make doubly sure about their upgrade by also increasing the weight of their anchor. We see this tendency a lot, and try to discourage it. As above, our official sizing is very conservative, and in many cases it's a case of "don't over-size – we already did that for you!"

On a weight-for-weight basis, the Rocna represents a very significant step up from most other types, and doubling the size (for example) could inadvertently cause serious problems with retrieval and other handling issues.
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I added the bold.  I really think we've discussed all the options you DO have in terms of sizing.  If YOU choose to get a Rocna 25, I personally believe it's overkill, and was so noted before.  But, it's your boat and your back (windlass?) [requested again - don't know if you hand-haul or crank your anchor up].

I continue to recommend that you consult, for instance, Calder's Cruising Handbook, page 394,which has a very good anchoring SYSTEM sizing section that we used to select our anchor size and also to size each and every one of our components.

I am just trying, as far as I can, to help you avoid overkill and ending up a potentially very unhappy skipper.  Perhaps I am missing something, and maybe you could be thinking of using the new Rocna as your "storm" anchor, and I suggest that is incorrect based on your new $ investment, because what you really want to do is select the right size Rocna for your daily use, which I discussed in detail earlier.  I did re-read your Reply #27, BTW.  If all you want is a "storm" anchor, and you choose the Rocna for it, by all means get the heaviest, meanest, most impossible to retrieve piece of hardware you possibly can.  But then, what are you planning to use as your "regular" anchor?  One of those old things you already have?  Which is the reason in the first place for you to even consider a Rocna (or any other new-style new generation anchor); it's the old ones that won't let ya sleep!

And I sincerely don't believe for a moment that you'd use one of your old anchors during the day and then haul out your new "storm" anchor if you decide to stay overnight at an anchorage.  Buy the right sized Rocna, and simply use it.  What could be easier, on you and your wallet?

Ron Hill has explained anchoring techniques many, many, many times here, and I don't wanna have to have him retype it all again (he's our "hunt-and-peck" typist):  Your daily anchor should be used, and it should hold your boat and sized for your anticipated conditions.  Lunch hooks are useless and dangerous.  The hook should hold and be appropriately sized for retrieval as well as holding power.

PS:::  BTW, Craig Smith of Rocna asked me to contribute photos of our setup with our new Rocna awhile ago.  I sent him a few, and today I suggested he come over and check out this thread with its many photos.  He may ask some of you for them in better res.

PPS:::  And, Braxton, many times Ron Hill has reminded us that if we have questions sometimes it's best to go to the horse's mouth, the manufacturer, and not simply rely on our opinions here, 'cuz we're just so opinionated, right?   8)  So, Braxton, why not get in touch with Craig directly?  Here ya go:  craig at rocna dot co dot nz  Ask him, please, and you may want to refer him to this thread and see what he has to say.  I'd love to know.
Title: Re: Roll bar anchors on bow roller
Post by: waterdog on April 18, 2009, 04:30:11 PM
I guess I'm miss reading the chart.   Looking at the chart it seems like their recommendations for us range from the 10 all the way up to the 25.   Am I reading this wrong?

BTW:  for those of you who want to follow along here is a link to the chart:
http://www.rocna.com/main.php?section=best&chapter=sizing&page=1

I think a little bit.   You start out with a length.   Seems like you're reading off the 33 foot row.   I read the rating off the 36 foot row, because we're closer to a 36 footer than a 33.   If you read along the 36 foot row, you would throw out the 10 because our boats are more than 3t. (unless you aren't looking for 50kts)    At 7t the 15 would be fine.   And I think you stop there with the 15 as your preferred size.   The 20 and 25 and 33 are recommended for 36 footers with severe dietary problems.   

 
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 18, 2009, 04:36:37 PM
... footers with severe dietary problems.   

Oh, shoot, you've defined a "cruiser!"
Title: Re: Roll bar anchors on bow roller
Post by: Stu Jackson on April 20, 2009, 10:09:12 AM
Thanks to Craig Smith of Rocna

Braxton, as previously reported, Craig's been in contact with me.  I sent him my high res photos, and he reported back to me as follows:

Hi Stu,

Thanks for those photos. I haven’t heard back from anyone else yet, but you can see your pics on the C34 page here:

http://www.rocna.com/kb/Catalina_34 (http://www.rocna.com/kb/Catalina_34)

I’ve also placed some abridged comments relating to fit compatibility plucked from your posts, feel free to tell me to edit if you wish.

I’m sure any of prospective Rocna owners with C34s will appreciate that resource.

This is an entry in our “knowledge base”, which you may like to explore further – one of the bigger sections is this collection of “boat cases”, which I hope will grow to a comprehensive size over time:

http://www.rocna.com/kb/Category:Rocna_bow_compatibility

Note also the links to articles on “bow roller assembly design” (for custom ‘from scratch’ bow rollers) and “common fit challenges” (as pertain to the Rocna).

Regarding your thread, actually I believe that you and Waterdog are doing a fairly good job, I don’t have much to add. The official Rocna sizing recommendation for the C34 is a Rocna 15, as the closest row on our sizing chart is 36’ and going out along the displacement ranges, the C34’s 5.4 tonne weight (plus a bit loaded) selects the 15 column. If we look at the Rocna 10, the closest we can get to the C34 specs is 33’ at 4 t, so we can be sure that the 15 is the correct choice. However, the C34 is not too far away from this point, so it is safe to say that the 10 would be adequate for most conditions, just not quite the conservative criteria we use (you are familiar with our philosophy on this). Similarly the 15 goes a bit in the opposite direction, making it even more conservative.

I hope that is of interest.

Best regards,

Craig Smith


For those of you with photos, please help Craig by sending him your pics and he will post them on the Rocna 'site.

For summary, again, we bought a Rocna 10 (22#), Steve has a 20 (do the math! :D).

I don't have anything professionally or personally to do with Rocna.  I just did my research and homework and sized our system and bought the Rocna 10 (also thanx to the C36 local fleet discount back then - very good promotional idea from the C36 fleet and Rocna).  I had two choices back then, pretty obvious, huh, as far as manufacturers were concerned - there really only still are two choices for the new V3.0 anchors these days.

Given this assistance direct from the manufacturer, and the way they fit on our toy bow rollers, I can report that we are very happy with our choice of both size and vendor.
Title: Re: Roll bar anchors on bow roller
Post by: Michael Shaner on April 21, 2009, 06:23:23 AM
"Re: Roll bar anchors on bow roller" happened to be the last project before splash this weekend. We opted for the 35# Manson and the long roller from CD. After several weeks of fear and trepidation, I finally put on my "big girl panties", picked up the grinder and started cutting stainless. Whittling on my boat gets me a little bunged up. All in all, I think it came out OK. Can't wait to get the hook dirty this weekend...hope I can get it back up!

The challenging part for me in piecing together the anchor "system" was the connection between the 1/4" HT chain to an anchor with a  3/8" shank and getting any kind of respectable working load out of it. Oh, yeah...and 8 plait to chain splice... (only took me 2 hours)  :shock: