Rocna, yes or no?
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I use both. The CQR is my secondary because the Beneteau bow-roller design requires a narrow swivel and the CQR is the most compatible anchor with a swivel. The Manson is a great anchor but as you can see by the damaged Rocna this design puts a huge strain on a swivel. Hence the secondary, rigged and ready.
Dan & Gunni: This is a long topic, but has an excellent contribution by Maine Sail - http://c34.org/bbs/index.php/topic,2705.0.html
BadO - the answer is in previous posts about whether to choose a Rocna or a MS these days.
BadO - the answer is in previous posts about whether to choose a Rocna or a MS these days.
Gunni,
Ideally the swivel should not be directly connected to the anchor shank. A swivel performs best when it can't easily be side loaded. If connected to an anchor with a short piece of chain, 3-4 links, it drastically limits the potential for side loading it. A swivel on Manson, Rocna, Delta, CQR et. al will all work the same with a safe and proper swivel installation.
Swivel installation = YES
Swivel installation = NO
This swivel failed likely due to being directly connected to the shank and then being side loaded..
SWL's on swivels are rated in straight line pull not laterally or side loaded. A few links of chain keeps the swivel from becoming laterally loaded in most instances..
Interesting info. I've never heard/seen this before. I'm guessing that there's supposed to be another photo showing the correct installation. Would you please provide it?Gunni,
The swivel should not be directly connected to the anchor shank. A swivel should be connected to an anchor with a short piece of chain, 3-4 links, to prevent side loading it. A swivel on Manson, Rocna, Delta, CQR et. al will all work the same with a safe and proper swivel installation.
Swivel installation = YES
Swivel installation = NO
-- Geoff
I'm guessing that you're in the Chesapeake and anchoring in mud, which the CQR likes, so you're fine. I used to use a CQR as my primary anchor and regularly had to dive on it to set it in the Caribbean when anchoring in sand. I then switched to a Rocna and never had to do that again. The Rocna is by far the best anchor that I've used. Once it's set, you're not moving.
-- Geoff
Geoff, here is a discussion about swivels, start from page 1
http://forums.catalina.sailboatowners.com/showthread.php?p=632039&highlight=swivels
Thanks for the pointer! I'll be switching my setup ASAP. I've had it incorrect since installing my Rocna in 2007. We've been in LOTS of blows at anchor with no ill effects, but I can certainly see how the current setup could be bad.
-- Geoff
Geoff,
This photo shows the correct installation. There is chain between the anchor shank and swivel. Look close and you can see the swivel.
The anchor-rode connection must be sleek and flexible or it will not clear the bow roller. A Crosby shackle for 3/8 chain is a beast, big ol' dog ear pintle, and it fouls every time, no go. A repair chain link doesn't have sufficient strength or rating for anchor attachment. Hence I have a double-articulated swivel on my Manson that is rated for 18,000lbs, suppose it is half that when side loaded?...it is still far stronger than my 3/8 BBB chain.
For those of us who must use a swivel on the anchor I believe a short chain leash from the chain rode to the rock slot may be the best insurance to keep the hook. I'll probably want that should I ever lose the Manson
I also use a swivel from Ultra similar to the Wasi. Very beefy with no obvious weak spots, mixed metals, or loaded threads. The jaws around the anchor are thick and the bolt is threaded to keep them from spreading. When I bought it, I was told that it will hold to the listed breaking load at a 90 degree side pull.
http://www.ultraanchors.com/ultraswivel.html
http://www.ultraanchors.com/ultraswivel.html
When I look at your post, I only see 2 photos. Under the title "Swivel installation = YES" there's nothing. Under "Swivel installation = NO", it shows the directly connected swivel.
I just looked at the HTML and can see the image that the YES references, and I can open that directly. Strange.
-- Geoff
Added: Now that I've opened the image directly, it appears in all of the posts. Must have been some strange caching problem.
Go with Manson Supreme
Coast Awhile
Hunter 310
I and several sailors have Manson Supreme Anchors - Deale, Md. We all swear by them - set fast and hold well (even with 180 swings - sets again). We say "Thank God for Manson Supreme" after anchoring. And for those without a windlass say "Oh God" in the morning when pulling up the anchor. And cost less than the Rocna a No Brainer!!!!
Coast Awhile
Hunter 310
Bending Anchors - What Do You Expect??
The shank of the anchor in Main Sail's photo in message #7 of this thread looked a tad thin so I decided to do some calculations.
Rocna do not state the thickness of their shank but it looked like 1/2" plus galvanising - so I used this in my calculations.
(BTW I have one of these anchors. No I didn't buy it but was asked to test it for a UK magazine and the result was it ended up on my bow! It is the size 15 (33lb) as recommended for my boat but I don't know if it is one of the dodgy ones).
I can visualize my anchor stuck in a rocky crevice or under a large rock and me trying to pull it out in reverse. At some time I would be pulling at 90° t5o the shank as would easily occur in a 90° wind shift.
My boat has a bollard pull of 745 lb (338Kgf) in reverse.
(H376; Yanmar 37 HP; 17 3/4" x 14" three blade feathering prop; 3600rpm; 2.83:1 gearbox).
So how much side load do we expect an anchor to handle?
Full reverse - YES.
50 knots of wind (force 10) - YES.
Then I downloaded Rocna's drawing and note the shackle hole is 22" (558mm) from the part of the shank so badly bent in Main Sail's photo. At the point of bend in the photo the neck of the shank is 4" (100mm) wide.
Even if it is made of the recommended Bisplate 80 steel and by applying my full reverse power at right angles to the anchor's shank I should be able to bend it just like the photo. Even more easily if I took a run at it as one does to try to break out a fouled anchor.
50 knots of wind will generate almost 4 TIMES the force needed to bend even the correct steel. No wonder Rocna are panicking - and so should we be.
Even only 25 knots (Force 5-6) will just about do it.
Frightening ain't it
My boat is on a mid stream mooring so I need to fit my outboard and launch my RIB to get to my anchor. I would be obliged if someone could mic up the shank of a Rocna - or any other anchor to confirm my 1/2" thickness calculations.
The shank of the anchor in Main Sail's photo in message #7 of this thread looked a tad thin so I decided to do some calculations.
Rocna do not state the thickness of their shank but it looked like 1/2" plus galvanising - so I used this in my calculations.
(BTW I have one of these anchors. No I didn't buy it but was asked to test it for a UK magazine and the result was it ended up on my bow! It is the size 15 (33lb) as recommended for my boat but I don't know if it is one of the dodgy ones).
I can visualize my anchor stuck in a rocky crevice or under a large rock and me trying to pull it out in reverse. At some time I would be pulling at 90° t5o the shank as would easily occur in a 90° wind shift.
My boat has a bollard pull of 745 lb (338Kgf) in reverse.
(H376; Yanmar 37 HP; 17 3/4" x 14" three blade feathering prop; 3600rpm; 2.83:1 gearbox).
So how much side load do we expect an anchor to handle?
Full reverse - YES.
50 knots of wind (force 10) - YES.
Then I downloaded Rocna's drawing and note the shackle hole is 22" (558mm) from the part of the shank so badly bent in Main Sail's photo. At the point of bend in the photo the neck of the shank is 4" (100mm) wide.
Even if it is made of the recommended Bisplate 80 steel and by applying my full reverse power at right angles to the anchor's shank I should be able to bend it just like the photo. Even more easily if I took a run at it as one does to try to break out a fouled anchor.
50 knots of wind will generate almost 4 TIMES the force needed to bend even the correct steel. No wonder Rocna are panicking - and so should we be.
Even only 25 knots (Force 5-6) will just about do it.
Frightening ain't it
My boat is on a mid stream mooring so I need to fit my outboard and launch my RIB to get to my anchor. I would be obliged if someone could mic up the shank of a Rocna - or any other anchor to confirm my 1/2" thickness calculations.
Re: Bending Anchors - What Do You Expect??
Great analysis, Don! In thinking through this, it seems any modern design would do the same thing in the conditions you describe. Only the CQR with it's hinged heavy shank would seem to have a chance. I've seen a lot of bent shanks, one on a CQR too, but most Danforth-type (and the most common type here). I had a bent one too, but it was from a piling which rushed right to my bow as I was backing out.
Great analysis, Don! In thinking through this, it seems any modern design would do the same thing in the conditions you describe. Only the CQR with it's hinged heavy shank would seem to have a chance. I've seen a lot of bent shanks, one on a CQR too, but most Danforth-type (and the most common type here). I had a bent one too, but it was from a piling which rushed right to my bow as I was backing out.
Your analysis doesn't tell us a thing. How many anchors can survive a sideways pull at your force rates without deflecting the shank? How would a similar Manson do (and don't assume that the chain slid down the shank which is not a given.)
If you have any anchor stuck in rocks and you're pulling at a 90 angle at 25 kts or using 37 HP, I wouldn't expect any anchor to survive without a bend. If you're so FRIGHTENED, why are you still using it? What would you use?
The bottom line is that this anchor holds extremely well and that while there were manufacturing issues with some of them, I wouldn't begin to think about switching.
-- Geoff
Geoff,
I checked this out because I wanted to know the extent to which a Rocna's integrity was compromised by having a shank of steel with only half the specified resistance to bending.
I was dismayed to see Main Sail's photo and horrified to discover that, even with the correct grade of steel, this anchor - and probably all others of similar design - is/are vulnerable.
Previously my conception - and most other people's too - was that my anchor was indestructible.
I have no control of the situation when it is on the bottom and I know that winds and tides reverse.
Also it, plus it's chain, are far too expensive not to use all possible horsepower to avoid losing it.
There have been a number of occasions when I have given mine full welly to break it free. e.g. when under a local power cable, under a massive mooring chain discarded from a buoy when acting as committee boat, entwined in a maze of hawsers outside a harbour when sheltering from a F9 gale. We didn't know these rusty hawsers were there until 3am at the height of the gale and suddenly the boat's motion went all smooth. We were adrift only 100 yards from the rocks on a lee shore.
No I am not frightened any more than the next man. But, sure as hell, I am now cognisant that my anchor is not to be trusted - whichever make it happens to be.
Interestingly all anchors could overcome this at no additional weight and only small extra expense.
All that is needed is to use TWO identical shanks, each half the thickness (1/4" plate), welded to the main plate only 2" apart and with their shackle ends welded together. Maybe a small cross strut too to prevent this weldment from collapsing.
Then it could handle anything the sea could provide. (Or at least anything the chain and bow fitting could withstand.)
Rgds,
Don.
I checked this out because I wanted to know the extent to which a Rocna's integrity was compromised by having a shank of steel with only half the specified resistance to bending.
I was dismayed to see Main Sail's photo and horrified to discover that, even with the correct grade of steel, this anchor - and probably all others of similar design - is/are vulnerable.
Previously my conception - and most other people's too - was that my anchor was indestructible.
I have no control of the situation when it is on the bottom and I know that winds and tides reverse.
Also it, plus it's chain, are far too expensive not to use all possible horsepower to avoid losing it.
There have been a number of occasions when I have given mine full welly to break it free. e.g. when under a local power cable, under a massive mooring chain discarded from a buoy when acting as committee boat, entwined in a maze of hawsers outside a harbour when sheltering from a F9 gale. We didn't know these rusty hawsers were there until 3am at the height of the gale and suddenly the boat's motion went all smooth. We were adrift only 100 yards from the rocks on a lee shore.
No I am not frightened any more than the next man. But, sure as hell, I am now cognisant that my anchor is not to be trusted - whichever make it happens to be.
Interestingly all anchors could overcome this at no additional weight and only small extra expense.
All that is needed is to use TWO identical shanks, each half the thickness (1/4" plate), welded to the main plate only 2" apart and with their shackle ends welded together. Maybe a small cross strut too to prevent this weldment from collapsing.
Then it could handle anything the sea could provide. (Or at least anything the chain and bow fitting could withstand.)
Rgds,
Don.
Don,
For me the issue is: Does the anchor continue to hold the boat without failing? The fact that it gets bent isn't nice, but having it fail and you end up going aground is very bad. At some point every anchor shaft will bend given the right (wrong) conditions and a sideways pull.
Your shank design sounds robust, but unfortunately it also sounds like it probably won't go through most bow rollers.
-- Geoff
P.S. Here's what happened to our bow-roller assembly after 72 kts at anchor in Roatan, Honduras where we had reef on one side and beach on the other.
For me the issue is: Does the anchor continue to hold the boat without failing? The fact that it gets bent isn't nice, but having it fail and you end up going aground is very bad. At some point every anchor shaft will bend given the right (wrong) conditions and a sideways pull.
Your shank design sounds robust, but unfortunately it also sounds like it probably won't go through most bow rollers.
-- Geoff
P.S. Here's what happened to our bow-roller assembly after 72 kts at anchor in Roatan, Honduras where we had reef on one side and beach on the other.
Donalex;
You are not considering the difference between the rocna and the manson. The manson has a "rock slot", you rig it differently and you most definitely do not recover it in the ham handed manner you detail. If I had the rocna I would rig a similar forward lifting capability using a traditional float retrieval line.
When I anticipate a wind shift and extreme conditions I utilize a bahamian anchor technic to limit swing against the manson. A bit of a hassle, but effective.
You are not considering the difference between the rocna and the manson. The manson has a "rock slot", you rig it differently and you most definitely do not recover it in the ham handed manner you detail. If I had the rocna I would rig a similar forward lifting capability using a traditional float retrieval line.
When I anticipate a wind shift and extreme conditions I utilize a bahamian anchor technic to limit swing against the manson. A bit of a hassle, but effective.
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