Anchor replacement

[P69]

I have three anchors, 35# danforth, 45#CQR, 45# Bruce knock-off.
CQR is rusty and pivot point hole is out-of-round, so I am going to replace it.

Will also be replacing two 200' 5/8 rodes with 200' 5/16" chain  (primary) and 100' chain with some length of 5/8" 3strand nylon (reuse existing 3strand).

I will likely get a 45# Mantus (maybe rocna), but am considering the 65# anchor.

Mantus and  Rocna size charts show that 20,000lbs is at the upper range of the 44/45# anchors.

Is there any reason to get the 45# anchor  and not get the 65# anchor?
Price difference is $150 to $200, within budget
Bow incompatibility can be solved.

Yes, I'll be keeping two anchors on bow, one of which will be this new anchor (the primary)
Windlass has  a 1200w motor

[PeteW]

From the charts I'm looking at 3/8 chain is correct for a 17,000 lb. boat with a 45# or 65#  anchor, not 5/16. You're better off swapping out your windlass gypsy for 3/8 chain if there is a mismatch.

As far as the anchor, what they say is if you can go bigger, by all means, go bigger. You won't live to regret it.

Pete

[Jim S]

A 65# anchor is more a storm anchor than a heavy working anchor.  It may be better to have that anchor, or an even heavier one for storm conditions, back in the lazarette than on the bow.  Setting and retrieving a 65# anchor will be much more difficult than a 45#, especially if the electric windlass becomes inoperable.  3/8" chain is a more logical choice because that half of the anchor's effectiveness comes from the catenary of the chain.  65# anchor and 5/16" chain seems a mismatch.

A good rule of thumb is that the anchor should be retrievable by the smallest member of the crew.  In my prime, I would have had difficulty handling a 65# anchor regularly.  This would not have been a problem for storm conditions, but not something to do on a day to day basis.

[Maddie]

I'm thinking about the same thing. I haven't looked at the Mantus, but the Rocna 20 (44 lb) model is recommended for 39 ft boats up to 22,050 lb, and I was considering going up a size to the 25 (55 lb) which is recommended for 39 ft boats up to 39,680 lb. My assumption is that the sizing guides are for sloops, and that my ketch will have more windage.

Some advice from the folks at Attainable Adventure Cruising (behind a paywall): your regular anchor should be your storm anchor. Otherwise, some day, for one reason or another, you'll decide that your regular anchor is fine for tonight, and it'll turn out it wasn't, and now you have to go set your storm anchor (which sounds like it might involve pulling 65 lb out of a lazarette in storm conditions? Will it be at the top or the bottom of that lazarette I wonder?). Sounds good to me.

That said 65 lb does sound like a lot. Rocna, currently my first choice for a replacement for the main anchor, doesn't have one that size; they jump from 55 to 73. A 65-lb Rocna would be sized for 39 foot boats up to something like 52,000 lb.

Nobody has addressed whether your windlass can handle the weight, and I have no idea. You should check with your windlass documentation or manufacturer about that. Does it have a manual fallback? Maybe try assembling 65 lb of steel and seeing how easy it is to manually weigh from the bottom of 30-foot-deep water.

[P69]

Well, ya'll have just made it harder to figure out.

The windlass will be Maxwell VWC 1500 (power up/power down, manual override: yes)
http://www.maxwellmarine.com/gen_vwc.php?dimensions

Maybe I should use the 55 lb anchor primary and an existing 45lb secondary.

Regarding the 5/16" vs 3/8", it is a matter SWL/UTS or weight in the water/cantenary?

It always seem like everything is always on  the border line between 'the next size up".

Anyway, thanks for the advice, I do appreciate it. I'm going to get back to the epoxy now.

[Randy]

I have a 45 lb Rochna with 50' of 5/16' chain. Sticks like glue all over the Chesapeake. I drug a 35 lb POS CQR all over the place. Go with the Rochna or similar type anchor. You will sleep well.

[Della and Dave]

We've been considering anchor options as well, and I am stuck in a hotel room bored at the moment, so I started playing with the numbers.  We currently have a 35 lb Delta, and 50 ft of 5/16 BBB chain, plus 400 ft of nylon twisted triple.  Neglecting the nylon, that is 50x1.2 lb/ft plus 35=95 lb.  Our Lewmar Pro 1000 winch has a 1000 lb limit, and a 250 lb recommended max working load.  (700 Watt motor).  That means we are ok now as far as the winch goes, but if we were to go with your idea for 200 ft of 3/8 chain and a 65 lb anchor we would have 200x1.7+65 = 405 lb, so that would exceed the working load limit of our windless, and my back. 

Our setup seems a bit marginal to me, ok for now, but eventually I think we need a more robust system.  Apparently, according to the ABYC code, at least according to an article that is linked on west marine's web site, a 35 foot boat with a 10 ft beam in 60 knots would see a 3,600 lb anchor load, about what a Pearson 365 is, but a little smaller.  http://www.westmarine.com/WestAdvisor/Anchor-Testing

My 35 lb delta, according to the test, in a hard mud bottom held 3,500 lb before dragging through the mud.  Other designs like the 32 lb Roca and the 35 lb Manson Supreme held the max test load of 5000 lb. 

On the Rode:

My 5/16 BBB chain is only rated for a safe working load of 1,900 lb. and a breaking load of 7,600 lb.  According to to the same ABYC guidelines, 30 knots on the same boat as above produces 1,800 lb, so that's about what it would take to exceed my safe working load, but not break the chain, might stretch it though.  30 knots seems like it is a bit light for hitting the safe working load of the chain.

The ABYC data follows a quadratic equation, which makes sense in aerodynamics, so I can curve fit that and extrapolate for higher wind speed (extrapolating is always dangerous, and doesn't account for severe sea states).  In addition, I can correct for the differences in boat length and beam.  This means if their data is correct for rode load and my correction for the Pearson 365 is correct, our Delta 35 lb would be good to about 55 knots, then would drag through the mud.  A Roca 32 or a Manson 35 would be good to 64 knots, but maybe more because they only went to 5000 lb in the test, it might have held for quite a bit more.  That is assuming the rode doesn't break. Here are the wind speeds to break the chain on a Pearson 365 according to my dangerous extrapolation. 

5/16 BBB 40 kts. at safe working load, 80 kts. at breaking  (breaks at Cat 1 Hurricane).

3/8 BBB. 48 kts. at safe working load, 96 kts.  at breaking (breaks at Top of Cat 2 Hurricane range).

5/16 High Test 57 kts. at safe working load, 114 kts.  at breaking (breaks at Bottom of Cat 4 Hurricane range).

3/8 High Test 67 kts. at safe working load, 134 kts.  at breaking (breaks at Top of Cat 4 Hurricane range).
Here is the curve that I generated based on the ABYC recommendations.  It still sort of leaves me with the question "how big is big enough?" 

[Maddie]

I don't think your windlass needs to hold 200 ft x 1.7 lb/ft for the chain because your windlass should only have to lift a length of the chain from the roller to the bottom. What's the deepest water you anchor in? Say 50 feet... that's 85 lb for the chain + 65 for the anchor = 150 lb, well below the working load limit. So you should be okay with 3/8" and a 65 lb anchor, though it sure does sound like overkill.

As for the strength of the chain, at the higher end of the ranges you're talking about, wouldn't you expect deck fittings to break before the chain. Actually this brings up another question: does anybody use a chain stopper? How big and where mounted?

[Randy]

Dave, Unless you plan on going to the Pacific, you do not need 200' of chain. 100-125' is plenty for the islands. Also, your current set up is a fine rig. Nothing wrong with a 35lb delta. Great anchor. It's the anchor of choice for all Navy "Special Boats". Cheers.

[Jim S]

Carrying the anchor for the ultimate storm on the bow seems to be a lot of overkill.  Obviously there will be storms with 70+ winds that will occur suddenly, but these storms are short lived and the 70+ winds are gusts.  Sustained hurricane force winds are of long duration, but they are long forewarned.  The venerable cruisers: Hiscocks, Roths, Smeetons, Pardeys all carried storm anchors, but not on their bow.  They carried them under the cabin sole where they did not affect fore/aft trim.  Phantom with a 35# Delta, a 22# Delta and 120 feet of 3/8" chain at the bow lowered the bow waterline about 4", not a good effect.  The effect of a 65# anchor and 200 feet of 3/8" chain would be even more pronounced.

For a world cruiser it seems logical to put a "one size larger than necessary" working anchor, 35#ish for the 365/367, and as much chain that does not affect fore/aft trim undesirably.  Of course, if you can find a way to run the chain further aft in the boat then a continuous length of chain is possible, and desirable for these cruisers.  Cruising is supposed to be fun and enjoyable, the daily effort of deploying and retrieving a 65# anchor and 200+ feet of 3/8" chain does not fit my description of fun.  The rule of thumb, and a well tested one, is to have one size larger than you need and be ever vigilant for the need to supplement that one should the need arise.

A live-aboard friend has a 100# fisherman storm anchor on the stern of his 45 foot cruiser.  His comment is that if he ever uses it, it will stay on the bottom after the event since he has no effective way to retrieve it once it is set in storm conditions.  I suspect that a 65# anchor well set will be a real bear to get up from the deck of a 365/367.

[Della and Dave]

Thanks Adam, Randy and Jim.  We have essentially no practical experience anchoring, outside of ASA classes and racing dinghies, and we didn't anchor those.  Those hurricane numbers look really big to me too, but the ABYC seems like a credible source.  It seems like what you said about your storm anchor not being your working anchor makes good sense, if you are equipping for major cruising or circumnavigation.  That seemed to be the advice that Beth Lenord and Evans Starzinger were giving in their book as well.  Beth and Evens had a whole chapter on anchoring including snubbers.  They were advising to use snubbers when the wind was expected to come up and gave advice on how to set one up.  I think with respect to the deck cleats, you are correct, that the chain could easily be strong enough to rip the cleats out.

It seems like if you want to be able to ride out a cat 4 hurricane at anchor, it's going to take a hell of a strong system, anchor, rode, cleats etc.  on Mantis's chart for a 365, a lunch hook is 35 lb, a working anchor is 45, and a storm anchor is 55lb.  They say a "storm" is up to 42 kts, and a "Violent Storm" is 60kts.  If you go by that logic, a violent storm anchor would be the 65 lb, but according to the chart, you would have to size the rode and cleats for a 3,600 lb load. 

One of the Mantus anchors can be broken down for storage.  That seems like a good thing for your storm gear, because it's heavy and you don't need it often, so store it low in the boat amidships like you mentioned.  Assemble it when needed.    I'm on the road right now and I just got back from a recreational visit to the local marine store and saw the 65 lb Roca, in Stainless no less, but it's really big when you see in in person.  Doesn't look that big in the online description....... The cost of the stainless version is eye popping. 

Beth and Evans say the snubber reduces the shock load on the cleats and divides the anchor load onto two cleats instead of taking it on the windless.  I've never put one together, but it seems fairly straight forward.  On he windless, I think you are right, unless you have what happened to a friend of ours in one of the safer anchorages, he woke up in 700 feet of water in the shipping lane when the tide went out.  He didn't set the anchor correctly, and it was probably too small for the boat.  He swung, tripped the anchor, and the tide took him out to sea.  He learned from that. 

Our sailing grounds are in Alaska, out of Seward, so it is good to be prepared and to have done your homework ahead of time.  Bottoms are either mud or rock.  Lots of steep mountains that don't stop at sea level, so scope and depth are a constant challenge.   Tidal swings can be 30 feet, so we see current plus wind, especially near the glaciers. The Williwaws can bring  some strong winds down the gaps in them mountains in some anchorages.  It's amazing scenery, so it's worth the effort. 

[Jim S]

Dave and Della...you obviously have some extreme conditions up there that will require some very serious thought...more so than many lower latitude cruisers.  I do not have any high latitude experience, nor I want any at my age.  I just try to get the right size equipment for my purposes plus a reasonable safety margin. I found that you can sink your boat with all the over sizing and must haves that may not have found that much usefulness for safe cruising.

Enjoy.

[Maddie]

D&D: consider subscribing to Attainable Adventure Cruising. They have tons of high latitude experience. I'm interested in heading equatorward myself, but  there's still a lot of valuable info in there.

The reason they recommend your primary anchor being your storm anchor is that if storm force winds surprise you at night - and in high latitudes you don't need a storm for that to happen - then by the time you manage to get your storm anchor out of the lockers and assembled, your boat is likely to be on the beach.

What's your procedure for setting up the storm anchor? Before you decide that this surprise-storm scenario is not a concern for you, try anchoring out someplace in a rolly anchorage. Also given that we're in Alaska let's throw some imaginary cold rain and salt spray into the mix. Set yourself an alarm for 2:30 am. After the alarm goes off, head out to the cockpit and imagine yourself following your procedure. Are you assembling the 55-lb anchor in the cockpit or cabin and then carrying it to the foredeck? Or carrying the pieces to the foredeck and assembling it there? Do you have to weigh your primary anchor before setting the storm anchor? If not, what rode are you going to use with the storm anchor, and how will you keep the rodes from fouling?

I'm not saying these questions don't have answers, I'm just saying you need to carefully think about it. Personally I would want that storm anchor to be the one I was already swinging on.

[Dale Tanski]

I have been following this thread closely and with much interest.  Some I agree with some I don't.  In short, you don't want to ride out a cat 4 hurricane on the boat on a hook.  If you are close enough to land to reach the bottom with an anchor, get off of the boat and head inland. Before you leave put some of that money you are going to spend on the ultimate anchor and buy insurance, there are plenty of P365's out there.

Dale

[Maddie]

That's a fair point I think there's a middle ground where this is still worth talking about, though.