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rgleason · 18-01-2022, 10:11

Anchor Rode Calculator is excellent for comparisons.

Depth 20'
Anchor angle 3 degrees, (effective ratio of 19)
Wind 30, 40 or 50 knots
Chain G43 1/4" or 5/8" with set length of 30'
Rope Yale Nylon brait 1/2" or 5/8" with a calculated length

with the results shown below. In other words:

Using 30' of 5/16" chain weighing 10 lbs more than 1/4" chain, saves me 30' of scope at 30 knots. This is about 6.7 lbs more than my current 15' x 3/8" rusty chain, and is more effective.
Using 5/8" nylon brait instead of 1/2" brings the %WL down to %16 at 40 knots, below 20% with no permanent stretch.
300'x 1/2" = 18.3 lbs and 300'x 5/8" = 27.6 lbs so that is about 9.3 lbs more.
The rode load shown at 30kn=221lbs, 40kn=390lb, 50kn=608lb.
There will be additional dynamic loads due to veering, changes in wind, etc. that have not been added.

rgleason · 18-01-2022, 11:10

Using Alain Fraysee's great spreadsheets I arrived at these figures, which correspond somewhat with BjarneK's web calculator below, though the parameters used are different.

Stu Jackson · 18-01-2022, 11:20

Quote:

Originally Posted by rgleason

My sweetheart has suggested that I just lead the anchor rope back to a cockpit winch or mast winch if I really need it. She says she'll power the boat forward appropriately so why consider a winch? I tend to agree, but as time goes on, I may have a different perspective....
...
...

rg, Not such a great idea. I've tried it and here is a picture (although it's on a different topic).

https://c34.org/bbs/index.php/topic,....html#msg29828

Downsides from reality:

You may not get a good fairlead from the stemhead, running against the base of your shrouds.

Think about the logistics of doing it: you either have to get a separate line onto your rope rode (rolling hitch?) or a chain hook (in which case your dragging chain across your deck); or you MUST remove a whole bunch of rode from your locker and move it aft.

I've BTDT and it is not so simple.

Please think it through first.

rgleason · 18-01-2022, 15:26

I agree it is not simple and probably won't work. I like the way we do it now using the engine, but if I were single handing a lot, I would have a problem to solve at times! Perhaps an AP remote control would help at times....

rgleason · 18-01-2022, 15:57

Stu what is What is a BTDT?

**Don C L** · 18-01-2022, 16:52

been there done that

ArmySailor · 19-01-2022, 00:11

Quote:

Originally Posted by Orion Jim

My bower is a Spade galvanized 33# anchor attached with two Crosby 7/16” G-209A forged anchor shackles to 110’ of Acco 5/16” galvanized grade 43 (G4) hi test chain. The chain is spliced to 115’ of New England Ropes 5/8” three strand nylon line.

My kedge is a Mantus galvanized 25# anchor attached with two Crosby 7/16” G-209A forged anchor shackles to 20’ of Acco 5/16” galvanized grade 43 (G4) hi test chain spliced to 175’ of New England Ropes 1/2” three strand nylon line.

I have a Lofrans Royal manual windlass, which I rarely use. This combination has kept me safe from New England to Bermuda.

We have a very similar hull shape and displacement. I consider my ground tackle my life insurance.

How / why do you have two shackles? I have nearly the same arrangement as you do... But only use one Crosby shackle.

Do you have a Stern anchor?

**boatman61** · 19-01-2022, 03:28

Quote:

Originally Posted by rgleason

I agree it is not simple and probably won't work. I like the way we do it now using the engine, but if I were single handing a lot, I would have a problem to solve at times! Perhaps an AP remote control would help at times....

Single handing I use the main sheeted in and centred, same with tiller and engine on tickover in neutral (JIC), this makes the boat sail forward taking the load off while I haul in the chain hand over hand and feeding it into the locker, as the boat reaches the point where load comes on I lock on and the boat rounds up and falls back slowly and comes onto the other tack and as she moves forward again I start hauling in once more.. keep repeating till the last 10 metres or 70* chain angle then pause till your fall onto a favourable tack for clearing other boats then haul in till the anchor is just below the surface.. Lock off and return to cockpit where you then have the option to either motor out or unfurl some genny and sail out.. Once clear switch to TP then return to the bow, hual up the anchor to sit on the roller, secure it and tidy up.
Practice in an open area/quiet anchorage till you have it and your boats rhythms sussed along with your routine.
I have used this method in busy anchorages like Soller in Mallorca mid season, made quite a few nervous as I tacked out through the mob..

rgleason · 19-01-2022, 05:54

boatman61
This sounds like a very reasonable approach, and parts of it we already do. I like the part about making others nervous

Thanks.

rgleason · 19-01-2022, 07:35

Ground Tackle Loads and Guides used by calculators

ABYC Guides used by Boat US webpage, which is conservative.
Robert Smith Ground Tackle Loads from Robert Smith book "Anchors: Selection and Use"

BjarneK's Anchor Calculation webpage and Mathias Wagner's app AnchorChainCalculator both use Robert Smith, which is also what Steve Goodwin (s/v Panope) has referenced occasionally.

Some of the tests done:

rgleason · 19-01-2022, 08:05

Checking Ground tackle with future anchor Rocna Fitment Guide

The boat is 9.76 meters, looking at the table, the Vulcan 12kg (27lbs) appears to be the right selection, under vessel length 10m, for less than or equal to 6 tons. I note that the chain suggested is 8mm or 5/16". This is 5 lbs heavier than our Bruce.

I had been considering using 1/4" chain and 9/16" 8 brait nylon to save about 14 lbs (which is below 20% of the working loads at 40knots) and then put that into a larger anchor, the Vulcan 15kg., as per rslifkin's suggestion, however 5/16" chain would add about 9 lbs.

1/4" chain is strong for expected loads, why should I go up to 5/16"?

rslifkin · 19-01-2022, 08:09

Quote:

Originally Posted by rgleason

Checking Ground tackle with future anchor Rocna Fitment Guide

The boat is 9.76 meters, looking at the table, the Vulcan 12kg (27lbs) appears to be the right selection, under vessel length 10m, for less than or equal to 6 tons. I note that the chain suggested is 8mm or 5/16". This is 5 lbs heavier than our Bruce.

I had been considering using 1/4" chain and 9/16" 8 brait nylon to save about 14 lbs (which is below 20% of the working loads at 40knots) and then put that into a larger anchor, the Vulcan 15kg., as per rslifkin's suggestion, however 5/16" chain would add about 9 lbs.

1/4" chain is strong for expected loads, why should I go up to 5/16"?

I personally ignore the anchor manufacturer's chain sizing recommendations. They suggest my 73 lb Vulcan should use 3/8" G43 instead of the 5/16" I'm actually using. Basically, they're sizing the chain based on best case holding power of the anchor, rather than the real-world loads the boat in question can apply to the anchor at the wind speeds you're using for a sizing basis (which will typically be less than best case holding loads, as you're sizing for the less than optimal holding scenarios).

mako · 19-01-2022, 09:11

@rgleason, this has turned into a long thread so I haven't read every post, but last I read you had decided on 100lbs of chain with a 25lb anchor.

I agree that a 11,000 lb displacement on a 22ft waterline is great, sounds like a wonderful boat. However that anchor sounds way too light. I use a 22lb CQR on a 22ft 5,000 lb boat, which is oversized but makes one feel warm and fuzzy when anchored.

If you're concerned about weight forward, I'd say drop down to 75ft of chain and use a 50lb anchor, especially a new-gen. Add in a Fortress as a kedge/stern anchor and you're good to go.

**Don C L** · 19-01-2022, 09:13

Quote:

Originally Posted by boatman61

Single handing I use the main sheeted in and centred, same with tiller and engine on tickover in neutral (JIC), this makes the boat sail forward taking the load off while I haul in the chain hand over hand and feeding it into the locker, as the boat reaches the point where load comes on I lock on and the boat rounds up and falls back slowly and comes onto the other tack and as she moves forward again I start hauling in once more.. keep repeating till the last 10 metres or 70* chain angle then pause till your fall onto a favourable tack for clearing other boats then haul in till the anchor is just below the surface.. Lock off and return to cockpit where you then have the option to either motor out or unfurl some genny and sail out.. Once clear switch to TP then return to the bow, hual up the anchor to sit on the roller, secure it and tidy up.
Practice in an open area/quiet anchorage till you have it and your boats rhythms sussed along with your routine.
I have used this method in busy anchorages like Soller in Mallorca mid season, made quite a few nervous as I tacked out through the mob..

That's my usual too. Last summer though I was on the unfavorable tack when the anchor lost traction. Good thing my boat is not so long. I was able to jump back to the cockpit and barely get enough headway to round up and tack away from the cliff I was next to!

There's always something to keep me humble!

Stu Jackson · 19-01-2022, 09:21

Quote:

Originally Posted by rgleason

I agree it is not simple and probably won't work. I like the way we do it now using the engine, but if I were single handing a lot, I would have a problem to solve at times! Perhaps an AP remote control would help at times....

I have tried using the AP for this. Never works. Boatie's suggestion is what I've used, especially when I raise the main first and sail off.

The issue is that the ap wants to find a course to steer while at the same time the bow is turning first one way and then the other until the anchor releases.

Another one of those "think it through first" thingies.

As in, yet again, BTDT!!!

The beauty of forums is that you don't have to reinvent the wheel.