wearing out anchor

[mako]

You know, your sketch made absolutely no sense to me until I figured out that with a name like "Mic" that you're probably down in Australia, and that everything down there is upside down

[MicHughV]

I rotated the pic.....hope this works

[JebLostInSpace]

Originally Posted by MicHughV

I rotated the pic.....hope this works

I was wondering how you got your anchor to float at the surface of the water, and why you were trying to anchor a sunken boat!

:bigg rin:

[MicHughV]

posting pics on this forum is sometimes a challenge for me....I'm left- handed but have a right-handed keyboard

[aqfishing]

Been such a critical safety item and relatively inexpensive, why not replace it more often?

[MicHughV]

It's the boaters curse....we like to buy stuff that is expensive, shiny and comes wrapped in a big box....
An anchor is a big heavy non-important object, that must be carried out the store without fanfare and usually stored in the trunk of a car, whereas anything else gets to ride in the front seat.

[hpeer]

Originally Posted by aqfishing

Been such a critical safety item and relatively inexpensive, why not replace it more often?

Sean in not hour “average” boater.

While he travels extensively he leads an extremely simple and frugal very low consumption life. It is an way of life for him. Quite impressive really.

[Jim Cate]

Originally Posted by aqfishing

Been such a critical safety item and relatively inexpensive, why not replace it more often?

If you are referring to the shackle, I agree. If you are referring to the anchor, it should NEVER require replacement due to wear at the shackle attachment point, and it sure as hell ain't "relatively inexpensive".

I suspect that in Sean's case buying a cheap knockoff anchor was the issue. Some of the ones on the market are appallingly poorly made.

Jim

[Muaddib1116]

Originally Posted by Jim Cate

and it sure as hell ain't "relatively inexpensive".

Why not? I guess for Sean, given the context we've been recently given about his lifestyle, it isn't. But it could be for some or many. Galvanized Lewmar claw anchors are pretty cheap relative to the boats they are sized for. A 44lb claw is $185 at west marine and is suitable for boats that can range into the 100's of thousands. Let's say you have a $100k 40ft sloop (very common), even a 55lb Rocna at $700 from west marine is relatively inexpensive, replacing it every 10 years. What do you think relatively means?


Especially considering where anchors rank on the hierarchy of critical boat gear.

[Jim Cate]

What do you think relatively means?

In this context, cost of an anchor vs cost of a shackle, the anchor is not inexpensive IMO. In light of Sean's well established frugality, I suspect that he agrees with this evaluation.

Jim

[seandepagnier]

Thanks for the discussion.. I continue to learn.

So perhaps, it is better to use 2 shackles to reduce wear. This would make it much easier to protect the anchor around the pin, for example, a zinc or delrin sleeve. I will experiment. I am mostly now concerned with the fortress anchor wearing, but I also have a rocna anchor I don't want to replace it anytime soon.

For reference, the one that wore out was a $60 anchor holding a $1000 boat, it was cast, and probably mild steel, no idea the exact alloy. This cheap bruce knockoff anchor is very similar to this (although inflation has taken it's toll it seems the price is $105 at least)
https://www.amazon.com/dp/B00YMUQ0WG...ter_B08576BXQQ

So consider your $100,000 boat example. This would be like spending $6000 for an anchor. At this price you could buy a titanium one. So even the cheapest anchor is very expensive.

My current boat the anchor cost 14% of what the boat cost and it's good to know it should last much longer, but just consider the cost of the boat vs anchor ratio and at 14% I want to make it last.

Originally Posted by MicHughV

I've attached a simple sketch to better explain my short chain theory.....every time a boat pitches in a wave...chop....etc....it can pick the chain up.....which then drops back down as the wind drops, etc.....this constant up and down motion undoubtably induces a lot of friction at the anchor/shackle location...leading to accelerated wear....

an anchor with a long chain doesn't have this problem.......

But it does have a problem. You are describing idyllic anchoring conditions where of course there is no wear issue.

I often anchored with 100ft or more of 3/8 chain and the chain drew tight from the wind. This usually happened around 40 knots when there was enough wind to throw spray through the air. By 50 knots, the spray is heavy, like rain on the deck, and the gusts shake the whole boat and throw the plastic kayak up in the air like a kite if it is tied behind. The gusts caused the boat to scoop water on the deck (heeling 60 degrees or more and putting the rail under) I was anchored in numerous storms like this. I recall talking to people in wellington nz where I was anchored for a few months and they said the moorings wear through the shackle connecting the chain to the block every year or two and this is a half inch or larger size and have to be inspected frequently.

I also anchored in many exposed locations, the windward side of islands in areas not protected from the ocean swells.

[MicHughV]

The topic of anchor chain, anchor selection, catenary, scope, type of chain/rode, etc, has been well been analyzed and discussed on this forum.
As a retired marine engineer, I have my own view on this subject from a purely technical point of view.

I know what works for me. I came about my own preferences thru' a procedure of trial and error. I listened to others, tried various things, did my own research, experimented, etc, and am to the point that I'm not particularly persuaded by what others think or do anymore and would not not ask for advice or direction from anyone on this forum regarding my anchoring setup or procedures.

I'm happy and comfortable in the way I do things, and am unlikely to change my preferences based on what others think or say. Before you critique me to much, I can assure you that I've been dere and dun dat.

I think that most posters on this CF have similar stances. There is no simple solution here. I myself, have 4 anchors on the boat with various combo's of rode, etc. It's not often that I have had to dig up more than two anchors, but it has happened. I simply adapt to my circumstances.

I offer my own perspective to present a different point of view. Little more. I have been at this for the better part of 35 years now. I offer only my perspective and view that you might gain some insight on how someone else does things, that you might gain an some food for thought so to speak. You need not do as I do, nor listen, nor give a damn,

[mako]

OP, I have to admit this thread is unique amongst the many anchor threads. If premature wearing of the shank hole is truly a concern then how about full penetration welding the link of a short length of chain to it. Then every year you can cut off one link and move your shackle connection point forward.

[Rightbrainer]

OK, from the bleacher seats...

1. Your old anchor was a cheap knock-off and probably wasn't heat treated with the same care that an actual Bruce anchor would have been. Now you have stepped up to a reputable maker that will stand by their design and manufacturing...good for you! That is most likely the end of your wear problems.

2. You got 10 years of continuous service in very tough conditions for $60 bucks delivered...sheesh, that's $6 bucks a year for a piece of safety gear that you used every day. That's cheap by any measure, relative or absolute.

3. Metal galling is a function of friction and materials. Keep the eye clean and a light smear of waterproof grease probably wouldn't hurt either.

4. Any drilling or welding will probably void your new Rocna warranty. Why don't you put your question directly to Rocna and follow their advice? They recommend a single proof tested shackle of the largest possible diameter and oriented pin-to-chain.

[seandepagnier]

Update:

I put zinc a bushing around shackle pin on both my anchors. This requires 2 shackles instead of one.

When it rotates it is the shackle pin against the zinc wearing. There was visible wear on my aluminum fortress anchor though no significant metal loss (yet)