Anchors - Bigger is Better ?

[conachair]

Originally Posted by robert sailor

Marketing hype, oh my god we are bending shackles! Lousy shackles I'd say.

+1

A decent shackle like a 5/8" crosby 209 should have an ultimate breaking load of close to 20t, if one is bending at just 4.2t something is dangerously wrong.

[sabray]

Not really. The west marine 7/16 china shackle has a Wll of 1.5 tons the Crosby has a wll of 2.6 tons. Yes you can bend or break a pos china shackle.. Given the cost no reason not to have a decent termination at the hook end.

[conachair]

Originally Posted by sabray

Not really. The west marine 7/16 china shackle has a Wll of 1.5 tons the Crosby has a wll of 2.6 tons. Yes you can bend or break a pos china shackle.. Given the cost no reason not to have a decent termination at the hook end.

Also worth bearing in mind WLL doesn't mean without knowing the factor of safety used.


And a well dug in anchor doesn't mean much on it's own either.

[Cotemar]

Cannot go wrong with Crosby Shackles for just a few dollars more than the China ones.

You have a very expensive boat hanging on this Shackle.

Crosby 7/16, G-209A Shackle (WLL) (Working Load Limit) is 5333 lbs. or 2.6 tons

Just looking at them tells you all the important info you need. No guessing

[sabray]

Course you could go spend hundreds on these new gen hooks. Load up with all chain and then have it all ride on crap shackle.

[Kettlewell]

Course you could go spend hundreds on these new gen hooks. Load up with all chain and then have it all ride on crap shackle.

I see that all the time. The most common thing is to see a cheapo anchor shackle connecting to the chain that is one or two sizes too small, and often not moused, probably rusty too.

[conachair]

Originally Posted by Cotemar

Cannot go wrong with Crosby Shackles for just a few dollars more than the China ones.

You have a very expensive boat hanging on this Shackle.

Crosby 7/16, G-209A Shackle (WLL) (Working Load Limit) is 5333 lbs. or 2.6 tons

Just looking at them tells you all the important info you need. No guessing

Yep, nice shackle, didn't this come up just the other day? The 209A has a 4.5:1 factor of safety of ultimate breaking strength to WLL whereas the 209 factor of safety is 6:1.
WLL on it's own doesn't tell you that much.
Same as some anchor digging in to 4.2t means little with no mention of the bottom or comparisons of other anchors tested in the same seabed.

[DumnMad]

Factors of safety often vary according to the reliability of the material being used rather than a more conservative approach. Annealed with internal cooling stresses reduced may result in a lower factor of safety being used for the same WLL.
The unpredictable loading regime means all shackles should have a higher factor of safety than say reinforcing steel where it is generally not much over 2.
For shackles I would rely more on the WLL than breaking load since a high factor of safety may just be saying there is more unpredictability for the breaking load.

[sabray]

West marine 7/16 shackle has a WLL of 1.5 and is made in china.. Crosby shackle is wll 2.6 made in USA. Guess which one I trust.

[DumnMad]

Agree, if the WestMarine one has lower WLL for same size then there is a good reason. Lower grade of casting material and less reliable breaking load maybe?
Crosby has a great reputation here in NZ too.

[conachair]

Originally Posted by DumnMad

Agree, if the WestMarine one has lower WLL for same size then there is a good reason. Lower grade of casting material and less reliable breaking load maybe?
Crosby has a great reputation here in NZ too.

I think worldwide Crosby is regarded as good as it gets for shackles & lifting equipment. The wll also varies with whichever particular type approval and certification it adheres to. 209a is 4.5:1 whereas others designed for the offshore market might be more like 8:1.
The Chinese ones might well be 1:1, if that

Anyway, back on topic, has this link been posted yet...

One Big Anchor Better Than Multiple Anchors In Almost All Situations

[JonJo]

Originally Posted by conachair

Anyway, back on topic, has this link been posted yet...

One Big Anchor Better Than Multiple Anchors In Almost All Situations

That's roughly where the thread started but it look as though it was becoming 'The Crosby Show'

[Andrew Troup]

I've long inclined towards the "one big anchor" philosophy as a prime strategy, (and, less fashionably, big chain) but there's something which has to be said: if you're sailing in tiger country, you have to expect that you may lose your main anchor and chain.

So you need (in my view) to keep the skills and knowledge alive to get by with several smaller anchors as a backup, until you can make it back to civilisation and replenish your big anchor stock.

Even if your lazarette is sufficiently large and well stocked, it's not very realistic to nonchalantly wander up to the bow with another 40 or 50kg anchor when it's blowing dogs off chains, you've had to slip your main rode because of some unforeseen contingency, and your location is now exposed.

Another thing: you may need to lay out another anchor in a new direction* in expectation of a wind change, when you don't have sufficient room to leeward to lie to the one you're on .... which may be so well buried and difficult to lift you daren't risk it in the conditions, or may literally be unable to, especially if it's a biggie.

*(whether from a dingy - or even swimming! no kidding - fenders and flippers - fixes the windage problem)

So while the "Single Big Anchor" is an ideal, as in the case of most ideals, I reckon it doesn't pay to put all your eggs in that one basket.

[Dockhead]

Originally Posted by Andrew Troup

I've long inclined towards the "one big anchor" philosophy as a prime strategy, (and, less fashionably, big chain) but there's something which has to be said: if you're sailing in tiger country, you have to expect that you may lose your main anchor and chain.

So you need (in my view) to keep the skills and knowledge alive to get by with several smaller anchors as a backup, until you can make it back to civilisation and replenish your big anchor stock.

Even if your lazarette is sufficiently large and well stocked, it's not very realistic to nonchalantly wander up to the bow with another 40 or 50kg anchor when it's blowing dogs off chains, you've had to slip your main rode because of some unforeseen contingency, and your location is now exposed.

Another thing: you may need to lay out another anchor in a new direction* in expectation of a wind change, when you don't have sufficient room to leeward to lie to the one you're on .... which may be so well buried and difficult to lift you daren't risk it in the conditions, or may literally be unable to, especially if it's a biggie.

*(whether from a dingy - or even swimming! no kidding - fenders and flippers - fixes the windage problem)

So while the "Single Big Anchor" is an ideal, as in the case of most ideals, I reckon it doesn't pay to put all your eggs in that one basket.

It's fairly standard procedure for cruisers to carry a spare anchor or two. The Fortress is ideal for this purpose since it is extremely light for its holding power. I have a Fortress F-65 In my anchor locker rigged with 100 meters of rode ready to go for these purposes. I also have a Delta 25kg (which was what came with the boat) in the laz, but I am planning to give it away before I launch next month. It's just dead weight. I think two anchors is enough for most people, unless you're cruising Greenland. Most people don't lose anchors very often (I never have, knock on wood).

[Andrew Troup]

Originally Posted by Dockhead

It's fairly standard procedure for cruisers to carry a spare anchor or two.....

Yes, but my point was about the knowledge, rather than the gear.

I was making a pitch about the advisability of knowing the ins and outs of using smaller spare anchors, sometimes more than one at a time, if the main anchor was lost.

And to consider strategies ahead of time, eg: If the spare is a Fortress, it's pretty desirable to back it up with another anchor (or shorelines) unless you can be certain the wind will only come from one quarter.

I'm not sure if it's relevant not to have lost an anchor ... I've never had a mountain hut burn down, but I sure keep my boots by my bunk ...