Anchors - Bigger is Better ?

[JonJo]

I tried to raise the question:' is a bigger anchor better' on the terminated SARCA Excel thread. Its not about a specific design but about whether 'bigger is better'

A thesis was proposed that a bigger anchor was better than 2 anchors with part of the argument based on the anchor in question being a new generation anchor. I am sure 'new generation' was not universally defined but for the sake of this thread I'm thinking of (in no particular order), Fortress, Spade, Super SARCA, Rocna, Supreme, Excel, Boss and Mantus (if someone want to add something I've missed, be my guest).

The argument, or thesis, was described here:

One Big Anchor Better Than Multiple Anchors In Almost All Situations

The thesis has had supporters on CF, witting or unwitting.

Simplistically the debate is:

In high latitudes conditions will be more taxing but carrying one anchor larger than normally recommended should be sufficient (those who enjoy lower latitudes suffering from cyclones, typhoons and hurricanes might care to bristle). The anchor carried should be one size larger, but the authors carry an anchor 2 sizes larger - which, in my biased opinion, seems to indicate some of their thinking. I repeat the thesis is predicated by the idea we are referring to modern anchors.

I care to differ:

I have tested a whole range of modern anchors with a winch from a beach, all anchors in the water. Testing anchors of 10-15kgs we stop the testing when the loads reach 2t as the anchors have dived so deep it takes so long to dig them out. An anchor maker, not Australian, has tested a 15kg anchor with a 90t tugboat (they had to upgrade the chain etc) to 5t. A common comment of anchors actually used under arduous conditions (quoted have been cyclones and hurricanes) suggest retrieval of 'normal' sized anchors after a big blow can be time consuming (they have dived so deep) and in the extreme have been abandoned. Classification Societies allow a 30% reduction in anchor weight for SHHP anchors, over the USL codes - so why go 2 sizes up?

So holding capacity is not an issue - even a 15kg anchor will produce a 'holding capacity' well in excess of the load needed to hold a yacht for which the USL recommends that size.

An argument is - how about poor holding seabeds, excellent point - but what sort of poor holding seabeds, ones with weed that might clog a concave anchor? rock in which only a fishermans/Luke might hold, thin mud - so if we are going to oversize - which design do we put our eggs into?

Interestingly the advocates of big is better - seem to use only one type of anchor - coincidence?

If your yacht would normally use a 33kg model of one specific brand then 2 sizes bigger is their 55kg model. Good for the anchor maker's income and probably good for windlass sales - but is it necessary?

Of most interest would be respondents who have used the recommended sized (new gen) anchor, found it wanting, and bought the same design only bigger - and found it satisfactory.