Bent Anchor

[incognito]

Re: Plea to PBO

If it were like that, it would be really difficult to get out again, ay?

The sea bottom feels the weight of water above, with a pressure of P. The sea bottom says 'hey, I'm not going to move!' and presses back with an equal and opposite pressure of P. Equal and opposite means seabed doesn't move.

Now comes down this 'ere anchor. It hits the bottom with it's weight W and all that water above it making an extra 'weight' P, so P+W.

Where the anchor touches the seabottom, it replaces the water pushing down with P, and pushes down with P+W. Still got that P pushing upwards, so we end up with a nett weight of W.

Simplified explanation, taking out the fact that the air-weight of the anchor is W, but the sea-weight is a bit less.

 

[Twister_Ken]

Re: Plea to PBO

Damn!

 

[AndrewB]

Results of another beach test.

Some years ago after an argument about which type of anchor is best, a group of us set up a challenge. We took our anchors to a beach, attached each to a length of rope, and tested how quickly we could drag them by hand a certain distance. Jerking on the rope was permitted to break the anchor out if it started to bite.

The ONLY anchor that was impossible to drag any distance was an old Fisherman's. Others tested were CQR (difficult), Danforth (fairly easy), Bruce (easy), Grapnel (child's play). We put this down to the hardness of the sand on the beach.

 

[charles_reed]

The weakest point on a Danforth is the shank - if you've got a genuine one (as opposed to a lookalike) it should have a forged shank with two strengthening ribs.

As your's probably hasn't, you'll be better off replacing it - a 35lb kedge is quite big - how large is the boat?

To get a similar holding power out of a Bruce you'll need to be looking at something like a 25kg (note kilos not lbs) - why not look at a Fortress, fantastic holding power for weight (and very effective in soft conditions) as long as you're not trying to drop it in a current (they hunt like mantas).

 

[charles_reed]

There are two conflicting views on this - the anchor chain view being expounded here and the anchor view.

The more experienced yotties (who've probably tried both approaches) tend to favour heavy anchor with lots of lightish high tension chain, rather than the trad English view of mudweight and heavy chain.

 

[Mirelle]

definitely disagree with that

but see no reason to start an endless debate about it, since we are discussing a kedge anchor, which presumably is on a warp not a chain, apart from the now customary short length at the anchor end!

For the record:

Bower: 45lbs CQR on 12mm chain

Kedge:35lbs CQR on 4 metres of 14mm chain and nylon warp

and a Fisherman stowed below for the very rare occasions when a CQR won't do.

Gave up on Danforths twenty years ago; nasty things, snag every rope going if stowed on deck, swine to disentangle from a mooring chain if it grabs one, (unlike the CQR where you can do Hiscock's loop of chain trick), awkward to stow below....and the shank bends!

 

[Chris_Robb]

Charles - yes it must be a look-alike as their are no ribs to strengthen it. I have only used this anchor twice, as a lunch stop on Nylon/chain, and was horrified at how easily it bent! The old adage, you pays for what you get, is so true.

The boat is a 40ft long keel Ketch weighing 13 tons, so 35lbs for a lunch time anchor may be over the top.

My main anchor is a cqr 45lb job, so I think I should have a spare anyway, so plan is to repair danforth and use advisedly, and purchase a 45lb Spade, which will probaly relagate the CQR to the spare.

Main reason for using the kedge was that the Lofrens winch was dead (overhauled last winter), and we were anchoring in 16 mtr, so I didn't want to pull up 50 mtrs of chain, so Ireally have to get this fixed!

 

[charles_reed]

As a kedge, do look at the Fortress, easy to handle with enormous power in sand or mud and always giving the greatest hold/weight factor in any test ever done.
You may, sometime, find yourself in rock or thick weed, when there is nothing to match the 3000 year-old Fisherman concept.
Generically I place the Spade with the Brittany and Danforth in the palm anchor category; whilst CQR, Delta are ploughs.
Though I don't use one, I suspect the Bruce is the closest approach to a GP anchor, but like most GP products it's not terribly good at any facet of anchoring - but providing you go way overweight (like 25kg for your boat), probably the best compromise.
A regular "rough" sailing acquaintance of mine reckons to have 4 fouls a year, giving plenty of opportunity for playing the changes. Mind you he sails 10 months a year in Pacific and Atlantic.
Good luck with finding your replacement - your guiding light has to be the general conditions of anchoring in your area, probably favouring the plough brigade.
I use the CQR as my GP anchor, the Delta as my main kedge, the Danforth in soft sand or mud and a Swedish folding grapnel in rock.
I've once had to buoy and slip the Danforth and return with scuba to dig it out - they are terribly good at digging into soft sand, tho' on that occasion it had picked up an underwater cable.