Which size anchor

[oakleyb]

Were looking into replacing the anchor and chain on our catamaran which is a Prout 33CS. Its looking like a Fortress and 10mts of 8mm chain + rope is whats required, the question is though should i go for the FX11 which is suitable for 8 - 10 mts or the FX16 which is suitable for 10 to 12 mts

 

[sailorman]

FX 16 20m chain warp to suit depths for your area

 

[Twister_Ken]

This is an anchor thread and I refuse to get involved, as I'm a sensitive soul and don't like being told I'm wrong.

 

[J Neeves]

I did some work on comparing windage of our cat with a monohull. I had access to Bav 35 and Bav 45 drawings of around a 2010 vintage and calculated that the cross section area, above waterline, of both beam and length of our cat and the Bav 45 were similar (and the Bav 35 was 30% less). I excluded mast, furled sails etc - so very simplistic - but it gives you an order of magnitude. Obviously underwater profiles differ and we weigh in at 6t, unladen vs (I recall) 11t for the Bav 45. Very crudely the windage of a cat is about the same as a mono that is 30% longer

Our cat is a 35' (10.5m) but has had the transoms extended by 1m (but the transoms 'just' clear the water). Our beam is a rather extensive 22' or 6.67m. If you want to check, or compare www.lightwaveyachts.com.au

We carry a Fortress FX 23 but use all chain, 8mm, because coral eats nylon overnight. We do have a windlass. Being all chain we use a bridle, which I would recommend you consider as it will reduce yawing at anchor. We have over 30,000nm on our cat and we sail the east coast of mainland Oz and down the west coast of Tasmania, the latter is considered fairly inhospitable (think NW Scotland, but colder water).

The difference in weight of the FX 11 and FX 16 is insignificant and if you are lifting by hand you simply would not notice. To me the FX 11 is too small and the FX 16 is acceptable but on the 'small' size. A decision might depend on how you use the anchor, in all and any weather in any location - or just for lunch.

I am not familiar with the FX 16 and the difference is size between it and the FX 23. I'd collate and consider comment on this thread - but I would also approach Fortress direct and ask them the question. They are very approachable and have been selling anchors for over 25 years (so have some real history as I think they claimed some months ago to have sold over 500,000 units). If you do contact them it is unlikely they will be familiar with a Prout, maybe send them a couple of images images or drawing.

Jonathan

 

[vyv_cox]

Jonathan's advice on cat v monohull windage is good. OTOH I suppose that wave effects are a little less on a cat although I have never worked it out. I carry a Fortress FX16 as a kedge on a Sadler 34 and find it holds astonishingly well. Whether it is a suitable anchor for a bower is debatable, personally I would prefer a NG anchor.

 

[Contest1]

I,m looking to upgrade from my old 15kg cqr and rusty chain.
Looked at a YM or was it a PBO test were the Fortress came well ahead of the older models for weight / holding ratio.
Planning to go for the FX 16 and 45 mts 8mm chain for my 8m Centaur.
Funny thing though thr CQR always held first time in Carlingfords soft mud, the only place I ever overnight at anchor. I keep the CQR cliped to the deck by the windless so a folding Fortress should sit even better.

 

[RichardS]

When I bought my Rocna for my cat years ago, the Rocna recommendation was to buy one size bigger for a cat than the size recommended for the same length monohull.

It works for me and Rocna are great!

(fire in the hole! :ambivalence

Richard

 

[vyv_cox]

Looked at a YM or was it a PBO test were the Fortress came well ahead of the older models for weight / holding ratio.
Planning to go for the FX 16 and 45 mts 8mm chain for my 8m Centaur.

There are several issues there.

Firstly, in the YM anchor tests the Fortress tested was a 21 lb model, the FX37, suitable according to Fortress for boats of 46 - 51 feet. All of the steel anchors were 35 lb versions, mostly intended for boats of somewhere around 35 ft. So the result, although very impressive, is not comparable.

Secondly, many people, including me, have had problems with a failure of Fortress anchors to reset when the tide or wind turned. I use an FX16 as a kedge where, with a constant pull direction, it holds incredibly well. For the bower you would be advised to buy an anchor that resets well and has greater versatility in the bottoms that it sets in, which almost without exception means a New Generation type

It is not surprising that your CQR holds well in soft mud, as it was developed in the Thames estuary, where there is plenty of it. On hard sand, mixed weed, gravelly sand etc. it might be a different story.

You may notice in the YM test figure that no anchor held fully in every test. It's an important point to remember - there is no perfect anchor. However, the NG ones tested were far superior in the variety of bottoms used (again, except the Fortress)

 

[J Neeves]

I confess not to have seen the YM article on anchors (one of the disadvantages of living in The Lucky Country is that YM arrives 2-3 months late!)

Our mantra is almost identical to that of Vyv's - anchors are a compromise. The skill is knowing and accommodating the weakness of what you use. Its fine knowing where it performs flawlessly - what is more important is where it might let you down and this is true of any anchor. What is notable is that most tests are conducted in sand - and virtually every anchor works in sand - its the peripheral (and largely untested) seabeds that are the achilles heals (and, for example, how many anchor tests have you seen in a pebble seabed, thin weed or loose coral debris?).

One thing I note of Fortress is that if it sets well, or if you set it well, then in a change of tide the anchor will remain unmoved (the tide is simply not strong enough to cause it to reset). However many people buy a Fortress, and often an overly large Fortress, which they then describe as their storm anchor. (edit I note that Vyv's is a kedge, close edit) The motivation appears to be its large (for the storm) but light (so not too difficult to handle and not too much extra weight). Unfortunately an overly large Fortress (and this is true of any overly large anchor) is difficult to set well (unless its a Storm) simply because the engine of the yacht is too small to do so. We then end up with a poorly set anchor - which might trip in a change of tide. This is true of any anchor - whether its an overly large CQR or Supreme - except, in general, most people buy an anchor of a size recommended for their yacht (or one size bigger). So the overly large Fortress, if used, might not set fully (and be prone to trip) but the correctly sized anchor works most of the time - so guess who get the bad rap.

Interestingly the small Fortress that was used in the Chesapeake tests conducted by Fortress returned astonishingly high hold, it punched well above its size, whereas the NG anchors were a different type of revelation. What was also interesting was that ostensibly similar designs performed so very differently. If anchoring in thin mud then a Fortress, correctly adjusted, is unbeatable. It is also superb in thicker muds and sand. Conversely most anchors simply do not work in thin mud (at all) and in a cloying seabed with some weed sone NG anchors will clog (and not reset in a change of tide).

its horses for courses - if you plan to be able to anchor in any seabed a reliance on one design is a potential recipe for dragging.

Jonathan

 

[macd]

If anchoring in thin mud then a Fortress, correctly adjusted, is unbeatable. It is also superb in thicker muds and sand. Conversely most anchors simply do not work in thin mud (at all)

Jonathan: just to clarify: by 'thick' and thin' I presume you're referring to the consistency of the mud rather than it's depth? If I remember correctly, the Chesapeake test referred to 'soft' mud (or what one might call mousse, judging by the results ).
(Great language, english: more words than any other and most of 'em have at least two different meanings.)

 

[vyv_cox]

I confess not to have seen the YM article on anchors (one of the disadvantages of living in The Lucky Country is that YM arrives 2-3 months late!)

I was assuming that the OP was referring to the YM/West Marine/Sail magazine test of quite a few years ago. I think PBO has run one by Prof Knox more recently but they are the only ones I know from those mags.

 

[Brian@Fortress]

I sent the OP a PM with some follow-up questions in order to assist him with a model recommendation.

In any type of common sand, mud, or clay bottom condition, the precision-machined Fortress with its two massive and sharpened flukes should deliver superior performance.

In bottoms such as grass, weeds, or rocks, where weight can be more of a factor, along with a single narrow fluke for penetration, a different anchor type might be preferable.

Regards,
Brian

http://www.fortressanchors.com

 

[vyv_cox]

Well said, Brian :encouragement:

 

[TimBennet]

In any type of common sand, mud, or clay bottom condition, the precision-machined Fortress with its two massive and sharpened flukes should deliver superior performance.

In bottoms such as grass, weeds, or rocks, where weight can be more of a factor, along with a single narrow fluke for penetration, a different anchor type might be preferable.

What? You mean that's all there is to this anchoring malarky?

Gosh, so if I have two different anchors of complimentary design function, enough chain to prevent abrasion on the bottom, sufficient nylon rode to ensure adequate scope and shock absorbing, some leather patches as anti chafe at the roller, plus a modicum of knowledge and common sense, I could happily cruise for decades anchoring where ever and when ever I liked?

Blimey, I was beginning to think it was far more complicated than that and that I had just been lucky.

 

[Brian@Fortress]

What? You mean that's all there is to this anchoring malarky?

Gosh, so if I have two different anchors of complimentary design function, enough chain to prevent abrasion on the bottom, sufficient nylon rode to ensure adequate scope and shock absorbing, some leather patches as anti chafe at the roller, plus a modicum of knowledge and common sense, I could happily cruise for decades anchoring where ever and when ever I liked?

Blimey, I was beginning to think it was far more complicated than that and that I had just been lucky.

TimBennet, there are many great quotes on simplicity, here's one that seems appropriate:

“Knowledge is a process of piling up facts; wisdom lies in their simplification.” ~ Martin H. Fischer

I might end by saying to you "good luck," but based on your expertise, as stated above, you obviously won't need it!

Brian

http://www.fortressanchors.com

 

[snowleopard]

Were looking into replacing the anchor and chain on our catamaran which is a Prout 33CS. Its looking like a Fortress and 10mts of 8mm chain + rope is whats required, the question is though should i go for the FX11 which is suitable for 8 - 10 mts or the FX16 which is suitable for 10 to 12 mts

I have a cat - 40 ft, 5 tonnes. I have anchored all round the Atlantic circuit and learned a few lessons. My complement is a 16 kg Delta for Bower, an FX-16 as a kedge and an FX-37 for when nothing else can save me.

Over a year's cruising there were two occasions when I dragged with the Delta. One was in heavy kelp in the Spanish rias where the only remedy was to re-anchor and probably nothing but a massive Fisherman would have held. The other occasion was in a hurricane hole in Antigua where the bottom was pretty much liquid mud. The Delta did nothing but the FX-16 (on the soft mud setting) headed towards the centre of the earth. The problem was that after 3 days it wouldn't come back up as it had dug in so deep. In the end it came up after 1/2 hour heaving short and motoring around. I am certain that if I had used the big fortress I'd have had to abandon it.

On a couple of occasions, once over hard mud, once over sand, I have tried to use the kedge by rowing it out and found to my amazement that when hauling on the line it just slid across the bottom without biting, for all the world like a manta ray. I'm happy to have my Fortresses folded up in a locker for those occasions I need a second anchor but my experiences mean I would never consider a Fortress as a bower.

For a Prout 33 which is a similar weight to my boat I'd choose a 16kg delta or, for those with a lot of cash, one of the new generation e.g. a Manson (3x the price of a Delta) For most coastal cruising a 10kg would do for a boat your size. I'm as weight-sensitive as the next multihuller but I wouldn't rely on aluminium for regular use.

 

[macd]

For a Prout 33 which is a similar weight to my boat I'd choose a 16kg delta or, for those with a lot of cash, one of the new generation e.g. a Manson (3x the price of a Delta)

Oh dear. This wasn't supposed to be a 'which is best' thread, but I'm bound to observe that in every test I've ever read, the Kobra came out better -- often substanitally better -- than the Delta amongst the more moderately-priced hooks. (I'm also bound to observe that almost all of those tests were conducted over sand.)

 

[vyv_cox]

I have a cat - 40 ft, 5 tonnes. I have anchored all round the Atlantic circuit and learned a few lessons. My complement is a 16 kg Delta for Bower, an FX-16 as a kedge and an FX-37 for when nothing else can save me.

Over a year's cruising there were two occasions when I dragged with the Delta. One was in heavy kelp in the Spanish rias where the only remedy was to re-anchor and probably nothing but a massive Fisherman would have held. The other occasion was in a hurricane hole in Antigua where the bottom was pretty much liquid mud. The Delta did nothing but the FX-16 (on the soft mud setting) headed towards the centre of the earth. The problem was that after 3 days it wouldn't come back up as it had dug in so deep. In the end it came up after 1/2 hour heaving short and motoring around. I am certain that if I had used the big fortress I'd have had to abandon it.

On a couple of occasions, once over hard mud, once over sand, I have tried to use the kedge by rowing it out and found to my amazement that when hauling on the line it just slid across the bottom without biting, for all the world like a manta ray. I'm happy to have my Fortresses folded up in a locker for those occasions I need a second anchor but my experiences mean I would never consider a Fortress as a bower.

For a Prout 33 which is a similar weight to my boat I'd choose a 16kg delta or, for those with a lot of cash, one of the new generation e.g. a Manson (3x the price of a Delta) For most coastal cruising a 10kg would do for a boat your size. I'm as weight-sensitive as the next multihuller but I wouldn't rely on aluminium for regular use.

Excellent post. Pretty much summarises my hour-long 'Anchors and Anchoring' talk. :encouragement:

 

[charles_reed]

Jonathan's advice on cat v monohull windage is good. OTOH I suppose that wave effects are a little less on a cat although I have never worked it out. I carry a Fortress FX16 as a kedge on a Sadler 34 and find it holds astonishingly well. Whether it is a suitable anchor for a bower is debatable, personally I would prefer a NG anchor.

Agree with Vyv - to amplify the Danforth/Fortress are alleged to be poor at re-setting - but nothing offers the holding power for weight of the Fortress and I've experienced 40knot winds lying to a 6kg Danforth.

 

[oakleyb]

Thanks for all the replies and tips, i think the 16kg Delta will be best suiting for the moment