Only One Anchor

[BigCat]

Originally Posted by Therapy

If the Fortress is used so much as a fall back/secondary/emergency anchor by so many (as I read) then why is it not a primary?

It is used as a primary by many, if you count the Danforth and its clones. It isn't great for rock, coral, or dense weed, though. IMHO, you are better off with a traditional Fisherman / Admiralty anchor if you are in rock or coral, though in coral waters you can usually find a sand patch, and you should if you can, for both practical and conservation reasons. The Fortress is also harder to set, I would think, because it can fly like a paper airplane. Until it is set, the combination of lightness and large fluke area works against you. As far as pricing goes, the Delta is a great bargain in an all around anchor. You might need a slightly heavier one than you would with a Rocna, but dollar for dollar, it can't be beat in a store-bought anchor.

I am designing my own anchors because I want a number of them for use in hurricanes, and I don't want to pay $1,400 each for 4 to 6 anchors for a 65' catamaran, nor even $700 each. Also, I can get anchors made in marine grade aluminum this way, for about 1/4 the price of equivalent Fortress anchors. I also don't want to pay $1,400 for a Luke anchor for use in rocks or coral, and so have designed my own knock down Admiralty anchor. (The drawing should read 4 1/2' shank, the longest part.)

[Ancora Latina]

Originally Posted by BigCat

IMHO, you are better off with a traditional Fisherman / Admiralty anchor if you are in rock or coral,

Still a well accepted wisdom..

If a Fisherman type anchor can get through weed, then it has a very low ration Holding/weight, Most modern anchors will also cut through weed.. with a much better holding.

Rock is another question, very often it’s the chain around a boulder which will hold.. regardless of the type of anchor.. On flat rock, nothing will hold and any lump of metal wedged between two rocks will hold like hell !

Forget about your oooooold Fisherman anchor and keep it as a decor for your garden !

[BigCat]

Originally Posted by Ancora Latina

Hi Tim,

They are wisdoms which are very well accepted, like anchors developed to hold oil rigs in the North Sea or holding of « aluminum » anchors...

In Tests, holding of anchors is always related to weight. If you consider that density of aluminum is about three times the one of steel, then for the same weight, the holding surface area of one aluminum anchor would be about three times bigger than the surface area of a steel anchor.

It would be very interesting to compare two similar anchors ( same type - same surface area)... and I’m not sure the holding difference will be that big?

Hi, AL Here's a good critique of the discussion of the issues involved:

Attainable Adventure Cruising—What's New

I think heavy anchors probably tend to dig in faster than light ones. Once dug in, I think area is a key factor. Of course, if a wind or current shift requires your anchor to reset, a heavy anchor would also have an advantage there.

You surely mean that steel is denser than Aluminum, for aluminum is famously "Half the weight and twice the strength" of steel. The issue is complicated by the fact that steel welds are 100% of the strength of the steel, but aluminum welds are less than 100%, so if welding is involved, aluminum scantlings used are heavier than you would expect from the strength of the raw materials.

My design is meant to give more weld area than the Bugel, and some reinforcement for the fluke, so as to make a more efficient design in terms of unit of fluke area per pound.

I think the winner on a pound for pound basis has been the Hydrobubble, which has a huge surface area for its weight.

[BigCat]

Originally Posted by Ancora Latina

Still a well accepted wisdom..

If a Fisherman type anchor can get through weed, then it has a very low ration Holding/weight, Most modern anchors will also cut through weed.. with a much better holding.

Rock is another question, very often it’s the chain around a boulder which will hold.. regardless of the type of anchor.. On flat rock, nothing will hold and any lump of metal wedged between two rocks will hold like hell !

Forget about your oooooold Fisherman anchor and keep it as a decor for your garden !

You will notice I didn't recommend it for weed. Another virtue of the Admiralty anchor is that it will hold with less scope than any other type. I wouldn't regard it as being for general use, of course. I stand my ground about anchoring in rock, however. On rock, or a thin sand or thin mud layer over rock or coral, the Admiralty anchor can find a crevice and jam where other types will skate. Just ask sailors from Maine, where anchoring in rock isn't unusual.

[GMac]

Size for size a Fortress (on std setting, not the mud one) holds the same as a steel danforth pattern. Weight for weight the Fortress obviously wins due to vastly larger area.

Area for area Fortress will be beaten by the new ones. Talking overall here. In some bottom types the Fortress will win but generally it doesn't.

Also the new ones are miles stronger than a Fortress. A Fortress has a short life expectancy down here, they bend too easy and stop working. Not to mention they are also the most expensive by quite a margin.

[BigCat]

Originally Posted by GMac

Size for size a Fortress (on std setting, not the mud one) holds the same as a steel danforth pattern. Weight for weight the Fortress obviously wins due to vastly larger area.

Area for area Fortress will be beaten by the new ones. Talking overall here. In some bottom types the Fortress will win but generally it doesn't.

Also the new ones are miles stronger than a Fortress. A Fortress has a short life expectancy down here, they bend too easy and stop working. Not to mention they are also the most expensive by quite a margin.

Testers have found the Fortress too strong for its own good too. It is lightly built with a huge area, and it holds so well that it bends instead of pulling out. The Bugel Wasi anchor doesn't have much fluke area compared to a Rocna or Manson. In my proposed anchor, I am increasing the area of the fluke so that it equals a Rocna of the same weight. It may well be that you need a larger size in the Bugel type than in a Rocna for equal holding.

The Rocna is currently the Rolls Royce of anchors, and it is becoming popular with the most experienced of cruisers. Unfortunately, in the US, Rocnas are distributed by West Marine, the most expensive of our chandlers. A 55 kilo Rocna costs $1,300 USD from them. I can make quite a few widened Bugel type anchors that weight 25% more for that price, even using manganese steel that has a strength of about 60% more than mild steel.

[GordMay]

In their 1995 report, “THE SAILING FOUNDATION ANCHOR TESTS PUGET SOUND”, USSAILING wrote:
1995 Anchor Study

Conclusion

“... Adequate holding power should be the most important criteria rather than the ease of setting. An average sailboat auxiliary engine of 30-40 H.P. can exert perhaps 300-400 lbs. backing down while setting an anchor. Many anchors would hold at that tension, giving the illusion that the vessel is secure, only to fail when the wind builds ...”

“... Damage. The MAX and Fortress anchors both sustained significant damage. The MAX bent its flukes twice and shank once (seriously). The Fortress bent both flukes on one test and the shank twice. However, most damage was sustained at strains in excess of 3,000 lbs. which was probably more tension than would be generated by a sailboat of less than 56 feet in winds of 63 knots. Boats that size should have bigger anchors. The Performance 35 sustained no damage although it sustained loads of 4,100 lbs. The Fortress did bend flukes at 2,100 lbs. on primarily sand bottom at Blake Island ...”

Among others, we used a Fortress FX-37 (as recommended for a 46'-51'boat) aboard “Southbound”, a C&C29 @ 28.5 Ft & 6800# displ, because we could.
Although way oversized, the anchor weighed (@ 21#) less than our Delta (@ 35#), with similar holding performance.

This huge weight advantage, allowing an easily handled LARGE anchor, was an important factor in our adding the Fortress to our anchoring arsenal.

The 2100# damage threshold in the above test, corresponds to the loading ABYC specifies for a PERMANENT Mooring for a (larger) typical 30 Ft. Boat, and vastly exceeds the 1,400# specified for a storm anchor.

[ssullivan]

Originally Posted by BigCat

Just ask sailors from Maine, where anchoring in rock isn't unusual.

You would think that is the case, but most harbors in Maine are mud.

The rock is on the outer edges of the harbor, while the middle (deep part) of the harbor is just a big ol' pile of mud or other "normal" holding ground.

Presumably, there is probably rock somewhere below that mud, but you never do anchor in rock in Maine unless you are doing something very strange and anchoring on a pile of boulders further out at sea to go fishing or something.

[BigCat]

Originally Posted by ssullivan

You would think that is the case, but most harbors in Maine are mud.

The rock is on the outer edges of the harbor, while the middle (deep part) of the harbor is just a big ol' pile of mud or other "normal" holding ground.

Presumably, there is probably rock somewhere below that mud, but you never do anchor in rock in Maine unless you are doing something very strange and anchoring on a pile of boulders further out at sea to go fishing or something.

Maybe that's why some call it the Fisherman anchor? Here in the Pacific NW, they are called halibut hooks because fisherman use them when laying out bottom hooks for halibut.

Defender.com, which is usually about 1/3 cheaper than West Marine, sells Manson 100# anchors for $1,200.

I've been doing research on the best steel for a lightweight anchor. It seems that it is
Hadfield steel, aka Austenitic manganese steel, 12 to 14% manganese, usually about 1% to 1.6% carbon, din 1.3401, X 120 MN 12, A 128 grade A, with a strength of 120 to 130 ksi.

There is lots of information on the Fortress anchor site, including charts for how much setting power you get from your engines, by boat type and horsepower, pounds of force exerted by wind speed on a typical yacht, etc. http://www.fortressanchors.com/safe_anchoring.html

[BigCat]

Here is a test of various anchors in soft mud:
Practical*Sailor*2006*Anchor*Test - XYZ Anchors - Page 4
They thought the Rocna was much too expensive for its holding power in soft mud. I might mention that the Fortress (FX) anchors numbers are not their weights, but rather what they think the competition would have to weigh to have equal holding. They are something like 2/3 of the weight in pounds of the number that designates them.

[colemj]

Originally Posted by GordMay

“... Adequate holding power should be the most important criteria rather than the ease of setting. An average sailboat auxiliary engine of 30-40 H.P. can exert perhaps 300-400 lbs. backing down while setting an anchor. Many anchors would hold at that tension, giving the illusion that the vessel is secure, only to fail when the wind builds ...”

They seem to be contradicting themselves here. They state that holding power is the most important criteria, but give an example of a poorly set anchor as the problem. An easily set anchor would not only set better initially, but also set better when the wind picked up or the direction of pull changed - not fail.

To me, ease of setting is the most important characteristic. GMac has given many examples of undersized anchors having adequate holding power once properly set. Getting that proper set is the key, though, and the ease in which an anchor reaches a proper set is often the deciding factor between holding and not holding.

When the yahoo in an anchorage plops his gear overboard 20 feet upwind of me and drifts back 10 feet before cleating it off and going below, I much prefer that he tosses over an anchor requiring minimal artisanal setting procedures to reach its holding power.

Mark

[colemj]

Originally Posted by BigCat

Unfortunately, in the US, Rocnas are distributed by West Marine, the most expensive of our chandlers.

Bigcat,

You are close to the Rocna NA manufacturer Suncoast Marine, who sells them cheaper than West Marine. Even with shipping across borders and across a continent they were cheaper than my local WM. The quote I got from Rocna to ship one from NZ to Boston, and then by UPS to CT was cheaper than picking one up at my local West Marine.

It might even be cheaper to BUY the whole Rocna company than to pick one up at your local West Marine.

Mark

[BigCat]

Originally Posted by colemj

They seem to be contradicting themselves here. They state that holding power is the most important criteria, but give an example of a poorly set anchor as the problem. An easily set anchor would not only set better initially, but also set better when the wind picked up or the direction of pull changed - not fail.

To me, ease of setting is the most important characteristic. GMac has given many examples of undersized anchors having adequate holding power once properly set. Getting that proper set is the key, though, and the ease in which an anchor reaches a proper set is often the deciding factor between holding and not holding.

When the yahoo in an anchorage plops his gear overboard 20 feet upwind of me and drifts back 10 feet before cleating it off and going below, I much prefer that he tosses over an anchor requiring minimal artisanal setting procedures to reach its holding power.

Mark

This reminds me of the time Steve Dashew, yes, that Steve Dashew, anchored too close to me in Pago Pago back when he was sailing a Columbia 52, I think it was. He asked me if I minded. I said yes, and he moved. At least he knew better, and asked. Maybe we need a bumper sticker that says "I share the anchorage with clewless newbies."

[colemj]

Originally Posted by BigCat

Maybe we need a bumper sticker that says
"I share the anchorage with clewless newbies."

Given the type of rig you are putting on your new boat, it's too much temptation to not point out your unintentional misspelling "clewless"!

[BigCat]

Originally Posted by colemj

Given the type of rig you are putting on your new boat, it's too much temptation to not point out your unintentional misspelling "clewless"!

I'm American, but sometimes I spell things the English way, as I went to school in England for a while when I was a boy.