Re: Let's talk about anchors some more
Thanks for your post. We have been in business now for 25 years, during which we have manufactured our product at the exact same facility in Fort Lauderdale, Florida....and being that Fortress anchors are made from an aluminum-alloy, there are still ongoing concerns as to their strength and performance, and we always welcome the opportunity to address those concerns.
The Danforth anchor, particularly the Deepset II and Hi-Tensile versions, are excellent products and they have enjoyed a loyal following among boaters for decades. This anchor type is certainly one of the most copied throughout the world.
Fortress anchors are obviously "Danforth fluke-type anchors", but the key difference is that they are precision-machined from aluminum-alloy extrusions, the result of which is a much sharper anchor that is better able to penetrate a sea bottom faster and deeper than a heavier, dull-edged steel version.
The sharper Fortress ike a razor slicing through a surface and thus is capable of burying very deeply into a sea bottom, and with the massive surface area of its two flukes, a Fortress is difficult to pull out once it does.
And that is the "secret", if there is one, to the Fortress anchor's legendary holding power performance, in which it has held to over 300x its weight in anchor tests. Examples would be the Miami test, in which a 65 lb Fortress held to 20,000 lbs until the rope broke, and then in a more recent French test, where a 7.1 kg Fortress held to over 2,500 kg.
"Real world" test examples would include when a 22 lb Fortress FX-37 held a 42 ft Silverton in 140+ knot winds during Hurricane Andrew (pictured below with lady holding it).
Additionally, Fortress anchors are tapered and thickened at critical stress points to ensure that they are able to disperse and handle loads more efficiently. Proof of this was evidenced by the extensive US Navy anchor tests that were conducted years ago.
All of the steel Danforth Hi-Tensile anchors were completely destroyed in this test, and there was some surprise to this result, as it was noted in the report that the high grade of steel used in the Danforth anchors was much stronger than the aluminum alloy used by Fortress, which was cause for this analysis in the final US Navy test report summary:
"The fact that the Fortress anchors incurred no significant structural damage at such high holding ratios suggests that the anchors have been extensively engineered from both the hydrodynamic and structural standpoints."
Finally, the stock (narrow round rod) is grooved and the flukes snugly fit into this groove, and the metal clips (you called the "straps' ) simply hold the flukes in place on the stock. Once the bolts on the clips are tightened, all of the anchor parts are secure.
I have attached other images and I hope this information is helpful!
Fortress Marine Anchors
Last edited by BrianFortress; 08-04-2012 at 06:13 AM.