FF,
The US Navy included a 90 lb Danforth H-3600 model in their 1989 test, along with the 47 lb Fortress FX-85, and these anchors are almost identical in physical size.
The sea bottom was sand/clay, and the Danforth held to 9,000 lbs and under "Reason for Test Termination," the US Navy noted: "Anchor Pulled Out - Structural Damage"
The FX-85 held to 10,200+ lbs, and under "Reason for Test Termination," they noted, "Test Stop, Anchor Held - Shank Bent on Retrieval"
Two other Danforth models were tested, the T-6000 and T-7000 of the "Deepset II" model series, and they also pulled out during their tests due to structural failure.
The Fortress models FX-55 and FX-125 were tested as well. In the same sand/clay bottom, the smaller 32 lb FX-55 pulled out at 8,800 lbs in the first test, and in a second test, it held to 10,600 lbs when they stopped the test. The 69 lb FX-125 held to 14,600 lbs when they stopped the test due to the engines overheating aboard the testing vessel.
Afterwards, the US Navy wrote this in their summary report:
"The fact that the Fortress anchors incurred no significant structural damage at such high holding ratios suggest that the anchors have been extensively engineered from both the hydrodynamic and structural standpoints."
And also:
"Under anticipated loading conditions, NAV-X (corporate name) has compensated for aluminum's susceptibility to deformations through careful structural design of their anchors."
Regards,
Brian