Anchor, Patent Model

Elisha Trask Barlow sought to improve how anchors grab the seabed. His design exploits the force of a vessel pulling on the anchor to, in the inventor's words, "induce an effort in the anchor to take hold." This is the model Barlow deposited at the Patent Office with his application in 1869.
Many nineteenth-century anchor designs featured pivoting flukes. Barlow's innovation was to link them to a sliding double shank. When strain is placed on the shackle at one end of the anchor, the uppermost part of the shackle is pulled forward, forcing the flukes to rotate down. As the anchor cable tries to drag the anchor forward, the downward pointing flukes are driven into the ground. "This arrangement of the parts of an anchor is most complete," Barlow said, "as the flukes are always governed by the strain on the cable, and [the anchor] can by no possibility become detached from its position when once it is set in the ground, unless a vertical strain should be brought to bear upon it, or the anchor should be turned over by the movements of the ship, in which case it will immediately take hold again."
Barlow, a machinist, lived in San Francisco, California.
Currently not on view
Date made
patent date
Barlow, Elisha Trask
Barlow, Elisha Trask
associated place
United States: California, San Francisco
Physical Description
nickel-plated iron (overall material)
overall: 5 1/2 in x 3 1/2 in x 1 1/2 in; 13.97 cm x 8.89 cm x 3.81 cm
ID Number
accession number
catalog number
patent number
Patent Models
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Work and Industry: Maritime
America on the Move
Data Source
National Museum of American History


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