What was the primary improvement introduced by Mr. Hall's mid-19th-century anchor design?

Answer

Flukes that pivoted on a hinge allowing them to stow flat against the hull

Mr. Hall introduced an anchor where the flukes pivoted on a hinge connected to the shank, which was a major advantage for stowing the anchor flat against the hull when retrieved.

What was the primary improvement introduced by Mr. Hall's mid-19th-century anchor design?
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