CSS David with spar torpedo
Drawings of the CSS David, a 50-foot steam torpedo boat of "cigar-shaped" hull design. The top drawing shows the ship's spar torpedo, a bomb placed at the end of a spar (a long pole). The ship would run the spar into an enemy vessel, leaving the explosive in place. When the attacking ship backed off, the bomb would trail a long detonator cord, and when the end of the cord was reached, the bomb would detonate.
Public Domain
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