[Type Plans of U.S. Navy Coast Defense Vessels]

The floating fortresses of W.E. Endicott’s proposed coast defense system in the late 1880s.

This fascinating set of ship diagrams shows a series of proposed steel-hulled coastal defense vessels, ranging in size from 300 tons to 7,000 tons. The heaviest vessels featured at least one swiveling turret with a pair of large (8″+) diameter cannons, supplemented by numerous smaller caliber weapons. The interiors, undoubtedly cramped for the crew, outline the location of the steam engine, twin screws, anchor chain, etc.

The plans were designed by the Board of Fortifications under the Secretary of War W.E. Endicott and originally published as part of an 1887 Congressional report. Endicott realized that America’s harbor defenses had become badly obsolete compared with modern European armored warships and heavy rifled artillery. In lieu of emplaced fortifications, a series of floating armored forts were recommended for construction. Their shallow draft allowed them to navigate the coastal waterways and effectively protect the shores. However, the ideas of Captain Alfred Thayer Mahan were gaining traction, and the acquisition of numerous overseas territories following the Spanish-American War led the Navy to shift its efforts toward the construction of ocean-going warships.