USRC Naugatuck - A Working "proof of Concept" Vessel

A Working "proof of Concept" Vessel

To demonstrate the practicality of the plan of the "Stevens Battery", the Stevens brothers bought, modified and fitted out at their own expense a small prototype. The iron steamer — originally named Naugatuck — was built in 1844 by H.R. Dunham & Company, a New York City locomotive builder, for the Ansonia Copper and Brass Company. During the 1850s, Naugatuck ran between New London and New York.

In 1861, Stevens bought Naugatuck as a test-bed for innovations intended for the Stevens Battery, still unfinished in the shipyard. During 1861 and early 1862, Stevens reinforced the deck to support one 100-pound Parrott gun amidships trained forward, later augmented with two 12-pounder howitzers. Stevens replaced the original engine with a twin propeller arrangement, driven by two inclined engines with one boiler . He also added interior ballast tanks fore and aft. The New York Times reported on March 22, 1862, that “The Naugatuck is not intended to be a model of Mr. Stevens’ iron-clad battery, but is designed to illustrate one or two novel ideas connected with that monstrous engine of war, viz: The ability to sink and raise a vessel with great rapidity; to turn and manage her by means of two propellers located one on each side of the stern; also, taking up the recoil of the gun by means of India-rubber.”

Stevens renamed the vessel after himself. Many contemporary newspapers and later historians mistakenly confused the E.A. Stevens with the Stevens Battery. Edwin Stevens designed the gunboat to operate in shallow waters. The iron hull's ballast tanks were placed at the fore and aft extremes of the hull, and utilized a patented gum rubber liner to ensure a watertight seal. These ballast tanks were used to make the vessel semi-submersible, allowing the hull to change its draft from 7 feet 8 inches (2.3 m) to 9 feet 10 inches (3.0 m). The 2-foot (0.6 m) reduced freeboard minimized the vessel’s vulnerability to gunfire, keeping the steam machinery below the waterline. Stevens added heavy duty centrifugal pumps that could fill ballast in minutes or, if the boat grounded while ballasted down, pump out to refloat the vessel quickly. With the ballast tanks dry, the vessel's speed increased from 4 knots (7.4 km/h; 4.6 mph) to over 9 knots (17 km/h; 10 mph).

While its hull boasted all-iron construction, its only armor consisted of a low-lying angled armor band or skirt surrounding the main deck. This band covered a wooden bulwark built of solid cedar, which rose 18 in (46 cm) above the deck and measured 4.5 feet (1.4 m) in depth. The bulwark surrounded the deck, keeping water off it and providing slight cover from enemy fire while ballasted down.

At the onset of the Civil War, Stevens offered to donate his gunboat to the Navy, but officials refused the gift, explaining that the untried prototype was not suitable for Navy missions. Stevens then donated her to the U.S. Revenue Cutter Service, providing them with their first ironclad gunboat. E.A. Stevens was stationed as one of the cutters patrolling the Varrazano Narrows entrance to New York harbor.