USS Tunxis (1864)

The first USS Tunxis was launched on 4 June 1864 at Chester, Pennsylvania, by Reaney, Son & Archbold; and commissioned at the Philadelphia Navy Yard on 12 July 1864. On 21 September 1864, the light-draft monitor departed the sheltered waters of the navy yard on her maiden voyage. However, she soon began taking on water at such an alarming rate that she came about and returned to Philadelphia where she was decommissioned later in the month.

Design revisions

Though the original designs for the Casco-class monitors were drawn by John Ericsson, the final revision was created by Chief Engineer Alban C. Stimers following Rear Admiral Samuel F. Du Pont's failed bombardment of Fort Sumter in 1863. By the time that the plans were put before the Monitor Board in New York City, Ericsson and Stimers had a poor relationship, and Chief of the Bureau of Construction and Repair John Lenthall had little connection to the board. This resulted in the plans being approved and 20 vessels ordered without serious scrutiny of the new design. $14 million US was allocated for the construction of these vessels. It was discovered that Stimers had failed to compensate for the armour his revisions added to the original plan and this resulted in excessive stress on the wooden hull frames and a freeboard of only 3 inches. Stimers was removed from the control of the project and Ericsson was called in to undo the damage. He was forced to raise the hulls of the monitors under construction by nearly two feet and the first few completed vessels had their turrets removed and a single pivot-mount 11 inch Dahlgren cannon mounted.