Renamed Ajax Monitor
The ships of the Canonicus-class were the first to incorporate the lessons of combat experience gained during the Monitor-Virginia clash and the attacks on Charleston as well as the practical ones gained from day-to-day experience with what was virtually an entirely new approach to warship design. Although their outward appearance was very similar to the Passaic-class, the single-turreted monitors of the Canonicus-class represented a major design advance. A protective glacis 5 inches thick and 15 inches high was placed around the base of the turret to prevent the turret from being jammed by a chance hit at its base; side armor was strengthened by the addition of a 4-inch stringer; deadwood aft was cut away in an effort to make the propeller more efficient; and ventilation was improved by the installation of more powerful blowers and a tall permanent vent from the head and galley. Perhaps more significantly, armament was increased to two 15-inch Dahlgren smoothbores from the one 15-inch and one 11-inch of the Passaic-class. The contracts for the Canonicus-class were let in September-October 1863; the first launching, of Canonicus, took place on 1 August 1863 and the last, Mahopac, on 17 May 1864. The contract price for each ship of the class was $460,000.
After the contract for construction of Manayunk was signed by agents of the Navy and the shipbuilding firm of Snowden and Mason on 15 September 1862, and the keel of this Canonicus-class monitor was laid down shortly thereafter at Pittsburgh, Pennsylvania. The ship was ready to be launched in April 1864, but the very low level of the Ohio River delayed her entry into water. She finally slid down the ways on 18 December 1864; but, by that time, most of the naval phase of the Civil War had ended. Therefore, the ship's fitting out was halted before she received her two 15-inch Dahlgren smoothbore guns. She was towed to the naval station at Mound City, Illinois., and laid up until 1867 when she was towed down the Mississippi and again laid up, this time at New Orleans. While there, Manayunk was renamed Ajax on 15 June 1867.
Commissioned on 1 January 1871, Lt. Comdr. Charles Love Franklin in command, the monitor was made seaworthy and moved to Key West, Florida. She operated out of that base on coast defense maneuvers with the North Atlantic Squadron until decommissioned on 1 July 1871 and laid up at the Philadelphia Navy Yard.
Following extensive repairs there, Ajax was recommissioned on 13 January 1874, Comdr. Joseph N. Miller in command, and returned to Key West, her base for further operations with the North Atlantic Squadron until again inactivated on 27 July 1875 and laid up at Port Royal, South Carolina. Recommissioned on 5 November 1875, the ship remained at Port Royal until moved to the James River. In ensuing years, she was moored at Brandon and at City Point, Virginia, before being placed in ordinary at Richmond on 30 June 1891.
On 26 September 1895, Ajax was transferred on loan to the New Jersey Naval Militia and moored at Camden. During the Spanish-American War, the monitor was returned to the Navy and recommissioned on 9 July 1898 for service at Baltimore as a guard ship under the auspices of the Auxiliary Naval Force. However, the rapid American success in that conflict obviated such defensive measures; and the ship was decommissioned on 1 September 1898 before work to make her battle worthy had been completed.
Ajax was sold at the Philadelphia Navy Yard on 10 October 1899.
Displacement, 2,100 tons; Length, 225'; Beam, 43'8'; Depth of hold, 13'4"; Draft 12'6"; Speed, 5. 5 knots; Complement, 85; Armament, none
Bibliography James L. Mooney, Dictionary of American Naval Fighting Ships, (Washington, D.C.: U.S. Government Printing Office, 1991), Vol.1 -- Part A, p. 100