(ScStr: t. 515; l. 170'; b. 25'; dph. 12'6"; dr. 7'6"; s. 12 k.; a. des. for 1 9" r., 1 8" r.)
Ajax and her sister, Hercules, were twin-screw, iron gunboats built under contract of 14 September 1864 with an old-line, Scottish yard, William Denny & Brothers, Dumbarton, for £17,500. "Designed as towboats to deceive Federal spies," they were the smaller pair ordered with Adventure (q.v.) and Enterprise, powered by "two pair of 120-horsepower collective" engines. Secretary of the Navy Mallory said they would "require insignificant alterations to convert them into serviceable gunboats for local work."—merely "fill up the space between the beams and add a few permanent stanchions under the permanent position of the guns."
Mallory wrote Commander Bulloch at Liverpool, 30 July 1864: "We require for the port of Wilmington two small steamers with low-pressure engines for service in and about the harbor. Their draft should not exceed…7 feet 6 inches, and it would be well if they could have at least 18 inches or 2 feet drag, so that they might be tipped by the head when they get ashore. With this light draft and pressure, two screws would be necessary to give them high speed.
"It is proposed to place upon them a single-pivot gun, weighing about 5 tons, on a circle, and the arrangements for quarters, etc., should be designed accordingly…[or] a pivot gun forward and aft…at least one large-shell gun, say a IX-inch pivot…They should be small, snug, strong, fast, and handy vessels for quick working with light crews…dimensions and details are left to your judgment. Four commission and six warrant officers would probably be required for each."
Bulloch reporting the contract signing to Mallory, 16 September, revealed: "They will be very strongly built, with heavy decks and beams, so as to carry a gun at each end, of from 5 to 6 tons weight, and the internal and deck arrangements will be such as to suit them for gun vessels, and yet not to excite suspicion. They will be designed for a speed of 12 knots on a draft of 7 feet 6 inches aft, but can be loaded to 8 feet 6 inches with safety as seagoing boats…one [Ajax]to be delivered on January 1, 1865, and the other [Hercules]6 weeks later."
A Briton, Captain Adams, was in command, representing "Mr. Denny, the ostensible owner," in order to hold Ajax' mercantile register, but Lt. John Low, CSN, went along as "supercargo" and actual commander, under orders to take over officially at Nassau. Ajax slipped out of the Clyde 12 January 1865 for the Bahamas via Madeira, but apparently the shadows of impending Confederate defeat deterred her; finis is written in Mallory to Bulloch, 1 March 1865: "A notice of the arrival of the Ajax at a port in Ireland has reached me through the United States papers, but no further advices as to her or the Hercules or other vessels have come to hand."