For several years, I've been trying to get specific data on the Arkansas' engines. One of the officers aboard actually cites the street in Memphis where the machine shop that built both sets of engines for Arkansas and Tennessee resided. Has anyone ever determined whether her engines were low-pressure or geared high-pressure engines? There is another set of memoirs which states that the engines functioned reasonably well when the Chief Engineer, George City, was present. He became ill and was replaced with a volunteer Army engineer with no background with this type of power-plant installation. I don't know enough about steam engines to speculate why a given design would have a reputation for stopping top dead center. There is enough information to make a reasoned guess that her steering problem with only one screw turning lay in that her drive line did not incorporate what is known as a "dog clutch". This was a mechanical decoupling device widely used in auxiliary screw-driven ships with sails. It was very expensive and structurally difficult to incorporate a "lifting screw", so the dog-clutches allowed the propeller to "pin-wheel" while the vessel was under sail. Arkansas' design had no need for a sail rig or lifting screw, but a dog clutch was an obvious useful design configuration for a vessel of her type. I'm assuming that the engine company either didn't know how they worked, or there just wasn't time or materials to incorporate them on the drive shafts. We do know that they did not have fire-bricking as insulation for the boilers - this is one of the reasons that she was so hot in the machinery spaces. Finally, the machine shop in Memphis had apparently completed two sets of engines (for both ironclads). There is a report that the second set of engines was also taken up the Yazoo with the unfinished Arkansas. Later in the conflict, Cdr. I.N. Brown was building or converting additional ironclads at Yazoo city. One is usually called "the unnamed monster". A 300 ft long vessel with both paddle wheels and propellers. The Union navy had vessels of a similar configuration. I suspect that the second set of engines was intended to go into the big ironclad to supplement standard riverboat side-wheels. It would be interesting to know how this machinery was to be arranged. The screw machinery would go into the hold, but the side-wheel machinery less the boilers would probably have remained on deck a la riverboat.