Though thus powerfully built, armored, and armed, the Tennessee must have been a very exasperating vessel to her commander. She had two grave defects; the first, perhaps unavoidable from the slender resources of the Confederacy, was lack of speed. Her engines were not built for her, but taken from a high-pressure river steamboat, and though on her trial trip she realized about eight knots, six seems to be all that could usually be got from her. She was driven by a screw, the shaft being connected by gearing with the engines. The other defect was an oversight, yet a culpable one; her steering chains, instead of being led under her armored deck, were over it, exposed to an enemy's fire. She was therefore a ram that could only by a favorable chance overtake her prey, and was likely at any moment to lose the power of directing her thrust. Such as she was the Tennessee was ready for service early in March, 1864, when Commander J.D. Johnston was ordered as her captain. She was taken from the city, through one of the arms of the Alabama, to the mud flats which reach to a point twenty miles down the bay, and are called Dog River Bar. The least depth of water to be traversed was nine feet, but throughout the whole distance the fourteen feet necessary to float the vessel could not be counted upon. She was carried over on camels, which are large floats made to fit the hull below the water line, and fastened to it, on either side, by heavy chains passing around them and under the keel, while the camels are filled with water. When the water was pumped out the buoyancy of the camels lifted the ram five feet, reducing her draught enough to let her go over the bar. Two months were taken up in building and placing the camels, during all which time Farragut was begging either for ironclads or for co-operation by the land forces, in reducing the forts. In either case he was willing to enter the bay, but he did not like to run the risk of getting inside with his wooden ships crippled, the forts intact in his rear, and the enemy's ironclads to contend with as well. Neither assistance was given, and he was therefore compelled to look on while the Tennessee was moved from a position in which she could do no harm to one in which she became the principal menace to the attacking fleet. On the 18th of May she was finally towed across and anchored in the lower bay six miles from the entrance. That night the camels were removed, steam raised, and everything made ready to cross the outer bar and attack the fleet; but when the anchor was weighed the ship was found to be hard aground. The intended attack was given up, and when the tide rose enough to float her, she was moved down to Fort Morgan, near which she remained from that time.