The three iron-clads under Tucker's command at Charleston were all slow vessels, with imperfect engines, which required frequent repairing; for that day, and considering the paucity of naval resources in the South, they were fairly officered, manned and armed. All of them were clad with armor four inches thick, and they were all of the type of the _Virginia_, or _Merrimac_, as that vessel is frequently but erroneously called. The commander of the vessels were all formerly officers of the United States Navy, who were citizens of the Southern States and had resigned their commissions in the Federal service when their States seceded from the Union. The lieutenants and other officers were appointed from civil life, but they were competent to perform the duties required of them, and conducted themselves well at all times and under all circumstances. The crews of each vessel numbered from one hundred and twenty to one hundred and sixty men, some of them able-seamen, and most of them efficient and reliable men. Each vessel carried a torpedo, fitted to the end of a spar some fifteen or twenty feet long projecting from the bows in a line with the keel, and so arranged that it could be carried either triced up clear of the water or submerged five or six feet below the surface. The squadron was in a good state of discipline and drill, and, so far as the personnel was concerned, in a very efficient condition. Every night one or two of the iron-clads anchored in the channel near Fort Sumter for the purpose of resisting a night attack on that place or a dash into the harbor by the Federal squadron. Not long before the evacuation of Charleston an iron-clad named the _Columbia_ was launched there. She had a thickness of six inches of iron on her casemate, and was otherwise superior to the other three iron-clads of the squadron. Unfortunately, she was run aground whilst coming out of dock, and so much injured as not to be able to render any service whatever.