as the Rip Raps, on the far side of the channel opposite Fort Monroe, and on this island they completed another fort, named Fort Wool. With Fort Monroe went control of the lower Peninsula as far as Newport News. Forts Monroe and Wool gave the Union forces control of the entrance to Hampton Roads. The blockade, initiated on April 30, 1861, cut off Norfolk and Richmond from the sea almost completely. To further the blockade, the Union Navy stationed some of its most powerful warships in the roadstead. There, they were under the shelter of the shore-based guns of Fort Monroe and the batteries at Hampton and Newport News and out of the range of the guns at Sewell's Point and Craney Island. For most of the first year of the war, the Confederacy could do little to oppose or dislodge them. Birth of the ironclads When steam propulsion began to be applied to warships, naval constructors renewed their interest in armor for their vessels. Experiments had been tried with armor during the Crimean War (1853–1856), just prior to the American Civil War, and the British and French navies had each built armored ships and were planning to build others. In 1860 the French Navy commissioned , the world's first ocean-going ironclad warship. Great Britain followed a year later with , the world's first armor-plated iron-hulled warship. The use of armor remained controversial, however, and the United States Navy was generally reluctant to embrace the new technology. CSS Virginia When the Civil War broke out in 1861, Confederate Secretary of the Navy Stephen R. Mallory was an early enthusiast for the advantages of armor. As he looked upon it, the Confederacy could not match the industrial North in numbers of ships at sea, so they would have to compete by building vessels that individually outclassed those of the Union. Armor would provide the edge. Mallory gathered about himself a group of men who could put his vision into practice, among them John M. Brooke, John L. Porter, and William P. Williamson. When Mallory's men searched the South for factories that could build engines to drive the heavy ships that he wanted, they found no place to do it immediately. At the best facility, the Tredegar Iron Works in Richmond, building engines from scratch would take at least a year. Upon learning this, Williamson suggested taking the engines from the hulk