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FROM-- SET FIVE, CIVIL WAR STUDIES
The Navy and Ironclads in the Civil War
HOW THEY WERE BUILT, THE PROBLEMS IN SUCH A QUI0CK DEADLINE, FIGHTING NEGATIVE OPINIONS
USS Merrimack becomes CSS Virginia
Preliminary sketch designs by Lieutenants John Mercer Brooke and John L. Porter
U.S.S. MERRIMACK SCUTTLED BY UNION TROOPS
When the Commonwealth of Virginia seceded from the Union in 1861, one of the important federal military bases threatened was Gosport Navy Yard (now Norfolk Naval Shipyard) in Portsmouth, Virginia. Accordingly, the order was sent to destroy the base rather than allow it to fall into Confederate hands.
USS Merrimack burning at Gosport Navy Yard, April 20, 1861
On the afternoon of 17 April, the day Virginia seceded, Engineer in Chief B. F. Isherwood managed to get the frigate's engines lit; but the previous night secessionists had sunk lightboats between Craney Island and Sewell's Point, blocking the channel. On 20 April, before evacuating the Navy Yard, the U. S. Navy burned Merrimack to the waterline and sank her to preclude capture.
MERRIMACK FOUND TO BE USABLE AND CONVERTIBLE
When the Confederate government took possession of the fully provisioned yard, the base's new commander, Flag Officer French Forrest, contracted on May 18 to salvage the wreck of the frigate. This was completed by May 30, and she was towed into the shipyard's only graving dock, (today known as Drydock Number One), where the burned structures were removed.
The wreck was surveyed and her lower hull and machinery were discovered to be undamaged, so Merrimack was selected for conversion into an ironclad by Stephen Mallory, Secretary of the Confederate Navy, as she was the only large ship with intact engines available to the Confederacy in the Chesapeake Bay area.
C.S.S. VIRGINIA DESIGNED AS AN IRONCLAD
Preliminary sketch designs were submitted by Lieutenants John Mercer Brooke and John L. Porter, each of whom envisaged the ship as a casemate ironclad. Brooke's general design showed the bow and stern portions submerged, and his design was the one finally selected; the detailed design work would be completed by Porter, as he was a trained naval constructor. Porter had overall responsibility for the conversion, but Brooke was responsible for her iron plate and heavy ordnance, while William P. Williamson, Chief Engineer of the Navy, was responsible for the ship's machinery.
RECONSTRUCTION AS AN IRONCLAD (HOW)
Cut away view showing the 4 inches of iron armor and 24 inches of wood backing it.
The hull's burned timbers were cut down past the vessel's original waterline, with just enough clearance to accommodate her large, twin-bladed screw propeller; a new fantail and armored casemate were built atop a new main deck, and a v-shaped cutwater was added to her bow, which attached to the armored casemate. This forward and aft main deck and fantail were designed to stay submerged and were covered in 4-inch-thick iron plate, built up in two layers. The casemate was built up of 24 inches of oak and pine in several layers, topped with two 2-inch layers of iron plating oriented perpendicular to each other, and angled at 36 degrees from horizontal to deflect fired enemy shells.
VIRGINIA BECOMES A RAM-- PREPARED TO FACE THE NEW UNION IRONCLAD
From reports in Northern newspapers, Virginia 's designers were aware of the Union plans to build an ironclad and assumed their similar ordinance would be unable to do much serious harm to such an armored ship. So the decision was made to equip their ironclad with a ram, an anachronism on a 19th century warship. Merrimack's steam engines, now part of Virginia, were in poor working order; they had been slated for replacement when the decision was made to abandon the Norfolk naval yard. The salty Elizabeth River water and the addition of tons of iron armor and pig iron ballast (added to the hull's unused spaces to submerge her eves) only added to her engines' propulsion problems.
C.S.S. VIRGINIA MANEUVERABILITY LIMITED
As completed, Virginia had a turning radius of about 1 mile and required 45 minutes to complete a full circle, which would later prove to be a major handicap in battle with the far more nimble Monitor.
The ironclad's casemate had 14 gun ports, three each in the bow and stern, one firing directly along the ship's centerline, the two others angled at 45° from the center line; these six bow and stern gun ports had exterior iron shutters installed to protect their cannon. There were four gun ports on each broadside; their protective iron shutters remained uninstalled during both days of the Battle of Hampton Roads. Virginia 's battery consisted of four muzzle-loading single-banded Brooke rifles and six smoothbore 9-inch Dahlgren guns salvaged from the old Merrimack.
Two of the rifles, the bow and stern pivot guns, were 7-inch caliber and weighed 14,500 pounds each. They fired a 104-pound shell. The other two were 6.4-inch cannon of about 9,100 pounds, one on each broadside. The 9-inch Dahlgrens were mounted three to a side; each weighed approximately 9,200 pounds and could fire a 72.5-pound shell up to a range of 3,357 yards at an elevation of 15°.The two amidship Dahlgrens nearest the boiler furnaces were fitted-out to fire heated shot. On her upper casemate deck were positioned two anti-boarding/personnel 12-pounder Howitzers.
VIRGINIA COMMANDING OFFICER APPOINTED BEFORE FIRST SORTIE
Virginia 's commanding officer, Flag Officer Franklin Buchanan, arrived to take command only a few days before her first sortie; the ironclad was placed in commission and equipped by her executive officer, Lieutenant Catesby ap Roger Jones.
The battle at Hampton Roads, that would ensue is covered in the great battles section of the Navy Learning Site.