_U.S.S._ Cairo _Type and class: Ironclad River Gunboat, City Class_ _Length: 175 ft._ _Breadth: 51 ft. 2 in._ _Full load keel draft: 6 ft._ _Tonnage: 512_ _Number of keels: 3_ _Armament: 3 4-pounder Army rifles, 3 64-pounder Navy smoothbores, 6 32-pounder Navy smoothbores, and 1 30-pounder Parrott_ _Bow ports: 3_ _Side ports: 4 each side_ _Stern ports: 2_ _Paint Colors: Black exterior, whitewashed interior, colored bands for identification on chimneys._ [Illustration: _Deck Plan of the_ Cairo (_scale ¼″ : 4′_)] _2½″ × 13″ iron plates_ _42-pounder Army rifles (port and starboard)_ _Galley_ _Three 8″ Navy smoothbores (forward ports)_ _1¼″ plating_ _Wood_ _32-pounder Navy smoothbores (port and starboard)_ _Officers’ quarters_ _Captain’s cabin_ _2½″ plating_ _Wood_ _32-pounder Navy smoothbores_ _Thickness of plate armor: 2½ in._ _Total weight of plate armor: 122 tons_ _Plate armor material: Charcoal iron_ _Wood backing for armor on three front panels of pilothouse: 19½ in._ _Wood backing for armor on five side and back panels of pilothouse: 12 in._ _Thickness of casemate timbers and sheathing: 26 in._ _Location of plate armor: Casemate front and casement sides abreast machinery_ [Illustration: _Bow of the_ Cairo (_scale 1/4″ : 4′_)] _Hammock berthing_ _Hammock berthing_ _Fireroom_ _Forward end of boilers_ _2½″ × 13″ iron plates_ _32-pounder Navy smoothbores (port and starboard)_ _Load waterline_ _Number and type of engines: Two reciprocating steam-non-condensing_ _Number of boilers: 5_ _Fuel: Coal_ _Fuel consumption per hour: 18 to 20 bu. (1,980 lb.)_ _Crew: 17 officers, 27 petty officers, 111 seamen, 3 landsmen, 1 apprentice, 12 firemen, and 4 coal heavers_ On April 1 the _Cairo_, with the gunboats _Lexington_ and _Tyler_, accompanied Brig. Gen. William T. Sherman’s command on an expedition against the Confederate batteries at Eastport, Miss., and Chickasaw, Ala. At Eastport, guns were run out and a few rounds fired, but there was no reply. The Confederates had fled. Chickasaw also was found deserted. Although the expedition proved disappointing, it did give the men on the _Cairo_ their first chance, except in practice, to exercise their guns. Upon her return from Eastport and Chickasaw, the _Cairo_ received orders to move to the Cairo Naval Station and defend it against a threatened Confederate attack. Foote had learned that the South had completed 13 gunboats at New Orleans, and he feared these would be joined with the ram _Manassas_ and run up the Mississippi against the Union fleet and bases. The _Cairo_ arrived at the naval station on April 5. The following day the Shiloh campaign opened, giving her crew new cause to complain about their inability to take part in battle action.