CSS Manassas CSS Manassas , formerly the steam icebreaker " Enoch Train " , was built in 1855 by James O . Curtis as a twin - screw towboat at Medford , Massachusetts . A New Orleans commission merchant , Captain John A . Stevenson , acquired her for use as a privateer after she was captured by another privateer ( later gunboat ) CSS Ivy . Her fitting out as " Manassas " was completed at Algiers , Louisiana ; her conversion to a ram of a radically modern design made her the first ironclad ship built for the Confederacy . Covered with 1 . 25 - inch iron plating , her above - water hull was reshaped into a curved " turtle - back " form ; at its highest when fully loaded , the hull projected only feet above the waterline , not counting her smokestack s ( surviving accounts and period illustrations vary showing " Manassas " was equipped with either a single or two side - by - side smokestacks , possibly slanted back at a rakish angle ) . The convex shape of her iron - plated topside caused cannon shot to glance off harmlessly . She was 128 feet in length , overall , and had a 26 - foot hull beam and 11 - foot draught . Her bow was fitted with a pointed iron ram to stave holes in Union vessels , and she also carried a forward - firing cannon behind a single gun port with an armored shutter . Her low profile made her a difficult target , while her armor protected her against all but the most well - directed Union cannon fire . Fast moving , lying low in the water , she looked like a floating cigar or submerged egg shell and was described by Union intelligence as a " hellish machine . " Commissioned as a Confederate privateer on 12 September 1861 , " Manassas was " seized soon afterwards by Flag Officer G . N . Hollins , CSN , for use in the lower Mississippi River . With Lieutenant A . F . Warley , CSN , in command , she participated in Flag Officer Hollins ' surprise attack on the Federal blockading squadron at Head of Passes on 12 October 1861 , the action being known as the Battle of the Head of Passes . In the action " Manassas " rammed USS " Richmond " , but the impact was partly absorbed by a coal barge tied alongside . " Manassas " , however , suffered the loss of her iron prow and smokestack ( s ) and had one of her two engines unseated from its mounts , temporarily putting it out of commission . She managed to retire under heavy fire from USS " Preble " and " Richmond " , whose shells glanced off her armor . Two months after this engagement , " Manassas " was purchased for direct ownership and re - commissioned in the CSN by the Confederate Government . Under Lieutenant Warley , CSS " Manassas " joined the force of Captain John K . Mitchell , CSN , commanding Confederate naval forces in the lower Mississippi . She participated in the Battle of Forts Jackson and St . Philip , during which Commodore David Farragut , USN , on his way to New Orleans , ran his fleet past the Confederate forts of Fort Jackson and Fort St . Philip . In the action " Manassas " attempted to ram USS " Pensacola " , which turned in time to avoid the heavy blow and delivered a full broadside at close range . " Manassas " then ran into more murderous fire from the whole line of the Union fleet . She then charged USS " Mississippi " and delivered a long glancing blow to her hull , also firing her single cannon as she rammed . Next she rammed USS " Brooklyn " , again firing her cannon , injuring her deeply , but not fatally . After this action " Manassas " followed the Union fleet quietly for a while , but as she drew closer " Mississippi " furiously turned on her . " Manassas " managed to dodge the blow but ran aground in the process . Her crew managed to escape as " Mississippi " poured heavy broadsides into the stranded Confederate ram . Now on fire , " Manassas " slipped off the bank and drifted down the river past the Union mortar flotilla . Commander David Dixon Porter , USN , in command of the mortar boats , tried to save her as an engineering curiosity , but " Manassas " exploded and immediately plunged under water , a total loss . Years after the war , in the book " Battles and Leaders of the Civil War , " there was a claim that a " Manassas " crewman was knocked off the ironclad by a Union sailor ; however Confederate Captain Lt . A . F . Warley reported no casualties among his " Manassas " crew in an official report dated 13 August 1863