The Arbemarle sinking
The Confederate Navys' CSS Albemarle was a steam-powered ironclad ram, designed with sloped sides to deflect incoming shot and powered by two steam engines of 200hp driving twin 3-blade propellors. In additon to the ram CSS Albermarle carried two 6.4in rifled cannon placed in armoured casemates, one forward one aft on the hull centreline, each having a 180 degree field of fire. The guns could fire explosive, anti-personnel (grape or canister shot) or solid 'bolts', a blunt-nosed shot intended to cause more damage to armoured targets than round shot fired by smooth bore cannon.
Commissioned in April 1864 the Albermarle succeeded in breaking the Union blockade of the Roanoke river. Protected from fire from Union held forts and Union ships forming the blockade CSS Albermarle succeeded in sinking by ramming the USS Southfield, a side wheel paddlesteamer and forced the USS Miami to withdraw from the Albermarle sound.
The Albermarle successfully controlled the Roanoke through the summer of 1864, driving off attacks by theorectically superior Union naval forces without serious damage to her ironclad hull. By the autumn the ironcald became the focus of Union navy planning and plans for dealign with the vessel were submitted by Lt. William Cushing to use small steam launches to approach the ironcald and attack with spar torpedoes. Two 30-foot picket boats under construction were selected, each being fitted out with a 12-pounder howitzer and a 14-foot spar torpedo which could be rigged to project from the bow.
One of the two picket boats having been lost on passage to Norfolk Lt Cushing set out on the night of October 27/8th 1864 to work their way upriver under cover of darkness. They were spotted approaching the Confederate held docks and came under small arms fire from shore and the Albermarle, but succeeded in pushing the small picket boat over the protective log booms and placing the torpedo charge against the Albermarles' hull.
Detonation of the charge blew a hole in the Albermarles' hull at the waterline, causing her to sink quickly in the 6-feet of water below her keel, leaving the casemates clear of the water, the guns being slavaged by Confederate forces and used later to defend Plymouth from Union attacks.
The Albermarle was raised by Union naval forces after the fall of Plymouth and the hull temporarily patched for towing to the navy yard at Norfolk. Although repairs to her hull with a view to commissioing the vessel in the US Navy were completed the Albermarle was condemned by the Washington DC prize court and saw no further military service before scrapping in 1867.