Kalamazoo - class monitor The " Kalamazoo " - class monitors were a class of ocean - going ironclad monitors begun during the American Civil War . Unfinished by the end of the war , their construction was suspended in November 1865 and the unseasoned wood of their hulls rotted while they were still on the building stocks . If the four ships had been finished they would have been the most seaworthy monitors in the US Navy . One was scrapped in 1874 while the other three were disposed of a decade later . Design and description . John Lenthall , Chief of the Bureau of Construction and Repair , ordered Benjamin F . Delano , naval constructor at New York City , to design a wooden - hulled ironclad that would carry her armament in two gun turrets . The deck was to be above the waterline and protected by of armor . The ship ' s side armor was to be thick , backed by of wood ; it was to cover the entire ship ' s side , down to a depth three feet below the waterline . It should carry enough coal to steam one week at full power with " sufficient speed to make good use of its ram " . Gideon Welles , Secretary of the Navy , called them enlarged versions of the s with greater speed and " adapted to coast service " , meaning more seaworthy . The " Kalamazoo " - class ships were long overall and had a length between perpendiculars of . They had a beam of and a draft of . The ships were designed to displace and were 3 , 200 tons burthen . They were the largest ships to be built in navy shipyards to date . Their unseasoned wooden hulls were massively reinforced by iron straps as well as iron stanchions to bear the enormous weight of their armor and guns . They retained the typical monitor overhang introduced by John Ericsson , designer of the , where the upper part of the hull was wider than the lower part of the hull . The " Kalamazoo " s wrought iron side armor consisted of two layers of three - inch plates , backed by 21 inches of wood , six feet in height . The outer layer of armor extended further below the waterline . The three - inch deck armor rested on of wood and was covered in another three inches of wood . They were powered by two 2 - cylinder horizontal direct - acting steam engines , each driving one propellers , using steam generated by eight tubular boilers . The engines were rated at and designed to reach a top speed of . They had a bore of and a stroke of . Two large funnels were positioned between the turrets to handle the combustion gases from the boilers . The " Kalamazoo " s were intended to carry of coal . The ships ' main armament consisted of four smoothbore , muzzle - loading , Dahlgren gun s mounted in two twin - gun turrets . Each gun weighed approximately . They could fire a shell up to a range of at an elevation of + 7° . The turrets were protected by 15 inches of armor . Construction and fate . Construction of the ships began between late 1863 and early 1864 and they were still being built when the war ended in early 1865 . Construction was suspended on all four on 17 November 1865 ; they remained on the stocks . The ships were renamed , usually twice , in 1869 to conform to several new ship naming conventions . Vice Admiral David D . Porter ordered that " Colossus " be rebuilt to carry 10 large broadside guns and fitted with iron masts in a ship rig , but this never happened . The unseasoned wood in their hulls quickly began to rot after construction was suspended and they were broken up beginning in 1874 . Unusually , " Passaconaway " was condemned by an Act of Congress on 5 August 1882 before she was finally broken up in 1884 .