The James Eads design for a riverine ironclad was called the City Class because they were all named after Federal river cities. Displacing 888 tons, mounting thirteen guns, and armored with 2 ½-inches of armor on the casemate and 1 ½-inches on the pilot house, these gunboats were distinguished by their very long casemate ending in an armored turtle back hump, which protected the centerline paddle wheel. The casemates were much wider than the common Confederate casemate design. The seven Eads ironclads became the heart and soul of the Union naval effort on the rivers of the western Confederacy. No blue water Union warship ever experienced even a quarter of the action into which these ironclads became involved. Eads set up two yards to produce his design. Hambleton, Collier & Company of Mound City , Illinois was to build three ironclads, USS Cairo, Cincinnati and Mound City , and Carondelet Marine Railway & Dry Dock Company of Carondelet , Missouri would build four, Carondelet, St. Louis , Pittsburgh and Louisville . Leodegar Berger has a 1:1250 scale model, USS Carondelet, of this very important and busy class of ironclad.