Paddlewheel

USS Cairo Paddlewheel

NPS Photo

USS Cairo's recessed paddlewheel is similar to the well-known stern wheel. It was placed within the raceway between the casemates to protect the wheel from enemy cannon fire. This paddlewheel propelled the gunboat at a speed of 6 knots (about 7 mph). The buckets, or paddles, were probably made of uniform-width wood and could easily be replaced when damaged.