Why paddle gunboats suited the Yangtze Patrol

American gunboats operated deep into China's river system, where shallow draft and low-speed maneuverability mattered more than blue-water efficiency. Their machinery could be kept running by the crew with limited outside assistance, a major advantage when local repair capacity was expensive, uncertain, or unfamiliar with the equipment. USS Ashuelot's voyage hundreds of miles inland illustrates the reach expected of the patrol. The episode shows how a supposedly obsolete propulsion system could remain the practical choice for a distant naval-presence mission.