Introduction to the keel waterwheel: The keel waterwheel is a machine used for drainage and irrigation. It is named because its main shape is like a keel. It is also called "roller", "treadmill" and "waterwheel". The waterwheel uses a wooden back as a trough, and the tail is immersed in the water flow. There is a small axle at one end; there is a small axle at the other end, which is fixed on the wooden frame of the embankment. When used, step on the crutch to rotate the large axle, driving the blades in the trough to scrape the water up and pour it into the fields with higher terrain. With the widespread use of agricultural water pumps, keel waterwheels have completed their mission and quietly withdrawn from the stage of history.