Advantages of Inclined-Axis Hydroelectric Units

The Corps of Engineers selected a relatively new type of low-head hydroelectric unit for installation at three multi-purpose projects now under construction. These units are known variously as inclined-axis, slant-axis and tube units. Unit blocks widths are 25% to 30% less with these units than with conventional vertical propeller units and therefore, a cost savings on the order of 10% to 15% can be realized. The units are similar in cost an in some other respects to bulb units but have the technical advantage of using conventionally designed generators operating outside the water passage. At two of the plants the units are planned for generation only while at the other plant they are to be reversible for pumped storage operation. The latter plant is part of the Kaysinger Bluff Project on the Osage River in Missouri. The other units are being installed at the Ozark and Webbers Falls Projects on the Arkansas River.