A rotating blade for a steam turbine includes a root section and an airfoil section contiguous with the root section. The airfoil section is shaped to optimize aerodynamic performance while providing optimized flow distribution and minimal centrifugal and bending stresses. The blade also includes a tip section continuous with the airfoil section, and a cover formed as part of the tip section. The cover defines a radial seal that serves to minimize tip losses. The rotating blade is capable of running at operating speeds between 5626 and 11250 rotations per minute.