They work by driving a vertical blade up and down, and cut by pulling upward.

It is 2.4 m in diameter, and made up of three vertical blades which rotate in the river's current, connected to a generator.

It wasn't a standing stone at all, but a long vertical blade of limestone formed by the elements.

This consists of vertical blades tearing into the soil and pulling out organic matter.

My nearly vertical blade, at the end of thrusting arms, met him in midair.

There it stood, a small box on the outside slope of a crater, somewhat tilted, the four broad vertical blades spinning merrily.

A face lift included a grille with 13 vertical blades set against a delicately cross-hatched rectangular opening.

The design is based on a flat disk with vertical flat blades vertically mounted.

By changing the orientation of the vertical blades, it could be made to function as a combined propeller and rudder.

Huge vertical blades bent to their task.