How Propellers Work? What are Propeller Thrusts?

AXIAL THRUST

• The fore and aft thrust, is a force which causes a ship to move ahead or astern through the water. It is most efficient when the ship is moving ahead.
• [Full Astern Axial Thrust = Half ahead Axial Thrust]
• The stopping distance of a ship depends upon axial thrust

TRANSVERSE THRUST/ SCREW`S EFFECT

• Sideways thrust of the propeller blades as they rotate which produce turning effect
• The upper blades meet less resistance because it is near the water surface and lower blades experience greater reaction to motion of propeller. The upper blade can’t easily cancel out the opposite effect of the lower blades.