Got confused about propellers rotating directions? Spend 2 minutes understanding left hand and right hand rotation, also which direction does most ship propellers rotates.
Definition of Rotation Direction
When we talk about the direction of rotation of vessel propellers, we're referring to the direction in which the propeller rotates to push the vessel forward when viewed from the stern of the ship.
Propellers can be right-handed or left-handed. The shape of the propeller determines the direction in which it must rotate to propel the vessel forward.
Key Terms, What are left hand rotation and right hand rotation
When viewed from the stern of the vessel, there are two directions of propeller rotation that generate forward thrust.
| Definition | Description | Illustration |
| Left Hand (LH) | The propeller rotates counterclockwise (CCW) |  |
| Right Hand (RH) | The propeller rotates clockwise (CW) |  |
How's does it comply to my ship
Most ships are installed with 1 or 2 propellers, which in common cases the direction of rotation of propeller(s) are:
Single Shaft - Single Propeller Ships
- Usually used in most merchant ships, bulk carriers, tankers.
- Typically equipped with a right-hand (RH) propeller.
A rotating propeller crates slight sideways force. A RH propeller tends to push the stern left and the bow right when moving forward. This effect is usually corrected by the rudder, and RH propellers have become the industry standard.
Double Shaft - Port & Starboard Ships
- Usually used in passenger ships, ferries, warships, large yachts.
- Outward Rotation (standard setup)
The starboard propeller rotates right-hand (RH).
The port propeller rotates left-hand (LH).
However there are quite small chance that the twin shafting vessel is Inward Rotation, which means
The port propeller rotates right-hand (RH).
The starboard propeller rotates left-hand (LH).
