Situation 1
- The ship is anchored
- She will cover 0 nm in one hour. SOG = 0Kn.
- But Log will show 3 knots on the indicator STW = 3Kn
Situation 2
- ship is steering 000°, at extreme full ahead which gives 12 knots in still water. (Called Engine Speed)
- She will cover (12 – 3) = 9 nm on ground in one hour. SOG = 9Kn
- Log will show 12 Knots. STW = 12 Kn
Situation 3
- Ship is steering 180°, at extreme full ahead which gives 12 knots in still water. (Called Engine Speed)
- She will cover (12+3) = 15 nm on ground in one hour SOG=15Kn
- Log will show 12 Knots. STW = 12 Kn
What is Engine Speed?
Engine speeds at various state of engines (Slow Ahead, Half Ahead, Full Ahead or Extreme Full Ahead) are measured by the shipyard under controlled conditions in still water. This data is available on the Bridge