Trim adjustment and loading
Trim has a significant influence on the resistance of the ship through water and of the effectiveness of the rudder and propeller. The trim of the ship is important both to carry the maximum amount of cargo safely and maximize the fuel efficiency of the ship. Optimized trim can give significant fuel savings and for any draft there is a trim condition which will give minimum resistance and increase the efficiency of the engine. Trim can be adjusted and improved by arranging bunkers, by positioning cargo or by varying the amount of ballast water but taking extra ballast more than needed can lead to an increased displacement and therefore increased fuel consumption. However, it may always not be possible to achieve optimum trim because of:
- Draft restrictions in a port
- Stability requirements
- Fully loaded condition
- Locations of fuel and ballast tanks as designed restricting their use for trim optimization
- Carriage of deck cargo and cargo safety (MariEMS 2017).