Ship powering or powering calculation is the calculation of total power required to propel a ship. This helps to decide rest of the vital things like propulsion plant, the amount of fuel storage required and the refinement of ship’s centre of gravity.
Powering is explained with the facts based on resistance and propulsion. When the ships move forward it is sure to experience resistance or a force against its forward movement which varies according to the speed, size, shape and state of hull and various parts of the ship.
Ship Powering Tests
Ship Powering includes various tests regarding self propulsion and resistance taking the dimensions of displacement hulls, barges etc both in deep and shallow water helping to track out the full scale powering performance and speed. Flow measurements and visualization is also done through the analysis of streamline flow, position of bilge keels, flow of stern, pressure in the hull, the wave patterns, propeller movements and vibrations and finally the analysis of other objects affecting the moving ships. It follows a line of procedure before confirming the ship resistance and powering as it also considers various other factors like Brake Horsepower (BHP), the power used by ship’s prime mover which turns heat energy into rotational energy, Shaft Horsepower (SHP) which is the power out of reduction gears that controls the movement of prime mover, Delivered Horsepower (DHP), the power on the propeller delivered by the shaft, Thrust Horsepower, the power delivered by propeller’s thrust. Finally the effective horse power is determined by measuring BHP, SHP and DHP which further helps to determine the power used in ship propulsion.