Introduction A propeller is a type of fan which generates an adequate thrust to propel a vessel at some design speed with some care taken in ensuring some “reasonable” propulsive efficiency. Considerations are made to match the engine’s power and shaft speed, as well as the size of the vessel and the ship’s operating speed, with an appropriately designed propeller. Generally, propellers are of two types - Fixed Pitch Propeller ( FPP) and Controllable or Variable Pitch Propeller ( CPP). Controllable Pitch Propeller or CPPThese propellers now have a relatively good track record for … [Read more...]
Ship Stability Definitions related to Hydrostatic Particulars
Density of a substance is its mass per unit volume, normally expressed as tonnes per cubic metre in ship calculations.Relative Density of a substance is the ratio between the density of that substance and the density of fresh water.Displacement of the ship is the weight of the ship and its contents or the weight of water displaced by the ship in that condition.Displacement = Underwater volume of the ship x the density of the water in which she is floating.It should be noted that the volume of displacement is the underwater volume of the ship. When a ship proceeds from water of … [Read more...]
Principles of Ship Handling
Ship Handling and Maneuvering is defined as the art of proper control of a ship while underway, especially in harbours, around docks and piers. It is one of the skills that any ship handler finds very satisfying when well accomplished. The most basic thing to be understood in ship handling is to know and anticipate how a ship behaves under all circumstances and what orders should be given in order to make the ship behave and move exactly the way you want her to. The difference between the ships' heading and the actual direction of movement of the ship should also be constantly attended to as … [Read more...]