Tham khảo tài liệu 'lesson 2-other seakeeping performances (1)', ngoại ngữ, anh văn thương mại phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Lesson 2 Other Seakeeping Performances 1 Apart from principal dimensions seakeeping performances cover floatability roll and pitch fast speed floodability and maneuverability. Floatability One of the important seakeeping performances is the floatability that indicates the ability of vessel floating positively on water under the condition of a certain amount of deadweight. When we deal with floatability we must first be clear about the following two technical terms i. e. reserve buoyancy and loadline mark. Fig. . buoyancy and hydrostatic pressure Then what is the reserve buoyancy As it is known to all a ship has to obtain a certain amount of freeboard when she s sailing at sea. That is to say to give you a concrete idea any vessel is to retain some volume above water for the sake of extra buoyancy so that its draft is allowed to increase without a sinking tragedy under particular but rare conditions such as rough sea or serious flooding due to hull damage. For instance the film Titanic popular in every corner of the world and presenting a moving love story to the sentimental audience describes the fatal hull damage owing to a huge iceberg. This extra buoyancy is called reserve buoyancy or to be exact the reserve buoyancy which is measured by freeboard refers to the watertight volume of hull above load line. Fig. 2. 2 In respect of load-line mark it denotes a variety of the max. drafts of vessels in different seasons and at varied navigating zones. Stability One more seakeeping performance is the stability which is the ability that vessels will incline when affected by an exterior force such as wind wave etc. and will restore its original position on the force removal. Stability is of course of great importance to shipbuilding since its failure will always lead to heavy loss of life. History has sadly witnessed tragic sinking of vessels so many a time by reason of poor stability. Vessel inclination may be divided into trim and heel. As the metacenter of .
