船舶航海性能

1、Lesson 5 Seakeeping Performances Contents ：1. Vocabulary and Sentence 2. Vocabulary summary 3. Exercise 一、一、Vocabulary and Sentencee.g.(P46-1-1)floatability 浮性One of the important seakeeping performances is floatability that indicates the ability of vessel floating positively on water under the cond

2、ition of a certain amount of deadweight.船舶航海性能中一个重要的性能是浮性，浮性是指船舶在载重量一定的情况下浮在水面上的能力。正的、积极的正的、积极的e.g.(P46-2-1)reserve buoyancy 储备浮力load-line mark 载重线标记When we deal with floatability, we must first be clear about the following two technical terms, i.e. reserve buoyancy and load-line mark.处理浮性问题的时候，我们必须

3、清楚两个术语：储备浮力和载重线标记。技术用语、术语技术用语、术语e.g.(P46-3-1)Then, what is the reserve buoyancy? As it is known to all, a ship has to obtain a certain amount of freeboard when shes sailing at sea. 那么，什么是储备浮力呢？众所周知，船舶在航行时要获得一定的干舷。e.g.(P46-3-2) buoyancy 浮力That is to say, to give you a concrete idea, any vessel is to

4、retain some volume above water for the sake of extra buoyancy so that its draft allowed to increase without a sinking tragedy under particular but rare conditions, such as rough sea or serious flooding due to hull damage. 也就是说，具体具体的描述为：船舶为为获得额外的浮力就要保留保留一些水上部分体积，从而吃水可以在不沉船的（悲剧）（悲剧）情况下有所增加，例如当遇到汹涛海浪或由

5、于船体破损破损而严重进水这种不太常见的情况。具体的具体的保留保留为了为了悲剧悲剧破损破损e.g.(P46-3-5)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. 例如：电影TITANIC众所周知，它为多愁善感的观众讲述了一个动人的爱情故事，描述的就是一个由于冰山所导

6、致的沉船故事。多愁善感的多愁善感的观众观众致命的致命的由于由于冰山冰山e.g.(P46-3-7)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.这种额外的浮力就叫做储备浮力，或者更准确的说，储备浮力是通过干舷来测量的，指的是船体载重线以上的水密容积。e.g.(P46-4-1) The Rules fo

7、r Load Line 载重线公约In respect of load-Line mark, it denotes a variety of the max. drafts of vessels in different seasons and at varied navigating zones. In China, CCS has worked out “The Rules for Load Line”关于载重线标记，它是指船舶在不同季节和不同航区下船舶的最大吃水的变化情况。在中国，CCS船级社已经制定出了“载重线公约”。指示、表示指示、表示航区航区e.g.(P46-5-1)stabili

8、ty 稳性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. 另外一个重要的航海性能是指船舶稳性，稳性是指船舶受到风、浪等外力时发生倾斜，当外力撤销后能够回复到最初位置的能力。外部的外部的恢复恢复最初的、原始的最初

9、的、原始的撤销撤销倾斜倾斜e.g.(P46-5-3) 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. 当然，稳性对船舶建造来说非常重要，稳性的不良经常导致生命的严重损失。历史已经多次见证了由于稳性的不良而发生的沉船

10、悲剧。证明、证据证明、证据悲惨的悲惨的e.g.(P46-6-1) metacenter 稳心Vessel inclination may be divided into trim and heel. As the metacenter of transversal inclination is much more essential than that of longitudinal inclination, the emphasis is invariably laid on the transversal stability and discussions are often limite

11、d to the small metacentric angle under 15 degrees.船舶的倾斜分为横倾和纵倾。由于横稳心比纵稳心重要的多，所以重点一直放在横稳性上，并且常限于15度以下的小倾角范围内讨论。重点重点不变的、恒定的不变的、恒定的度数度数重要重要e.g.(P46-7-1)In order to obtain fine stability, precautions will normally be taken in two different ways. On one hand, gravity center is to be lowered; on the other

12、 hand, metacenter to be raised. 为了获得良好的稳性，通常采取两种不同的方式。一方面降低重心。另一方面提高稳心。措施措施e.g.(P46-7-2)The gravity center of a ship to be calculated by means of an inclination test. The test is generally to be performed in calm water and with lovely weather. If you have got a drydock for the test, so much the bett

13、er.船舶重心通过倾斜试验计算的。试验通常在静水和晴朗的天气下进行。如果能在干船坞中进行试验是更好的。倾斜试验倾斜试验静水静水e.g.(P47-1-1)fast speed 快速性Another seakeeping performances the fast or rapidity which describes the ability for a ship to gain faster speed at lower consumption of power.另外一个航海性能是快速性，描述的是船舶在消耗较低功率时获得较高速度的能力。消耗消耗功率功率e.g.(P47-2-1)Vessels w

14、ill be affected mainly by water resistance during voyage. We do not bother our brain about air resistance because it is far smaller than water resistance. Perhaps the only exception is high-speed boats.船舶在航行过程中主要受水阻力的影响。我们不要为空气的阻力而大伤脑筋，因为它远远小于水的阻力，在这方面唯一的例外也许就是高速艇 。智慧、大脑智慧、大脑e.g.(P47-3-1) friction r

15、esistance 摩擦阻力swirl resistance 漩涡阻力wave-forming resistance 兴波阻力Water resistance to be encountered by a ship consists of friction resistance, swirl resistance and wave-forming( wave-making) resistance.船舶遭受到的水阻力由摩擦阻力、漩涡阻力和兴波阻力组成 。遭受到遭受到e.g.(P47-4-1)engine power 主机功率There are two ways to raise ship spe

16、ed, namely, to minimize water resistance and to increase main engine power. 提高船速可以有两种途径，即降低水阻力和增加主机功率。 e.g.(P47-4-2)bulbous bow 球鼻首rated horsepower 额定马力effective horsepower 有效马力To achieve this, a bulbous bow is widely used in many types of ships and the rated horsepower of main engines is generally

17、to be over two times is big as the effective horsepower of ships. 为了提高船速，我们在许多类型的船舶上广泛采用球鼻艏；另外，一般来说，主机的额定马力比船舶的有效马力要大两倍多。e.g.(P47-5-1)roll 横摇横摇pitch 纵摇纵摇When floating on water or sailing at sea, vessels will roll or pitch owing to wave motions as well as the influence of wind, current and propeller.

18、当船舶在水上漂浮或在海上航行时，由于当船舶在水上漂浮或在海上航行时，由于波浪的运动、风、水流和螺旋桨的影响，波浪的运动、风、水流和螺旋桨的影响，船舶会发生横摇或纵摇。船舶会发生横摇或纵摇。水流、电流、气流水流、电流、气流e.g.(P47-6-1)The fatal results of excessive roll and pitch are as follow:First, the ship upsetting arising from excessive inclination due to roll. 过度的横摇和纵摇会产生如下的致命后果 ：首先，横摇引起的过度的倾斜导致船舶的倾覆。 致

19、命的致命的过渡的过渡的倾覆倾覆e.g.(P47-7-1)In the next place, the hull structure damage because of sharp roll and pitch as well as the violent movement of bulk cargoes, or even worse the hull might break.第二，引起船体结构的损坏；或者因为剧烈的横摇和纵摇以及散货剧烈移动而造成船体的破裂。剧烈的、尖锐的剧烈的、尖锐的猛烈的、强烈的猛烈的、强烈的e.g.(P47-8-1) propulsion plant 推进装置Still

20、next, the affection on the propulsion plant, i.e. the increase of water resistance and the reduction of speed by reason of roll and pitch.其次，推进装置受到影响，即由于横摇和纵摇，水阻力会增加而船速会降低。降低降低e.g.(P47-9-1)Then, the affection on proper operation of various kinds of machines and instruments.再次，影响各种机械和仪器的正常运转。 运转运转e.g

21、.(P47-10-1)Last of all, the hard working condition which causes the crew to be seasick.最后，造成引起船员呕吐的恶劣工作条件 晕船、呕吐晕船、呕吐引起引起e.g.(P47-11-1)Therefore, we have to take roll and pitch into our consideration during the design stage, for they are closely related to the whole seakeeping performance.因此，从设计阶段起，我

22、们就必须考虑到横摇和纵摇，因为它们与航海性能密切相关。 设计阶段设计阶段e.g.(P47-12-1)roll period 横摇周期initial metacentric height 初稳性高度As you know, the roll period is greatly concerned with the initial metacentric height and, in some degree, stability is contrary to roll. 大家知道，横摇周期与初稳心高关系很大；某种程度上讲，稳性与横摇相矛盾。矛盾矛盾e.g.(P47-12-2)It seems to

23、 be strange that violent roll, as many people might think, is not derived from poor stability.很多人都会感到奇怪，剧烈的横摇并不是由于稳性的不良而引起的。获得获得e.g.(P42-13-1) stabilizing unit 减摇装置So far different stabilizing units have been invented, and found wide application to decreasing roll and pitch. 人们已经发明了不同的减摇装置，并将其广泛应用于降

24、低横摇和纵摇中。应用应用e.g.(P42-13-2) wing buoyant tank 减摇水舱Common stabilizing units now in practical use are bilge keels, stabilizers and wing buoyant tanks.目前普遍使用的减摇装置有舭龙骨、减摇鳍和减摇水舱。e.g.(P42-14-1) floodability 抗沉性Floodability states the ability for a vessel to keep afloat with sufficient floatability, stabili

25、ty and other seakeeping performances in case one or several compartments are flooded. 抗沉性是指：在船舶一舱或数舱进水的情况下，仍能浮在水面上，并具有足够的浮性、稳性和其他航海性能的能力。 指指一旦、如果一旦、如果e.g.(P42-14-2)Should sea damage take place, reserve buoyance would be the principal condition to keep a vessel afloat.一旦发生海损时，储备浮力将是保持船舶漂浮的主要条件。 一旦、万一

26、一旦、万一海损海损e.g.(P42-14-4)With the help of the watertight bulkheads and decks which separate the inside of hull into a number of compartments and spaces, reserve buoyance enough is to be retained so that the intake of sea water may be confined to the damaged compartment without water pouring into the a

27、djacent compartments.借助于将船体内部划分为若干舱室的水密舱壁和甲板，船舶可以保持足够的储备浮力；因而我们可将进水封闭在受损的舱室，海水不至于进入相邻的舱室。 保持保持吸入吸入相邻的相邻的灌入、进入灌入、进入e.g.(P48-2-1) maneuverability 操纵性操纵性The last seakeeping performance that we are coming to is maneuverability, which refers to the ability for a vessel to retain or change its course in a

28、ccordance with the pilots intention. 我们涉及到的最后一个航海性能是操纵性。操纵性指是船舶按照驾驶员的意图保持或改变航向的能力。航线航线驾驶员驾驶员e.g.(P48-3-1) directional stability 航向稳定性turning ability 回转性能Maneuverability is composed of two abilities, that is, the directional stability and the turning ability. 操纵性可分解为两种能力，即航向稳定性和回转性。 e.g.(P48-3-2)The

29、former indicates the ability for a vessel to keep to its given course, while the latter sets forth the ability for a vessel to change its course.前者指船舶保持预定航线的能力，而后者指船舶改变航向的能力。预定航线预定航线e.g.(P48-3-3) turning circle 回转半径Ocean-going vessels require strict directional stability, whereas short-range ships ask for a better turning abi