【正文】 ce of the sea on a selfinduced cushion of air． These relatively lightweight vehicles are capable of high speeds， since air resistance is considerably less than water resistance， and the absence of contact with small waves bined with flexible seals reduces the effects of wave impact at high speed． Such vessels depend on lift fans to create a cushion of lowpressure air in an underbody chamber. This cushion of air must be sufficient to support the weight of the vehicle above the water surface． The first type of vessel has flexible “skirts” that entirely surround the air cushion and enable the ship to rise pletely above the sea surface. This is called an air cushion vehicle（ ACV）， and in a limited sense it is amphibious． The other type of aircushion craft has rigid side walls or thin hulls that extend below the surface of the water to reduce the amount of air flow required to maintain the cushion pressure. This type is called a capturedairbubble vehicle（ CAB）． It requires less liftfan power than an ACV， is more directionally stable， and can be propelled by water jets or supercavitating propellers． It is not amphibious， however， and has not yet achieved the popularity of the ACVs，which include passenger ferries， crosschannel automobile ferries， polarexploration craft， landing craft， and riverine warfare vessels． 靜力支撐 有兩種類型船舶是靠前身產(chǎn)生的空氣墊而支撐在海面之上的。 第一種類型船的四周具有柔性的“裙”，在船底圍成一個空氣墊，使船能完全升離水面。這種船所需的升力風(fēng)機(jī)功率要小于氣墊船的，方向穩(wěn)定性也更好，并可以由噴水裝置或者超空泡螺旋槳推進(jìn)。一個物理原理表明任何帶來不對稱流體的運(yùn)動物體都會在垂直于運(yùn)動的方向上產(chǎn)生一個升力。大多數(shù)滑行艇都要求在靜水中航行，盡管某些深 V 型船體具有在波浪中航行的能力。 vessels that float（ or submerge） in water—salt or fresh． And from this statement the name of the 從這一聲明在類船舶的名稱來源； ships in the category are derived； they are generally called displacement hulls． 他們一般稱為 排水型 船體。 obviously the result of “tradeoffs”． 這種類型的結(jié)果明顯“折衷” 。 carrier， a seagoing vessel． It may be employed for passenger service， light cargocarrying， fishing 它可用于客運(yùn)服務(wù)，輕型載貨，捕魚的拖網(wǎng)， by trawling， or for hundreds of other tasks that do not require exceptional capacity， speed， 或其他的任務(wù)，不需要特殊的能力，速度，或其他特殊性能。 for all seasons”． It is the standard to which all other ship classifications in the displacement 它是“四季船”。 industry itself has created a far more explicit nomenclature． Based upon the index of 100,000 tons 該行業(yè)本身也創(chuàng)造了一個更明確的命名法。這些名稱目前的必要性變得清晰時， realize that before 1956 there were no tankers larger than 50,000 tons, and not until the early 我們意識到在 1956 之前沒有超過 50000 噸的油輪， sixties were any ships built larger than 100,000 tons. In 1968 the first ship over 300,000 tons was 直到 60 年代早期進(jìn)行的任何船舶建造超過 100000 噸。他們的導(dǎo)航橋一英里的近四分之一， quarter of a mile from their bows. Their top service speed is so low that a voyage from an Arabian 他們的服務(wù)速度很低，一次由一個阿拉伯石油港口， oil port to a European destination normally takes two months. 一個歐洲目的地通常需要兩個月。 water required for a fully loaded VLCC runs to 50 or 60 feet and the ULCC may be 80 feet． Such 對滿載油輪運(yùn)行 50 或 60 英尺和 ULCC 可能 80 英尺的水所需的深度。 designed for relatively high speed and stable platform in moderately rough water． Its future is 簡而言之，這相當(dāng)稀有的船是專為相對高的速度和穩(wěn)定平臺適度粗糙的水。 necessary here to emphasize that submersible vessels are specifically displacement vessels 這里強(qiáng)調(diào)的是 潛艇 是專門的 排水船的 applying the theory of Archimedes? Principle and all that it implies． 應(yīng)用阿基米德原理的理論 Multihull vessels There is one other type hull in mon use that has not yet been mentioned， primarily 有一個其他類型的船體的普遍使用，尚未被提及， because it fits into none of the categories described but rather can exist fortably in any． This 主要是因為它適合的類別而存在 很多不同 。 interhull working area． Other Criteria There are other criteria that justify the widely varied configurations of ship design． They are 有其他的標(biāo)準(zhǔn)，為船舶的 配置 廣泛 而 不同的 設(shè)計 。 vessels， and pleasure craft． Merchant and mercial ships New designs of all mercial vessels， including cargo ships， passenger liners， fishing 新的商業(yè)船只的設(shè)計，包括貨船，客船，漁船， boats， offshore supply vessels， and tugboats， must pete economically with similar vessels 海洋平臺供應(yīng) 船，拖船，必須在經(jīng)濟(jì)上具有相似的 船 可形成 available form the many worldwide shipbuilders． Government subsidies protecting the national 許多全球造船廠競爭。 離岸需求補(bǔ)給船舶則是擔(dān)心 with speed for oilrig crew transport or emergency services， but slower speeds may be acceptable 油運(yùn)輸或者是緊急服務(wù)的速度， 但是較慢的速度也許是可以接受的 when payloads such as drill pipe and drilling mud are the principal cargo． Operating environment 在轉(zhuǎn)載是例如鉆井船和挖泥船是主要的貨船。 countries． The latter ports impose other cargohandling restrictions on the ship designer． 最后的港灣推斷出其他貨倉在船舶設(shè)計中的限制。 在戰(zhàn)斗條件下的， 軍隊力量的外觀 of military power， crew habitability that influences reenlistments， and the political importance of 全船員影響航行的是居住能力， 和主要的合同和基本的 who bees the prime contractor and principal weaponssystem subcontractors： all these are 武裝系統(tǒng)的政治重要性：所有的這些因素都必須被考慮 factors that must be taken into consideration， making the construction and operation of warships 對于納稅人來說， very expensive for taxpayers． 戰(zhàn)船的重建和操作是非常昂貴的。 endurance． The more exotic craft discussed in the previous sections generally sacrifice payload 更多的太空船在之前的討論中一般犧牲有效載荷和續(xù)航力來獲得速度。 第二課 船舶主尺度 (何達(dá)喜 /何冠豪 ) 假如你去翻閱一下被人們視作造船法規(guī)的技術(shù)規(guī)格書，你總是會發(fā)現(xiàn)，目錄中第一大部分是總體。因此， 很有必要在一開始就探討船體的主尺度和幾何特征。 主尺度 總長 — 從船艏至船艉的最大水平距離稱之為總長。 型深 在舯橫剖面內(nèi)，從龍骨的上表面至上甲板下表面的垂直高度稱之為型深。 水線面系數(shù) CW 是（與基平面平行的任一）水線面的面積 Aw 和其外接矩形（由船長 L、型寬 B 所構(gòu)成的長方形）面積之比。 CM=AM/BT 方形系數(shù) CB 是排水體積與其（外接）長方體的體積之比，該長方體邊長分別等于最大船寬， 平均吃水和設(shè)計水線長。 Cp=V/AML 垂向菱形系數(shù) CVP 是排水體積與一個棱柱體體積之比，該棱柱體的長等于吃水，橫剖面積等于水線面面積。滿載排水量指船上的 貨物，定員，燃料等都達(dá)到最滿狀態(tài)時的排水量。大家知道，載重量是船舶在滿載排水的條件下所能裝載的船貨和人員的最大重量。 第三課 (侯建 ) Lesson 3 Ship Structure(1) A ship is something like a grand mansion floating on water and with a number of