船舶基(ji)礎(chu)知識:造船業(ye)的噸位和排水量
為表(biao)(biao)(biao)(biao)示(shi)(shi)(shi)船(chuan)(chuan)(chuan)(chuan)舶(bo)(bo)(bo)的大(da)小(xiao),除(chu)用船(chuan)(chuan)(chuan)(chuan)長、船(chuan)(chuan)(chuan)(chuan)寬等尺度以外,通常(chang)用噸(dun)(dun)位。船(chuan)(chuan)(chuan)(chuan)舶(bo)(bo)(bo)噸(dun)(dun)位種類繁雜(za)又易混(hun)淆,主要有(you)四種:①表(biao)(biao)(biao)(biao)示(shi)(shi)(shi)船(chuan)(chuan)(chuan)(chuan)舶(bo)(bo)(bo)的重(zhong)(zhong)量,排水量噸(dun)(dun);②表(biao)(biao)(biao)(biao)示(shi)(shi)(shi)船(chuan)(chuan)(chuan)(chuan)舶(bo)(bo)(bo)的容積,用總噸(dun)(dun)(GT)或凈噸(dun)(dun)(NT)表(biao)(biao)(biao)(biao)示(shi)(shi)(shi);③表(biao)(biao)(biao)(biao)示(shi)(shi)(shi)裝載貨物的重(zhong)(zhong)量,用載重(zhong)(zhong)噸(dun)(dun)(DWT)表(biao)(biao)(biao)(biao)示(shi)(shi)(shi);④表(biao)(biao)(biao)(biao)示(shi)(shi)(shi)船(chuan)(chuan)(chuan)(chuan)舶(bo)(bo)(bo)建(jian)造工作(zuo)量,用修正總噸(dun)(dun)(CGT)表(biao)(biao)(biao)(biao)示(shi)(shi)(shi)。
排水(shui)(shui)量噸(dun)(dun):船(chuan)(chuan)舶(bo)浮(fu)在水(shui)(shui)面上(shang)時,排開水(shui)(shui)的(de)(de)重量等于浮(fu)力(li),也等于船(chuan)(chuan)舶(bo)本身的(de)(de)重量。因此(ci),排水(shui)(shui)量噸(dun)(dun)也就等于船(chuan)(chuan)舶(bo)的(de)(de)重量。排水(shui)(shui)量噸(dun)(dun)在軍用艦艇上(shang)廣泛應用,但(dan)在民船(chuan)(chuan)上(shang)除待拆船(chuan)(chuan)舶(bo)用空載(zai)排水(shui)(shui)量噸(dun)(dun)(即輕噸(dun)(dun),LDT) 作為買賣(mai)廢船(chuan)(chuan)的(de)(de)尺度外,很少實(shi)際(ji)用作新船(chuan)(chuan)度量單位。只是在中國(guo),對于非貨運船(chuan)(chuan)舶(bo)類的(de)(de)拖船(chuan)(chuan)、漁船(chuan)(chuan)、工程船(chuan)(chuan)等,往(wang)(wang)往(wang)(wang)使用滿載(zai)排水(shui)(shui)量噸(dun)(dun)作為表示(shi)船(chuan)(chuan)舶(bo)大小的(de)(de)單位。
載(zai)(zai)(zai)(zai)重噸(DWT):是貨船可用于裝載(zai)(zai)(zai)(zai)貨物(wu)的最(zui)大(da)營運噸位。一般指(zhi)貨船在結(jie)構吃水(shui)或滿載(zai)(zai)(zai)(zai)吃水(shui)時裝載(zai)(zai)(zai)(zai)的貨物(wu)、淡(dan)水(shui)、燃料潤(run)滑油、爐水(shui)、備品、供應品及人員、行李等(deng)噸位之和(空載(zai)(zai)(zai)(zai)排水(shui)量+載(zai)(zai)(zai)(zai)重噸=滿載(zai)(zai)(zai)(zai)排水(shui)量噸)。
總(zong)噸(dun)(dun)(GT):是(shi)國際通行的(de)船舶(bo)計量單(dan)位之(zhi)一,是(shi)登記噸(dun)(dun)位的(de)一種,主要用來衡量民用船舶(bo)的(de)大(da)小(容(rong)積)。總(zong)噸(dun)(dun)是(shi)指各航海(hai)國家(jia)按照(zhao)《國際船舶(bo)噸(dun)(dun)位丈量公(gong)約》(1982年7月(yue)18日起實行)制定的(de)丈量規范丈量的(de)船舶(bo)圍蔽處所的(de)容(rong)積噸(dun)(dun)。
修正(zheng)(zheng)(zheng)總噸(dun)(dun)(CGT):是國(guo)(guo)際(ji)(ji)通行(xing)的(de)船(chuan)(chuan)舶(bo)(bo)計(ji)量(liang)單(dan)位之(zhi)一。在(zai)船(chuan)(chuan)舶(bo)(bo)總噸(dun)(dun)基礎上(shang)(shang)考慮船(chuan)(chuan)舶(bo)(bo)復(fu)雜度而(er)計(ji)算出(chu)的(de)船(chuan)(chuan)舶(bo)(bo)度量(liang)單(dan)位,計(ji)算方法(fa)為(wei)(wei):修正(zheng)(zheng)(zheng)總噸(dun)(dun)GT=GT×C,其中為(wei)(wei)GT總噸(dun)(dun)數,C為(wei)(wei)修正(zheng)(zheng)(zheng)系數。中國(guo)(guo)民用(yong)鋼(gang)質船(chuan)(chuan)舶(bo)(bo)修正(zheng)(zheng)(zheng)系數按船(chuan)(chuan)舶(bo)(bo)行(xing)業標(biao)準《民用(yong)船(chuan)(chuan)舶(bo)(bo)修正(zheng)(zheng)(zheng)噸(dun)(dun)計(ji)算》標(biao)準號為(wei)(wei)CB/T3484-2005確(que)定(ding)。目前國(guo)(guo)際(ji)(ji)上(shang)(shang)均(jun)按0ECD造船(chuan)(chuan)工作(zuo)組1994年1月(yue)制(zhi)定(ding)的(de)修正(zheng)(zheng)(zheng)系數表選(xuan)用(yong)。修正(zheng)(zheng)(zheng)總噸(dun)(dun)不僅(jin)比載(zai)重噸(dun)(dun)、總噸(dun)(dun)更能正(zheng)(zheng)(zheng)確(que)反(fan)映(ying)造船(chuan)(chuan)工作(zuo)量(liang)大小,同時還(huan)在(zai)一定(ding)程度上(shang)(shang)反(fan)映(ying)船(chuan)(chuan)價高(gao)低和(he)產值大小。因而(er),能比較正(zheng)(zheng)(zheng)確(que)地用(yong)來(lai)表示造船(chuan)(chuan)產量(liang)、造船(chuan)(chuan)工作(zuo)量(liang)(新接船(chuan)(chuan)舶(bo)(bo)訂單(dan)量(liang)和(he)手(shou)持訂單(dan)量(liang))和(he)造船(chuan)(chuan)能力。特(te)別是在(zai)產品結構(gou)差異很大的(de)國(guo)(guo)家之(zhi)間和(he)企業之(zhi)間進行(xing)比較,用(yong)修正(zheng)(zheng)(zheng)總噸(dun)(dun)作(zuo)為(wei)(wei)統計(ji)單(dan)位比載(zai)重噸(dun)(dun)、總噸(dun)(dun)要準確(que)得多。
中國主(zhu)要(yao)采用(yong)載(zai)重(zhong)噸(dun)(dun)(DWT)和(he)排水量噸(dun)(dun),而國際上采用(yong)較多是總(zong)(zong)(zong)(zong)噸(dun)(dun)(GT)、修正噸(dun)(dun)(CGT)。國際造船(chuan)(chuan)(chuan)業,包括造船(chuan)(chuan)(chuan)企業、船(chuan)(chuan)(chuan)級社、咨(zi)詢研究機構(gou)和(he)國際造船(chuan)(chuan)(chuan)組(zu)(zu)織(zhi)(如經濟(ji)合作(zuo)與發展組(zu)(zu)織(zhi)(OECD)造船(chuan)(chuan)(chuan)工(gong)(gong)作(zuo)組(zu)(zu)),在(zai)船(chuan)(chuan)(chuan)舶(bo)生產(chan)總(zong)(zong)(zong)(zong)量的統(tong)(tong)計(ji)中,較少使用(yong)載(zai)重(zhong)噸(dun)(dun)。只有一(yi)些大(da)型常規貨(huo)船(chuan)(chuan)(chuan)的造船(chuan)(chuan)(chuan)公司為顯(xian)示其噸(dun)(dun)位(wei)大(da)而采用(yong)載(zai)重(zhong)噸(dun)(dun);一(yi)些咨(zi)詢研究機構(gou)在(zai)統(tong)(tong)計(ji)貨(huo)運船(chuan)(chuan)(chuan)舶(bo)時也(ye)有以載(zai)重(zhong)噸(dun)(dun)為統(tong)(tong)計(ji)單位(wei),但是他們更多地使用(yong)總(zong)(zong)(zong)(zong)噸(dun)(dun)和(he)修正總(zong)(zong)(zong)(zong)噸(dun)(dun)。作(zuo)為當今世界重(zhong)要(yao)的國際造船(chuan)(chuan)(chuan)組(zu)(zu)織(zhi)OECD造船(chuan)(chuan)(chuan)工(gong)(gong)作(zuo)組(zu)(zu),在(zai)造船(chuan)(chuan)(chuan)統(tong)(tong)計(ji)不(bu)使用(yong)載(zai)重(zhong)噸(dun)(dun),而只使用(yong)總(zong)(zong)(zong)(zong)噸(dun)(dun)和(he)修正總(zong)(zong)(zong)(zong)噸(dun)(dun)。