80T六梁橋式鑄造起重機結(jié)構(gòu)設(shè)計的畢業(yè)論文正稿

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1、. 80T六梁橋式鑄造起重機結(jié)構(gòu)設(shè)計的畢業(yè)論文 摘要 六梁鑄造起重機是橋式起重機的重要組成部分,是中大型起重設(shè)備,由四根主梁和兩根端梁組成。本設(shè)計采用偏軌箱型主梁,設(shè)計過程中從強度、剛度、穩(wěn)定性三個方面來計算,對于A7工作級別的起重機來說還要進行疲勞強度校核,這就和A6以下工作級別的起重機的設(shè)計有了很大的區(qū)別,在設(shè)計時會出現(xiàn)靜強度有很大的富余,在計算局部穩(wěn)定性的時候還要注意局部輪壓的作用,這時候需要驗算加勁肋的區(qū)格驗算,很有可能需要再次驗算。設(shè)計中在滿足剛度、強度、穩(wěn)定性的前提下,探討了該機型金屬結(jié)構(gòu)受力的空間傳遞分配規(guī)律,推導(dǎo)出內(nèi)力計算公式。本文針對空間橋架內(nèi)力的傳遞進行探討,在一定假

2、定條件下,得出主、副梁及主、端梁間的傳遞規(guī)律。 關(guān)鍵詞：鑄造起重機,應(yīng)力, 疲勞強度, 穩(wěn)定性 Abstract Casting six beams overhead cranes are an important component part of the medium and large lifting equipment, by the four main girder beams and two-component, the design based on the partial tracks box girder, the design process from the str

3、ength, stiffness, Stability three aspects, for the working-level A7 crane will run for calibration. This and the followingworking-level A6 crane design with vastly different, in the design when there are large static strength of the surplus in the calculation of regional stability but also to the pa

4、rtial pressure of the round, This needs time checking STIFFENER checking the grid, is likely to be checked again. The structure of the crane is composed of the primary centrol girder, the assistant centrol girder, the primary dead-end girder and the assistant dead-end girder according to the trait o

5、f the crane. On the advance of the intensity, rigidity and structure supporting the load is studied mainly. At the same time we also include the formulate which is used to calculate the internal force. Some kinds of conditions are assured in order to hold the internal relation between them. Key wor

6、ds: rigidity, intensity, fatigue strength, stability 第一章 總體方案設(shè)計 §1.1 原始參數(shù) 起重量Q<主/副> 180/50t 跨度S 22m 工作級別Ai A8 起升高度H<主/副> 20/22m 起升速度V<主/副> 4.5/11.4 m/min 運行速度<主/副/大車> 36/33.7/73.5 m/min 輪距<主/副/大車>

7、4080/1850/9800 mm 軌距<主/副/大車> 8700/3000/22000 mm 輪壓<主/副/大車> 34500/19640/87600 kg 起重機重量 220t §1.2總體結(jié)構(gòu)及設(shè)計 根據(jù)已給參數(shù),此橋式鑄造起重機噸位、跨度較大,為減少結(jié)構(gòu)的超靜定次數(shù),改善受力,方便運輸,選用六梁鉸接式結(jié)構(gòu)。結(jié)構(gòu)框架如圖<1> 圖<1> §1.3 材料選擇及許用應(yīng)力 根據(jù)總體結(jié)構(gòu),鑄造起重機工作級別A8為重級,工作環(huán)境溫度較高,設(shè)計計算時疲勞強度為其首要約束條件,選用Q235-A,考慮起重量

8、較大,主/副梁均采用偏軌箱型梁。 材料的許用應(yīng)力及性能常數(shù)見表1、表2。 表1.1 材料許用應(yīng)力 板厚 正應(yīng)力 剪應(yīng)力 mm >16 370 152.0 167.9 184.4 87.76 96.94 106.5 370 158.8 175.4 192.6 91.7 101.3 111.2 表1.2 材料性能常數(shù)表 彈性模量E 剪切彈性模量G 密度 §1.4各部件尺寸及截面性質(zhì) 1. 主主梁尺寸 初選高度=1294~1571mm 考慮大車運行機構(gòu)安裝在主梁內(nèi),且主主梁與副主梁的高度差必須滿足一

9、定得要求,故將主主梁取為大截面薄鋼板的形式,以達到節(jié)省材料、重量輕的要求。因此取腹板高度mm。 為了省去走臺,對寬型偏軌箱型梁,主主梁腹板內(nèi)側(cè)間距取mm>=440mm。 上下翼緣板厚度mm,上翼緣板長2530mm,下翼緣板長2326mm,主腹板厚度 mm,副腹板厚度 mm。上下翼緣板外伸部分長 不相同。有軌道一側(cè)上翼緣板外伸長度mm,取250mm。其它翼緣外伸部分長度 mm。 mm <焊縫厚度> 取=50mm。 軌道側(cè)主腹板受局部壓應(yīng)力,應(yīng)將板加厚,由局部壓應(yīng)力的分布長度,設(shè)計離上翼緣板350mm的一段腹板板厚取為18mm。 主主梁跨中截面尺寸如圖<2> 圖<2> 2．主主梁

10、跨端截面尺寸 高度mm 要確定主主梁跨端截面尺寸,只需確定其高度,取=1300mm,跨端下翼緣板厚度為18mm。 主主梁跨端截面尺寸如圖<3> 3．截面性質(zhì) <1> 主主梁跨中 建立如圖示的坐標系,計算形心位置 =1256.851257mm。 =1238.881239mm 計算彎心位置 mm 彎心近似地在截面對稱形心軸上,其至主腹板中線的距離為1021mm。 凈截面面積 毛截面面積 計算慣性矩 對形心軸的慣性矩 對形心軸的慣性矩 <2> 主主梁跨端截面性質(zhì) 凈截面面積 毛截面面積 建立圖示的坐標系,

11、計算形心位置 計算慣性矩,對形心軸的慣性矩 對形心軸的慣性矩 二、副主梁尺寸 1. 初選梁高 =1294~1571mm,取腹板高度 ,上下翼緣板厚度 ,腹板厚度：主腹板 ,副腹板厚度 ,副主梁總高 副主梁寬度 , 取腹板內(nèi)側(cè)間距 且 1100,主腹板一側(cè)上翼緣板外伸長度 ,取外伸長 ,其余懸伸長大于1.5倍的焊縫厚度,取。其尺寸如下圖 圖<4> 2. 副主梁跨端截面尺寸的確定 確定其高度 ,取腹板高度為800 副主梁跨端截面尺寸如圖<5> 圖<5> 3. 截面性質(zhì) < 1> 跨中 建立圖示的直角坐標系,求形心位置 凈截面面積 毛截面面積

12、 計算彎心位置A 彎心距主腹板板厚中線的距離為 計算慣性矩 對形心軸的慣性矩： 對形心軸的慣性矩： 副主梁跨端截面性質(zhì) 建立圖示的坐標系,求截面形心位置 凈截面面積 毛截面面積 對形心軸的慣性矩： 對形心軸的慣性矩： 三、端梁截面尺寸 考慮大車車輪的安裝及臺車的形狀尺寸,端梁內(nèi)寬取為600。初設(shè)截面尺寸如下圖 圖<6> 形心即對稱中心 對形心軸的慣性矩： 凈截面面積 毛截面面積 四、各截面尺寸及性質(zhì)匯總表 圖<7> 尺寸匯總表 1.3 單位：mm 主主梁 跨中 18 18

13、 14 12 2530 2326 2200 2400 跨端 18 18 14 12 2530 2326 2200 1264 副主梁 跨中 16 16 10 8 1270 1180 1100 1500 跨端 16 16 10 8 1270 1180 1100 800 端梁 12 12 10 10 660 660 600 776 截面性質(zhì)匯總表1.4 凈面積 毛面積 主主梁 跨中 1239 1257 151208 5351034 跨端 1237 675

14、 121672 2837066 副主梁 跨中 629 782 66200 1681244 跨端 624 427 53600 904944 端梁 330 400 31360 480680 第二章 橋架分析 §2.1 載荷組合的確定 一、動力效應(yīng)系數(shù)的計算 1．起升沖擊系數(shù) 0.9 對橋式鑄造起重機 2．起升動載系數(shù) 主主梁 副主梁 3．運行沖擊系數(shù) 為大車運行速度 =73.5,為軌道街頭處兩軌面得高度差 ,根據(jù)工作級別,動載荷用載荷組合 進行計算,應(yīng)用運行沖擊系數(shù)。 §2.2 橋架假

15、定 為了簡化六梁鉸結(jié)橋架的計算,特作如下假定： 1． 根據(jù)起重機的實際工作情況,以主、副小車一起工作為最不利載荷工況。 2． 主主梁、副主梁的端部與端梁在同一水平面內(nèi)。 3． 由于端梁用鉸接分成5段,故副主梁的垂直載荷對相互間受力分析互不影響。 4． 將端梁結(jié)構(gòu)看作多跨靜定梁,主主梁受力作為基本結(jié)構(gòu)對副主梁無影響；副主梁受力作為附屬部分對主主梁有影響。 5． 計算副主梁水平載荷時,將鉸接點看成剛性連接。 §2.3 載荷計算 1．主主梁自重 由設(shè)計給出的主小車輪壓34500kg,選用車輪材料ZG35CrMnSi,車輪直徑,軌道型號QU12

16、0,許用值38700kg。由軌道型號QU120查得軌道理論重量,主小車軌道重量 欄桿等重量 主梁的均布載荷 2．主小車布置,兩側(cè)起升機構(gòu)對稱布置,重心位于對稱中心。 吊具質(zhì)量 起升載荷 小車重量 因主小車噸位較大,采用臺車形式八個車輪,可求實際主小車滿載時的靜輪壓 一根主主梁上 空載小車輪壓 3．慣性載荷 一根主主梁上小車慣性力 主小車上主動輪占一半,按主動車輪打滑條件確定主小車的慣性力 大車起、制動產(chǎn)生的慣性力 4．偏斜運行側(cè)向力 一根主主梁的重量為 主主梁跨端焊接上兩塊耳板,與副主梁端梁連接,在計算時,按假想端梁截面進行計算。 圖<8>

17、 與主主梁連接的端梁部分〔將超出軌距的一部分所假想而成的端梁截面尺寸 其截面尺寸如下 形心 對形心軸 的慣性矩： 對形心軸的慣性矩： 端梁凈截面積 端梁毛截面積 一根端梁單位長度重量 一組大車運行機構(gòu)重量 司機室及其電氣設(shè)備的重量 主主梁側(cè)假想端梁重 (1) 滿載小車在主主梁跨中 左側(cè)端梁總靜輪壓由下圖<12>計算 由 查圖3-8得,側(cè)向力為 滿載小車在主主梁左端極限位置 左側(cè)端梁總靜輪壓為 此處省略?NNNNN NNNNNNN NNNN NNN NN 字 起升質(zhì)量 起升載荷 起升鋼絲繩滑輪組的最大下放長度為 取,為吊

18、具最小下放距離 橋架跨中靜位移為 查選用倍率 ,, 由鋼絲繩靜拉力 選用型鋼絲繩 起升鋼絲繩滑輪組的靜伸長 結(jié)構(gòu)質(zhì)量影響系數(shù) 橋式起重機的垂直自振頻率 4．水平動剛度 起重機水平動剛度以物品高位懸掛,滿載小車位于橋架跨中的水平自振頻率來表征。 半橋架中點的換算質(zhì)量為 半剛架跨中在單位水平力作用下產(chǎn)生的水平位移為 橋式起重機的水平自振頻率為 §4.5 橋架拱度 橋架跨度中央的標準拱度值 考慮制造因素,實取 跨度中央兩邊按拋物曲線 設(shè)置拱度,如下圖<34> 距跨中為 的點, 距跨中為 的點, 距跨中為 的點, 第五章 端梁校核 §5.1 主主梁端部

19、耳板設(shè)計 計算主主梁跨端結(jié)構(gòu)受力,工況：滿載小車位于主梁跨端,大小車同時運行起制動及橋架偏斜。 1．垂直載荷 主梁最大支承力 因作用點的變動引起的附加力矩為 按假想端梁計算自重 計算簡圖<35> 端梁支座反力如圖, 截面1-1 彎矩 剪力 截面2-2 彎矩 剪力 2．水平載荷 端梁的水平載荷有,,,,亦按簡支梁計算,見圖<36> 因作用點外移引起的附加水平彎矩為 彎矩 截面1-1 剪切力 截面2-2 在,,,水平力作用下, 2-2處水平反力 3．主梁端部耳板設(shè)計 截面性質(zhì)：建立如圖

20、示坐標系 校核截面2-2處 腹板中軸處切應(yīng)力 合格 1． 截面1-1處銷軸所受剪應(yīng)力在驗算端梁完計算,見后面。 §5.2 副主梁一側(cè)端梁的校核 1.端梁校核 載荷計算：副主梁與端梁看作是多跨靜定梁的附屬部分；主主梁對附屬部分無影響。 工況：取滿載小車位于主梁跨端,大小車同時起、制動及橋架偏斜。 <1> 垂直載荷 主梁最大支承力 因作用點的變動引起的附加力矩為 端梁自重 端梁在垂直載荷作用下按簡支梁計算 端梁支反力 截面1-1 截面2-2 <2> 水平載荷 端梁的水平載荷有,,,,按簡支梁計算。 因作用點外移引起的附加水平彎矩為 先求支

21、反力： 端梁的水平反力 水平剪切力 彎矩 截面1-1 剪切力 軸向力 2．強度校核 只需校核2-2截面 截面角點①處應(yīng)力 腹板邊緣的應(yīng)力 翼緣板對中軸的靜矩為 折算應(yīng)力為 3．疲勞強度 只考慮垂直載荷,工況：滿載小車位于跨中及跨端截面2-2。 滿載小車在副主梁跨端時,端梁截面2-2的最大彎矩和剪切力為 空載小車位于跨中時,端梁支反力 下翼緣板焊縫應(yīng)力 根據(jù)A8及Q235,下翼緣板采用雙面貼角焊縫,應(yīng)力集中等級,查得 焊縫拉伸疲勞許用應(yīng)力 合格 按查得 取拉伸疲勞許用應(yīng)力 合格 4．穩(wěn)定性 整體穩(wěn)定性 〔穩(wěn)定 局部穩(wěn)定性

22、 翼緣板 〔穩(wěn)定 腹板 不需設(shè)置橫隔板。 5．校核銷軸所受的力 如圖<40>,耳板與端梁連接處銷軸1、4,所受垂直方向的剪力較大,而2、3受水平方向拉力,其在垂直方向幾乎不受力。只需校核受力較大的1、4銷軸。 設(shè)計銷軸直徑為 對銷軸 合格 對支撐板的擠壓應(yīng)力,設(shè)支撐板厚20mm。 支撐板的擠壓力 合格 6．副主梁與端梁的連接 副主梁與端梁采用連接板貼角焊縫連接,主梁兩側(cè)各用一塊連接板與端梁的腹板焊接,連接板厚 ,高度 ,取 主梁腹板與端梁腹板之間留有的間隙,在組裝橋架時用來調(diào)整跨度。主梁翼緣板伸出梁端套裝在端梁翼緣板外側(cè)。用貼角焊縫,周邊焊住,必要

23、時在主梁端部內(nèi)側(cè),主、端梁的上下翼緣板處焊上三角板,以增強連接的水平剛度,承受水平剪力。 副主梁最大支承力 連接處需要的焊縫長度為： 〔合格 至此橋架設(shè)計全部合格,橋架結(jié)構(gòu)施工圖見附圖。 致謝 經(jīng)過近三個月的設(shè)計,我對橋式鑄造起重機的設(shè)計步驟、內(nèi)容和方法有了更深入的了解,同時鞏固了已學的金屬結(jié)構(gòu)的相關(guān)知識,為以后的工作學習打下了堅實的基礎(chǔ)。 這次設(shè)計橋式鑄造起重機的突出特點是工作級別高、起重量大。在設(shè)計計算時高工作級別的結(jié)構(gòu)所允許的疲勞強度許用值很低,疲勞強度成為設(shè)計計算的首要約束條件,因此要重點校核疲勞強度。另一個收獲就是要學會根據(jù)結(jié)構(gòu)受力的特點應(yīng)用材料,將材料用到該用的地

24、方。而受力小的地方就盡可能少用材料。比如主腹板上側(cè)受局部壓應(yīng)力較大,則局部加厚主腹板上側(cè)部分,使其能夠承擔更大的應(yīng)力。這種有針對性的設(shè)計能最大限度地節(jié)省材料,更加合理。 在設(shè)計過程中,得到了學院有關(guān)領(lǐng)導(dǎo)的關(guān)心和支持,尤其是指導(dǎo)老師給了我們很大的幫助,在此對他們認真負責的精神和付出的辛苦表示衷心的感謝。 由于時間較緊,而且我也是第一次完成這樣完整的設(shè)計,由于實踐經(jīng)驗的欠缺,在設(shè)計中一定有許多考慮不周的地方。需要在今后的學習和工作中總結(jié)提高。希望各位老師和同學批評指正。 參考文獻 [1] 徐克晉主編 《金屬結(jié)構(gòu)》 北京：機械工業(yè)出版社 1982. [2] 徐格寧主編 《起重運輸機金屬

25、結(jié)構(gòu)設(shè)計》 北京：機械工業(yè)出版社 1995. [3] XX起重機器廠編 《起重機設(shè)計手冊》 XX：XX人民出版社 1979. [4] 徐格寧主編 《機械裝備金屬結(jié)構(gòu)設(shè)計》 普通高等教育‘十一五’國家級規(guī)劃教材 2008.9 [5] 起重機設(shè)計手冊編寫組 《起重機設(shè)計手冊》 北京：機械工業(yè)出版社 1977. [6] 倪慶興、王殿臣主編 《起重輸送機械圖冊》 北京:機械工業(yè)出版社 1992. [7] 張質(zhì)文、王金諾主編 《起重機設(shè)計手冊》 北京：中國鐵道出版社 1997. [8] 陳道楠、盛XX主編 《起重機課程設(shè)計》 冶金工業(yè)出版社 1982. [9] 徐格寧、智浩編

26、 《XX重型機械學院學報》 1993年第4期第14卷《鑄造起重機橋架空間結(jié)構(gòu)分析與疲勞計算》 1993. [10] 劉鴻文主編 《材料力學》 高等教育出版社 2003. 附錄A Portal power China’s rapid economic growth in the past decade has resulted in a big increase in freight traffic through the country’s seaports . Old ports are being expanded and new ports built to handle the

27、 large growth in container and bulk cargo traffic all along the Chinese coastline. China’s port expansion programme has provided a strong boost to the domestic port equipment industry, which has enjoyed a strong increase in demand for port cranes of various types, including container cranes and por

28、tal cranes along with bulk cargo handling equipment. State-run China Harbour Engineering Corporation Ltd, established under the ruling State Council, is China’s largest supplier of port cranes and bulk cargo handling equipment. The organization controls both Shanghai Zhenhua Port Machinery

29、Co Ltd ,the world’s largest manufacturer of quayside container cranes, and Shanghai Port Machinery Plant , which specializes in the manufacturer of portal cranes and other cranes used in ports along with dry bulk cargo handling equipment. SPMP’s main market is China, although the compan

30、y is looking to expand its overseas sales. Although less well known than its associate ZPMC, SPMP also operates large manufacturing facilities, and is due to move part of its production shortly to Changxing Island near Shanghai where ZPMC already operates a large container crane fabrication plant.

31、Portal and other harbour cranes are SPMP’s major production item. During the past two years, the corporation has won contracts for 145 portal cranes from port authorities throughout China, both from new ports under construction and ports undergoing expansion. In recent years, SPMP has also supplied

32、 portal cranes to the United States, Iraq,and Myanmar.The port Rangoon of Myanmar in has purchased a 47m,40t portal crane while BIW of the United States has purchased three cranes-15t,150t, and 300t portal cranes. Elsewhere, SPMP has supplied 12 portal cranes to several ports in Iraq since the end o

33、f the Saddam regime. In China, SPMP’s recent major orders for portal cranes include eight 40t, 45m radius cranes for Tianjin Overseas Mineral Terminal, while Yan Tai Port Bureau in Guangdong in southern China has purchased six 40t, 45m radius cranes. Other large orders include seven 10t, 25m radi

34、us cranes for Zhenjiang Port Group and an order of 1025t, 33m radius cranes from Fangcheng Port Bureau, while the Yingkou Port Group has ordered 1325t,35m radius cranes along with two 40t, 44m radius port cranes. MANY CRANES BUILT TO ORDER SPMP also supplies other cranes used in ports and harbours

35、, many of which are built to order for clients. Quayside container cranes have been supplied to a number of foreign clients including Bangkok Port in Thailand, Kaohsiung Port in Taiwan, and Port of Vancouver in Canada. In China, SPMP has supplied quayside container cranes to Shanghai Port, Tianjin P

36、ort, Yin Kou Port, Yan Tai Port and others. The company also supplies rubber-tyred container gantry cranes to domestic and overseas clients. Customers for other cranes used in ports include Guangzhou Port in Guangdong, which purchased a 25t floating crane while Zhonggang Port has bought two double

37、trolley 125/63t gantry cranes, along with a700t overhead crane, In 2003 Zhonggang Port awarded a contract to SPMP for a 2,600t floating crane, whichi is the largest crane the company has made in recent years. Other customers include Zhongyuan Nanytong Shipyard of Jiangsu Province has purchased two

38、300t goliath cranes for use in its shipyard, while Shanghai Waigaoqiao Shipyard uses two of SPMP’s 600t goliath cranes for its shipbuilding operations. SPMP has two factories. The Shanghai plant employs 2,000 workers while a factory in Jiangsu Province employs 1,500 workers. The combined total of 3,

39、500 workers includes 800 technical and management staff involved in designing, developing, and building portal and other cranes along with dry bulk cargo loading and unloading equipment. Currently, SPMP is preparing to vacate its Shanghai factory site as the company’s existing plot of land is part

40、of a riverside area earmarked by the Shanghai Expo in 2010. SPMP’s Shanghai factory will close at the end of 2006, and move to a new site on nearby Changxing Island. "The new factory will be much bigger than the present plant," Li said. "Phase 1 will be ready for us when we move at the end of 2006.

41、" In addition to moving the Shanghai factory to a new site, SPMP expects future business operation with ZPMC. Officials at China Harbour Engineering Corporation are understood to have told SPMP of plants for SPMP and ZPMC to co-operate more in bidding for projects in future. Both companies

42、 are expected to retain their individual manufacturing capability, however, with precise details of future co-operation still some way from being finalised. Meanwhile, SPMP associate company ZPMC is strengthening its position as the world’s largest manufacturer of ship-to-shore container cranes, su

43、pplying slightly more than half the annual international container crane market. In addition to operating four crane production complexes for its crane manufacturing and other businesses. ZPMC’s full range of products includes quayside container cranes, rubber-tyred gantry cranes, bulk material shi

44、p loaders and unloaders, bucket-wheel stackers and reclaimers, portal cranes, floating cranes, and engineering vessels. The company has also diversified into manufacturing other large steel structures including large steel bridges. ZPMC EXPANDING PRODUCTION ZPMC’s cranes and other products are in

45、use at over 150 shipping terminals in 37 countries and regions worldwide. By the end of December 2005, ZPMC had supplied 705 quayside container cranes, and had orders in hand to deliver another 128 quayside container cranes in 2006. In addition, at the end of 2005 ZPMC had delivered 1,148 rubber-tyr

46、ed gantry cranes to customers worldwide and had orders in hand to deliver 308 rubber-tyred gantry cranes to customers in 2006. ZPMC is expanding production facilities in expectation that the volume of orders will grow in future. The company owns four crane production complexes in Shanghai and the s

47、urrounding area at Jiangyin, Changzhou, Zhangjiang and Changxing Island. The Changxing production site, which was completed in 2001, covers one million sq m, and has a 3.5km coastline. The facility is capable of manufacturing 160 quayside ship-to-shore container cranes each year along with 300 rubb

48、er-tyred gantry cranes and 200,000 metric tons of large steel bridge structures. Plans call for a futher 3 million sq m of land to be reclaimed at Changxing, which ZPMC will develop to become its largest production centre. Korea looks inward In a fragmented global port cr

49、ane industry, Korean manufacturers are being forced to look for more business in their domestic markets South Korea’s container crane and port crane equipment manufacturing industry has become more focused on the domestic market in recent years as manufacturers have faced tough price competition fr

50、om ZPMC of China in major foreign markets. The problem is the same as that faced by other port crane manufacturers around the world, none of which account for more than about an 8% share of the world container crane market. As well as ZPMC, competition from European and Japanese equipment supplie

51、rs is also strong, both for quayside container cranes and for rubber-tyred gantry crane contracts. While South Korean firms-including Hyundai Heavy Industries, Samsung Heavy Industries, Doosan Heavy Industries, and Hanjin Heavy Industries – continue to bid for international contracts, winning large

52、orders has become increasingly rare. Doosan Heavy Industries & Construction Co Ltd is believed to be the only South Korean port crane maker to have won a large container crane contract during the past few years, with most orders booker by Korean manufacturers being for less than 10 crane units.

53、 Doosan recently completed delivery of a 42-unit rubber-tyred gantry crane order to the Port of Singapore Authority PSN that was awarded in 2004. Including a recent contract. Doosan has received orders to supply the Port of Singapore with a total of 120 RTGCs since 1997. The recent batch of

54、RTGCs is designed for increased safety. Esch of the RTGCs is fitted with 16 wheels instead of the usual eight. "We have supplied container cranes locally and overseas. Most projects are one or two units, but Singapore has been 120 units," commented a source in Doosan Heavy Industries’ material ha

55、ndling equipment division. "Container cranes can lift one or two containers depending on the client, but the twin spreader design is normal now. Our biggest contract before was with Pusan Port for over 10 container cranes." BUILDING POWER PLANTS Doosan Heavy Industries’ major activities include th

56、e design and construction of power plants. Apart from supplying protection equipment, Doosan also manufactures turbines and generator sets. Doosan has a large castings and forging division. Other major activities include the construction of desalination plants in the Middle East. Container port h

57、andling equipment is produced by Doosan’s material handling equipment division, which supplies coal handling equipment and bulk cargo handling facilities for other industries. Port of Singapore Authority is the largest customer for RTGCs. Other recent clients include Southern Gateway Terminals in

58、 Colombo, Sri Lanka, and Korea Express in the Port of Pusan. Doosan also supplies ship to shore container cranes. Recent quayside gantry crane clients include Jakarta Container Terminal in Indonesia, Jawaharlal Nehru Port near Mumbai in India, and Frazer Terminal in Vancouver. "Prospects for o

59、ur port crane sales are not bright. ZPMC is dominating the world market due to price," the source commented. "We are looking for projects not invoving ZPMC as they are not concerned with all projects. We got contracts in Singapore in 2004 and 2005. We had no success anywhere else, but we are still b

60、idding on various tenders." Doosan is expected to be one of the bidders for container cranes to be installed in South Korea’s planned Kwangyang Bay Port expansion. The company’s R&D division is involved developing new automated controls that will be required for quayside container cranes installe

61、d in the port expansion. "Container cranes are well developed in technical terms. There is nothing else to develop except for automation," the source said. "We are developing more automated controls, but the new features are not commercialized yet. Our government has a plan for Kwangyang Bay 3

62、-2 terminal project, which they announced will be developed as an automated terminal. We have to adapt to this. The tender has been postponed for about six years. We expect the project will be tendered again in 2007 or 2008." South Korea’s other container crane manufacturers also are expected to

63、bid for the Kwangyang Bay project, which is likely to be awarded to a local supplier. Hyundal Samho Heavy Industries will be among the bidders having recently commissioned five automated rail mounted gantry cranes also known as automated transfer cranes at Pusan East Container Terminal

64、> . The terminal has become the first terminal in Korea to install automated cranes, which are in service at new berths four and five . The cranes stack nine-wide between a 28.5m rail gauge, and have dual cantilevers covering two road lanes . Stack height is 1 over 6 by 9ft 6in high and operat

65、ional speeds are 150m/min for the gantry , 120m/min for the trolley and 75-80m/min for the empty hoist . Among other recent orders that Hyundai has won is a contract for four quayside container cranes from Hutchison Port Holdings and one for Uam Port. Competition from ZPMC remains the main cha

66、llenge in winning overseas contracts according to Hyundai Heavy Industries sales manager Lee Yong Tae : " We are trying to get more projects , but ZPMC has a very low price . We will try to cut our price but we think it will lead to a bad situation in future . " " if customers think that quality is important then we are ok , but if they just think about price we cannot win the project . We have experience of building cranes to lift one or two containers .We buy the main crane controls system