机械设计制造及其自动化专业毕业论文180t六梁桥式铸造起重机结构设计

机械设计制造及其自动化专业毕业论文-180T六梁桥式铸造起重机结构设计 大学毕业设计 任务 说明书学院直属系 时间 学 生 姓 名指 导 教 师设计论文题目180吨六梁桥式铸造起重机结构设计主要研究内容载荷分析及其组合内力计算按照不同的载荷组合计算各危险面的内力简化计算模型是必须考虑主端梁之间相互约束的影响在此基础上进行各截面的静强度静刚度动刚度疲劳强度局部稳定性和整体稳定性的验算以及主端梁的连接计算最后确定结构的截面工程尺寸研究方法在满足结构的强度刚度稳定性以及疲劳强度的情况下减小结构的尺寸做到经济性安全性最优组合主要技术指标 或研究目标 工作级别为A8级且为六梁结构副主梁与副端梁的连接可采用焊接主要参考文献1 徐克晋主编 金属结构 北京机械工业出版社 19822 徐格宁主编 起重运输机金属结构设计 北京机械工业出版社 19953 大连起重机器厂编 起重机设计手册 沈阳辽宁人民出版社 19794 徐格宁主编 机械装备金属结构设计 普通高等教育十一五国家级规划教材 200895 起重机设计手册编写组 起重机设计手册 北京机械工业出版社 19776 倪庆兴王殿臣主编 起重输送机械图册 北京机械工业出版社 19927 张质文王金诺主编 起重机设计手册 北京中国铁道出版社 19978 陈道楠盛汉中主编 起重机课程设计 冶金工业出版社 1982目 录摘要IIAbstractIII前言IV第一章 总体方案设计- 1 -11 原始参数- 1 -12总体结构及设计- 1 -13 材料选择及许用应力- 1 -14各部件尺寸及截面性质- 2 -第二章 桥架分析- 10 -21 载荷组合的确定- 10 -22 桥架假定- 10 -23 载荷计算- 10 -24简化模型- 18 -25 垂直载荷- 19 -26 水平载荷- 22 -第三章 主主梁计算- 27 -31 强度校核- 27 -32 主主梁疲劳强度校核- 28 -33 主梁的稳定性- 30 -34 刚度计算- 35 -第四章 副主梁校核- 38 -41 强度校核- 38 -42 副主梁疲劳强度校核- 39 -43 副主梁的稳定性- 41 -44 刚度计算- 44 -45 桥架拱度- 46 -第五章 端梁校核- 48 -51 主主梁端部耳板设计- 48 -52 副主梁一侧端梁的校核- 51 -致谢- 57 -参考文献- 58 -附录A- 59 -附录B- 65 -摘 要六梁铸造起重机是桥式起重机的重要组成部分是中大型起重设备由四根主梁和两根端梁组成本设计采用偏轨箱型主梁设计过程中从强度刚度稳定性三个方面来计算对于A7工作级别的起重机来说还要进行疲劳强度校核这就和A6以下工作级别的起重机的设计有了很大的区别在设计时会出现静强度有很大的富余在计算局部稳定性的时候还要注意局部轮压的作用这时候需要验算加劲肋的区格验算很有可能需要再次验算设计中在满足刚度强度稳定性的前提下探讨了该机型金属结构受力的空间传递分配规律推导出内力计算公式本文针对空间桥架内力的传递进行探讨在一定假定条件下得出主副梁及主端梁间的传递规律关键词铸造起重机应力 疲劳强度 稳定性AbstractCasting 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 strength stiffness Stability three aspects for the working-level A7 crane will run for calibration This and the following working-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 partial 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 of 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 themKey words rigidity intensity fatigue strength stability前 言本设计为18050t桥式铸造起重机金属结构设计由于此桥式铸造起重机的起重量大跨度大工作级别高在设计计算时疲劳强度为其首要约束条件因此在选材时选用稳定性好对应力集中情况不敏感的Q235-A降低材料的成本为减少结构的超静定次数改善受力同时又方便运输桥架采用六梁铰接式结构主副小车的起重量均偏大故采用偏轨箱型梁桥架偏轨箱型梁桥架不仅可减小小车的外形尺寸同时也增大了起升空间有利于铸造厂间的应用在设计时本着满足疲劳强度刚度稳定性的前提下尽可能节约材料考虑铸造起重机主副小车之间有一定得高度差使副小车能自如地从主小车下面通过故在设计主主梁时采用大截面薄钢板从而达到节省材料重量轻的要求同时采用大截面又提高了梁的刚度和稳定性根据梁的受力特点偏轨箱型梁主腹板上侧受局部压应力将主腹板上侧的板加厚而其它受力较小的地方则采用较薄的板以节约材料在设计过程中全部采用国家标准并借鉴了在实习时所参观的太原重工大连重工起重同类产品的设计在结构上进行改进对桥架的受力进行了较详尽的分析整个设计安全可靠节材耐用满足了设计要求第一章 总体方案设计11 原始参数起重量Q 主副 18050t跨度S 22m工作级别Ai A8起升高度H 主副 2022m起升速度V 主副 45114 mmin运行速度 主副大车 36337735 mmin轮距 主副大车 408018509800 mm轨距 主副大车 8700300022000 mm轮压 主副大车 345001964087600 kg起重机重量 220t12总体结构及设计根据已给参数此桥式铸造起重机吨位跨度较大为减少结构的超静定次数改善受力方便运输选用六梁铰接式结构结构框架如图 1 图 1 13 材料选择及许用应力根据总体结构铸造起重机工作级别A8为重级工作环境温度较高设计计算时疲劳强度为其首要约束条件选用Q235-A考虑起重量较大主副梁均采用偏轨箱型梁材料的许用应力及性能常数见表1表2表11 材料许用应力板厚正应力剪应力mm 1637015201679184487769694106537015881754192691710131112表12 材料性能常数表弹性模量E剪切弹性模量G密度14各部件尺寸及截面性质1 主主梁尺寸初选高度 12941571mm考虑大车运行机构安装在主梁内且主主梁与副主梁的高度差必须满足一定得要求故将主主梁取为大截面薄钢板的形式以达到节省材料重量轻的要求因此取腹板高度mm为了省去走台对宽型偏轨箱型梁主主梁腹板内侧间距取mm 440mm上下翼缘板厚度mm上翼缘板长2530mm下翼缘板长2326mm主腹板厚度 mm副腹板厚度 mm上下翼缘板外伸部分长不相同有轨道一侧上翼缘板外伸长度mm取250mm其它翼缘外伸部分长度 mmmm 焊缝厚度 取 50mm轨道侧主腹板受局部压应力应将板加厚由局部压应力的分布长度设计离上翼缘板350mm的一段腹板板厚取为18mm主主梁跨中截面尺寸如图 2 图 2 2主主梁跨端截面尺寸高度mm要确定主主梁跨端截面尺寸只需确定其高度取 1300mm跨端下翼缘板厚度为18mm主主梁跨端截面尺寸如图 3 3截面性质 1 主主梁跨中 建立如图示的坐标系计算形心位置 1256851257mm 1238881239mm 计算弯心位置mm弯心近似地在截面对称形心轴上其至主腹板中线的距离为1021mm净截面面积 毛截面面积 计算惯性矩 对形心轴的惯性矩对形心轴的惯性矩 2 主主梁跨端截面性质净截面面积 毛截面面积 建立图示的坐标系计算形心位置计算惯性矩对形心轴的惯性矩对形心轴的惯性矩二副主梁尺寸1 初选梁高 12941571mm取腹板高度 上下翼缘板厚度 腹板厚度主腹板 副腹板厚度 副主梁总高 副主梁宽度 取腹板内侧间距 且 1100主腹板一侧上翼缘板外伸长度 取外伸长 其余悬伸长大于15倍的焊缝厚度取其尺寸如下图图 4 2 副主梁跨端截面尺寸的确定 确定其高度 取腹板高度为800 副主梁跨端截面尺寸如图 5 图 5 3 截面性质 1 跨中 建立图示的直角坐标系求形心位置净截面面积 毛截面面积 计算弯心位置A 弯心距主腹板板厚中线的距离为 计算惯性矩 对形心轴的惯性矩对形心轴的惯性矩副主梁跨端截面性质 建立图示的坐标系求截面形心位置净截面面积 毛截面面积 对形心轴的惯性矩对形心轴的惯性矩三端梁截面尺寸考虑大车车轮的安装及台车的形状尺寸端梁内宽取为600初设截面尺寸如下图 图 6 形心即对称中心 对形心轴的惯性矩净截面面积 毛截面面积 四各截面尺寸及性质汇总表图 7 尺寸汇总表 13 单位mm主主梁跨中181814122530232622002400跨端181814122530232622001264副主梁跨中16161081270118011001500跨端1616108127011801100800端梁12121010660660600776截面性质汇总表14净面积毛面积主主梁跨中123912571512085351034跨端12376751216722837066副主梁跨中629782662001681244跨端62442753600904944端梁33040031360480680第二章 桥架分析21 载荷组合的确定一动力效应系数的计算1起升冲击系数 09 对桥式铸造起重机 2起升动载系数 主主梁 副主梁 3运行冲击系数 为大车运行速度 735为轨道街头处两轨面得高度差 根据工作级别动载荷用载荷组合 进行计算应用运行冲击系数22 桥架假定 为了简化六梁铰结桥架的计算特作如下假定根据起重机的实际工作情况以主副小车一起工作为最不利载荷工况主主梁副主梁的端部与端梁在同一水平面内由于端梁用铰接分成5段故副主梁的垂直载荷对相互间受力分析互不影响将端梁结构看作多跨静定梁主主梁受力作为基本结构对副主梁无影响副主梁受力作为附属部分对主主梁有影响计算副主梁水平载荷时将铰接点看成刚性连接 23 载荷计算1主主梁自重 由设计给出的主小车轮压34500kg选用车轮材料ZG35CrMnSi车轮直径轨道型号QU120许用值38700kg由轨道型号QU120查得轨道理论重量主小车轨道重量 栏杆等重量 主梁的均布载荷 2主小车布置两侧起升机构对称布置重心位于对称中心吊具质量 起升载荷 小车重量 因主小车吨位较大采用台车形式八个车轮可求实际主小车满载时的静轮压一根主主梁上空载小车轮压 3惯性载荷一根主主梁上小车惯性力主小车上主动轮占一半按主动车轮打滑条件确定主小车的惯性力 大车起制动产生的惯性力4偏斜运行侧向力一根主主梁的重量为 主主梁跨端焊接上两块耳板与副主梁端梁连接在计算时按假想端梁截面进行计算图 8 与主主梁连接的端梁部分将超出轨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 对形心轴 的惯性矩对形心轴的惯性矩端梁净截面积 端梁毛截面积 一根端梁单位长度重量一组大车运行机构重量 司机室及其电气设备的重量 主主梁侧假想端梁重 满载小车在主主梁跨中左侧端梁总静轮压由下图 12 计算由 查图3-8得侧向力为 满载小车在主主梁左端极限位置左侧端梁总静轮压为 起升质量 起升载荷 起升钢丝绳滑轮组的最大下放长度为 取为吊具最小下放距离桥架跨中静位移为查选用倍率 由钢丝绳静拉力 选用型钢丝绳 起升钢丝绳滑轮组的静伸长 结构质量影响系数 桥式起重机的垂直自振频率4水平动刚度起重机水平动刚度以物品高位悬挂满载小车位于桥架跨中的水平自振频率来表征半桥架中点的换算质量为半刚架跨中在单位水平力作用下产生的水平位移为桥式起重机的水平自振频率为45 桥架拱度桥架跨度中央的标准拱度值考虑制造因素实取跨度中央两边按抛物曲线 设置拱度如下图 34 距跨中为 的点距跨中为 的点距跨中为 的点第五章 端梁校核51 主主梁端部耳板设计计算主主梁跨端结构受力工况满载小车位于主梁跨端大小车同时运行起制动及桥架偏斜1垂直载荷主梁最大支承力 因作用点的变动引起的附加力矩为按假想端梁计算自重 计算简图 35 端梁支座反力如图截面1-1 弯矩 剪力 截面2-2 弯矩 剪力 2水平载荷端梁的水平载荷有亦按简支梁计算见图 36 因作用点外移引起的附加水平弯矩为弯矩 截面1-1 剪切力 截面2-2在水平力作用下2-2处水平反力3主梁端部耳板设计截面性质建立如图示坐标系校核截面2-2处腹板中轴处切应力 合格截面1-1处销轴所受剪应力在验算端梁完计算见后面52 副主梁一侧端梁的校核1端梁校核载荷计算副主梁与端梁看作是多跨静定梁的附属部分主主梁对附属部分无影响工况取满载小车位于主梁跨端大小车同时起制动及桥架偏斜 1 垂直载荷主梁最大支承力 因作用点的变动引起的附加力矩为端梁自重 端梁在垂直载荷作用下按简支梁计算端梁支反力 截面1-1 截面2-2 2 水平载荷端梁的水平载荷有按简支梁计算因作用点外移引起的附加水平弯矩为先求支反力端梁的水平反力 水平剪切力 弯矩 截面1-1剪切力 轴向力 2强度校核只需校核2-2截面截面角点处应力腹板边缘的应力翼缘板对中轴的静矩为折算应力为 3疲劳强度只考虑垂直载荷工况满载小车位于跨中及跨端截面2-2满载小车在副主梁跨端时端梁截面2-2的最大弯矩和剪切力为空载小车位于跨中时端梁支反力下翼缘板焊缝应力根据A8及Q235下翼缘板采用双面贴角焊缝应力集中等级查得 焊缝拉伸疲劳许用应力 合格按查得取拉伸疲劳许用应力 合格4稳定性整体稳定性 稳定局部稳定性 翼缘板 稳定腹板 不需设置横隔板5校核销轴所受的力如图 40 耳板与端梁连接处销轴14所受垂直方向的剪力较大而23受水平方向拉力其在垂直方向几乎不受力只需校核受力较大的14销轴设计销轴直径为对销轴 合格对支撑板的挤压应力设支撑板厚20mm支撑板的挤压力 合格6副主梁与端梁的连接副主梁与端梁采用连接板贴角焊缝连接主梁两侧各用一块连接板与端梁的腹板焊接连接板厚 高度 取主梁腹板与端梁腹板之间留有的间隙在组装桥架时用来调整跨度主梁翼缘板伸出梁端套装在端梁翼缘板外侧用贴角焊缝周边焊住必要时在主梁端部内侧主端梁的上下翼缘板处焊上三角板以增强连接的水平刚度承受水平剪力副主梁最大支承力 连接处需要的焊缝长度为 合格至此桥架设计全部合格桥架结构施工图见附图致 谢感谢参考文献1 徐克晋主编 金属结构 北京机械工业出版社 19822 徐格宁主编 起重运输机金属结构设计 北京机械工业出版社 19953 大连起重机器厂编 起重机设计手册 沈阳辽宁人民出版社 19794 徐格宁主编 机械装备金属结构设计 普通高等教育十一五国家级规划教材 200895 起重机设计手册编写组 起重机设计手册 北京机械工业出版社 19776 倪庆兴王殿臣主编 起重输送机械图册 北京机械工业出版社 19927 张质文王金诺主编 起重机设计手册 北京中国铁道出版社 19978 陈道楠盛汉中主编 起重机课程设计 冶金工业出版社 19829 徐格宁智浩编 太原重型机械学院学报 1993年第4期第14卷铸造起重机桥架空间结构分析与疲劳计算 199310 刘鸿文主编 材料力学 高等教育出版社 2003附录APortal powerChinas rapid economic growth in the past decade has resulted in a big increase in freight traffic through the countrys seaports Old ports are being expanded and new ports built to handle the large growth in container and bulk cargo traffic all along the Chinese coastlineChinas 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 portal cranes along with bulk cargo handling equipmentState-run China Harbour Engineering group Corporation Ltd established under the ruling State Council is Chinas largest supplier of port cranes and bulk cargo handling equipment The organization controls both Shanghai Zhenhua Port Machinery Co Ltd ZPMC the worlds largest manufacturer of quayside container cranes and Shanghai Port Machinery Plant SPMP which specializes in the manufacturer of portal cranes and other cranes used in ports along with dry bulk cargo handling equipmentSPMPs main market is China although the company 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 plantPortal and other harbour cranes are SPMPs 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 expansionIn recent years SPMP has also supplied portal cranes to the United States Iraqand MyanmarThe port Rangoon of Myanmar in has purchased a 47m40t portal crane while BIW of the United States has purchased three cranes-15t150t and 300t portal cranes Elsewhere SPMP has supplied 12 portal cranes to several ports in Iraq since the end of the Saddam regime In China SPMPs 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 radius cranes for Zhenjiang Port Group and an order of 1025t 33m radius cranes from Fangcheng Port Bureau while the Yingkou Port Group has ordered 1325t35m radius cranes along with two 40t 44m radius port cranesMANY CRANES BUILT TO ORDERSPMP also supplies other cranes used in ports and harbours 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 Port Yin Kou Port Yan Tai Port and others The company also supplies rubber-tyred container gantry cranes to domestic and overseas clientsCustomers for other cranes used in ports include Guangzhou Port in Guangdong which purchased a 25t floating crane while Zhonggang Port has bought two double trolley 12563t gantry cranes along with a700t overhead crane In 2003 Zhonggang Port awarded a contract to SPMP for a 2600t floating crane whichi is the largest crane the company has made in recent yearsOther customers include Zhongyuan Nanytong Shipyard of Jiangsu Province has purchased two 300t goliath cranes for use in its shipyard while Shanghai Waigaoqiao Shipyard uses two of SPMPs 600t goliath cranes for its shipbuilding operations SPMP has two factories The Shanghai plant employs 2000 workers while a factory in Jiangsu Province employs 1500 workers The combined total of 3500 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 equipmentCurrently SPMP is preparing to vacate its Shanghai factory site as the companys existing plot of land is part of a riverside area earmarked by the Shanghai Expo in 2010 SPMPs Shanghai factory will close at the end of 2006 and move to a new site on nearby Changxing IslandThe 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 2006In addition to moving the Shanghai factory to a new site SPMP expects future business operation with ZPMCOfficials at China Harbour Engineering Group 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 are expected to retain their individual manufacturing capability however with precise details of future co-operation still some way from being finalisedMeanwhile SPMP associate company ZPMC is strengthening its position as the worlds largest manufacturer of ship-to-shore container cranes supplying slightly more than half the annual international container crane market In addition to operating four crane production complexes for its crane manufacturing and other businessesZPMCs full range of products includes quayside container cranes rubber-tyred gantry cranes bulk material ship 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 bridgesZPMC EXPANDING PRODUCTIONZPMCs cranes and other products are in 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 1148 rubber-tyred gantry cranes to customers worldwide and had orders in hand to deliver 308 rubber-tyred gantry cranes to customers in 2006ZPMC 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 surrounding area at Jiangyin Changzhou Zhangjiang and Changxing IslandThe Changxing production site which was completed in 2001 covers one million sq m and has a 35km coastline The facility is capable of manufacturing 160 quayside ship-to-shore container cranes each year along with 300 rubber-tyred gantry cranes and 200000 metric tons of large steel bridge structuresPlans call for a futher 3 million sq m of land to be reclaimed at Changxing which ZPMC will develop to become its largest production centreKorea looks inward In a fragmented global port crane industry Korean manufacturers are being forced to look for more business in their domestic markets South Koreas 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 from 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 suppliers 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 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 Doosan recently completed delivery of a 42-unit rubber-tyred gantry crane RTGC 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 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 handling 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 cranesBUILDING POWER PLANTSDoosan Heavy Industries major activities include the 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 handling equipment is produced by Doosans 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 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 our 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 bidding on various tenders Doosan is expected to be one of the bidders for container cranes to be installed in South Koreas planned Kwangyang Bay Port expansion The companys RD division is involved developing new automated controls that will be required for quayside container cranes installed 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 3-2 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 Koreas other container crane manufacturers also are expected to 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 RMGCs also known as automated transfer cranes at Pusan East Container Terminal PECT 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 285m rail gauge and have dual cantilevers covering two road lanes Stack height is 1 over 6 by 9ft 6in high and operational speeds are 150mmin for the gantry 120mmin for the trolley and 75