大型集装箱船甲板堆重的影响因素

以某14 500 TEU集装箱船为对象,基于DNV GL规范对影响集装箱船甲板堆重的主要因素进行分析。首先介绍新规范采用的横向加速度系数计算方法,对比新旧方法对甲板许用最大堆重的影响;然后对比分析绑扎形式以及绑扎桥层数对甲板许用最大堆重和系固系统设计的影响。结果表明:随着规范的更新,集装箱横向加速度系数明显降低;同时,由于采用外绑形式和3层绑扎桥,大型集装箱船甲板堆重能力明显提高,但这也对集装箱系固系统设计带来了一些新的影响。     

超大型集装箱船绑扎桥选型及设计探讨

考虑到绑扎桥是超大型集装箱船的关键设备,其合理选型及设计关系到甲板上集装箱的堆装能力及系固安全性,以堆重指标、航线要求、集装箱布置为设计出发点,分析绑扎桥各个设计要点的关键因素,基于有限元方法进行绑扎桥的强度计算分析,探讨绑扎桥高度增加的经济性。     

大型内贸集装箱船甲板上集装箱绑扎设计

以某型4200TEU内贸集装箱为研究对象,对大型内贸集装箱船甲板上集装箱绑扎设计进行研究,提出3种绑扎布置方案。针对5个装箱Bay位、2个GM值和不同的风压载荷,分别对3种绑扎布置方案的20ft和40ft箱列进行绑扎计算,得到各绑扎布置方案可实现的最大堆重沿船长方向的分布情况和各绑扎布置方案在最大堆重状态下20ft和40ft内部箱列的箱重分布情况。通过对堆重计算结果进行分析,从保证船舶装载能力的角度确认其中2种绑扎布置方案的可行性;通过对比各方案在最大堆重状态下的箱重分布,验证绑扎桥对配载灵活性的有利影响;同时,从经济性和绑扎作业量2方面对2种绑扎布置方案的优缺点进行比较。     

两种横向加速度计算方法对集装箱系固的影响

基于700～4 200 TEU等5种典型的集装箱船,对《CCS-2012》规范和《CCS-2017》规范给出的2种用于集装箱系固计算的横向加速度计算方法进行对比,计算5种船型不同纵向位置的横向加速度及可实现的最大堆重,基于4 200 TEU集装箱船讨论船型参数对《CCS-2017》计算结果的影响,结果表明,与《CCS-2012》相比,《CCS-2017》对船舶尺度大于1 900 TEU级的中、大型集装箱船的系固设计有利,但将给船舶尺度小于1 900 TEU级的小型集装箱船的系固设计带来不利影响;对于船舶尺度大于1 900 TEU级的集装箱船,随着船舶尺度的增加,《CCS-2017》的优势越明显;方形系数、航速、船宽对《CCS-2017》的横向加速度及最大堆重计算结果存在一定影响,其中船宽是最主要的影响因素。     

超大型集装箱船绑扎桥结构强度分析

大型集装箱船的甲板堆重和绑扎桥高度均大幅增加,保证绑扎桥结构强度是设计的关键。针对某万箱级集装箱船,分析不同型式的绑扎桥结构特点,优化设计一型新型剪力墙式绑扎桥,满足英国船级社(LR)规范的相关要求。建立结构有限元模型,分析计算不同载荷工况下绑扎桥的结构强度,探讨绑扎桥的应力分布特点和不同绑扎桥布置方式对结构强度的影响,为绑扎桥结构设计提供参考。     

大型集装箱船绑扎桥结构优化设计

为有效降低大型集装箱船的空船重量,针对绑扎桥结构轻量化设计进行研究。以某14500TEU集装箱船为研究对象,根据船级社规范要求针对结构设计方案进行有限元计算分析,依次从剪力墙布置、立柱设置和局部尺寸优化等三个层次对原始方案进行优化设计。研究结果表明,优化方案在满足船级社规范要求、保证堆重指标的同时有效降低了绑扎桥的结构重量。本文的设计思路和优化方法可以为今后大型集装箱船绑扎桥的结构设计提供一定参考。     

大型集装箱船绑扎桥下加强结构强度分析及拓扑优化设计

近年来,集装箱船向大型化趋势发展,甲板堆箱不断增加,对绑扎桥的设计要求随之不断提高,绑扎桥下加强结构也需要承受更大的载荷。本文以某大型集装箱船为研究对象,对绑扎桥及舱口围结构进行有限元强度计算,分析整体的应力分布特点。采用基于改进遗传算法的双向渐进结构优化法（G-BESO）,对绑扎桥下加强结构进行拓扑优化设计,在保证结构安全性的前提下,有效减轻绑扎桥下加强的结构重量,提高经济性。     

集装箱系固计算综述

针对集装箱船航行过程中集装箱的运输安全,探讨了集装箱系固的计算方法。以德国劳氏规范和中国CCS规范为依据,分析了集装箱的受力及力的传递与分配,重点阐述了集装箱堆重计算的原理。并以堆重计算为基础,介绍了捆扎计算的基本方法。希望对集装箱船的结构设计以及舾装设计有参考作用。     

超大型集装箱船绑扎桥结构轻量化设计

为了有效降低绑扎桥重量对超大型集装箱船空船重量和重心的影响,针对某20 000 TEU集装箱船剪力墙式绑扎桥设计任务,根据某船级社规范要求和绑扎桥结构强度有限元计算分析的基本流程,依次从立柱优化、剪力墙优化、立柱和剪力墙对常规方案进行优化设计,结果表明,优化方案能满足船级社规范要求,且能有效降低绑扎桥的结构重量。     

多式联运环境下集装箱的安全

<正>海运在国际集装箱多式联运中占据主导地位,为了不断提高船舶运营的规模经济效益,用于远洋运输的集装箱船一直朝着大型化方向发展,集装箱装载量已达到2.4万箱,船舱内集装箱堆垛层数增至12层,通过应用更高的绑扎桥,甲板上集装箱堆垛层数也增加至最高13层。近年来,随着集装箱船的大型化趋势,坠箱事故呈频发态势,已成为一个日益严重的问题。坠海丢失的集装箱会带来严重的安全和环境风险,特别是当它们运载的是危险货物或海洋污染物时。     

Evaluation of expected maximum values of forces acting on containers and lashing rods on a container ship

The appearance of a number of large container ships in the 8000 TEU range raises the importance of a plan for container lashing arrangements on deck in relation to the design of the ship. Therefore, it is expected that a new method for evaluating the lashing arrangements on deck will be introduced which is applicable regardless of the ship's size and the lashing pattern, instead of using the standards of several different societies, as happens at present. To evaluate the lashing arrangements on deck, the expected maximum values of the forces acting on the containers and lashing rods should be evaluated. This paper presents a new method of evaluating the container lashing arrangements on a container ship using an "acceleration ellipsoid." The applicability of the acceleration ellipsoid to an evaluation of the expected maximum values of the forces was examined by comparing the expected maximum values of the forces calculated by the long-term distribution calculation known as the "Fukuda method," to those calculated using the acceleration ellipsoid. By comparing these results, it was confirmed that the expected maximum values of the forces calculated using the acceleration ellipsoid were not less than those calculated through by the long-term distribution calculation. It is concluded that the acceleration ellipsoid can be used to evaluate the expected maximum values of the forces acting on containers and lashing rods. Received: December 14, 2000 / Accepted: March 22, 2001     

Experimental and numerical investigation of lashing bridge and container stack dynamics using a scaled model test

Previously reported container losses were generally attributed to extremely violent motions of containerships due to adverse weather conditions. However, most existing specifications or standards adopted for containers and lashing equipment meet the requirement of static conditions. Hence, further researches on safer container shipping under heavy sea states are required. Consequently, an experimental study method is proposed to measure the dynamic response of 1/10 scaled lashing bridge and container stack. The scaled model of the lashing bridge is constructed based on the similarity theory. Based on two dimensionless numbers, Froude's number and Cauchy's number, eleven container scaled models are employed. A series of experiments with controlled parameters are performed using a three-degrees shaking table (roll, pitch, heave) to present sufficient data to verify the effectiveness of the numerical model. The results of experiments, numerical simulations and calculations of the VERISTAR procedure (developed according to the BV rule) are compared. This study aimed to explore the mechanical behavior of the lashing bridge and container stack under predetermined driving excitations (roll and pitch) which simulated heavy sea states. According to the results, the model can predict conditions similar to real situations of the lashing bridge and container stacks while storages on the weather deck.     

Investigations of vehicle securing without lashings for Ro-Ro ships

To reduce the area on deck occupied by each car and the labour and time required for lashing and unlashing cars, it has been proposed by the author that in some conditions, cars on decks could be transported without lashing. To evaluate cargo securing based on this “lashing-free” concept, computational code was developed to calculate the vehicle–deck interactions for various ship motions. The code was structured by incorporating a vehicle model into a piece of ship motion calculation code. A series of time-domain simulations were conducted to evaluate vehicle securing. It was found that for a target ship consisting of a 6000-unit Ro-Ro vessel, vehicle securing is mainly influenced by the ship's rolling motions and is highly dependent on the wave height and loading conditions. It was suggested from the analysis that vehicles could be secured without being lashed in a large area of the ship in specific weather conditions and on some routes with less adverse sea states. However, it is still suggested that conventional lashing holes should be constructed on the deck because in severe sea states the cars will still need to be lashed. The limitations of the current investigations are also presented. The relevant research work was carried out at the Division of Ship Design and Engineering, Department of Shipping and Marine Technology, Chalmers University of Technology.     

On board measurement of stresses and deflections of a Post-Panamax containership and its feedback to rational design

One of the most important points in structural design of containerships is the strength of hatch corners. Formerly, hatch corners used to be assessed by combining the component induced by hull girder vertical bending and the component induced by hull girder torsion. In the design of new generation containerships without deck girders, the effect of cross deck fore-aft deflection has also become prominent.Another point is the impact of structural displacement on the deck fittings. About new generation ships, large fore-aft deflection of cross decks raised the new problem of interference of hatch covers, lashing bridges and other deck fittings.To cope with such problems, comprehensive analysis has been carried out during the design stage of a Post-Panamax containership. In parallel with this analysis, on-board measurement had been conducted for 3 years after delivery, in order to confirm wide varieties of structural reaction of a large container ship in seaways. Procedure to derive components of stress and deformations from selected measurement points was developed, and actual values were calculated based on actual measurement.From long-term prediction of each component, it was found that design assumption was in general appropriate. However, regarding the fore-aft deflection of cross deck strip, actual stack load is generally much smaller than the design value, and the resulting predicted extreme value was much smaller than design assumption. This factor should be taken into account in the design stage.Regarding the correlation between hull girder vertical bending and fore-aft deflection of cross deck strip, design assumption of full combination is too conservative. From the measurement, no explicit correlation was observed. Regarding the correlation between hull girder vertical bending and wave induced torsion, design assumption of no correlation was appropriate. From these results, new formulae to combine these three deflection modes were proposed.Whipping was observed in the measured data, indicating that more careful attention should be paid to avoid large stress concentration in deck area to enhance fatigue strength.     

Statistical study of lashing forces measured on-board a PCTC vessel

Lashing forces and reaction forces between the car tyres and ship deck were measured on-board a PCTC vessel operating in the North Atlantic and statistically evaluated. A study was done of the characteristics of lashing forces and defined required friction coefficient. The lashing forces and the required friction coefficient were found to be small. The influence of wave direction on the forces was also small.     

14000kW海洋救助船直升机平台的结构设计

本文介绍了“14 000 kW海洋救助船”直升机平台的结构设计。分别对横骨架式和纵骨架式这两种结构形式的直升机平台进行优化设计和比较,得到了相对较优的设计方案,并取得了一些结论。     

三用工作船挡货栏杆结构设计与分析

诸多功能集于一身的三用工作船(Anchor Handing Tug Supply Vessel, 以下简称AHTS)在有限的甲板空间内既要保证载货面积,又要预留足够的人员通行和设备空间。挡货栏杆作为甲板上主要的结构件,其设计一直是个难点。本文以某AHTS为例,就挡货栏杆的立柱、顶梁、拦挡构件和设备基座等主要组成部分及其结构特性进行概述,并给出立柱受货物侧向压力和受绑扎件集中力的强度校核方案,为挡货栏杆的设计提供参考和借鉴。     

船运木材货物的注意事项

介绍了木材货物在甲板及舱内积载时的注意事项、系固绑扎方法及船舶航行途中应采取的措施,提出一些有益的建议,对木材船的安全运输有一定的帮助。