Fatigue damage calculation for oil tanker and container ship structures

The fatigue behaviour of longitudinal stiffeners of oil tankers and container ships, subjected to dynamic loads, is analysed. The following dynamic load components are considered: hull girder vertical wave bending moment, alone and combined with the horizontal wave bending moment, hydrodynamic pressure and inertial forces caused by cargo acceleration.

The spectral method was selected to calculate the fatigue damage, based on S—N curves and Miner's rule. Following this approach, the fatigue damage may be calculated as a function of a stress parameter Ω_p, which represents the cumulative effect of wave induced loads in the unit of time and incorporates the combined effects of stress level and its occurring frequency.

Simple formulas for Ω_p of oil tankers and container ships are given, obtained from the results of hydrodynamic analyses performed on several ships, in different wave environments.

Several examples show the applicability of the methods to real ship structures. The method, however, still needs to be calibrated because of the simplifying hypotheses introduced in the loading conditions.     

MARPOL73/78公约附则Ⅱ2004年修正案对海事监管的影响分析

MARPOL73/78公约附则II2004年修正案实施对化学品船防污操作产生很大影响,文章介绍该修正案的新变化及对海事监管的影响。     

晃荡对CSR油船设计的影响

为明确船舶营运过程中晃荡载荷对不同船型液货舱构件的影响,基于《散货船和油船结构共同规范》,分析晃荡载荷的形成及决定晃荡载荷的因素,结合纵向和横向晃荡在油船中的具体载荷水平,分析晃荡运动对CSR油船液货舱结构的影响,以VLCC制荡舱壁为优化目标,提出新的设计方案,采用MSC.Patran&Nastran有限元分析软件,论证制荡舱壁局部开孔的可行性。     

关于液货船运输安全监督管理的现状与建议

长江沿江经济和化学工业的飞速发展,带动了长江液货船运输业的异军突起,同时也给水上安全与防污染工作带来了严峻挑战。文章对液货船运输安全监督管理的现状进行了分析,提出了加强安全管理的相关建议。     

Should chemical tankers' tank cleaning waters be banned from discharging into the sea?

Entering of chemical substances into aquatic environment occurs either by involuntary accidents or discharging of chemical wastes resulting from tank washing operations of tankers carrying chemicals. MARPOL 73/78 Convention strict regulations on discharging of chemical residues left in their tanks to the sea, but permits the discharging of such residues provided certain conditions are met. In the present study; the period from 1996 to 2016 is examined and the number of new tankers participating in the chemical tanker fleet and the distribution of these tankers according to dwt tonnage is shown. The tanker fleet which consisted of 1.882 ships in 1966 reached 3.923 units in 2016. Accordingly, the volume of chemical merchandise carried by sea was 132 million tons in 1996, but it reached 287 million tons in 2016. According to the order books, it is understood that these figures will increase even more. The increase in the number of tankers and the growth of the capacities means that more chemical substances are transported at the same time and the tonnage of the chemical waste discharged to the sea is also on increase. Based on the scientific background which proves that chemicals cause biological accumulation and acute and chronic toxicity on aquatic life, and the results of chemical tanker development over the last 20 years that has been presented; It is necessary for maritime authorities to reconsider the legal arrangements for allowing chemical tankers to discharge chemical wastes from tank washing waters to the sea.     

油轮洗舱的安全管理

油轮在洗舱时会给船舶和海洋环境带来风险,易发生人身伤亡事故和海难,因此如何做好洗舱时的安全管理是十分重要的。针对油轮洗舱中的各种风险,船长和船员要有充分的思想准备和应对措施,最重要的是要按照操作规程和规章制度办事,才能够保障船舶、人员和海洋环境的安全。     

加速单壳油船淘汰新规则的研究

国际海事组织 ( IMO)第 5 0届海洋环境保护委员会 ( MEPC)通过了有关单壳油船加速淘汰的修订案 ( MARPOL公约附则 I第 1 3G条 ) ,包括为油船延长申请状态评估计划( CAS)和禁止单壳油船装载重等级油 ( HGO)的新规则 ,有望于 2 0 0 5年 4月 5日在默认接受程序之下被强制执行。本文对此进行了介绍。并论述了其对油船市场影响     

大型油船航速估算方法

对现有的船舶航速估算方法分析比较，提出了大型油船的航速估算方法。其中有效功率估算是根据上海船研所肥大船系试验图谱和实船试验资料经分析、修正得出，与荷兰Ｈｏｌｔｒｏｐ法、大连造船厂法比较，本文方法均方差最小，估算值与试验值最接近；自航因子估算以ＳＳＰＡ大油轮系列自航试验资料为基础，用上海船研所大量肥大船模型自航试验数据修正得出。     

Modelling and forecasting the demolition market in shipping

ABSTRACT

We model the demolition market, an integral part of the international shipping industry. It is shown through the implementation of a Vector Autoregressive (VAR) model that international steel-scrap prices contribute decisively towards price discovery in the ship-demolition industry. Our finding is explained and attributed to the fact that the growth models of Southeast Asian countries, where the ship-demolition market is primarily located, rely on scrap metal imports. These are mainly obtained from the developed economies rather than the recycling of vessels. We then proceed to test the forecasting ability of our model and use it for price prediction in the ship-demolition market. We establish that it provides the decision-makers with a useful prediction tool which enables all stakeholders involved, the ship owner, the recycler and the cash buyer alike, to gain valuable insights of the underlying trend in the sector.     

逐步破坏法破损油船剩余强度研究

基于IACS共同规范研制了逐步破坏法计算完整油船极限强度和破损剩余强度的程序.考虑了船体发生搁浅碰撞后,其剩余有效剖面是非对称的,船体还可能发生不同程度倾斜的实际情况,计算了双壳油船在不同破损情况下破损船体的剩余强度,并给出了实例及结果分析.