Prediction of capsizing probability for a ship with trapped water on deck

The authors have already examined a method for evaluating the capsizing probability of a ship in the dead ship condition based on a piecewise linear approximation of the restoring arm. Here, this method is extended to ships with trapped water on deck. This is because the stability of ships having a relatively high bulwark, such as fishing vessels, could substantially deteriorate due to trapped water on deck. First, the mean amount of water trapped on deck was estimated as a function of the significant wave height and the mean wave period using a model experiment in irregular beam seas. Second, the restoring arm curve with trapped water on deck was calculated hydrostatically and then approximated with a piecewise linear curve. Third, the roll angle was estimated using a nonlinear and uncoupled equation of absolute roll angle under stochastic wave and wind exciting moments. The short-term and long-term capsizing probabilities were calculated for a fishing vessel operating off Kyushu. Numerical results quantitatively demonstrated that the effect on capsizing probability of trapped water on deck cannot be ignored when accurately evaluating the stability of fishing vessels.     

关于提升西江渔业船舶安全管理的思考

文中从西江渔业船舶水上交通安全现状出发,深入分析西江渔业船舶事故多发的原因,从加强安全宣传,提高渔业船舶安全性能,畅通与商船沟通联系渠道,加强商船瞭望值班,提高灾害性天气的预防预控能力,调整西江渔业船舶安全监管职能,健全渔业船舶安全管理的法律法规等方面提出安全管理对策,望有助于规范西江航运干线渔业船舶水上交通行为,降低西江渔业船舶事故发生率。     

船舶靠泊操纵模拟过程中的计算方法研究

在船舶靠泊操纵仿真中,由于船舶不能视为质点运动,因此船岸距离的计算不能简单地归结为点线距离,而应该用多边形间距方法进行计算。本文对这一问题进行了专门研究,找到一种将计算与判别合二为一的数值计算方法。该方法能避免坐标的组合判别,减少出错可能,而且简单易用。经仿真实践使用,能正确有效地完成多边形间距离的计算,具有一定的实用价值。     

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随着航运联营与联盟形式的出现,航运公司的船队及航线规模不断扩大,航线优化及运力配置变得更为复杂.本文结合航运业发展实际,在对传统的班轮航线配船模型进行改进的基础上,建立新的模型应用到航运联盟情况下航运公司箱位租赁决策与航线规划中.结果表明,在自身运力不足时,航运公司通过航运联盟箱位租用,对降低其系统成本、弥补航线运力、保证完成货运任务、加快船舶航班周期等的方面有突出的优点.     

NAPA软件在铺管船完整稳性计算的应用

NAPA软件是目前船舶稳性计算中应用较广的软件。应用该软件进行铺管船完整稳性计算,过程快捷简便、数据准确可信,并得到ABS船检认可。该软件的应用对同类船的研究设计人员有一定的参考价值。     

Optimal container ship size: a global cost minimization approach

ABSTRACT

Currently, the best container ship size in a service is determined mainly by the liner operator, considering only the economies of scale of ships. Its external diseconomies to the ports and shippers are usually not considered in the decision-making process, which may reduce the overall efficiency and lead to global nonoptimality. This study incorporates the cost to the shipping companies at the main lines, ports, and feeder services, as well as the external costs to shippers and ports in a hub-and-spoke network, and determines the best ship size and the number of weekly services to minimize the overall costs. The external cost to the shippers in the feeder ports is assumed to be proportional to the feeder cost, and a sensitivity analysis is provided. The maximum container ship size is estimated according to different levels of freight demand. A numerical analysis shows that the optimal size should be smaller than the current biggest container ships in service.     

Essential elements in tactical planning models for container liner shipping

Tactical planning models for liner shipping problems such as network design and fleet deployment usually minimize the total cost or maximize the total profit subject to constraints including ship availability, service frequency, ship capacity, and transshipment. Most models in the literature do not consider slot-purchasing, multi-type containers, empty container repositioning, or ship repositioning, and they formulate the numbers of containers to transport as continuous variables. This paper develops a mixed-integer linear programming model that captures all these elements. It further examines from the theoretical point of view the additional computational burden introduced by incorporating these elements in the planning model. Extensive numerical experiments are conducted to evaluate the effects of the elements on tactical planning decisions. Results demonstrate that slot-purchasing and empty container repositioning have the largest impact on tactical planning decisions and relaxing the numbers of containers as continuous variables has little impact on the decisions.     

Centralized versus distributed feeder ship service: The case of the Maasvlakte harbour area of Rotterdam

Coastal and inland feeder shipping is a critical factor for intercontinental container transport. The question is whether each intercontinental terminal should be equipped with its own service stations for feeder shipping, or whether pooling of the facilities would be more effective. For this paper, the service station examined for the service of feeder ships is equipped with two quay cranes operating in parallel supported by a small active quay stack. The centre for this feeder service consists of several of these stations. Simulation shows that a crane productivity of 96% is feasible with an average vehicle waiting time of 1 min, that a central service requires fewer service stations than a distributed service and that the quay transport for central and distributed transport requires the same number of terminal vehicles. The analysis shows that a centralized service is preferable, attracting 70% of the market potential.     

Container terminal employees’ perceptions of the effects of sustainable supply chain management on sustainability performance

ABSTRACT

Sustainability has become an important issue in container terminal operations. However, relatively little research has been conducted to assess its association with sustainable supply chain management (SSCM). In this study, SSCM consists of internal sustainability practices and external sustainability collaboration. We empirically examined the effects of internal sustainability practices and external sustainability collaboration on sustainability performance in container terminal operations at the Port of Kaohsiung in Taiwan. We developed a model adopting the SSCM construct, which consisted of two dimensions: internal sustainability practices and external sustainability collaboration. Several research hypotheses were formulated from the theory and the hypotheses were tested using survey data collected from 141 employees who worked with container terminals. We found that internal sustainability practices and external sustainability collaboration positively affected sustainability performance, whereas external sustainability collaboration had a positive influence on internal sustainability practices. There is a discussion of the implications of these findings for developing sustainability and improving sustainability performance in container terminals and ports.     

论二手船买卖下卖方无负担保证的违反与买方的法律救济

买卖合同中,卖方除了对货物负有品质担保义务之外,还负有船舶无负担保证义务。但实践中,被出售的船舶往往存在一些无需登记,买方也很难查找到的各种负担。虽然卖方有义务赔偿买方因发生在交船前的索赔而遭受的损失,但是在买方遇到此类索赔时,可能卖方已经破产,或已宣布清盘,所谓的担保也就成为一纸空文,故买方应注意事前的防范而非事后补救,以保护自己的利益。本文从二手船买卖的特点出发,解析其特点下卖方的无负担保证义务的内容和买方可能面临的风险,以及在卖方违反其义务时买方的法律救济问题。