集装箱船舶大型化对中国班轮运输的影响

通过竞争情报分析提供了各班轮公司未来船队结构和运力的变化趋势,由此观察到各班轮公司为了降低自身的营运成本,在最近几年大量订购超巴拿马型甚至更大型的集装箱船舶参与运输,但是却不能达到其预期的规模效应。原因就在于相当一部分成本随着船型的增大而线性增加,规模不经济。我们探讨了中国的班轮运输市场的几个重要特点:中外贸易的不平衡导致了货源的不平衡;未来贸易结构的调整会影响航线的布局和调派;贸易上的不稳定因素使班轮公司遇到外在的风险。这些特点会深远地影响集装箱船舶大型化的经济受益,相反的,集装箱船舶大型化的趋势也会加剧这些负面的影响,危及整个班轮运输市场。     

Designing optimal routes in a liner shipping problem

A real liner shipping problem of deciding optimal weekly routes for a given fleet of ships is considered and a solution method for solving the problem is proposed. First, all feasible routes for each ship are generated together with the cost and the duration for each route. The routes are given as input to an integer programming (IP) problem. By solving the IP problem, routes for each ship are selected such that total transportation costs are minimized and the demand at each port is satisfied. The total duration for the routes that are selected for a given ship must not exceed one week.

The real liner shipping problem is solved together with four randomly generated test problems. The computational results show that proposed solution method is suitable for designing optimal routes in several liner shipping problems.     

Designing optimal routes in a liner shipping problem

A real liner shipping problem of deciding optimal weekly routes for a given fleet of ships is considered and a solution method for solving the problem is proposed. First, all feasible routes for each ship are generated together with the cost and the duration for each route. The routes are given as input to an integer programming (IP) problem. By solving the IP problem, routes for each ship are selected such that total transportation costs are minimized and the demand at each port is satisfied. The total duration for the routes that are selected for a given ship must not exceed one week.

The real liner shipping problem is solved together with four randomly generated test problems. The computational results show that proposed solution method is suitable for designing optimal routes in several liner shipping problems.     

Fleet deployment optimization for liner shipping: an integer programming model

Extending and improving an earlier work of the second author, an Integer Programming (IP) model is developed to minimize the operating and lay-up costs for a fleet of liner ships operating on various routes. The IP model determines the optimal deployment of an existing fleet, given route, service, charter, and compatibility constraints. Two examples are worked with extensive actual data provided by Flota Mercante Grancolombiana (FMG). The optimal deployment is solved for their existing ship and service requirements and results and conclusions are given.     

Fleet deployment optimization for liner shipping Part 2. Implementation and results

We use linear programming (LP) for solving the problem of the optimal deployment of an existing fleet of multipurpose or fully containerized ships, among a given set of routes, including information for lay-up time, if any, and type and number of extra ships to charter, based on a detailed and realistic model for the calculation of the operating costs of all the ship types in every route and on a suitable LP formulation developed in earlier work of the authors. The optimization model is also applicable to the problem of finding the best fleet compostion and deployment, in a given set of trade routes, which may be the case when a shipping company is considering new or modified services, or a renewal of the existing fleet. In addition, two promising mixed linear-integer programming formulations are suggested.     

Fleet deployment in liner shipping: a case study

The fleet deployment problem is an important planning problem in liner shipping. It deals with optimally assigning voyages to available vessels in the fleet and determining vessel routes and schedules in a way that minimizes costs or maximizes profit. This paper presents a new model for a fleet deployment problem in liner shipping, and we also propose a multi-start local search heuristic to solve the problem. The heuristic has been embedded in a prototype decision support system (DSS) that has been implemented and tested at Höegh Autoliners, a major global provider of ro-ro (roll-on roll-off) vehicle transportation services. The heuristic was able to produce high-quality solutions within a few minutes to a real planning problem with more than 55 vessels and 150 voyages over a planning horizon of 4–6 months. Tests indicated that the solutions suggested by the DSS gave between 2 and 10% improvements compared with solutions from manual planning. What is almost equally important is that using the DSS can ease the planning process.     

Fleet deployment optimization models. Part 1

The problem of minimum-cost operation of a fleet of ships that has to carry a specific amount of cargo between two ports in a given time period for a specific, fixed contract price is studied. Detailed and realistic operating cost functions are developed. Sensitivity analyses are performed to study the effects of small or large changes in one or more cost components on the total costs. A realistic model for the annual transport capacity as a function of speed is also used, in contrast with the linear relation most often used in the literature. The full load and ballast speeds for those ships of the fleet that we operate are selected to minimize the total fleet operating costs including lay-up costs for unused vessels, using nonlinear optimization algorithms.     

论方便旗船突出存在的几个问题及PSC对策

方便旗船凭借在政治、经济上的巨大优势已成为国际海运的主流,但部分船舶在安全方面的痼疾日益突出。此文从5个方面分析了方便旗船存在的影响船舶安全的突出问题,通过PSC检查提出扼制低标准方便旗船和提高船舶安全适航性的对策。     

高速客运船队规划模型构建及应用

针对高速客运的特点,在现有船队规划线性模型基础上,构建引入船舶更新的高速客运船队规划非线性模型,对该模型求解方法进行探讨,实例验证该模型的可行性和有效性。     

基于遗传算法的编队条件下舰船修理周期结构优化

舰船的部署和修理活动在全寿命期内是按其修理周期结构进行,而编队的使用则需要编队内各舰艇的修理周期结构的相互配合,通过组合优化各舰艇的修理周期结构,可以使编队拥有更多的部署时间。在舰船修理周期结构的定量描述模型基础上,构建了编队的修理调度模型,并采用遗传算法对编队的部署能力进行了优化分析。实例分析结果表明:优化后编队的部署时间可达到近110个月,相对于未优化前提高了50个月。     

Optimal reefer slot conversion for container freight transportation

Given a fleet of container ships of varying capacity, a cost-efficient approach for improving fleet utilization and reducing the number of delayed containers is to optimize the sequence of container ships in a given string, a problem which belongs to the large ship-deployment class. A string sequence with ‘uniformly’ distributed ship capacity is more likely to accommodate a random container shipment demand. The number of one’s total ship slots acts as a gauge of the capacity of the container ships. Meanwhile, there are two types of ship slots: dry slots and reefer slots. A dry slot only accommodates a dry container, while a reefer slot can accommodate either a dry or a reefer container. The numbers of dry and reefer slots for ships in a string are different. Therefore, in this study, we propose a model that considers both dry and reefer slots and use it to elucidate the optimal ship-deployment sequence. The objective is to minimize the delay of dry and reefer containers when the demand is uncertain. Furthermore, based on the optimal sequence deduced, the study also investigates the need to convert some dry slots to reefer slots for the container ships.     

A dynamic model and algorithm for fleet planning

By analysing the merits and demerits of the existing linear model for fleet planning, this paper presents an algorithm which combines the linear programming technique with that of dynamic programming to improve the solution to linear model for fleet planning. This new approach has not only the merits that the linear model for fleet planning has, but also the merit of saving computing time. The numbers of ships newly added into the fleet every year are always integers in the final optimal solution. The last feature of the solution directly meets the requirements of practical application. Both the mathematical model of the dynamic fleet planning and its algorithm are put forward in this paper. A calculating example is also given.     

Korean liner shipping in the era of global alliances

In the course of the last two decades Korean shipping has emerged as a major player in the liner market. In 1970 there was not a single container ship in the Korean fleet; yet, within the next two decades, shipping companies from Korea have become included among the top 10 liner operators in the world, in the context of a spectacular ascent of Asian companies in international container shipping. During the same period the organization of liner shipping itself underwent major changes. In the 1970s and 1980s, pools and powerful consortia prevailed, maximizing frequency and optimizing fleet deployment under pressure from the high investment entailed by containerization. The era of consortia, however, came to a close in the early 1990s; intermodalism and the expansion of the major liner companies into forward and backward segments of the transport chain rendered them inflexible for pursuing individual strategies of product diversification with a view to larger market shares. Global alliances were finally born as a result of a major reshuffling of co-operation agreements and of the globalization of the production process on the demand side. The aim of this paper is to follow and assess the options available to an aggressive low-cost national fleet in its journey to competitive maturity through a period of changing organization of liner shipping, focusing on the course of the leading Korean container company, and one of the largest in the world today, Hanjin. It highlights at the same time both the deep structural changes which liner shipping has undergone in the last two decades and the effects of current changes, such as the recent wave of mergers in this sector.     

SHIPPING IN CHINA

China opens maritime satellite mobile telephone services;China＇s first ship-related talent market settles in Zhoushan;Yangshan port will expand policy application scope;Tianjin electronic terminal and logistics information platform opened;     

Bigger vessels: How big is too big?

Growth in container liner traffic has been high for several decades and current growth rates are expected to continue, putting pressure on ports and liner companies to increase investment. Several factors are pushing up the capacity of new buildings, and bigger, rather than more, ships alleviate pressure on ports. But ship operating cost benefits will be eroded unless cargo handling performance can be upgraded. Because of physical inhibitions in existing facilities the recent pace at which lines have increased the size of the biggest ships operating seems likely to plateau in the next few years.     

Estimation of CO2 reduction for Japanese domestic container transportation based on mathematical models

This research discusses domestic feeder container transportation connected with international trades in Japan. Optimal round trip courses of container ship fleet from the perspective of CO₂ emission reduction are calculated and analyzed to obtain basic knowledge about CO₂ emission reduction in the container feeder transportation system. Specifically, based on the weekly origin–destination (OD) data at a hub port (Kobe) and other related transportation data, the ship routes are designed by employing a mathematical modeling approach. First, a mixed integer programming model is formulated and solved by using an optimization software that employs branch and bound algorithm. The objective function of the model is to minimize the CO₂ emission subject to necessary (and partially simplified) constraints. The model is then tested on various types of ships with different speed and capacity. Moreover, it is also tested on various waiting times at hub port to investigate the effect in CO₂ emission of the designated fleet. Both the assessment method of container feeder transportation and the transportation’s basic insights in view of CO₂ emission are shown through the analysis.     

三峡船闸等惯性输水系统船队(舶)系缆力的探讨

本文依据三峡船闸的水力学试验结果,对船闸灌水过程中闸室内停泊条件的试验进行了分析,认为船队(舶)系缆力与进入闸室的流量增率,闸室、船舶尺度,排列型式以及停泊位置等因素有关,以此分析整理出用于船闸等惯性输水系统闸室内船队(舶)系缆力的经验公式,并选取了部分实例的计算结果与实测值进行对比,两者较吻合。     

护航编队中防空舰艇反导作战队形的研究

基于随机服务系统理论,建立了舰载防空导弹武器系统排队论模型,对其作战效能进行评估。文章分析了舰艇反导作战队形对防空导弹武器系统效能的影响,为护航编队中防空舰艇反导作战的编队形式提供了参考。     

Strategic fleet size planning for maritime refrigerated containers

In the present economic climate, it is often the case that profits can only be improved, or for that matter maintained, by improving efficiency and cutting costs. This is particularly notorious in the shipping business, where it has been seen that the competition is getting tougher among carriers, thus alliances and partnerships are resulting for cost effective services in recent years. In this scenario, effective planning methods are important not only for strategic but also operating tasks, covering their entire transportation systems. Container fleet size planning is an important part of the strategy of any shipping line. This paper addresses the problem of fleet size planning for refrigerated containers, to achieve cost-effective services in a competitive maritime shipping market. An analytical model is first discussed to determine the optimal size of an own dry container fleet. Then, this is extended for an own refrigerated container fleet, which is the case when an extremely unbalanced trade represents one of the major investment decisions to be taken by liner operators. Next, a simulation model is developed for fleet sizing in a more practical situation and, by using this, various scenarios are analysed to determine the most convenient composition of refrigerated fleet between own and leased containers for the transpacific cargo trade.     

Combined ships: an empirical investigation about versatility

Combined ships have been built in order to minimize ballast voyages and to take advantage of the highest freight rates on either market, oil or dry cargo market. Then their versatility should have been very attractive for shipowners. So why has the combined fleet shrunk to such an extent? This paper provides an analysis of the employment of combined ships, how this has been influenced since the 1970s, and how these ships may have influenced oil and dry market balances. The research identifies the decisive role that grain trade seems to be able to play about shifting markets, and that combined ships were the largest bulk carriers in the 1970s. It is an opportunity to stress that freight rates are not always the only salient point for a shipowner's decision and to consider the importance of combination ships contribution to shipping markets.