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This paper gives a detailed overview of the last 50 years of research in maritime transportation, with special focus on operations research techniques applied to the seaside operations. We describe the evolution in industrial, tramp and liner shipping, identify the driving trends, and discuss future challenges.

This article is largely based on the surviving records of two Scottish tramp shipping firms, Hugh Hogarth & Sons and Lyle Shipping, the former privately owned throughout its history and the latter later a public company. It traces their birth and growth up to what became, after 1958 when ocean freight rates dropped, an increasingly difficult operational environment for British shipping firms dealing with increased international competition, political and economic volatility and financial pressures. As family owners died, chartered accountants increasingly took control of company boards to negotiate credit terms, arrange loans and overdrafts, and to chase tax-free allowances and investment grants from governments. In this regard, Hogarth and Lyle were no different to other British shipping companies. [ABSTRACT FROM AUTHOR]

This study explores the influence of uncertain waiting times together with uncertain fuel prices, in the selection of bunker fuel stops for a shipowner engaged in tramp shipping. We analyze the stochastic bunkering waiting times in the bunkering optimization problem using scenarios constructed from vessels' Automatic Information System (AIS) records and test their relevance to the bunkering decision. Our findings highlight the tradeoff between port efficiency, as characterized by waiting times, and the economic advantages of purchasing bunkers from cheaper port options and finishing the voyage in higher-priced bunker regions. Although the absence of waiting time would have produced similar results in our empirical setup, introducing waiting times altered the dynamics, making a price-attractive port like Piraeus not as attractive when risk-aversion is modeled, particularly given the risk of prolonged waiting.

The paper considers the vessels operating on carriages of bulk cargoes to get the maximum profit for the shipowner as his main goal. The items in search are the long-term contracts of affreightment with some clauses indicated as indeterminate values, that can be described using a range of values. It leads to a range of voyage indicators. The vessels’ deployment for getting the maximum profit depends on the market situation that is to say possible changes in vessels' time-charter rates and freight rates. This paper presents the mathematical model, based on the fleet and volumes of carriages under a set of contracts of affreightment during the due time. It includes the necessity for the commitment fulfilment by owned and time-chartered vessels and takes into account possible changes in freight rates for cargoes carriages. The presented numerical example demonstrates the opportunity for practical implementation of the model.

The paper searches the work process of a ship agent - providing a set of representation services and ensuring compliance with the interests of a vessel located in a sea port for the purpose of loading/discharging of cargo and/or for other purposes. Agents organize and coordinate the arrival, staying and departure of vessels from the seaport. In the paper, the agency service of ships in sea ports is presented as one consisting of three stages of the work of a ship agent - operations that are carried out before the arrival of the vessel in the port, during the stay of the vessel in the port and after her departure. The events that fixed the beginning and end of each stage are defined. The agency service process is rather complex due to the large number of third parties to be involved in the procedures and formalities that allow a vessel to arrive in the port and depart. Such a process is accompanied by the issuing of a number of documents that the agent must fill in in order to inform all interested parties. The main time of the vessels' stay in the port are cargo handling - loading and discharging operations. During this period, agency service includes non-stop control of cargo handling, considering the interests of the shipowner. The three stages of the process under consideration are formalized in their mutual dependence and mutual conditioning using the apparatus of temporal logic. Their clear coordination in time ensures the coordination of the process in general, because only the timeliness and correctness of each stage of the agency service process and its completion allow the next stage to begin. The presented process was formalized with the help of temporal logic operators, which can establish cause-and-effect relationships between the stages and ensure the continuity of the process and the interconnection of the stages themselves. A set of documents necessary for the start, execution and completion of each of the stages has been defined. Some of the documents are external to the ship agent, some are issued directly by him, but each of them is key in the implementation of certain operations in the process of agency service. [ABSTRACT FROM AUTHOR]

The paper considers the vessels operating on carriages of bulk cargoes to get the maximum profit for the shipowner as his main goal. The items in search are the long-term contracts of affreightment with some clauses indicated as indeterminate values, that can be described using a range of values. It leads to a range of voyage indicators. The vessels' deployment for getting the maximum profit depends on the market situation that is to say possible changes in vessels' time-charter rates and freight rates. This paper presents the mathematical model, based on the fleet and volumes of carriages under a set of contracts of affreightment during the due time. It includes the necessity for the commitment fulfilment by owned and time-chartered vessels and takes into account possible changes in freight rates for cargoes carriages. The presented numerical example demonstrates the opportunity for practical implementation of the model. [ABSTRACT FROM AUTHOR]

Tramp shipping operates in a highly competitive environment and is fundamentally considered a free trade economic model. Water transport ensures the supply of raw materials and the distribution of finished products in international trade. The main task for water transport is to ensure the reliability of supplies, at prices that are on the one hand profitable for carriers, and on the other hand, stimulate international trade. In this regard, carriers are taking various measures to improve supply. One of the measures that are in constant development is the organization of shipping. It is known that with good organization and cooperation in shipping, better results are achieved, which benefit everyone – carriers and consignors. Shipowners are in a constant process of renewing their fleet and organizing fleet management. The organizational forms are different, but some of them affect the application of the Treaty on the Functioning of the European Union. This publication examines checks in tramp shipping and their compliance given the Art. 101 of the Treaty on the Functioning of the European Union. The topic is under-researched and is of theoretical and practical interest. [ABSTRACT FROM AUTHOR]

Tramp shipping has played an important role in world seaborne trade since the 19th century. Shipowner companies operating in tramp shipping, which is a mean of maritime transport associated with bulk cargoes that make up three-quarters of all maritime trade, also provide an important economic power to the sector. These shipowners need to grow by making profitable investments in order to survive and maintain their competitive advantage in such a dynamic and competitive market. Based on this, in the exploratory study, fifteen interviews were made with the managers of the fifteen shipowner companies operating in the field of tramp shipping sector, and their opinions were taken about the concept of growth, growth in terms of quality-quantity, the reasons for growth, the factors considered, and the problems encountered in growth process. The data obtained as a result of the interviews were analysed with MAXQDA 2020, a computer-aided qualitative data analysis program. According to the results of the research, it has been determined that the shipowner companies mostly grow by expanding their fleet; market conditions and economic situation of maritime sector play an important role in the decision to grow, and financing, economic crises and government policies and laws are barriers to growth. [ABSTRACT FROM AUTHOR]

Due to the high initial costs and the uncertain returns of investment, the efficient green technology in shipping industry, shore power (SP), is still in a developmental dark age, especially its installation at bulk terminals and ships. This study examines the factors influencing the SP installation for bulk terminals and ships, elucidates the impacting mechanisms of one party's installation on the investment returns of the other, and reveals the decisive role of fleet operations in the installation decisions of both parties and corresponding carbon emissions. Employing a dataset representing real-world shipping routes and cargo types, the ship-cargo matching and ships' port-of-calls within a planning horizon are optimized with the objective of maximizing the profit of tramp shipping business by taking SP installation and usage cost into account. Portside SP decision-making model is also conducted to estimate the revenue generated by portside SP usage, and guide portside installation decisions based on the cost-benefit ratio. Finally, recommendations are proposed for ship owner, port operator and government to collaboratively navigate through the dark age of SP development, supported by the further discussion regarding fuel-electricity price gap and port loading efficiency. • Factors influencing the shore power (SP) installation for bulk terminals and ships are listed. • Decisive role of fleet operations in the decisions of both parties are revealed. • Ship-cargo matching and ships' port-of-calls in a horizon are optimized. • Recommendations are proposed for ship owner, port operator to collaboratively navigate through SP dark age. [ABSTRACT FROM AUTHOR]

The transition from sail to steam had more profound effects than any other development in the recorded history of merchant shipping. In combination with iron and steel hulls, steam power enabled ships to become larger, more reliable and more efficient, with far reaching effects on the shipping industry and world trade. But the question has rarely been asked, did the change make ships safer? This was of immediate concern to those working aboard the ships, but also to those who operated, financed, employed and insured them. It might be expected that an iron or steel hull, propelled independently of wind and tide, would be in less danger from accidental loss than a wooden ship largely at the mercy of the elements, but evidence is largely lacking. This paper reports a survey comparing the loss rates of sailing and steam-powered vessels in the British coastal bulk trades, where sail and steam were doing similar work in the same geographical setting. Although steam vessels were marginally safer, the difference in rates of loss are not as great as expected, and reasons for this are discussed, with particular focus on those who worked aboard them or had a financial or commercial interest. [ABSTRACT FROM AUTHOR]

A conference in shipping can be understood as a cartel-like association of competing shipping companies. The purpose is to ensure stable framework conditions in the form of 'sensible' freight rates. Conferences were first used in the second half of the nineteenth century by liner shipping companies. In tramp shipping, conferences became relevant at the beginning of the twentieth century. This article tells the story of two conferences in the tramp-shipping segment of the ice-transport business, both of which were active in the early twentieth century. Two groups of shipping companies, inspired by international developments, were established. One grouping was organized as most conferences were, while the other was organized more broadly. The former was a conference for shipping companies with wooden steamships, while the latter was for shipping companies with sailing ships. The development of these two organizations is followed in relation to the export of Norwegian natural ice. The article assesses the significance of ice freight for Norwegian shipping during the early twentieth century, the extent to which the two conferences were able to establish minimum rates for the transport of ice, and why the two conferences developed differently. [ABSTRACT FROM AUTHOR]

Between the late nineteenth century and the Second World War the global commerce of British, French, and German shipping firms relied heavily on seamen from South Asia, China, the Middle East, and Africa. This article focuses on the little-known story of Somali seamen from Northeast Africa on European steamships. As a particular category on the labor market, Somalis were subject to stigmatization. Somali seamen, moreover, became associated with a specific segment of maritime labor in the engine rooms of British tramp ships. In this sector, however, Somali firemen operated as individuals rather than bound by their origin or ethnic identity in the globalizing maritime labor market of the time. The analysis explores the recruitment, journeys, and employment patterns of Somali firemen, before arguing about their agency in connection with the structuring of global labor markets and in the context of colonialism. [ABSTRACT FROM AUTHOR]

Purpose. The presented study aims to systematize the definition of the terms «demurrage» and «detention», which are used in the theory and practice of maritime transportations, but are characterized by different meaningful definition when used in liner and tramp shipping, which requires the need for a comparative analysis. Methodology. For the stated comparative analysis, the applied information sources allowed to determine the specificity of the terms «demurrage» and «detention» both at the scientific level and at the level of practical implementation. Findings. The authors proved that despite their synonymous character, the terms «demurrage» and «detention» have fundamental differences when used in transportation contracts for the vessels of liner and tramp shipping. Taking into account the specific conditions of these organizational forms of shipping, the terms, the meaningful interpretation of which are the object of the study, have a different object of accrual, the procedure for substantiating the value of the corresponding rates and the procedure for calculating the total amount. Originality. The authors for the first time carried out a study in the context of two forms of organization of maritime transport (tramp and linear) and established the semantic features of the marine terms «demurrage» and «detention». Practical value. The commercial practice of transport companies, in particular shipping ones, is closely connected with technical, technological, organizational, legal, economic and even linguistic issues. The last aspect concerns the role of the accuracy of understanding of the terms by the parties to the transportation contracts concluded by shipping companies (liner and tramp shipping) with counterparties, since it is the responsibility of a material nature that follows from them. Clear interpretation of the terms is crucial to prevent possible disputes regarding the relevant payments. Uncertainty, which is currently present in scientific publications and literary sources of practical nature, leads to a free interpretation and substitution of the analyzed terms with each other without a clear distribution of the parties' responsibility in different forms of shipping.

In comparing the costs between the Northern Sea Route (NSR) and the Suez Canal Route (SCR), the NSR icebreaking tariffs are critical. A balance question of pricing rises: to cut the tariffs to attract more ship operators to use the NSR, or to increase the tariffs to cover the cost of the icebreaker fleet? However, currently active NSR icebreaking tariffs are in ceiling level, and the practical icebreaking fee is often negotiated and lacks transparency. This study explores the optimal NSR icebreaking tariff level from the price maker side for the transit tramp shipping on the NSR. The interlock of the exchange rate of Russian ruble per US dollar and the bunker price is also considered. By establishing a framework with four components and applying real data to implement the empirical study, we find that the optimal NSR icebreaking tariff level is 15% higher than the current ceiling level. At the optimal tariff level, the NSR can save 4.5–12.4% of the annual shipping cost from the SCR, whereas in a single voyage can save as high as 49.4%. [ABSTRACT FROM AUTHOR]

Currently, elements of ship procurement such as stores, lubricants, manning and various regulatory obligations represent a considerable amount of daily running costs. Specifically, ship provision decision-making consists of many uncertainties and a wide number of decision parameters due to the regional price and product quality differences. The primary objective of this study is to establish a decision support system for provision decision-making process. In order to achieve this, a policy management algorithm framework integrating the Delphi Technique (DT) and the Hesitant Fuzzy Set (HFS) approach was established. In the Delphi process, a survey was distributed to a group of experts from regional shipping companies. The overall consensus revealed that ship location, company policy, and inventory of products could be determined as the main decision-criteria consisting of various attributes which are expressed with linguistic terms. In order to transform linguistics terms to numerical values, the HFS was applied. This integrated methodological framework was also applied to selected case studies of two ships. It was found that it would be possible to reduce daily provision cost per crew from $10.36 to $8.24 and from $16.16 to $11.64, and to save, respectively, $19717.45 and $7404.45 within 453 and 470 days for given ships. [ABSTRACT FROM AUTHOR]

Copyright of Science-Based Technologies is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper studies the problem of the sailing speed optimization for tramp ships. The transportation time requirements which are associated with shippers' satisfaction are considered by a fuzzy membership function. A bi-objective model is proposed in which the minimum operation cost and the maximum shippers' satisfaction are optimized simultaneously. The optimal speed on each leg of a given ship route is determined. A fast elitist non-dominated sorting genetic algorithm (NSGAII) is improved to solve the problem. To test the performance of the proposed model and algorithm, a numerical experiment is designed. The results show that the proposed algorithm has good convergence property and convergence speed. [ABSTRACT FROM AUTHOR]

• The Tidal Berth Time Window concept is introduced for the first time in the routing problem. Tides can influence the feasibility of ship routes, leading to nonlinear multiple time windows associated with the shipload and the tidal pattern. • A formulation of nonlinear mixed integer programming is developed, encompassing ship routing, pickup-and-delivery scheduling, speed optimization, and tidal berth time windows. To the author's knowledge, this is the first study to jointly consider routing and speed optimization while incorporating both pickup-and-delivery and multiple time windows. • A Branch-and-Price(B&P) framework is proposed to solve the aforementioned model. The framework decomposed the model into a set partitioning master problem and a pricing subproblem. To generate possible routes, a spatial-tempo labeling algorithm and a heuristic acceleration are designed., These algorithms address pickup and delivery as well as speed optimization. Furthermore, tailored domination rules are implemented to handle multiple time windows. • Realistic simulated instances are used to test the model and algorithm. The results compare the effectiveness of the two proposed algorithms and demonstrate the economic benefits of considering the tidal berth time windows in tramp ship schedules. Tramp shipping companies need to schedule shipping routes and decide on appropriate speeds based on short-term demand. This task differs from traditional vehicle routing problems (VRPs) in that the ship may wait for the tide, which changes with time. The wait time is a nonlinear function of the load, and in this paper, we describe this kind of wait as the ship following a tidal berth time windows. Additionally, the speed of the ship affects both the wait time and the sailing cost. This paper proposes a mixed-integer nonlinear programming model to tackle this problem. A branch-and-price framework is applied to solve the model efficiently, decomposing the model into a set partitioning master problem and an elementary shortest path subproblem. A labeling algorithm incorporating ship speed is developed to handle the subproblem, and further enhancements are made by optimizing the speed separately. Computational experiments show the effectiveness and accuracy of the proposed solution approach for large-scale instances. Moreover, considering the tidal time windows allows for exploiting the practical benefits of raising tides, which benefits the tramp shipping industry. [ABSTRACT FROM AUTHOR]

This article investigates the rise to prominence and power of the British tramp shipowner Walter Runciman (1847–1937), a man who rose up from modest beginnings, to become a nationally renowned household name by 1914. For North East England tramp shipowners like Runciman, membership of various local and national institutions was extremely useful for forging business and personal connections, the foremost of these being the businessman-led Tyne Improvement Commission. In national contexts, the two main public shipping institutions Runciman became involved in were the Chamber of Shipping and the Shipping Federation. Moreover, Runciman and a few of his contemporaries found that their public and business credibility could be enhanced through their personal connections and associations with a specific network of nationally powerful businessmen and politicians. By entering the national public stage, shipowners like Runciman came to hold positions of real influence, power and control in matters of national importance in the late nineteenth and early twentieth centuries in Britain and beyond. [ABSTRACT FROM AUTHOR]

In this paper we explore tramp ship routing and scheduling. Tramp ships operate much like taxies following the available demand. Tramp operators can determine some of their demand in advance by entering into long-term contracts and then try to maximise profits from optional voyages found in the spot market. Routing and scheduling a tramp fleet to best utilise fleet capacity according to current demand is therefore an ongoing and complicated problem. Here we add further complexity to the routing and scheduling problem by incorporating voyage separation requirements that enforce a minimum time spread between some voyages. The incorporation of these separation requirements helps balance the conflicting objectives of maximising profit for the tramp operator and minimising inventory costs for the charterer, since these costs increase if similar voyages are not performed with some separation in time. We have developed a new and exact branch-and-price procedure for this problem. We use a dynamic programming algorithm to generate columns and describe a time window branching scheme used to enforce the voyage separation requirements which we relax in the master problem. Computational results show that our algorithm in general finds optimal solutions very quickly and performs much faster compared to an earlier a priori path generation method. Finally, we compare our method to an earlier adaptive large neighbourhood search heuristic and find that on similar-sized instances our approach generally uses less time to find the optimal solution than the adaptive large neighbourhood search method uses to find a heuristic solution. [ABSTRACT FROM AUTHOR]

The refined oil transportation problem investigated in this paper lies on the intersection of the scheduling and routing of tramp shipping and the petroleum supply chain, with unprecedented large-scale and complex rules. Two mixed-integer linear programming formulations are developed for the assignment between tasks, vessels, and timing issues. The first model uses a time-slot concept under a continuous-time representation, where the constraints that deal with vessel assignment, capacity, timing, demand, and slack stock control are considered. The second model uses a discrete-time representation with time assignment, portal counting, and strict stock control constraints. By virtue of the data collected from an oil company, this modeling approach is validated and used to generate feasible scheduling solutions with lower costs than are currently achieved in the real situation. Finally, the impact of the model parameters is analyzed under different optimization scenarios. [ABSTRACT FROM AUTHOR]

Shipping markets are dependent on international trade transactions that generate transport needs. These needs can dynamically change depending on global natural resources and commodity markets situation. The changes affecting shipping markets can also be caused by changes to the existing cargo flows and by establishing new ones in different geographies. It is anticipated that in the future shipping markets will change, visible by a decline in shipping in North America and Europe and an increase in Asia.

U radu se razmatraju horizontalni sporazumi o suradnji prijevoznih poduzetnika u segmentu pomorskog prijevoza. Najznačajniji horizontalni sporazumi prijevoznih poduzetnika u linijskoj plovidbi zasigurno su linijske konferencije. Linijske konferencije u mnogim su pravnim poredcima uživale određene oblike izuzeća od primjene prava tržišnog natjecanja, među njima je i Europska zajednica. Vijeće ministara je u rujnu 2006. godine usvojilo prijedlog Europske komisije za ukidanje izuzeća od primjene pravila tržišnog natjecanja na linijske konferencije koje djeluju na prometnim pravcima s EU. Ukidanje izuzeća stupit će na snagu u listopadu 2008. godine. To označava početak primjene novog, kompetitivnog pravnog režima u segmentu linijskog prijevoza. Kako bi se prijevoznim poduzetnicima olakšao prelazak na potpuno kompetitivni sustav, Komisija je u rujnu 2007. godine izradila Nacrt smjernica o prim jeni članka 81. Ugovora o osnivanju Europske zajednice na usluge prijevoza morem u kojima je najveću pozornost posvetila upravo horizontalnim sporazumima o suradnji prijevoznih poduzetnika u segmentu pomorskog prijevoza, sporazumima o razmjeni podataka među konkurentima u linijskoj plovidbi i pool-ovima u slobodnoj plovidbi. U svezi s horizontalnim sporazumima poduzetnika u linijskoj plovidbi, u Nacrtu smjernica navodi se kako razmjena podataka o količini, kapacitetu i cijeni između linijskih prijevoznika može proizvesti pozitivne gospodarske učinke u smislu povećanja učinkovitost pružanja usluga linijskog prijevoza, dok je razmjena podataka koji se smatraju trgovinski osjetljivima protivna pravu tržišnog natjecanja. U Nacrtu smjernica sadržani su i drugi naputci prijevoznim poduzetnicima u linijskoj plovidbi o tome u kojim će slučajevima razmjena podataka biti u skladu s pravilima tržišnog natjecanja EZ-a. Kad je riječ o pool-ovima, u Nacrtu se navodi kako, zbog njihovih različitih obilježja, svaki se pool mora analizirati zasebno kako bi se utvrdilo krše li se njime pravila o tržišnom natjecanju EZ-a te se daju podrobne upute o načinu provođenja te analize. U radu se razmatraju rješenja usvojena Nacrtom smjernica te prijedlozi i komentari zainteresiranih stranaka na koje se kritički osvrće.

Linijske konferencije su u mnogim zakonodavstvima uživale određene oblike izuzeća ili imuniteta od primjene prava tržišnog natjecanja. U EU Vijeće ministara je 1986. godine donijelo Uredbu 4056/86 kojom se određivanje cijena i reguliranje upotrebe kapaciteta linijskih konferencija, uz ispunjavanje određenih uvjeta, izuzima od primjene čl.81 i 82. Ugovora o osnivanju Europske zajednice. Opravdanje za donošenje Uredbe 4056/86 temeljilo se na pretpostavci kako određivanje vozarinskih stavova i druge aktivnosti linijskih konferencija dovode do stabilnih vozarina, osiguravajući tako prijevoznicima pouzdane prijevozne usluge prema redovitom rasporedu. Međutim, u posljednje vrijeme imunitet linijskih konferencija je podvrgnut reviziji u nekoliko dijelova svijeta, jedan od njih je i EU. Komisijin prijedlog za ukidanje skupnog izuzeća za linijske konferencije rezultat je njenog trogodišnjeg istraživanja tijekom kojeg su održane mnogobrojne konzultacije s prijevoznicima i korisnicima prijevoza. Vijeće ministara je u rujnu 2006. usvojilo Komisijin prijedlog za ukidanje izuzeća od primjene pravila tržišnog natjecanja na linijske konferencije koje djeluju na pravcima iz i prema EU. Ukidanje izuzeća će stupiti na snagu u listopadu 2008. Vijeće je također ovlastilo Komisiju da primjenjuje pravila tržišnog natjecanja na kabotažu i slobodnu plovidbu, tako što je proširilo područje primjene Uredbe 1/2003, koja sadrži provedbena pravila tržišnog natjecanja. Kako bi se olakšao prelazak na potpuno kompetitivni sustav, Komisija će donijeti Smjernice o primjeni prava tržišnog natjecanja na pomorski prijevoz, u dogovoru sa svim zainteresiranim stranama. U radu se analiziraju recentne izmjene materijalno-pravnih i procesno-pravnih pravila tržišnog natjecanja, koji se odnose na linijske konferencije, kabotažu i slobodnu plovidbu, a na različite prijedloge i argumente zainteresiranih strana kritički se osvrće.

Maritime transportation is one of the most capital-intensive industries. Fleet planning is vital but challenging to shipowners because the industry is extremely volatile. Relatively few papers have studied strategic fleet planning in tramp shipping, which is intertwined with contract analysis and different from that in industrial or liner shipping. This article develops a mixed-integer programming model, and it is the first of its kind that jointly optimizes strategic fleet planning and the selections of long-term and spot contracts in tramp shipping. The model can be used to determine the best mix of long-term and spot contracts for a given fleet and/or to find the optimal fleet size and mix for a set of contracts. It can be used as a basis for a fleet renewal programme, informing decisions on when to sell, whether to buy old or new ships, and when to charter in or out vessels. A numerical example is given to illustrate how to use the model to evaluate different operations strategies. [ABSTRACT FROM AUTHOR]

This paper addresses the Ship Routing and Scheduling Problem with Discretized Time Windows. Being one of the most relevant and challenging problems faced by decision makers from shipping companies, this tramp shipping problem lies in determining the set of contracts that should be served by each ship and the time windows that ships should use to serve each contract, with the aim of minimizing total costs. The use of discretized time windows allows for the consideration of a broad variety of features and practical constraints in a simple way. In order to solve this problem we propose a hybridization of a Greedy Randomized Adaptive Search Procedure and a Variable Neighborhood Search, which improves previous heuristics results found in the literature and requires very short computational time. Moreover, this algorithm is able to achieve the optimal results for many instances, demonstrating its good performance. [ABSTRACT FROM AUTHOR]

This paper deals with a practical tramp ship routing problem while taking into account different bunker prices at different ports, which is called the joint tramp ship routing and bunkering (JSRB) problem. Given a set of cargoes to be transported and a set of ports with different bunker prices, the proposed problem determines how to route ships to carry the cargoes and the amount of bunker to purchase at each port, in order to maximize the total profit. After building an integer linear programming model for the JSRB problem, we propose a tailored branch-and-price (B&P) solution approach. The B&P approach incorporates an efficient method for obtaining the optimal bunkering policy and a novel dominance rule for detecting inefficient routing options. The B&P approach is tested with randomly generated large-scale instances derived from real-world planning problems. All of the instances can be solved efficiently. Moreover, the proposed approach for the JSRB problem outperforms the conventional sequential planning approach and can incorporate the prediction of future cargo demand to avoid making myopic decisions. [ABSTRACT FROM AUTHOR]

This paper presents a novel column generation algorithm for managing the logistics activities performed by a fleet of multi-parcel chemical tankers. In our procedure, for providing elementary routes, the conventional dynamic programming routes-generator is replaced by an efficient continuous-time MILP-slave problem. The performance of the decomposition method is evaluated by solving several examples dealing with the operations of a shipping company operating in the Asia Pacific Region. Computational results show that the proposed approach outperforms a pure exact optimization model and an alternative heuristic solution method reported in the literature. [ABSTRACT FROM AUTHOR]

This paper considers a class of cargo ship routing and scheduling problems from industrial and tramp shipping and presents a wide range of benchmark instances that have been created to represent realistic planning problems for various shipping segments. Initial results for the benchmark instances are provided both through exact and heuristic methods. Optimal solutions to smaller problem instances are provided by a commercial mixed-integer programming solver, and high-quality solutions to larger problem instances are provided by a state-of-the-art adaptive large neighborhood search heuristic. The provided benchmark instances, as well as an instance generator, intend to stimulate future development of solution algorithms for this important planning problem, and to provide a basis for modelling and solving various real-life problem extensions that go beyond what is included in the benchmark instances. [ABSTRACT FROM AUTHOR]

The merchant steamship market in the late nineteenth and early twentieth centuries was dominated by the UK shipbuilding industry but past studies have portrayed a market characterized by the strong relationships between UK shipbuilders and shipowners where competition between firms was the exception rather than the rule. The objective of this article is to shed new light on this market by drawing on UK shipbuilding and shipping records to examine four characteristics that indicate the intensity of competition for new orders from 1889-1914: customer concentration, firms' business strategies, sales activities and price negotiation. Overall a market is revealed with many examples of shipbuilders deploying a high level of sales and marketing expertise which contributed both to the success of individual firms and to the UK shipbuilding industry as a whole. [ABSTRACT FROM AUTHOR]

Abstract: Tramp shipping companies are committed to transport a set of contracted cargoes and try to derive additional revenue from carrying optional spot cargoes. Traditionally, models for ship routing and scheduling problems are based on fixed speed and a given fuel consumption rate for each ship. However, in real life a ship’s speed is variable within an interval, and fuel consumption per time unit can be approximated by a cubic function of speed. Here we present the tramp ship routing and scheduling problem with speed optimization, where speed on each sailing leg is introduced as a decision variable. We present a multi-start local search heuristic to solve this problem. To evaluate each move in the local search we have to determine the optimal speed for each sailing leg of a given ship route. To do this we propose two different algorithms. Extensive computational results show that the solution method solves problems of realistic size and that taking speed into consideration in tramp ship routing and scheduling significantly improves the solutions. [Copyright &y& Elsevier]

Abstract: In this paper, we consider the ship routing problem of tramp shipping (SRPTP) and propose a combined mathematical model that simultaneously takes into account the ship allocation, freight assignment and ship routing problems of SRPTP. To solve this problem, we investigate the practical operational issues of SRPTP and develop a genetic algorithm. The empirical studies demonstrate the applicability of the proposed solution scheme for solving real-world problems that are beyond the reach of a widely used commercial optimization package. The technical, computational, practical and calibration issues involved in this unique tramp shipping problem are discussed in detail in this paper. [Copyright &y& Elsevier]

Copyright of International Journal of Maritime History is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this paper is to solve a planning problem faced by many shipping companies dealing with the transport of bulk products. These shipping companies are committed to carrying some contract cargoes and will try to derive additional revenue from optional spot cargoes. An efficient tabu search algorithm has been developed to ensure quick decision support for the planners. The solutions generated by the tabu search heuristic are compared with those produced by a previously published multi-start local search heuristic. Computational results show that the tabu search heuristic yields optimal or near-optimal solutions to real-life instances within reasonable time. For large and tigthly constrained cases, the tabu search heuristic provides much better solutions than the multi-start local search heuristic. A version of the tabu search heuristic will be integrated as an improved solver in a prototype decision support system used by several shipping companies. [ABSTRACT FROM AUTHOR]

The article examines the importance of coastal shipping to East Asian economic activity throughout the late 19th century. Emphasis is given to the work of German shipowner Michael Jebsen and his decision to contract his tramp ships in the Far East. Jebsen's impressions of Chinese merchants are discussed, as they chartered his ships. Shipping largely revolved around the movement of bulk goods, cattle, and Chinese laborers (coolies). The author also analyzes the changing conditions of the area's shipping market and how Jebsen's business strategies responded to them.

This paper is about the confluence of a number of factors that have each experienced a rapid rate of change in the last 15 years. Combined, they continue to modify the business of shipping in the early 21st Century. The areas in which I see the most pronounced commercial change are: ◻ Trade -◻ Shifting geography - ◻ The ship owners - ◻ The operation of ships - ◻ The financing of ships- ◻ Disintermediation - ◻ Freight markets - ◻ New Players - ◻ Industry Governance and Regulation [ABSTRACT FROM AUTHOR]

Here, we describe a real planning problem in the tramp shipping industry. A tramp shipping company may have a certain amount of contract cargoes that it is committed to carry, and tries to maximize the profit from optional cargoes. For real long-term contracts, the sizes of the cargoes are flexible. However, in previous research within tramp ship routing, the cargo quantities are regarded as fixed. We present an MP-model of the problem and a set partitioning approach to solve the multi-ship pickup and delivery problem with time windows and flexible cargo sizes. The columns are generated a priori and the most profitable ship schedule for each cargo set-ship combination is included in the set partitioning problem. We have tested the method on several real-life cases, and the results show the potential economical effects for the tramp shipping companies by utilizing flexible cargo sizes when generating the schedules. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Maritime History is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)