Ship speed optimization: Concepts, models and combined speed-routing scenarios

Psaraftis, Harilaos N.; Kontovas, Christos A.

doi:10.1016/j.trc.2014.03.001

Cited by 224 publications

(124 citation statements)

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“…Ship operating costs are affected by the ship deployment decisions as well as decisions with respect to sailing speeds, because of the non-linear relationship between speed and fuel consumption, and of the fact that fuel costs represent a major portion of a ship's operating costs [28,26]. In maritime transportation, many of the OR/MS models found in the literature assume fixed speeds for the ships either explicitly, or implicitly through the calculation of other inputs such as sailing times, due dates and fuel costs [24]. In this study, we consider speed optimization simultaneously with deployment decisions in our chartering problem in order to capture the economic trade-offs between (a) the lower charter costs associated with a higher speed and (b) the higher fuel costs and hence higher operating costs associated with such higher speeds.…”

Section: Problem Descriptionmentioning

confidence: 99%

Planning for charters: A stochastic maritime fleet composition and deployment problem

Wang

Fagerholt

Wallace

2018

Omega

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(2017). Planning for charters: a stochastic maritime fleet composition and deployment problem. Omega, in press. doi: 10.1016/j.omega.2017.07.007 AbstractThis paper introduces a chartering problem that arises in the shipping industry. The chartering decisions determine the time-charter contracts to enter into, in particular, how many ships of each type to charter in, and for how long they are to be hired. We show that this problem can be modeled as a tactical fleet composition problem, with integrated fleet deployment and speed optimization, which also takes into account market uncertainties. We propose a two-stage stochastic programming model, and present a computational study based on the case of Odfjell, a leading chemical shipping company based in Bergen, Norway. We show how the charter plans produced can change depending on different modeling choices. We also show why and how different charter plans affect the company's overall performance, in order to provide guidance in helping the company make its chartering decisions.Planning for charters: a stochastic maritime fleet composition and deployment problem Abstract This paper introduces a chartering problem that arises in the shipping industry.The chartering decisions determine the time-charter contracts to enter into, in particular, how many ships of each type to charter in, and for how long they are to be hired. We show that this problem can be modeled as a tactical fleet composition problem, with integrated fleet deployment and speed optimization, which also takes into account market uncertainties. We propose a two-stage stochastic programming model, and present a computational study based on the case of Odfjell, a leading chemical shipping company based in Bergen, Norway. We show how the charter plans produced can change depending on different modeling choices. We also show why and how different charter plans affect the company's overall performance, in order to provide guidance in helping the company make its chartering decisions.

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Section: Problem Descriptionmentioning

confidence: 99%

Planning for charters: A stochastic maritime fleet composition and deployment problem

Wang

Fagerholt

Wallace

2018

Omega

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“…Hydrodynamic characteristics also play a factor in fuel comsumption. Psaraaftis & Kontovas state, "hull condition can also be an important factor that influences the frictional resistance of a ship, and, as a result, fuel consumption" and continues with"ship resistance and hence fuel consumption at a given speed can be drastically different if the ship is full, empty or at an intermediate leading condition" (Psaraftis & Kontovas, 2014). Along with load of ship, fuel prices themselves are a critical piece to the optimal speed puzzle as well.…”

Section: Literature Reviewmentioning

confidence: 99%

“…"Fuel prices are a very critical determinant of fuel costs, and, as such, of the speed chosen by the vessel. In fact fuel price is the one of two main factors that play a critical role in the determination of ship speed (the state of the market being the other one)" (Psaraftis & Kontovas, 2014). Freight rates can have an impact on the decision of how fast or slow a ship chooses to go as well.…”

Section: Literature Reviewmentioning

confidence: 99%

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Beneficial Effects of Slow Steaming in Bulk Freight Markets

Boone

Laverne

Mileski

2017

RASI

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ABSTRACT:Slow steaming has recently been adopted into normal practice by many maritime shipping companies for the fuel and monetary savings it offers. The practice also offers savings in Greenhouse Gas (GHG) emissions. With regulations coming into play such as the 2020 sulfur cap, slow steaming may be the least costly option for some maritime companies to adjust their operations. While some have accepted the new practice, there are still companies and vessels that see this exercise as a loss of revenue due to the extra time it takes to deliver goods to their destination. This paper reviews how rating ships by their GHG emissions per nautical mile can be directly related to factors other than slow steaming such as age, deadweight tonnage and cargo type. We propose that ships with poor ratings (E, F, G) should rely on slow steaming but may also improve their CO 2 output addressing the other factors. Those with superior ratings (A, B, C, D) may also benefit from the implementation of slow steaming, but may also gain from practices addressing age, tonnage and cargo type. Further we will also examine how lowering emissions can benefit maritime businesses both economically and environmentally. Finally this paper reviews possible chain reactions that may occur if these eco-friendly shipping practices are observed. KEYWORDS: slow steaming, greenhouse gases, vessels, ecological transport Redução de emissões no transporte além do vapor lento RESUMO:O vapor lento foi recentemente adotado na prática normal por muitas companhias marítimas para a economia de combustível e monetária que oferece. A prática também oferece economias em emissões de gases de efeito estufa (GEE). Com os regulamentos que entram em jogo, como o limite de enxofre de 2020, o vapor lento pode ser a opção menos dispendiosa para algumas empresas marítimas ajustar suas operações. Enquanto alguns aceitaram a nova prática, ainda existem empresas e embarcações que vêem esse exercício como uma perda de receita devido ao tempo extra que leva para entregar bens ao seu destino. Este artigo analisa como a classificação dos navios por suas emissões de GEE por milha náutica pode ser diretamente relacionada a fatores como idade, tonelagem de peso morto e carga. Nós propomos que os navios com classificações ruins (E, F, G) encontrem regulamentos obrigatórios para diminuir o vapor ou melhorar sua produção de CO2 de alguma forma. Aqueles com classificações superiores (A, B, C, D) se beneficiariam de pacotes de incentivos ligados à sua implementação de vapor lento ou outras práticas. Também examinará como a redução das emissões pode beneficiar as empresas marítimas de forma econômica e ambiental. Finalmente, este artigo analisa possíveis reações em cadeia que podem ocorrer se essas práticas de transporte ecológico forem observadas. PALAVRAS-CHAVE: vapor lento, gases de efeito estufa, embarcações, transporte ecológico R. Desembargador Ellis Hermydio Figueira, 783, Bloco A, sl. 218, Aterrado.27213-415 -Volta Redonda, RJ -Brasil www.uff.br Copyright © 2017 RASI. Todos os dir...

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“…The effect of speed on voyage selection has been examined in Psaraftis and Kontovas (2014) using accurate expressions for fuel consumption as a function of speed and load. They show that voyage choice and speed will depend on the variations of the ship's hydrodynamic resistance, fuel cost and of course freight rates.…”

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confidence: 99%