To mitigate climate change due to international shipping, the International Maritime Organization (IMO) requires shipowners and ship technical managers to improve the energy efficiency of ships’ operations. This paper studies how voyage planning and execution decisions affect energy efficiency and distinguishes between the commercial and nautical components of energy efficiency. Commercial decisions for voyage planning depend on dynamic market conditions and matter more for energy efficiency than nautical decisions do for voyage execution. The paper identifies the people involved in decision-making processes and advances the energy-efficiency literature by revealing the highly networked nature of agency for energy efficiency. The IMO’s current energy efficiency regulations fail to distinguish between the commercial and nautical aspects of energy efficiency, which limits the ability to mitigate climate change through regulatory measures. Policymakers should expand their regulatory focus beyond shipowners and technical managers to cargo owners to improve energy efficiency and reduce maritime transport emissions.
Reverse Logistics (RL) of end-of-use/end-of-life products has become a vital part of circular economy practices for manufacturers. However, significant quantities of resources are still landfilled instead of being recovered. With mounting pressure on businesses to address the sustainability crises (resources, climate change, waste, toxicity) on account of the take-make-dispose-based linear economy, companies today realise the importance of RL but face several barriers to implementing it, including a lack of knowledge. Although several studies have investigated different aspects of RL in various industries in different country settings, less attention has been devoted to developing a systematic and holistic approach for designing and implementing RL. To address these gaps, this paper reviews 116 scholarly articles published between 2011 and 2021 to identify attributes related to the design and implementation of RL systems. Based on a systematic literature review, a conceptual framework is presented covering the key activities, drivers and barriers, stakeholder engagement and performance management in RL. Such a framework can support companies evaluate different approaches and strategies, as well as the opportunities and challenges of designing and implementing RL and transitioning towards a Circular Economy.
A serious ship-bridge collision accident happens about once a year. These accidents cause fatalities and large economic losses due to loss of transportation service and replacement cost of the bridge structure. One of the most recent, widely published, ship-bridge collisions was the collision where the containership Dali in 2024 collided with the Baltimore Key Bridge in the US city of Baltimore. The resulting collapse of the bridge girder caused six fatalities as well as large financial losses. One effect of this event has been that engineers around the world now are being engaged in evaluation of the vulnerability of existing bridges and establishment of rational design criteria for new bridges.
The presentation will outline elements of a rational design procedure for bridge structures against ship collision impacts. A set of risk acceptance criteria will be proposed and a mathematically based procedure for calculation of the probability of ship collision accidents caused by human as well as technical errors will be presented. This first part of the presentation leads to identification of the largest striking ship, “design vessel”, a given bridge element must withstand without structural failure in order for the bridge connection to fulfil the risk acceptance criteria.
The final part of the presentation will be devoted to an analysis of the needed impact capacity for the bridge pylons and piers exposed to ship bow impact loads from design vessels. A procedure will be described for derivation of expressions for ship bow crushing forces, which can be used in design against ship collision impacts. The resulting collision force expressions are verified by comparison with large-scale laboratory experiments and an analysis of a fullscale shipping accident. Finally, the proposed impact force expressions will be compared with existing standards for modelling ship collisions against bridges as published by AASHTO, IABSE and Eurocode.
The paper outlines a rational design procedure for bridge piers and pylons against ship collision impacts. Firstly, a set of risk acceptance criteria are proposed. This is followed by a mathematically based procedure for calculation of the probability of critical ship meeting situations near the bridge, and the probability of ship collision accidents caused by human errors as well as technical errors. This first part of the paper leads to identification of the largest striking ship, “design vessels”, a given bridge pier must withstand without structural failure in order for the bridge connection to fulfil the risk acceptance criteria. The final part of the paper is devoted to an analysis of the needed impact capacity for the bridge pylons and piers exposed to ship bow impact loads from these “design vessels”. For a number of different ship types and different tonnage merchant vessels, load – displacement relations for ship bow collisions against rigid walls are derived. Based on these comprehensive numerical results, a new empirical relation is derived which is suited for design against bow collisions. This expression for maximum bow collision forces is compared with a previously published expression for ice-strengthened ships and with existing standards for assessment of bow crushing forces. It is shown that there is need for an update of these existing standards. For design of piers and pylons against local impact pressure loads, a pressure - area relation for bulbous bow impacts is derived.
Container shipping is generally considered a global business. This truth may not hold from a single-company perspective. The companies’ physical operation networks show that container carriers operate differently and follow different paths in their internationalisation development. Additionally, the degree of internationalisation, measured on the basis of sea-oriented operations, differs from that measured according to land-oriented front-end marketing and sales activities. The purpose of this study is to further examine the internationalisation patterns of shipping lines. An examination of the front-end activities and the structures of leading container-shipping companies is conducted. The sales office networks of the sector’s 20 largest companies worldwide (by twenty-foot equivalent unit capacity) are analysed as key indicators. The numbers of sales offices are measured by analysing the websites of the sample (20 companies), as well as annual reports and other publicly available data sources. The findings show that not all shipping companies are international, by virtue of the industry. While it is difficult to observe differences in the overall patterns of the sales networks at a macro level, some companies differ in their activities. The data set also shows that market share and total capacity are not necessarily good indicators of a carrier’s worldwide presence. This research is based on secondary data. Other important transactional and market-oriented considerations should be examined before drawing conclusions about the internationalisation of container-shipping companies and of the industry. This paper contributes to the relevant existing research, particularly by adding its view on the demand-oriented criteria as suggested by Dunning and Lundan (2008).
The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.
“Speed optimization and speed reduction” are included in the set of candidate short-term measures under discussion at the International Maritime Organization (IMO), in the quest to reduce greenhouse gas (GHG) emissions from ships. However, there is much confusion on what either speed optimization or speed reduction may mean, and some stakeholders have proposed mandatory speed limits as a measure to achieve GHG emissions reduction. The purpose of this paper is to shed some light into this debate, and specifically examine whether reducing speed by imposing a speed limit is better than doing the same by imposing a bunker levy. To that effect, the two options are compared. The main result of the paper is that the speed limit option exhibits a number of deficiencies as an instrument to reduce GHG emissions, at least vis-à-vis the bunker levy option.
International shipping is at a crossroads as regards decarbonization. The Paris climate change agreement in 2015 (COP21) was hailed by many as a most significant achievement. Others were less enthusiastic, and more recently American President Trump decided to take the U.S. out of the agreement. Four years earlier, the International Maritime Organization (IMO) had adopted the most sweeping piece of regulation pertaining to maritime greenhouse gas (GHG) reduction, in the name of the Energy Efficiency Design Index (EEDI). In addition, one year after COP21, the IMO adopted a mandatory data collection system for fuel consumption of ships and agreed on an initial strategy and roadmap on the reduction of GHG emissions from ships. This paper takes a critical look at the above and other recent developments and focuses on the challenges faced by the industry if a path to significant CO2 reductions is to be successful. Difficulties and opportunities are identified, and the paper conjectures that the main obstacles are neither technical nor economic, but political.
The purpose of this paper is to clarify some important issues as regards ship speed optimization at the operational level and develop models that optimize ship speed for a spectrum of routing scenarios in a single ship setting. The paper’s main contribution is the incorporation of those fundamental parameters and other considerations that weigh heavily in a ship owner’s or charterer’s speed decision and in his routing decision, wherever relevant. Various examples are given so as to illustrate the properties of the optimal solution and the various trade-offs that are involved.
The International Maritime Organization (IMO) is a specialized United Nations (UN) agency regulating maritime transport. One of the very hot topics currently on the IMO agenda is decarbonization. In that regard, the IMO decided in 2018 to achieve by 2050 a reduction of at least 50% in maritime green house gas (GHG) emissions vis-à-vis 2008 levels. The purpose of this paper is to discuss the possible role of Market Based Measures (MBMs) so as to achieve the above target. To that effect, a brief discussion of MBMs at the IMO and the EU is presented, and a possible way forward is proposed, focusing on a bunker levy.