The cold ironing system is gaining interest as a promising approach to reduce emissions from ship transportation at ports, enabling further reductions with clean energy sources coordination. While cold ironing has predominantly been applied to long-staying vessels like cruise ships and containers, feasibility studies for short-berthing ships such as ferries are limited. However, the growing demand for short-distance logistics and passenger transfers highlights the need to tackle emissions issues from ferry transportation. Incorporating electrification technology together with integrated energy management systems can significantly reduce emissions from ferry operations. Accordingly, this paper proposes a cooperative cold ironing system integrated with clean energy sources for ferry terminals. A two-stage energy management strategy combining sizing and scheduling optimization is employed to reduce the port's emissions while minimizing system and operational costs. The proposed system configuration, determined through the sizing method, yields the lowest net present cost of $9.04 M. The applied energy management strategy managed to reduce operational costs by up to 63.402 %, while significantly decreasing emissions from both shipside and shoreside operations. From the shipside, emissions reductions of 38.44 % for CO2, 97.7 % for NOX, 96.69 % for SO2, and 92.1 % for PM were achieved. From the shoreside, the approach led to a 28 % reduction across all emission types. Thus, implementing cold ironing powered by clean energy sources is a viable solution for reducing emissions generated by ferry operations. The proposed energy management approach enables emissions reduction and delivering cost-effectiveness at ferry terminals.
Seafarers and fishers have inequity in health at work, with a higher risk of having metabolic syndrome. They are at increased risk of developing prediabetes, which can be reversed to normoglycemia based on the evidence from other industries. This study aims to educate and activate seafarers and fishermen with the support of coaches to reverse their prediabetes to stop the further development of diabetes type 2.
Methods
Random samples of seafarers and fishermen with newly diagnosed prediabetes and HbA1c levels ranging from 5.7%-6.4% from the maritime medical health examinations constitute the study population in a 16-week prediabetes coaching program. In addition to monthly Zoom meetings, they are asked to provide weekly reports via questionnaires on personal measurements and improvements in physical activity and diets.
Results
The preliminary data from 2 maritime clinics (n=405) show prevalences of prediabetes 18.8%, 36.4%, and 49.2% in the ages 20-29, 30-49, and 50+ years respectively, all p-values < 0.02.
Analysis of the clinical data from the maritime health clinics and the questionnaires from the seafarers collected weekly will formulate the effect of the intervention. Summarizing data from various national prediabetes coaching fora will be the evidence base for remission of prediabetes.
Conclusions
A significant portion of seafarers have prediabetes with the potential to achieve remission of their pre-diabetes by eating healthy and being physically active. The goals are to lose at least 5%–7% of their starting weight, be accustomed to doing at least 150 min. of physical activity weekly, and follow a pre-diabetes-relevant dietary plan.
Within realistic time constraints we successfully trained six occupational health and safety professionals in applying a Design Thinking (DT) approach to solve complex musculoskeletal and psychosocial problems at work. DT may be defined by the double diamond model pointing to a non-linear and user-centred problem-solving process iterating through divergent and convergent phases A key characteristic of DT is the ability to frame a problematic situation in new and interesting ways. The training was done in a full-day workshop followed by a learning-by-doing phase in which they planned and completed design sprint workshops in companies. The professionals went from novices into advanced beginners according to the Dreyfus model of skill acquisition. In the overall question of the usefulness of DT in OHS management, the average rating went from 6 before the training course to 9.5 after. In an evaluation of the DT approach on a 1–5 scale they rated design sprints at 3.8 to be more appropriate to manage complex problems than the methods they normally used. However, more experience seems necessary to adopt the DT mind set of an iterative process, in which they need to decide which tools to use in an emergent, nonlinear and iterative fashion.
Med inspiration i Schumpeters teorier om kreativ destruktion undersøger denne artikel centrale aspekter af omstillingerne i dansk erhvervsliv i forbindelse med 1980'ernes og 1990'ernes fire største danske værftslukninger. Det drejer sig om B&W i 1980, Nakskov Skibsværft i 1986, Aalborg Værft i 1987-88 og endelig Danyard Frederikshavn, der lukkede i 1999. Artiklen identificerer 27 spin-off virksomheder, som videreførte forskellige aktiviteter fra de lukkede værfter, og følger deres udvikling frem til 2013. Artiklen dokumenterer, at gruppen af spinn-off virksomheder i årene omkring 2013 havde en omsætning svarende til de gamle værfters omkring 1975. Mens nogle spin-offs ophørte efter få år, formåede de tilbageværende 12 virksomheder at generere langt højere overskud end de værfter, de opstod fra. Artiklen kaster dermed nyt lys på centrale omstillings- og fornyelsesprocesser i dansk erhvervsliv igennem de sidste tre årtier.
Determining the key characteristics of a ship during the concept and preliminary design phases is a critical and intricate process. In this study, we propose an alternative to traditional empirical methods by introducing a model to estimate the main particulars of diesel-powered Z-Drive harbor tugboats. This prediction is performed to determine the main particulars of tugboats: length, beam, draft, and power concerning the required service speed and bollard pull values, employing Bayesian network and non-linear regression methods. We utilized a dataset comprising 476 samples from 68 distinct diesel-powered Z-Drive harbor tugboat series to construct this model. The case study results demonstrate that the established model accurately predicts the main parameters of a tugboat with the obtained average of mean absolute percentage error values; 6.574% for the Bayesian network and 5.795%, 9.955% for non-linear regression methods. This model, therefore, proves to be a practical and valuable tool for ship designers in determining the main particulars of ships during the concept design stage by reducing revision return possibilities in further stages of ship design.
Ammonia-fueled operation of solid oxide fuel cells is a promising alternative to their hydrogen-fueled operation. However, high ammonia decomposition rates at elevated operating temperatures of the solid oxide cells lead to a significant temperature drop at the stack inlet, causing increased thermal stresses. A multi-scale model is used in this study to investigate stack performance under direct feed and external pre-cracking of ammonia. Additionally, the effects of co- and counter-flow configurations, gas inflow temperatures, current density, and air flow rate on the stack performance under direct ammonia feed are examined. The simulation results show that for gas inlet temperatures above 750 °C, the power densities with direct feed and external cracking of ammonia differ by less than 5%. Moreover, it is indicated that the thermal stresses are lowest for the co-flow case, which decrease with decreasing gas inlet temperature and current density and with increasing air flow. Finally, this study shows that under practically applicable operating conditions, the risk of mechanical failure of the cells under direct ammonia feed operation is small.
The dynamic characteristics of ship structures are becoming more important as the flexibility of modern ships increases, for example, to predict reliable design life. This requires an accurate dynamic model of the structure, which, because of complex vibration environment and complex boundary conditions, can only be validated by measurements. In the present paper the use of operational modal analysis (OMA) for dynamic characterization of a ship structure based on experimental data, from a full-scale measurement of a 210-m long Ro-Lo ship during sea trial, is presented. The measurements contain three different data sets obtained under different operating conditions of the ship: 10 knots cruising speed, 18 knots cruising speed, and at anchor. Natural frequencies, modal damping ratios, and mode shapes have been successfully estimated for the first 10 global modes. Damping ratios for the current ship were found within the range 0.9%-1.9% and natural frequencies were found to range from 0.8 to 4.1 Hz for the first 10 global modes of the ship at design speed (18 knots). The three different operating conditions showed, in addition, a speed dependency of the natural frequencies and damping ratios. The natural frequencies were found to be lower for the 18-knots condition compared with the two other conditions, most significantly for the vertical bending modes. Also, for the vertical bending modes, the damping ratios increased by 28%-288% when the speed increased from 10 to 18 knots. Other modes were not found to have the same strong speed dependency.
The European maritime transport policy recognizes the importance of the waterborne transport systems as key elements for sustainable growth in Europe. A major goal is to transfer more than 50% of road transport to rail or waterways within 2050. However, waterways are at a disadvantage as they normally depend on transhipment and land transport to and from final destination. To meet this challenge we need a completely new approach to short sea and inland waterways shipping in Europe. This needs to include ships as well as ports and the digital information exchanges between them. A key element in this is automation of ships, ports and administrative tasks. The AEGIS project has been funded by the EU Commission to develop new knowledge and technology to address this challenge.
Long considered a cultural contact zone, the Mediterranean has become a weaponised border zone keeping refugees from Africa and the MiddleEast away from ‘Fortress Europe’. The Mediterranean has become excessively dangerous to cross, leading many commentators to call this maritime space a ‘massive graveyard’. The widespread indifference and enmity towards migrants in Europe is, amongst other things, countered by documentary and commemorative projects by artists drawing attention to the suffering of drowned refugees. In this paper, I zoom in on documentary and memorial artistic projects by Mimmo Paladino, Jason deCaires Taylor, Christoph Büchel, Ai Weiwei and Đỉnh Q. Lê. In the frequent absence of dead bodies and specific grave sites on the ‘high seas’, they make claims regarding the humanity, singularity and memorability of the human lives of refugees drowned at sea. Based on a description of the artworks and their public, I make two interlinked theoretical arguments. First, the commemorative materialisations by contemporary artists are temporal claims to constitute the cultural heritage of the future. Second, given the sea’s aquatic materiality, the commemorative claims of these art projects require that commemorative materialisations must spatially move from the flux of the sea to the fixity of the land.
A mixed integer linear programming model is presented for the operational level cargo allocation and vessel scheduling problem of a liner shipping company in Turkey, where flow-dependent port-stay lengths, transit times and transshipment synchronizations are considered. The proposed model aims to assign shipments to routes to decrease total tardiness and construct partial vessel schedules for establishing coordination with port authorities to comply with the berthing time windows. In addition to the mathematical model, novel valid inequalities and benders decomposition algorithm are implemented. Performance of the developed algorithm is evaluated on real-life problem instances. The results show that benders decomposition with valid inequalities yields the best performance.