This paper deals with two different approaches in modelling corrosion wastage over the fuel tanks’ structures on the example of ten aged bulk carriers. The first applied method might be treated as a short-term, rather random oriented one, and it is based on the Monte Carlo simulation technique. This technique has been used in creating an appropriate predictive model for the characteristic steel damages over the bulk carriers’ fuel tanks caused by general corrosion in relatively short time interval of two years, within the period between the 5th and the 25th year of the bulks’ operational life. The second employed method might be treated as a long-term one, and it is based on a Weibull distribution analysis. The purpose of these analyses is optimal assessing of the average corrosion losses for the bulk carriers’ fuel tanks areas at different points of time during the whole exploitation cycle, within the ultimate goal of raising the structural stability and safety of bulk carriers in operation.

KEY WORDS: bulk carriers, fuel tanks, corrosion wastage, Monte Carlo simulation, Weibull probability analysis

The increase of demand for transport service in rail commuter traffic stipulates higher ratio of consumed infrastructure capacity. In this method of traffic flow even minor deviations from the planned timetable can have negative influence on its stability, and this can result in major reduction of the quality of transport service. This research has defined the commuter rail traffic management system model with the application of real-time timetable rescheduling. It understands the application of the decision support system during the procedure of adjusting the timetable to the real condition in traffic in the form of genetic algorithm defined on the basis of the valid rules for the train and traffic control. Besides, this model in all the commuter trains understands the existence of the driver advisory system which is based on the algorithm for determination of the most favourable running regime with the aim of saving in energy consumption. The paper proves that by applying the proposed model the commuter rail traffic can be improved regarding the increase of the timetable stability and energy-efficient train operation. KEY WORDS: rail traffic management, genetic algorithm, energy efficient timetabling and train operation

The accuracy of measuring mass of loaded or discharged cargo by draft survey mass measuring method varies due to both systematic and accidental errors. The paper analyzes an error of draft readings on the calculated quarter mean draft, displacement based on the calculated quarter mean draft and the final displacement. By analyzing this problem, the authors have reached the conclusion that the influence of an error made in draft readings can be significant, especially on the draft marks amidships. Optical fibre technology has been suggested as a new option for draft readings. In this paper, the authors propose a liquid level optical sensor for measuring the sea level in the sounding pipe. Draft readings obtained by optical sensors will be entered into ships’ navigational system and load master. KEY WORDS: ship’s draft, error of draft readings, optical fibre technology, liquid level optical sensors.

In air freight industry, blood samples are classified as time and temperature sensitive biologically produced pharmaceuticals. To determine the level of influence that the handling processes and air transportation have on blood sample quality, a research has been conducted through transportation of whole blood samples on two European scheduled routes. Two shipping models were defined: the standard one without defined transportation temperature regime and the controlled one, where transportation is conducted under appropriate temperature regime. The blood samples were packed and transported respecting all relevant national and international regulations. The analysis was conducted and the results compared to control sample kept in the laboratory. Significant changes were identified on all components analyzed after crosschecking with the control sample. KEY WORDS: regulatory issues, blood sample quality, shipping model, packaging instruction, temperature profiles

This paper presents and analyses the redefined Rijeka railway junction. The redefined concept of the Rijeka railroad hub in the context of port and railway interdependence dictates the need to find the accommodation of cargo transport to peripheral locations such as: Krasica, Kukuljanovo, Bakar, Ivani, Bršica and capacity for the island of Krk, while passenger transport would be implemented in the urban area. The most important projects related to Rijeka rail transport system are the construction of a new line of high efficiency between Zagreb and Rijeka, and a new railroad through the tunnel of Učka which will link the ports of Rijeka, Koper and Trieste. Together with the reconstruction of cargo stations Rijeka and Brajdica, an extension of the other tracks on the railroads Škrljevo-Rijeka and Rijeka-Opatija/Matulji should be performed as well as the construction of Krasica, Ivani, Tijani and Vrgljevo stations. The construction includes a multipurpose bridge to the Island of Krk and a railway line to the new container terminal as well as the new railway bypass to “elevation 200”. KEY WORDS: Rijeka railway junction, railway transport system, railway transport, Port of Rijeka

The paper investigates conditions and circumstances of the occurrence of emergencies during ship exploitation. The concept and different forms of emergencies are defined while conditions of their occurrence are simulated, as well as possible modes of prevention of their occurrence or development. On the basis of the results of the investigation covering 240 professional seamen an appropriate organisational algorithm of participative ship management is defined as foundation for the application of the management algorithm in emergencies. On this basis the method of Risk and Hazard Assessment is applied. Also, the algorithm of Decision Making Process is derived from the related investigations. The proposed algorithm is not based only on the organisational presuppositions of participative management but also on complex human relationships as well as acting in stressful circumstances through all the phases of emergencies. The appropriate decision support system to help decision-makers during the emergencies is described. KEY WORDS: emergencies, algorithm, team work, participative management, hierarchical acting, scenario, communication

Urban road infrastructure is daily burdened by heavy traffic volume. Pavement structure roughness observations are significantly more difficult in urban agglomerations than on roads in unpopulated areas. Roughness, expressed by IRI (International Roughness Index), directly affects the quality and safety of road traffic. Within the framework of the pavement management in relation to safety and the achievement of the best possible ride comfort, it is very important to foresee when a road should be reconstructed. The method for quality evaluations of safety and ride comfort on urban roads presented in this paper is based on vehicle vibrations measurements. In the article, measuring of vehicle vibrations was performed on the main urban roads in Zagreb (Croatia). Measurements covered roads with different pavement surface roughness. This method can be simply and very easily used in pavement management aimed at achieving road safety and better ride comfort. The results of measurements according to this method could be used by traffic and civil engineering experts as an indication for the roads that require reconstruction or maintenance. KEY WORDS: urban roads, traffic flow, safety, vehicle vibrations, road surface roughness (IRI)

This port service quality study is an important precondition for an efficient development of port industry and traffic system as a whole. It is due to the complexity of any port, as a system consisting of a large number of stakeholders rendering services to customers with various requirements, that a unique set of port service quality indices has been still missing. For this reason, the paper explains the port service quality concept in compliance with stakeholders and their requirements within the context of port service quality. The aim of the paper is to present a proposal for a customer-based port service quality model based on empirical study and its reliability testing on a selected sample. The proposed model is defined by five factors and fits satisfactorily into the obtained poll questionnaire results. The statistical data processing package SPSS 16.0 and the LISREL 8.54 programme were used in the study. KEY WORDS: port service, customer, model, factor analysis

In all the cities of Serbia that have organized systems of public mass passenger transport (PMPT), over the past several years more and more private transport companies are being included in the network of city and suburban transportation lines. The inclusion of private transport companies in the PMPT system via public tenders should be preceded by the procedure of calculation of the realistic income and system functioning expenses in order to establish possible balances of needs for City Budget subsidies, as well as the elements on Contract of entrusting this vital communal activity of every city. The new principle for determining the total cost of PMPT system functioning, based on line difficulty ranking, has been presented in this paper. KEY WORDS: expenditure model, price, PMPT system, line, exploitation parameters, evaluation, line rank

Simulation methods are widely used in railway planning and operation. However, at the moment there are no applicable solutions in the process simulation for a smooth transition among different infrastructure levels on the basis of a unified structure with consistent algorithm. In this paper, a multi-scale simulation model is designed with consideration of the level of detail of the investigated infrastructure model and the homogeneity of the processes running in the simulation model. A comprehensive and synthesized view of railway planning and operation is therefore obtained. Within the multi-scale simulation model, railway planning and operation processes can be simulated, evaluated and optimized consistently. KEY WORDS: railway planning, simulation, multi-scale, aggregation, discrete scaling, continuous scaling, homogenous process, inhomogeneous process

The liberalization of the aviation market has enabled low-cost airlines to take over a significant share in the aviation market. Benefits of low-cost models are multiple, both for passengers and for secondary and regional airports, which were neglected in the past and which record significant inflow of passengers with the arrival of low-cost airlines. In the structure of the air traffic in the Republic of Croatia in the last ten years, there has been a progressive growth of foreign low-cost airline operations, which suggests a potential for the operation of a Croatian low-cost airline. This paper defines the criteria applicable to modelling of a low-cost airline in the Republic of Croatia in the relevant context of fleet management, route networking and operator’s processes in traffic technology. It analyzes the dynamics of low-cost airlines operations in the structure of air traffic in Croatia and the impact of traffic on the status of airports and the national operator. KEY WORDS: low-cost airline, traditional airline, airport, route network, fleet management

The paper provides a description of tribological aspects and the latest type of laboratory equipment which is expected to offer particular new knowledge in the field of railway wheel - rail contact phenomena diagnostics. The main considerations stated in this work imply that the coefficient of adhesion is among others dependent on contact temperature, and therefore it is possible to theoretically predict the value of the coefficient of adhesion. This fact has not been considered in the theory of adhesive contact so far. The entirely credible prognosis of the studied unfavourable effects is hardly satisfactorily solvable in theory. Hence, the authors present a new testing device by which the predicted effects will be verified. At the same time, the oscillation effect on the state of surface will be observed in the attached formulas. The work also implies that the effects evaluating possible initiations and local degradations of the contact area of railway wheel and rail are closely bound to the tribological effects that are comprehended here as dynamic processes. KEY WORDS: contact fatigue, railway wheel - rail contact, tribology, safety of transport