Range of technical-economic competitiveness of rail-road combined transport

Abstract Purpose Road haulage has been the most widely used mode of freight transport in many European countries for several decades. Given the attention to sustainable transport in this century, the rail-road combined transport may result to be a good alternative, under specific conditions, to road haulage. This paper analyses the main conditions to make the option competitive, using a simplified method useful for the stakeholders involved in decision processes. Method Relevant cost items have been identified since previous studies available in literature. The proposed formulas consider the different phases of transport chain and have been used to investigate such parameters as the external costs and the location of terminals. Results If the pre- and post-phases are too long or simply too onerous, the economic advantages of the rail section may not be sufficient to guarantee the convenience of the combined transport. It can be economically competitive over long distances, even when the drayage covers greater distances. Conclusions The method has been used to examine those situations, in terms of distance covered and frequency of the service, in which rail-road combined transport can be cost-effective as an alternative to the full-road solution. The obtained range can be reviewed based on the services, such as shuttle trains to connect seaports with dry ports: the short distance covered may be more convenient due to the high quantities of goods as well as the fixed train composition and path allocation, which means lower terminal cost and times. Finally, some innovative proposals have been introduced

Monitoring truck's operations at freight intermodal terminals: traffic observation by scanning on-board devices

Monitoring operations at freight intermodal terminals are useful for estimating their performance, while collecting traffic data allows them to properly manage and control truck flows. Nevertheless, the key role of observation can be in contrast with users' privacy. A valuable solution to obtain traffic information preserving players' anonymity may be provided by scanning radio signals emitted by commonly used on-board devices, which can be locally identified by their unique media access control address. In this solution, no personal, freight or vehicle information is collected. An uncommon application of bluetooth scanners for monitoring operation of truck flows inside terminals is presented, based on a simple methodology for data processing. The algorithm starts from the data collection and the selection of information at relevant points of the terminal, then the network observation is composed by matching the data recorded in connected points. Finally, key performance indicators are estimated, starting from vehicle trajectories, node by node, and their travel time. The method is applied with on-field tests in a large-size rail-road terminal, where the detected counting results are lower than the ground truth, being not all the users equipped with bluetooth devices; however, the pioneering application results replicable in other contexts related to logistics

Treni merci lunghi e pesanti in esercizio: analisi sulla resistenza dei ganci ed evidenze sperimentali sugli effetti termici in frenatura / Long and heavy freight trains in operation: analysis on the strength of couplings and test evidences on thermal effects during braking

The so-called heavy freight trains (over 1600 t), sometimes even long (740-750 m), are now among the leaders of the future of rail transport of goods. The aim of this paper is to analyse, both theoretically and experimentally, the impact that this solution may have on the traction units (hooks with their traction castle or yoke) and the braking system. Concerning the traction units, the technical reference in Italy, no longer binding from 2021, is Tab. 20, art. 61, of the General Preface of the Timetable of Services (named PGOS) containing the correlations between the maximum towed mass and the plan-altimetric characteristics of the line (performance grade). This reference is questioned and compared with other foreign institutional sources and with analytical calculations referring to “quasi- static” conditions of the trainset, departing from a standstill, and again in “dynamic” conditions at high speeds. As far as the analysis in the braking phase is concerned, this was carried out by means of thermal evaluations on data collected from experimental observations compared with data available in the literature. Among the main results, considering a precautionary limit hook load of 400 kN, both in the quasi-static and dynamic conditions, it appears that the maximum load section or degree of performance on which a train of 2000 t can circulate is 15/16, corresponding approximately to an equivalent resistance deriving from the infrastructure (i.e. gradient and resistance in curves) of 15‰, without prejudice to the possibility of using thrust or booster locomotives at the rear, in compliance with the provisions of art. 60 of the mentioned PGOS. The thermal evaluations of the braking system confirmed that the maximum values reached are compatible with those in the literature and that the behaviour of the braking blocks is different according to their type

Evoluzione dell'auto verso l'autonomia: collocazione storico-evolutiva, motivazioni ed effetti sulla sicurezza

Intervento di sintesi sull'evoluzione dell'auto verso l'autonomia: dopo la collocazione evolutiva dell'innovazione e dell'automazione nella storia dell'automobile, vengono esposte le motivazioni per l'introduzione della guida assistita, forse un domani dell'autonomia integrale, con gli effetti attesi sulla sicurezza stradale

Hydrogen Refueling Stations: Prevention and Scenario Management. Large Scale Experimental Investigation of Hydrogen Jet-Fires

Hydrogen is becoming an attractive alternative for energy storage and transportation, because of the elevated energy content per unit of mass and possibility to have zero carbon-emission vehicles. For these reasons, hydrogen's share in global market is expected to grow substantially in the coming years. Today, hydrogen-fueled buses and cars are already available, and several refueling stations are operating in different countries around the world. A key role of the deployment of hydrogen fueled-vehicles is the presence of a widespread network of refueling stations, especially close to residential and industrial areas. This fact poses attention to the safety aspects related to hydrogen, with particular interest to its high flammability that can lead to catastrophic consequences for personnel and equipment. As a matter of fact, hydrogen is a comparatively less safe fuel compared to conventional fuels such as gasoline and diesel. Hydrogen infrastructures are characterized by operating pressure up to 1000 bar that, in case of an unintended loss of containments, produce a highly under expanded turbulent jet. If ignited, this hydrogen jet may give rise to very severe scenarios, mainly related to high temperatures and the oriented flows. As recently suggested by Moradi and Groth (Moradi and Groth, 2019), there is a lack of experimental and on-site data for almost all of the storage and delivery technologies relevant to the hydrogen infrastructures. Experimental data is vital to support model validation, especially in the case of the very peculiar combustion process of hydrogen. In this way, a real-scale experimental campaign is proposed to investigate the main characteristic of the hydrogen jet fire resulting from its rapid fired depressurizations. Focus of the experimental campaign is evaluation of safety distance for person and device (i.e. pressurized tanks) in order to avoid critical conditions and domino effects in real refueling station. Different initial conditions, i.e., storage pressures, are exploited, and the resulting jet across specified orifice is investigated. More specifically, temperatures at various locations are measured through an arrangement of thermocouples. Values up to 1200 °C were obtained in the core of the jet. Moreover, it was found that the recorded temperatures, especially those at the outer portion of the jet, are very sensitive to the initial conditions

Valproic acid triggers erythro/megakaryocyte lineage decision through induction of GFI1B and MLLT3 expression

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