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This paper presents an in-depth investigation of the engineering aspects related to the design and operation of distributed-power freight trains (F-EMU, freight Electric Multiple Unit), and their potential advantages, by evaluating the various components of this new kind of train and comparing its performance with a traditional freight train. Electric motors, distributed along certain motorised carriages of connected wagons, allow, among others, the power necessary to avoid multiple locomotives, used on traditional lines for the heaviest trains, to be supplied, and access to high-speed lines, which were originally designed and constructed – in Italy for example – for mixed use (i.e. for passengers and freight). Interesting speed levels (140160 km/h) could be achieved, subject to the other requirements of the rolling stock, which are indicated later on in the paper. EMU trains are known to be used for passenger services, as they allow high speeds to be reached, energy to be recuperated during braking and, in general, increases in the performances of the rolling stock to be obtained. Analyses of the operation of freight trains have pointed out that distributed-power trains are able to reach appreciable acceleration values, during traction, because of a better distribution of the adhesive weight. High performances can be achieved, during the braking phase, when electro-dynamic braking, which allows energy to be recovered, is adopted together with a dominant electro-pneumatic braking system: this also prevents the infrastructure operator from having to lengthen the block sections to allow any poorly-braking 700-750 m long traditional trains to transit. The use of such innovative freight trains also satisfies the modern requirements of intermodal transport: electrification of the whole train makes it possible to transport units of refrigerated goods and perishable goods, and to conduct a constant monitoring of the load. After having examined the design and functional requirements of the F-EMU train and a traditional one, a comparison is made of the performances of a distributedpower freight train and a conventional one, on the TurinSavona railway line, through the use of a micro-simulating software package that is able to reproduce the railway operations along the considered stretch and saturate the current passenger timetable with freight trains. From the results, it has emerged that the adoption of distributed-power freight trains leads to a marked reduction of the travel times and an increase in the intermodal transport units (UTI) that can be transported over the reference time frame, especially when considering the use of 750 m long trains. [ABSTRACT FROM AUTHOR]

The paper presents an original approach to perform capacity assessments o f railway systems, based on the automatic generation and evaluation o f feasible timetables. This method relies on a microscopic model o f railway systems, used to simulate the train runs and the operation o f the signalling system. The resulting simulated train paths are utilised to arrange the input dataset for a scheduling algorithm which generates conflict-free timetables, which are then analysed in order to point out how and how much capacity is consumed. The described method and model are applied to a real case study, provided by a singletrack railway in Piedmont, Italy. Given a baseline scenario, a set o f infrastructural and operative improvements are taken into account. The relevant capacity increases are evaluated in terms o f reduction o f the global travel times of trains with respect to the baseline scenario. Results are analysed and discussed, highlighting the potentialities o f the presented method to performing effective capacity evaluations useful for a better exploitation o f railway systems. [ABSTRACT FROM AUTHOR]

The article presents a study which develops a capacity assessment of the two railways which connect the ports placed near the town of Savona to Piedmont in Italy to find solutions for setting up effective freight services.

The paper proposes an analysis methodology of energy consumptions in the railway field, presenting a comparison between an analytical calculation model and some measurements. It is hereafter assessed the influence of some parameters which characterise the travel diagrams of trains. The first part illustrates the analysis of the measured speed profile of a regional passenger train and of a TGV train covering a conventional line, with a high grade (the Torino-Modane), then introducing the comparison with the hypothetical profile obtained through simulation. Such comparison therefore allows deducing and quantifying the differences between the real and the simulated travel diagram. The latter employs completely the traction performances of the convoy and, therefore, features the smallest travel time on the considered line. The second part of this paper focuses the attention on the run of a freight train covering only one of the first sections of the same line, through the integration of the motion equation implemented on a spread sheet. In this part the analysis is carried on introducing important simplifications, as neglecting the effects of the line profile (rather flat in the considered stretch), in order to facilitate the analytical model. With such assumptions the influence on energy consumptions due to the scheduled travel diagram and to the driving style is evaluated. Special emphasis is given on the consumption connected to the braking stages and the relevant influence on the maintenance of brakes and wheel-sets, which has a direct economic impact for the transport operators. The role of innovative technological solutions is highlighted. [ABSTRACT FROM AUTHOR]