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DC urban light railway systems are used for public transportation in many towns worldwide. In these systems, short-circuit currents are often similar, both in steady-state magnitude and in rate-of-rise, to normal operation currents. In order to properly set the protection relays, to obtain short-circuit discrimination and to avoid nuisance trippings, it is important to analyze short circuit and normal operation current patterns. It is also important to highlight that normal operation current patterns are not only those related to rolling stock acceleration, but also to zone commutation. This paper presents the results of several measurement campaigns, performed for this purpose, on the tram network of Turin, Italy. The measurements results are then used to propose optimized settings for the installed overcurrent protections. [ABSTRACT FROM AUTHOR]

The paper estimates the standard cost in Italian regional public rail passenger transport services (LPTR), depending on service characteristics. The results highlight the crucial role of: number of seats per ride, commercial speed, service size and length of rail tracks. The model also shows the positive link between investment in rolling stock and the unit cost of the service. Finally, based on the empirical evidence, we propose regulatory adjustments to accomplish policy targets regarding the fair allocation of public LPTR funds to Regions and Local Authorities and a more efficient use of (scarce) local and national public resources. [ABSTRACT FROM AUTHOR]

A full electrification of many local railway lines is often not feasible or sustainable in terms of construction and maintenance costs or alternatively for the presence of additional constraints and limitations deriving from environmental or infrastructural limitations. Battery Operated or other kind of hybrid solutions powertrains are currently proposed as sustainable alternatives to Internal combustion engines for the propulsion of rolling stock on not electrified lines. In this work, authors propose the adoption of a partial electrification of lines to assure higher performances and reliability of battery-operated rolling stock designed to be recharged and feed using standard technologies such as pantographs gathering power from suspended catenaries. This innovative solution is designed and sized for a vehicle inspired from an existing one and simulated for two different existing lines, also proposing an optimal distribution of electrified sections dedicated to train recharge. This Case Study is simulated considering some possible applications to some existing railway lines in Italy. [ABSTRACT FROM AUTHOR]

In this work we tackle a real-world application of railway rolling stock planning, known as the train unit assignment problem (TUAP), arising for a regional train operator in the North of Italy. Given a set of timetabled train trips, each with a demand of passenger seats, as well as a set of train units, each with a cost and a number of available passenger seats, the goal is to determine the minimum cost daily assignment of the train units to the trips, satisfying a set of operational constraints. The context we focus on is that of a competitive bid process whereby a train operator competes to win a contract for providing rolling stock circulation in a regional railway network. From a theoretical perspective, we prove that even a relaxation of the TUAP is NP-hard. To solve the TUAP, we propose a heuristic algorithm based on the optimal solution of the restricted problem associated with a peak period (i.e., a period of the day in which many trips overlapping in time must be performed). The heuristic algorithm is tested on real-world instances provided by the regional train operator and on larger realistic instances of TUAP. The obtained results are compared with those of previously developed methods, showing the effectiveness of the new algorithm that finds optimal or near-optimal solutions and outperforms, for what concerns both the solution quality and the computing time, the considered methods from the literature. [ABSTRACT FROM AUTHOR]