Christos Pyrgidis

Railway Transportation Systems: Design, Construction and Operation

This book presents an overview of railway passenger and freight transport systems. The book focuses on issues related to safety, interface with the environment, cutting-edge technologies, and techniques that govern the stability and guidance of railway vehicles on track. The chapters of the book include: The Railway as a Transport System; Loads on Track; Behavior of Rolling Stock on Track; Tramway; Monorail; Automatic Passenger Transport Railway Systems of Low and Medium Transport Capacity; Suburban Railway; Rack Railway; Cable Railway Systems for Steep Gradients; Organization and Management of Passenger Interurban Railway Transport; High-Speed Trains; Tilting Trains; Metric Track Gauge Interurban Railway Networks; Organization and Management of Freight Railway Transport; Heavy Haul Rail Transport; Impact of Traffic Composition on the Economic Profitability of a Railway System; Railway Safety; Railway and the Natural Environment; and Cutting-Edge Technologies in Railways.

Speed as a stand-alone indicator of the quality of the railway track

Abstract A method for the assessment of the quality of the railway track is presented, introducing speed as a stand-alone quality indicator. Speed is expressed by means of the maximum permissible track speed V TR, max, which is considered to depend upon the satisfaction of a predefined set of safety, comfort, and reliability criteria. Calculations are performed by means of analytical models. The method can be applied to any railway network, regardless of technical or operational characteristics; it can assist infrastructure managers in their track maintenance management decision-making process. Extensions of the proposed method are feasible in order to include additional speed-related performance criteria, e.g. noise and vibrations.

Investigation of the impact of traffic composition on the economic profitability of a new railway corridor

This paper investigates, with the help of a mathematical model, the impact of traffic composition on the economic profitability of a new railway corridor. The model permits, for various exploitation scenarios (mixed traffic operation, dedicated passenger operation, dedicated freight operation), first, the calculation of the economic profitability of each scenario (net present value (NPV) and the internal rate of return of the investment), and second, the selection, on the basis of demand for passenger and/or freight to be transported via rail on the new corridor, the exploitation scenario that presents the highest economic profitability. The obtained results show that the basic criterion for the selection of the optimum scenario concerns the characteristics of transportation demand (type of goods and volume transported) and, second, the topography of the landscape. Specifically, for average demand values, mixed exploitation scenarios present the highest NPV, whereas for high demand values, dedicated operation scenarios are the most profitable. Furthermore, the dedicated freight operation scenarios presents a higher NPV compared with passenger operation scenarios when the ratio of the demand of the number of passengers to freight tonnes approaches 1:3 (traffic train composition percentage of 50:50), this favours mixed operation scenarios.

Comparison of the Economic Profitability of a Conventional Freight-Dedicated Railway Corridor and a Heavy Load Freight Corridor

Article history: Received: 8.07.2017 Accepted: 14.09.2017 Published: 14.12.2017 By using mathematical models, this paper will compare the economic profitability of a heavy load freight corridor (30 t per axle) with a conventional freight-dedicated railway corridor (22.5 t per axle). This comparison concerns the construction and operation of a new, single-track of normal gauge, exclusively for freight traffic, and takes into account various demand values of freight volume (10,000-130,000 t daily per direction) and connection length (500km and 1,000 km). Within the framework of this research, the rail infrastructure manager is also the owner of the rolling stock and the operating company. The mathematical model simulates the algorithm “revenues minus expenses” for each of the above railway systems and permits among other things the calculation of the Net Present Value (NPV) of the investment. The results showed that: a) the conventional load corridor can cater for up to approximately 40,000t per day per direction while the heavy freight corridor can carry around three times that volume, b) for daily freight volumes of up to 40,000t, the conventional freight corridor is more profitable c) for loads greater than approximately 25,000t-30,000t, the increase in the connection length results in a marked increase in the economic profitability of both systems since it leads to roughly the doubling of the NPV.

Estimation of required ground plan area for a tram depot

This article proposes and develops a methodology that allows the estimation of the required minimum ground plan area for the facilities in a tramway depot, as well as the total area of the depot, taking into account the fleet size, tram length, number and type of performed activities. The study formulates simple mathematical equations to calculate the useful area of various depot installations in relation to the characteristics of the vehicle fleet (number and length of trams). It also presents tables of data, from which the total depot area can be estimated. Finally, the layouts of typical ground plans of tram depots are presented for tram fleets of between 15 and 83 vehicles and for tram lengths of 30, 35 and 40 m. From the presented results it is concluded that: (i) the construction of depots for 15 vehicles (very small depots) requires an area of 30–35 acres; (ii) the construction of depots for 45 vehicles (medium-sized depots) requires an area of 42–50 acres; and (iii) the construction of depots for 80 vehicles (large-sized depots) requires an area of 52–60 acres.