Bono Focacci Lanni - La Sovrastruttura Ferroviaria
Esveld - Modern Railway Track
Lichtberger Track Compendium
Lopez Pita - Infraestructuras Ferroviarias
Marx - Arbeitsverfahren für die Instandhaltung des Oberbaus
Wang - High-Speed Turnouts
Zaayman - Mechanised Track Maintenance
Learning Objectives
CA1: Applying knowledge and understanding related to problem identification and formulation of solutions, in the field of mechanical engineering, to set up, design, implement and verify systems and apparatus, even of high functional complexity, taking into account the implications related to environmental, economic and ethical aspects, employing well established methods.
CA2: Applying knowledge and understanding related to the analysis and optimization of mechanical devices and systems, as well as to their innovation also through the development and improvement of design methods, constantly confronting with the rapid evolution of mechanical engineering.
CA3: Applying knowledge and understanding related to the choice and application of appropriate analytical and modelling methods, based on mathematical and numerical analysis, in order to better simulate the behavior of components and plants in order to predict and improve their performance.
CA4: Applying knowledge and understanding related to the implementation of engineering projects adapted to their level of knowledge and understanding, working in collaboration with engineers and non-engineers. The projects may concern components, equipment and mechanical systems of various kinds and for the widest possible applications.
CA9: Applying knowledge and understanding related to the critically assessment of data and results, drawing appropriate conclusions, aware of the degree of uncertainty that may affect them.
CA12: Applying adequate knowledge and understanding to understand English texts.
CA15: Applying knowledge and understanding to achieve adequate preparation for tertiary level university studies (frequency to post-master's degree courses and doctoral schools) in order to further deepen knowledge and skills in research.
CC1: In-depth knowledge and understanding of the theoretical-scientific aspects of engineering, with a specific reference to mechanical engineering, in which students are able to identify, formulate and solve, even in an innovative way, complex and/or interdisciplinary problems. The ability to understand a multidisciplinary context in the engineering field and to work with a problem solving approach
CC5: Knowledge and understanding of materials and their behaviour in the various loading conditions found in design practice. Methods for characterising material behavior.
CC7: Knowledge and understanding of the design principles of production plants and processes, logistical facilities for material handling and storage. Understanding the advantages and limitations of process and plant design choices in different application contexts.
CC8: Knowledge and understanding of the land-based vehicle sector by deepening the structural aspects of the various vehicle types. Knowledge and understanding of electrical machinery and related traction power supply systems. Knowledge and understanding of the structural and thermo-fluiddynamic aspects of internal combustion engines.
CC10: Knowledge and understanding of the automation and control industry. Knowledge and understanding of mechatronic systems.
CC12: Knowledge and understanding of methods for conceiving, planning, designing and managing complex and/or innovative systems, processes and services.
Prerequisites
It is preferable to have taken the "Construction of Rail Vehicles" course in the first semester.
Teaching Methods
Face-to-face lessons
Type of Assessment
Oral exam
Course program
Introduction and aims of the course. Bibliographic references. Development of the railway system over time. Catenary systems. Boundary gauges. Natural (deep) and artificial (cut-and-cover) tunnels. General track constitution. Track support function Coordinates describing track geometry. Wheel-rail interface Track gauge Explanation of Klingel motion Dynamic running stability
Wear at the wheel-rail contact. Increase in equivalent conicity with variation of track gauge. Tension at wheel-rail contact. Gauge spreading forces and sliding at the wheel-rail contact (reminder). Competing mechanisms of RCF and wear. Railway curves. Curve effects on vehicles Uncompensated acceleration Clotoid couplings. Integral of Fresnel equations. (The lesson continues following an ICRI-RCF seminar on rail profile management).
Curve transitions. Backlash or jerk. Different types of fittings according to EN 13803-1:2010. Curves and counter curves. Slopes. Graphic timetable. Homotachic and heterotachic circulations. Loads acting on the track Axle loads Axle load and load per metre. Line classification. Nadal trip coefficients and Prud'Homme lateral forces on the track (reminder). Thermal cycles of rails. Buckling phenomena arising from high temperatures. References to UIC leaflet 720 on the long welded rail. Elongation at the ends of the LRS. Information about the accident at Gricignano (July 2020). Expansion joints.
Influence of vertical loads and speed on the geometrical quality of the track. Variation of stresses as a function of line curvature. Facets on wheels resulting from locking. Loads. Definition of P1 and P2 forces according to Jenkins. Faceted wheel detectors. Rail roughness and roughness growth in metro lines. Static track design. Winkler model of beam on elastic soil. Foundation coefficient. Solution of the differential equation. Characteristic length of track. Trends in rail deflections and bending moment in rails. Effect of rail uplift. Notes on cases with multiple loads (bogies). Effect of rail joints. Double beam models Rail tensions Dynamic amplification of forces according to Eisenmann. Slab track. Hertzian tensions. Sections of the most common rails (60E1, 60E2, 50E5). Tensions in sleepers. One-piece and two-piece sleepers. Ballast and its supply Numerical track models
Dynamic track design Finite element modelling. Dynamic stress response analysis. Frequency responses for basic forcing and excitation. Influence of damping and velocity fields. Defects in the spatial and frequency domains. Origin of binary excitations Effect of cyclic track irregularity. Modelling of track with discrete elements (forcers, supports) and continuous elements (rails). The Kisilowski model and the PDE solution. Dynamic solution on elastic ground. Superposition of track response functions (inertia). Critical train speed according to track irregularities. Critical track speed for soft ground ('vibration boom'). Contact stiffness (Herztian spring). Hertzian contact filters. Numerical model DPRS (hints). Response of the wheelset. Transfer function between track geometry and bush acceleration. Problems of reconstructing track geometry from axlebox accelerations ('ill-conditioning'). Example of anti-resonances (modal analysis ETR500 hall). Autoregressive models for dynamic modelling of track at high frequencies (hints).
Weighing of measured accelerations for comfort and ride quality assessment. Influence of vibrations on the human body Dynamic diagram of the human body. Weighing functions for estimating the effects of vibrations on the human body according to ISO 2631-1. Weighted acceleration as disturbance parameter ISO filter equations Passenger comfort according to Fiche UIC 513. Sperling index Wz. Calculation of the dynamic response of a flexible body vehicle. The EN 12299:2009 standard on passenger comfort. Modelling with multibody codes. Dynamic response of the vehicle on vertical transitions (e.g. entering a bridge).
Track stability and longitudinal forces. Effect of transverse track stiffness on the occurrence of buckling. Description of articles by Ciobanu (2017) published in Journal of Permanent Way Institution.
Description of articles by Ciobanu (2017) published in Journal of Permanent Way Institution. Description of the presentation CIFI ing. Treffiletti. Identification of the neutral temperature of rails using the VERSE system from Pandrol.
Track on ballast. Introduction. Constitution of the superstructure. Use of geotextiles. Ballast procurement criteria. Ballast sizing. Ballast cleaning criteria. Rails: standardised sections. Conventional joints (with expansion) and glued joints (without expansion). Supporting "copings" of conventional joints. Constitution of glued insulating joints (IRJ) and use in track circuits (brief description). Railway sleepers. One-piece and two-piece wooden and concrete sleepers. Management of gauge widening. Description of different types of sleepers Steel sleepers Y sleepers Other types of special sleepers (hints). Illustration of the Margaritelli Ferroviaria catalogue.
Introduction to rail attachment systems. Direct and indirect couplings. K-coupling and CK1 couplers. Railpad. Baseplate. Keyways. Pandrol, Vossloh and Nabla spring attachments. Pandrol assembly films of the e-clip and Fastclip couplings. Vossloh DFF coupling. Catcher. Clamping forces. Railpads with low rigidity. Ballast mats. Load distribution according to ballast stiffness. Rockdelta in stone wool. USP = under sleeper pads Pandrol. EN 16730:2016 standard on USP. Superelastic attachments (Cologne Egg, Pandrol Vanguard). STRAIL level crossing systems.
Slab track. Slab track requirements. Continuous rail support and related railpads. Rheda fitting. Discontinuous slab reinforcement (Japanese). Double resilient plates. Direct attachments on steel decks. Pandrol Vanguard attachment. Booted sleepers (Sonneville system). Fully insulated slab track. Floating slab track (discrete supports and stoppers). Milano Massive armament. Possible combinations type of track / type of bindings. Comparison of track costs on ballast/slab. Vibration control. Groundborne noise and airborne noise. Influence of coupling stiffness on vibration. Control of thermal expansion Laboratory tests on the Vanguard coupling. Top-down or bottom-up track construction methods.
Ballast-on-ballast / ballastless track transitions. Summary of the main types of track. Example of application of all track types: Line 1 of the Naples metro. Vibration tests in tunnels. Modified Milan connection. Booted sleepers on floating slab track. Rail corrugation phenomena. Growth of marbling over time. Measurement of noise and vibration and associated disturbances. Example of track with booted sleepers on slab track: Copenhagen metro. Calculation of insertion loss of booted sleepers. Vanguard couplings: drawings, installation on Line A of the Rome Metro.
Railway rails. Rail production process, from blast furnace to final checks. Transport of rails on special railway wagons. Torpedo wagons. Converters, degassing, ladles, tundish, stirrers, continuous casting. Rolling mill Cooling plate. Rectifier. Ultrasonic and eddy current controls. Profile and longitudinal geometric tolerances. Mechanical properties: tensile strength, hardness, elongation. Fracture toughness and relationship with hardness.
Straightness control of rails. Wavelength spectrum. Detection of residual waviness after straightening using advanced techniques. Metallurgical properties and relationship of interlamellar spacing to mechanical properties. Hardness/burden ratio. Heat treatment of rails (off-line head hardening). Hardness in the rail head. VoestAlpine method. Non-alloy steel grades, hardened by alloying, hardened by heat treatment. Steelmaking equations. Analysis of standard EN 13674-1:2017. Wear of rails in service. Influence of lubrication on wear at 45°. Archard's model and influence of hardness. Electric spark welding of rails. Heat affected zone.
Heat treatments in spark welding. Aluminothermic welding. Energy and mass balance. Reusable and disposable crucibles. Preheating of rails to be welded. Preparation of moulds and crucible. Final cleaning of the joint with deburring and grinding. Hardness profile. Cooling rate of the joint and resulting metallographic structures. Geometric checks on the straightness of the welded joint.
Rail defects. Fiche UIC 712. Description and discussion of the main types of defects.
Switches and crossings Typology, general description. Nomenclature Switch operation with electromechanical turnouts. FS P80 box. Packable bodies. Shunting box in a sleeper. Shunting, stopping and control units. Notes on hydraulic shunting systems.
Geometric layout of the turnouts. Tangent and radius of curvature. Needle-Tangent differences between the 50E5 and 60 E1 track sets. Secant needle and tangent needle. Mechanical processing of needles and conrods. Switches with a movable point core
Vehicle dynamics on switches and crossings. Grids. Switches with curved branches with clotoid connections. Types of turnouts (single, double, intersections, etc.). English inside slip and outside slip switches (Baeseler).
Geometrical requirements for switches and crossings Conventional jerk. Protection and free passage quotas. Seminar Ing. Megna on vehicle-track interaction in turnouts.
Conclusion of the course.