Leaves on railway tracks affect the level of adhesion between the wheel and rail, especially in autumn. When crushed by wheels, leaves form a tarnished, low level of adhesion layer that sticks to the railhead and often requires mechanical removal. A Stockholm local traffic track with a long history of adhesion problems was subjected to field tests on railhead contamination. On five occasions under different conditions, spaced over a year, the friction coefficient was measured using a tribometer and samples of the rail were taken. The techniques of electron spectroscopy for chemical analysis and glow discharge optical emission spectrometry were conducted to determine the composition of the top layer of rail contaminants and hardness was measured using the nano-indentation technique. The tarnished layer contains much higher contents of calcium, carbon and nitrogen than do leaf residue layers and uncontaminated samples. These high element contents are generated from the leaf material, which chemically reacts with the bulk material. The hardness of the tarnished layer is one-fifth that of the non-tarnished layer of the same running band. A chemical reaction occurs from the surface to a depth of several microns. The thickness of the friction-reducing oxide layer can be used to predict the friction coefficient and extent of leaf contamination.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    A field test study of leaf contamination on railhead surfaces


    Beteiligte:
    Zhu, Yi (Autor:in) / Olofsson, Ulf (Autor:in) / Nilsson, Rickard (Autor:in)


    Erscheinungsdatum :

    2014-01-01


    Format / Umfang :

    14 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch





    National Railhead

    Graham, V. | British Library Online Contents | 1997


    Requirements for Transverse Railhead Profile and Railhead Roughness Following Grinding

    Grassie, S. L. / International Heavy Haul Association | British Library Conference Proceedings | 1997


    Field evaluation of thermite railhead repair weld

    Gutsher, Daniel | IuD Bahn | 2011


    Roadtest:Foden 4350 Drawbar: Railhead Double

    Brock,B. / Foden Trucks,GB | Kraftfahrwesen | 1994