Railway business (both in Sweden and internationally) is in need of efficient and non-destructive methods for convenient measurements of the neutral temperature. Banverket has hitherto made some investigations of different such methods and this analysis aims in this perspective to · Identify different techniques and methods that are possible to use for measuring the neutral temperature and sort out those that are not useful for rail applications. · Give the theoretical basis for each method in order to obtain a firm base for further investigations and judgements. · Perform critical examinations of the development potential, cost and time consumption for each of the methods and identifying those methods and equipments that are of most interest for further investigations. · Identify additional actions to be taken in combination with efficient neutral temperature determinations for reduction of the heat distortion risk in CWR-tracks. The following methods are possible candidates for further investigations: Ultrasonic methods Based on either the longitudinal wave principle or the birefringence principle with methods developed by, for example, NIST and RIPL. Deformation methods Based on measurements of either strains or of positions with commercial methods as the Pfender device, the MS-02 device, the MP method or the geodesic method. Magnetic methods The Barkhausen noise principle seems to be more promising than the magnetic parameter method with developed testing methods by Railscan, Railtest and Rollscan. X-ray diffraction method Based on diffraction of X-rays in crystal planes, portable equipment exists although the method has traditionally been used under laboratory conditions. Rail vibration techniques method Based on the relation between stiffness and force in combination with an accurate laser measurement system, this method is a promising alternative. In parallel to improved measurement techniques for neutral temperature, a list of possible additional actions has been identified. These are additional logical ways to reduce the risk for rail heat distortions and they do not have any technical solutions today. The author is currently not aware of all possible efforts that have been made regarding these issues but they should be kept in mind during future work. For example: · Could rail cooling be performed by heat conduction to the cooler regions below the track? · Should the neutral temperature be increased (cf. chapter 3)? · Could rail grinding improve the mechanical integrity? · Are there possible modifications of the CWR-concept itself that could reduce the thermal stress build up? · One obvious action is to improve the lateral resistance of the track region. This is the main focus of the accompanying report within this preliminary study. This preliminary study shows that there exist promising methods that would improve the measurements of neutral temperature. When this preliminary study is completed, it is therefore proposed that actions are taken for more detailed investigations of the one or two most promising methods. This should be done through field studies and laboratory studies in Sweden but also, where appropriate, through visits to places in Europe where the methods have been evaluated. It would also be of interest to study additional ways of reducing the risk for rail heat distortions.