Additional railway noise source terms for "Calculation of Railway Noise 1995"

Executive Summary When the procedure " Calculation of Railway Noise 1995 " (CRN) [Ref 1] was devised, the list of stock that was included was aimed at representing the majority of typical vehicles operating on the railway at that time. However, since 1995 the nature of the rolling stock fleet has changed considerably and there are many types of vehicle currently in operation that are not included in CRN. There are also several types of stock pre-dating CRN that are not included. Within this report, data for CRN rolling noise terms for a range of vehicles agreed with Defra have been calculated by application of AEA Technology's experience in this field and by reference to its database of information on the acoustic and physical characteristics of the stock. Data have also been obtained from field measurements for the Class 390 Pendolino Brittanico, the Class 220 Virgin Voyager, the Class 221 tilting Virgin Voyager and the Class 170 Turbostar. Rolling noise source term corrections, measured previously in the field by AEA Technology for the main UK rail freight operator EWS, are also provided for an agreed set of freight wagons and diesel locomotives, and the measured " on-power " source term is also provided for these locomotives. These latter sets of data are provided with the permission of EWS. Eventually it would be advisable to base all such terms on measurement, especially if they are to be incorporated within a revised CRN document, but the calculated values presented in this report can be considered as being sufficiently accurate for initial noise mapping purposes.