The purpose of this document is to define a set of reference masses that can be used as a common starting point for specifying the requirements for the design, testing, delivery acceptance, marking and operation of rail vehicles. It is not the intention of this European Standard to change the dimensioning of vehicle system components by the definition of these common reference masses. However, when the relevant standards are revised or new ones developed, the masses to be used in these vehicle system component standards as the basis for the design should be expressed as a function of the reference mass states defined in this standard. Until the standards are changed the existing criteria continue to apply. This document covers all types of rail vehicles. For the purpose of vehicle mass definitions rolling stock is divided into three vehicle groups which are: High speed and other long distance trains; passenger vehicles other than high speed and long distance trains, including metro and tramway; freight vehicles (wagons and freight motored units). Locomotives are treated as passenger vehicles without payload. The specification of the technical requirements of the railway vehicle should contain the information to which vehicle group it belongs. The masses defined in this document are as follows: Dead mass, design mass and operational mass.