BS EN 13803-2:2006 pdf download

BS EN 13803-2:2006 pdf download.Railway applications——Track — Track alignment design parameters — Trackgauges 1435 mm and wider —— Part 2: Switches and crossings and comparable alignment design situations with abrupt changes of curvature.

5 General requirements
The track alignment designer Is free to specify the most aPpropriate values foe’ the various parameters at the specified operating speeds, when considering safety, geographical, engineering, historical, and economic constraints These values and parameters shall be specified in the contract documents.
The designer shall endeavour not to exceed the recommended lwn.ting values specthed In this European Standard and avoid unnecessary use of the maximum (or minimum) limiting values. Annex G describes the constraints and risks associated with the use of maximum (or minimum) limiting values.
Whenever necessary, the track alignment designer shall take into account nahonal standards when these are more restrictive.
The most important requirements for the installation of switch and crossing layouts are specified ii Annex B. These requwements have an influence on the design of the alignment elements for both tracks in switch and crossing layouts and, consequentty. they Influence the maximum operating speeds and life cycle costs. The designee’ should, as far as it ie practicable, comply with these requirements.
Existing installations, which do not conform to this European Standard, should be modified as soon as possible It safety requirements (foe’ example abrupt change of cant defic*ncy. length of element(s) between abrupt changes of curvature and tne safety related parameters listed In ENV 13803-1) are compromised. Other non-conforming installations should, If possible, be modified during the next track renewal.
The railway authority or the manufacturer shall specify the limits (e.g. requirement for the switch entry angle) for non-tangential switches (see also EN 13232-9). Annex F describes a method for calculatwig the maximum permissible speed at the toe of a non-tangential switch.