BS EN 13803-2:2006+A1:2009 - Page 2

Railway applications. Track. Track alignment design parameters. Track gauges 1435 mm and wider. Switches and crossings and comparable alignment design situations with abrupt changes of curvature | Status: Superseded, Withdrawn

1 Scope This European Standard specifies the rules and values for the track alignment design parameters used to determine the maximum operating speeds over tracks with abrupt changes in curvature and, consequently, abrupt changes of cant deficiency. Such conditions occur in the following situations:

• — in the diverging tracks in switch and crossing layouts;
• — when it is not practical to design an alignment with transition curves;
• — if the length of a transition curve is less than the minimum required for plain line track.

Engineering requirements specific to the mechanical behaviour of switch and crossing components and subsystems are to be found in the relevant standards. This European Standard presupposes that the homologation of the operating vehicles will be valid and specified for conditions corresponding to the limiting values specified in this European Standard. This European Standard is applicable to abrupt changes in curvature in switch and crossing layouts and plain lines with track gauges of 1 435 mm and wider. Annex C is applicable to track gauges wider than 1 435 mm. This European Standard specifies the requirements for preventing buffer locking. The limiting values specified in this European Standard, when applied at the switch toe, are for switches with tangential geometry (as defined in EN 13232‑1). This European Standard need not be applicable to certain urban and suburban lines. This European Standard is not applicable to track alignment requirements for tilting body vehicles. However, Annex H draws the designer’s attention to the consequences and the restrictions imposed when tilting vehicles are operated over switch and crossing layouts and alignments without transition curves.