What is BS EN 13803 - Track alignment design parameters about?
The purpose of BS EN 13803 is to specify rules and limits for track alignment design parameters, including alignments within switches and crossings. Several of these limits are functions of speed. Alternatively, for a given track alignment, BS EN 13803 specifies rules and limits that determine permissible speed.
BS EN 13803 applies to nominal track gauges 1 435 mm and wider with speeds up to 360 km/h. Normative Annex A describes the conversion rules which shall be applied for tracks with nominal gauges wider than 1 435 mm. Normative Annex B is applied for nominal track gauges 1 520 mm, 1 524 mm, and 1 668 mm.
BS EN 13803 is also applicable where track alignment considers vehicles that have been approved for high cant deficiencies (including tilting trains).
Note3: More restrictive requirements of technical specifications for interoperability relating to the ‘infrastructure’ subsystem of the rail system in the European Union (TSI INF) and other (national, company, etc.) rules will apply.
Note4: BS EN 13803 need not be applicable to lines, or dedicated parts of railway infrastructure that are not interoperable with railway vehicles tested and approved according to BS EN 14363.
Who is BS EN 13803 - Track alignment design parameters for?
BS EN 13803 on track alignment design parameters is useful for:
- Railway management authorities
- Infrastructure managers
- Site supervisors
- Inspection and testing department in railways 
- Railway engineers
Why should you use BS EN 13803 - Track alignment design parameters?
A new railway track should be aligned very carefully as improper alignment would result either in the capital loss in the initial cost of construction or recurring loss in maintenance and vehicle operation cost, or both.
In the design process, the values of the track alignment parameters are chosen accordance with BS EN 13803 which helps to ensure safe riding with at least a minimum comfort level.
It is permissible to use the exceptional limits specified in BS EN 13803 if the use of the normal limits incurs unacceptable costs in achieving the maximum desired speed. However, every effort shall be made to design the alignment with a substantial margin to the limits.
BS EN 13803 specifies rules and limits that determine the permissible speed which ensures that the vehicle stability and lateral track force criteria are met.
