# The orphan rule of cant design over a reverse transition

Motto: Tolle lege. Most of the railway track design standards around the world are presenting the particular issue of the reverse transition. All these standards are insisting on keeping a constant rate of change of curvature – a constant A. By doing this in fact the design will include a single continuous transition between the two opposite circular…

# British Railway Track

Another classic book it sure is “British Railway Track Design, Construction and Maintenance”, edited by Geoffrey H Cope and having around 40 contributors for writing the 30 chapters of this essential track compendium. Its last six edition was published in 1993 by The Permanent Way Institution. Presenting the essential principles but also the British specifics…

# Alternative Approach to Permanent Way Alignment Design Explained&Challenged

The slides of the presentation I gave in November at the West of England section meeting of the Permanent Way Institution:   The main topics presented: – Cant parameters definition. The origin of the 11.82 (UK) cant constant. Ways of applying cant. – Track geometry recording. Track Quality Standard deviation. Inherent standard deviation. Quality bands…

# La voie ferrée

When it comes to Railway track engineering literature, there are a few books we can consider “classic”. Even old, some very old, these books still have significant railway engineering value and can be always a good reference both for young and inexperienced engineers as for the ones that already have robust railway track experience and…

# How is the cant measured?

The good old times Since the early beginnings of the railway, the track engineers were aware of the centrifugal forces influence to the train riding when passing through a curved section of track. To compensate this influence, the track was inclined laterally by creating a positive level difference between the outer and inner rails of a…

# Virtual Transition

This is an animation showing how a PWay Track Horizontal Alignment Virtual Transition is defined by the trajectory of the vehicle centre, when is passing over a railway track section with a sudden change in curvature: The nature of this curve is presented in this post: THE VIRTUAL TRANSITION CURVATURE VARIATION. More details about this principle…

# Cant and Cant Deficiency. Where is the 11.82 coming from?

A railway vehicle moving along a circular curve is subjected to an inertial centrifugal acceleration (ac), directly proportional with its speed and in reverse proportion with the curve radius. This lateral acceleration is perceived by the passengers as an uncomfortable sensation and, above a certain limit, endangers the lateral stability of the running vehicle. In…

# The limits of the track alignment design parameters

(A commented extract from BSEN 13803-1 (2010) Railway Applications – Track – Track alignment parameters – Track gauges 1435 and wider – Part 1: Plain Line) The track alignment design PARAMETERS (BSEN 13803-1 – 5.1.2) In the design process the values of the track alignment parameters are chosen to ensure a safe riding with at least…