This document:
— establishes the design process for switches and crossings (S&C), and the use of the other parts of this standard;
— specifies the geometric design principles for wheel guidance;
— establishes the basic limits of supply;
— establishes the applied forces and their adequate support;
— specifies tolerance levels.
These are illustrated herein by application to a turnout. The main switch and crossing components are represented in turnouts and the principles used in turnouts apply equally to more complex layouts.