The density of Switches and crossings (S&C) in most railway networks is estimated to be ~1 every km which equates to over 300,000 units within the networks of EU27 countries and the cost of maintenance of an S&C unit is believed to be equivalent to that for ~0.3km of plain line track. Further costs are incurred at renewals which, even at very modest rates of renewal, mount up to a very large figure. Thus the economic impact of S&C units on the maintenance and renewal budgets of railway authorities is very apparent. Hence any increase in the life span of this important infrastructure asset through better design or maintenance practices is considered highly desirable and is one of the primary objectives of this project. The recently completed EU project, Innotrack, has emphasized the need to identify the major cost factors and use this knowledge as the drivers for essential improvements to design, installation, and maintenance practices. An understanding of the degradation mechanisms associated with S&C units is essential for the optimization of design and maintenance procedures to eliminate or minimize the impact of the causes of the life limiting degradation. This deliverable of a catalogue of defects that are encountered in S&C units is a contribution towards this objective.