Experimental evaluation of tramway track wear by means of 3D metrological optical scanners

Wear evaluation of rolling components is crucial for tramway dynamics, maintenance and safety. 2D contact wear measurement techniques are the most commonly used to detect the health conditions of rails. In this paper, the novel use of a portable metrological 3D optical scanner is proposed and compared to the prior 2D methods. Laboratory results show that the application of 3D optical digitizers gives results consistent with the 2D results but gives also a more complete and global view of the wear phenomenon. Different inspection procedures are compared and discussed in order to propose the best method to perform 3D wear mapping. The results of on-line experimental campaigns on the real tramway line of Florence (Italy), performed with the current and the new proposed instruments and methods, are also presented and compared. From the results of this paper, new strategies for the maintenance service of tramways, and especially of the Florentine tramway, can be proposed.