Ulrich Spangenberg
Transportation Technology Center, Inc.

Hollow worn wheels are known to cause rail damage in the transition zones of special track work and contribute to rolling contact fatigue initiation and development on main lines. Moderately to severely hollow worn wheels can increase the truck-side lateral to vertical (L/V) ratios and decrease resistance to rail roll-over. A study of worn wheel profiles and wheel wear data from wayside wheel profile monitoring systems were conducted to understand the development of hollow worn wheels and asymmetric wheel wear patterns. Pre-existing wheel diameter differences on mate wheels of the same axle and truck type was investigated as potential causes of asymmetric hollow wear. The results from the study showed that severely hollow worn wheels are associated with an asymmetric wheel wear pattern. The occurrence of asymmetric hollow wear was found to be more prevalent on certain car types and resulted in a lateral tracking position offset with no change in angle of attack of the wheelset. The pre-existing wheel diameter difference did not show any correlation to the development of asymmetric hollow wear, though the influence of the truck type on asymmetric hollow wear showed more promising results.