In the 1990’s the founder of Elpa was commissioned by the Slovenian Railways to find a solution for excruciating squealing/screeching (generated by the hump retarders) in the marshalling yard in Ljubljana. He studied the phenomenon of railroad friction with unprecedented commitment. For some time he even lived by the tracks in his caravan to be able to study the friction day and night. More than two decades later, the railway sector is served by an accepted technology that expanded its scope from marshalling yards to the trackside and on-board devices.