Di4 652 – wheelset failure

Unstad was responsible for extending the wheel service life of the Di4-655 locomotives by reducing abnormally high wear and improving maintenance procedures. The goal was to increase operational efficiency and reduce service interruptions through more precise, data-driven wheel maintenance.

Unstad established a monitoring process for systematic tracking of wheel wear over time, using accurate measurements to determine the correct cutting depth during wheel lathe operations. In addition, re-profiling intervals were reviewed and optimized to make better use of the wheels and extend service life without compromising safety or performance.

The result was a substantial improvement in wheel service life—from 150,000–180,000 km to 300,000–350,000 km. The increased service life reduced the need for re-profiling and wheel replacement, lowered maintenance costs, and contributed to less downtime and more stable operations. The project demonstrates Unstad’s expertise in life-extension and condition-based maintenance of critical components in rolling stock.