The repairing of the bogies' underframes, on which appeared systematically cracks, makes the re-operating of the bogies possible, thus avoiding their replacement.

This repairing requires in the first place the analysis of the causes and of the concerned part.

A new 'reinforced' part is studied and manufactured (forging).

This part is fixed up, after the cutting of the bogie, following a specific welding process, that can keep the geometry of the bogie as well as its resistance.