The Ptuj Maintenance Section has successfully replaced the monobloc wheels on modern Stadler passenger trainsets for the first time. This is a complex and specialised process which marks a notable step in maintaining a new generation of railway vehicles and is an important milestone for the growth of our Ptuj maintenance team.

At present, the replacement is mostly done on driving wheels, which typically experience higher loads and hence wear more quickly than trailing wheels. The chief criteria for replacing monobloc wheels are the wear and the condition of the wheel tread. Depending on the level of wear, monobloc wheels are replaced on two or on all four wheelsets of an individual trainset.

A distinctive feature of Stadler trainsets is the procedure by which the bogie and wheelsets are dismounted from the vehicles, which makes the maintenance process considerably different from that of conventional Y-series trains and Wegmann 25 and 26 bogies. The lifting and roll-out of Stadler wheelsets require more precision, specialised tools and close coordination between several teams of technicians. Because Stadler trains are fitted with Jakobs bogies, where two consecutive vehicle bodies are always supported on a common bogie, the entire trainset must be lifted during the process, requiring special lifting jacks with precise, varying load capacities which operate in large, synchronized groups, and which were purchased specifically for the project at hand.

The replacement of monobloc wheels also requires the CTBU bearings to be unmounted and replaced. Another Stadler-specific feature is that different maintenance and wheelset refurbishment processes are applied between Class 313, 510 and 610 units because the wheelsets vary in tread diameter, axle material, vehicle class, length and the maintenance process to be applied.

This project required us to purchase, in advance, specialised tools, equipment and lifting jacks which are able to lift the entire trainset simultaneously. The new equipment is a significant upgrade of Ptuj Maintenance Section’s technical capabilities and allows us to deliver complex maintenance in the coming projects, too.

The next big step is building the expertise and mastering the equipment required for refurbishing Stadler bogies. This will boost our know-how and expand our service portfolio in the maintenance of modern rolling stock.