From idea to impact
How lightweight axles drive innovation at VTG.
At VTG, innovation does not mean chasing trends. It is about making a real difference where it matters most—for our customers, our operational processes, and our long-term competitiveness.
The “Lightweight Axle” (LwA) project, developed in close collaboration with Siemens Mobility, is a compelling example of how our FOCUS strategy is brought to life through tangible, high-impact innovation.
FOCUS challenges us to closely examine our value chain and ask a central question: where can we achieve the greatest impact? One clear answer lies in maintenance, and within that, in the wheelset. As the most cost-intensive component over the entire lifecycle of rail freight wagons, every improvement here has disproportionate strategic relevance. This is exactly where the lightweight wheelset comes in. By rethinking a long-established component, we unlock efficiency gains that go far beyond incremental optimization.
Conventional wheelsets are based on a solid forged axle onto which the wheels are press-fitted. The lightweight axle follows a different approach: a seamless steel tube axle with bolted wheel connections. The result is a significantly lighter system—around 600 to 800 kg less per wagon.
Rethinking the wheelset and the system behind it
What may initially sound like a technical detail quickly unfolds into system-wide benefits:
Innovation thrives on strong partnerships
Breakthrough innovation rarely emerges in isolation. That is why VTG deliberately seeks strategic partnerships that combine complementary strengths.
Siemens Mobility is a recognized technology leader in high-speed passenger transport—an environment with extremely high requirements for safety, lightweight construction, energy efficiency, and durability. The lightweight axle was originally developed for this demanding environment. Due to long regulatory timelines in passenger transport, freight traffic offers the ideal initial use case.
VTG was able to offer exactly what Siemens needed: a large fleet, in-depth maintenance expertise, and a clear willingness to innovate. After initial contacts at industry events in 2021, the technical discussions intensified and, by summer 2023, developed into a structured collaboration—at a point when VTG was still able to actively shape the development.
The result is a partnership with strategic depth:
• Delivery of 120 fully approved wheelsets, including all verification documentation
• Role of VTG as a preferred development and reference partner, with advantages in future development phases and supply situations
This collaboration shows how FOCUS and innovation work together: targeted, pragmatic, and value-driven.
Innovation driven from within the company
It is important to note: this project did not originate externally, but within VTG. The starting point was in Technical Innovation, where new technologies are continuously identified, evaluated, and advanced.
Before the launch, the lightweight axle was comprehensively assessed by interdisciplinary teams—an example of lived collaboration, bringing together technical, safety-related, and economic perspectives. The key stakeholders included:
Safety Systems
Safety Maintenance
Wheelset Management
Wheelset Workshop Brühl
After approval by the Executive Board, the project was expanded into a group-wide initiative with clear governance. Funding Management provided additional support and resulted in an exceptional funding rate of 50 %, which is significantly higher than many comparable innovation projects.
The next step: validation and scaling
The development is not yet complete. In 2027, the lightweight axles will be delivered and installed in around 27 wagons. This will be followed by a dedicated phase of technical and economic validation. The objective is clear: to confirm the identified benefits and create the basis for a decision on series deployment.
At the same time, Siemens is optimizing production costs to ensure long-term economic viability. At VTG, Technical Innovation is already working on the next lever—the optimization of the wheel disc design to fully align it with the extended maintenance cycles of the LwA and unlock additional availability potential.
This is how an idea becomes a real contribution—and how VTG actively shapes the future of rail freight transport.
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