Additive Manufacturing has reached a level of technical maturity that makes it highly attractive for industrial use, particularly in mobility sectors that demand efficiency, flexibility, and robust supply chains. At the same time, in safety‑critical environments such as the rail sector, innovation can only unfold its full potential if approval, standardization, and certification are fully aligned with technological progress. No matter how advanced a 3D‑printed component may be, its real value only emerges once it can be safely certified, reproducibly approved, and reliably integrated into regulated operational environments. For Additive Manufacturing, the path from innovation to series application therefore does not primarily lead through the machine hall, but through structured approval processes that create trust, transparency, and scalability.
This challenge has long been recognized within the Mobility goes Additive (MGA) network. Several years ago, the MGA Approval in Rail Working Group, together with strong industrial and scientific partners, achieved a landmark success: through extensive testing and computational verification, the first safety‑relevant additively manufactured component was approved for use in a commercial train. This breakthrough demonstrated that Additive Manufacturing can meet the stringent safety requirements of the rail industry, provided that approval is addressed systematically and collaboratively. At the same time, it became clear that single approvals, however successful, are not enough. To enable widespread adoption, the rail sector needs generic, transferable, and economically viable approval paths for 3D‑printed components.
This realization laid the foundation for DigiZUG3D – Digitale Zulassung 3D‑gedruckter Komponenten für Schienenfahrzeuge (Digital Approval of 3D- printed parts for rail vehicles), a publicly funded research project that builds directly on the experiences and results generated within the MGA network. Supported by the European Union and the German Federal Ministry for Economic Affairs and Climate Action (BMWK) as part of the economic stimulus program “Digitalisation of vehicle manufacturers and supplier industry”, DigiZUG3D brings together rail operators, OEMs, certification bodies, research institutions, and AM technology providers to rethink how approvals for additively manufactured rail components are performed.
Instead of focusing on individual components, DigiZUG3D addresses the approval process as a whole. The project aims to map, structure, and ultimately digitalize the approval chain for additively manufactured parts in the rail sector, making it more transparent, efficient, and reproducible. A central element of this work is the classification of demonstrator components according to defined load cases and component classes. These classes are then systematically correlated with testing categories, creating a clear logic for determining future testing scopes and requirements. This approach enables a reduction in required testing effort while maintaining the high safety standards expected in rail applications.
Technically, the project concentrates on laser powder bed fusion (L‑PBF) and 316L stainless steel, deriving parameters that enable analytical strength verification, for load‑bearing components. The long‑term goal is to anchor these results in established engineering frameworks such as the FKM guideline, thereby strengthening the integration of Additive Manufacturing into existing regulatory structures. In parallel, DigiZUG3D also documents approval workflows and develops criteria for their digital representation, paving the way for a future digital platform that can serve as a database, guidance tool, and communication interface along the entire approval chain.
Within this context, Mobility goes Additive plays a key enabling role. As a cross‑industry AM network, MGA supports the project by structuring approval logic, facilitating discussions within European rail communities, and ensuring that findings are formulated in a generative way that allows transfer to other regulated sectors. MGA also actively promotes cross‑industry exchange, connecting DigiZUG3D to parallel initiatives in aerospace and medical technology, and fostering early dialogue with certification bodies and standardization committees. Through conferences, trade fairs, and network communication channels, MGA ensures that results are disseminated early and aligned with broader developments in digitalization, certification, and standardization.
Initial project results were presented at the 21st International Railway Vehicle Conference in Dresden, where TÜV NORD and Applus+ IMA jointly reported on progress in the calculation and certification of additively manufactured load‑bearing metallic components for rail vehicles. Topics included AM‑specific component design, process certification according to DIN EN ISO / ASTM 52920, and the development of computational strength verification methods based on component classes. These results clearly show how DigiZUG3D is translating research into practical tools for approval and certification.
With a total project volume of €4.9 million and a strong, interdisciplinary consortium, DigiZUG3D stands as a flagship example of collaborative, funded innovation within the MGA network. By combining technical validation, digital process development, and standardization efforts, the project is helping transform approval from a barrier into an enabler. For Mobility goes Additive, DigiZUG3D is a clear success story demonstrating how collaboration can accelerate the certified, large‑scale use of Additive Manufacturing in the rail sector and beyond.