WORDS: sam davies
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ften based along dangerous coastlines or nearby safe passages to land, the lighthouse is at once a structure to aid maritime navigation and a metaphor for risk, guidance and direction. In their evolution from hilltop fires to constructed towers with electric light, perhaps we can add improvement in function and performance to that list too. Siemens Mobility, in its application of additive manufacturing (AM) for the rail industry, can relate to many of those characteristics. It was 2013 when the company started to pull together six project leaders, all with engineering expertise; five support staff, with responsibilities ranging from application management and logistics; and six manufacturing engineers, to additively manufacture what would become more than 13,000 spare parts for the sector in seven years. Many of its street cars customers were then gathered to take in a presentation, where Siemens would make its pitch. In this meeting, where the potential to shorten the turnaround times for replacing components that are several decades old and often hard to procure was discussed, a representative from SWU Verkehr outlined how they wanted to alter the design and functionality of their tram drivers' armrests. They asked whether it would be possible to 3D print such a component. It was. And it became the first of 1,300 designs that would not only meet the necessity to replace components but align with Siemens Mobility’s idea to advance parts at the same time. Siemens’ Sparovation – a portmanteau of ‘spare’ and ‘innovation’ – programme was born. “If you touch a part which is 30 to 60 years old, and we change the production method and sometimes also the material, you have to do the complete approval by the newest standards regulations,” explains Michael Kuczmik, Siemens Mobility Head of Additive Manufacturing. “If our designers have to do the engineering and consider the new standards and regulations, then we said, okay, we [might as well] improve the part.”
THE GROUNDWORK
Siemens would come to learn how, as a general rule, the certification of ‘first of its kind’ replacement components would require more time – sometimes the best part of a year – for certification to be granted. There have been other instances, however, where extensive research and development hasn’t been required and newly certified spare parts have been delivered within just nine days. Of course, these lead times are one-
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offs – once certification is granted, a spare part that required months of engineering work and then spent months in the certification process can be continually delivered in the time it takes to manufacture, finish and ship. And the less time the better, for Siemens has some customers who are losing thousands of Euros a day on idle vehicles at the depot. For some companies, like SWU Verkehr, those thousands a day mean much more than compared to some of Siemens’ larger clients like Deutsche Bahn. SWU operates fleets of ten Siemens Combino NGT UL trams and twelve Siemens Avenio M NGT 6 UL trams in the cities of Ulm and Neu-Ulm, meaning one idle vehicle represents around 5% of its fleet and 5% of its revenue within its tram service offering. Per the company’s Head of Rail Vehicles Jürgen Späth, SWU 'simply cannot afford' to shut down a vehicle because a replacement part is missing. But while the urgency of installing spare parts and getting trams back on the rails is paramount, there’s an understanding how improving the parts as they’re replaced makes sense in the long run. The company, who has been working with Siemens since 2003, started out on its implementation of 3D printed parts with the updated driver’s armrest raised in the initial meeting, which would go on to feature three additional operational controls, channels for cables to run through, an increased stiffness to guard against future damages, assembly aids for long screws, more stable wiring harness routing, integrated cable fixation, and part and serial numbers for part identification and traceability. All were implemented after an assessment of the traditional part, with Siemens leaning on judgements from its customers and its rail design and maintenance departments. It is a key part of the process. “[Our six project leaders] look into the conventional design and try to understand what the reason for the failures was – what can be improved?” says Kuczmik. “With additive manufacturing, there’s a really high freedom of design. And my team is in contact with Siemens’ designers of new vehicles, they have a close exchange to really understand the newest standards and regulations with the experience we have at Siemens. And in the end, there’s a product which is definitely better than a part which is 30 to 60 years old. This is the advantage of Siemens as a designer, maintainer and spare parts supplier.”
MAKING PROGRESS
Another instance in which SWU leveraged that experience was to make improvements to the exterior of a tram vehicle. Since SWU’s trams navigate through
