Chiltern Railways, which runs trains from Stourbridge, Stratford-upon-Avon and Aylesbury into London, is using 3D printed parts on its passenger trains, which is believed to be the first such trial in the UK.
One of the many problems facing the UK train system is that the trains are manufactured in relatively small numbers, and many operators are still running very old trains, meaning that spare parts are increasingly difficult to source.
James Brown, Data and Performance Engineer for train leasing company Angel Trains, explains: “The problem is that traditional manufacturing methods only make it cost-effective to produce high volumes of spare parts, even though an operator may only need a few obsolete train parts replaced. In addition, lead times can take months. This is why we have teamed up with (engineering consultancy) DB ESG and Stratasys, showing how operators can overcome these hurdles by using 3D printing to produce the exact amount of parts they need at a fraction of the time and cost of traditional methods.”
The parts involved include four passenger armrests and seven grab handles. The company that originally manufactured the grab handles no longer exists, so that conventional methods would have required new tooling, costing up to £15,000 and with a production lead time of two and a half months. But these parts were 3D printed in three weeks at a much lower cost. Equally, the armrests were 3D-printed within one week, significantly faster than the four months needed for conventional production, and at roughly half the cost.
The parts were produced on a Stratasys Fortus 450mc FDM printer, using Ultem 9085 resin, which was certified to the rail industry’s fire, smoke and toxicity standards. The rail engineering consultancy DB ESG tested a range of industrial-grade 3D printing materials to ensure compliance with the UK rail industry standard EN45545-2.
Martin Stevens, Mechanical Engineering manager DB ESG, explained: “Achieving certification removes a major barrier that has prevented more widespread implementation of 3D printing across UK trains. Our role in this project has been to investigate the design, production and finishing of FDM parts, verifying whether the parts comply with rail standards and checking whether they work in the operating environments. We have also optimised the component design of FDM manufacture.”
The most important element of this trail has been to establish a repeatable process that complies with rail industry standards. So far the trail has proved successful and a second train operator, Great Western Railway, is also looking to use 3D printed parts.
Brown adds: “With this technology, train operators can be much more responsive to replacing passenger-facing parts that get damaged or vandalized. A 3D printed replacement part can be produced on-demand and installed immediately. With low-volume production now achievable, we’re also starting to explore how we can leverage 3D printing to customize interiors that are better suited to the passenger commute. For example, we’ve tested 3D printing seat back tables with braille informing the passenger that the toilet is ten rows back from that particular seat. This level of customization is unprecedented and can only be enabled by 3D printing, offering the potential to significantly improve both the servicing of trains and the passenger experience in the future.”
Sadly, 3D printing won’t do anything for the many years of under-investment, poor management, political interference and excessively high ticket prices that also blight the UK’s train system. All of these factors help explain why the UK’s train operators have been relatively slow to look at 3D printing. The bigger picture here is that if we really want to do something about reversing climate change and reducing pollution then we need to make better use of our train network. Reducing cost and time for maintenance is a big part of this so this is a good step forward. Nonetheless, if the rail industry had been as quick at adopting 3D printing as it has been to ask for more money from tax payers then this would have happened a long time ago.