How 3D Printing is Transforming the Rail Sector

One of the many advantages of 3D Prinring is the rapid availability of spare parts produced by additive manufacturing – ideal e.g. for sporadic demand that can’t be scheduled, such as parts needed due to accidents or vandalism. Even complex part geometries can be fabricated quickly, reliably, and flexibly – even with the smallest quantities.

Attractive as well is the continuous potential for re-engineering: Whether to meet new statutory requirements, improve working conditions, or fulfill passengers’ changing design demands, additive manufacturing enables you to incorporate new insights gained from practical applications and materials technology, implement ergonomic improvements, and integrate additional functions – turning your spare parts into “improved parts”.

Get Started with 3D Printing for Railways

Additive Manufacturing provides unrivalled design freedom but is an unfamiliar manufacturing process to many engineers. Our consultants can help educate and guide you through every step of the journey from concept to fitted part. We will assist you with material and machine selection and help optimise your designs so that they are more cost-effective for AM.

What’s more, we can even carry out cost estimation and supply chain planning to inform your procurement team of the realities of using this alternative manufacturing process.

One of the unique aspects of rail is that equipment is in service for a long time – often 30 to 40 years and beyond. As the decades roll by, keeping trains running and in good repair requires service parts. Unfortunately, parts go out of production, suppliers go out of business, and spare parts get expensive. Often, operators must absorb tooling costs to re-manufacture parts. This is where 3D Printing can have a major impact on the operations of the railway sector.

The Sweet Spot for Additive Manufacturing: Low Volume, High Value, Long Lead-Time Parts

Often, the sweet spot for additive manufacturing is in low-volume, high value, long lead-time parts. Why? 3D printing reduces lead times and allows you to avoid the high up-front costs of traditional manufacturing: supply chain, tooling, and setup.

On the cost side, 3D printing often eliminates tooling and setup costs associated with traditional manufacturing. These lowered fixed costs mean that production at low volumes becomes economically viable. The graph below shows visually why this happens:

There’s a time benefit too: Since additive manufacturing doesn’t require setup or tooling, 3D-printed parts can often be produced with lead times in days versus weeks or months for traditional manufacturing.

How Does This Translate into Rail?

Given that 3D printing sweet spot in low-volume, high-value, low cost spare parts, it should be clear that there is some opportunity for 3D printing to make an impact in rail maintenance, but what does that look like at a tactical level?

Based on our engagements with clients, Blueprint has identified four categories of cases where additive manufacturing is poised to add the most value to rail and the value drivers associated with each use case:

Bridge parts – In rail, the cost of having a coach out of service is massive. The direct costs of having a single commuter rail trainset out of operation is Lakhs in Rupees a day. When the financial penalties add up quickly, having the ability to quickly produce replacement parts in house is critical, because the alternative would keep a trainset out of service for 16 weeks while they waited for a replacement part.

Low volume spare parts – It’s no secret that everything costs more in rail, but why is this? In order to service rolling stock for 30+ years, inventories of spare parts need to be curated, maintained, and paid for. Not only is stocking parts for 30 years expensive in terms of carrying costs, shrinkage, and spoilage, but inevitable there will be some parts that go out of stock. When spare parts are no longer available in inventory, they must be recreated, either as one-off parts from a fabrication shop or by retooling for a limited run production. This is expensive and causes massive lead times. Having the ability to 3D print toolsets can enable you to create many of these parts in-house, with lower lead times and at a lower cost than traditionally sourced parts.

Quality/Process improvement – World class manufacturers employ several tools to mistake-proof their operations, ensuring that first pass yield (a common measure of manufacturing quality) is high and that rework is kept to a minimum. These can be anything from a drill guide, to a fit-up check device, to redesigning parts to be keyed so they can only be installed correctly. This trend has been slow to take hold in rail, but that doesn’t mean there isn’t opportunity. Holders for common toolsets can ensure that loss and shrinkage is kept to a minimum. Work guides and fixturing devices can be employed to ensure that everything from decals to custom locking devices can ensure a more robust lockout/tag-out safety program.

Customer experience – Between ridesharing, scooters, hourly car rental, and bicycling sharing, everyone has more options for urban mobility today than ever before. Having vehicles, stations, and equipment in good repair goes a long way toward providing the kind of customer experience that incents riders to choose public transit over other options. Too often, traditional supply chains can’t provide the support required to keep equipment in good repair, leaving transportation providers choosing between repairing or removing non-essential cosmetic parts. In many cases, 3D printing provides a feasible option for obtaining the parts needed to keep vehicles in good repair.

Key Applications:

HVAC & Electrical Systems

With the increasing pressure on rail vehicle manufacturers to improve the operational performance of their products, it is no surprise that Additive Manufacturing is being viewed as a potential solution to overcoming the engineering and logistical challenges in optimising cabin packaging, light-weighting and structural design. But what specific solutions can Additive Manufacturing provide in this continuous drive towards better carriage design and performance? One area that Additive Manufacturing naturally lends itself to is the printing of components for HVAC & electrical systems.

Tooling, Jigs and Fixtures

Siemens Mobility, a company specialising in intelligent traffic systems and rail technology, has adopted 3D printing at its RRX Rail Service Centre to produce complex tooling, in addition to spare parts. 

In one example, the new maintenance depot has 3D-printed an essential connector tool used in train bogie maintenance (the bogie is the chassis or structure that bears the wheelset axle). It is quite difficult to produce, using conventional methods, because the tool has a complex shape that requires a high degree of customisation. 

Furthermore, bogies weigh several tonnes, which means they need to be made with robust and durable materials that can stand up to the significant stresses exerted when the train is moving. 

As an alternative, the team at the centre used FDM technology and industrial-grade materials. 3D printing allowed Siemens Mobility to leverage the customisation benefits of 3D printing and replace traditional manufacturing methods for this tooling application. 

The company also reports that 3D-printed tooling helped them reduce their dependence on outsourcing tools through suppliers and also cut costs per part. 

Spare Parts

The chosen components are now being trialled on in-service passenger trains. So far, the trial has been positive. For example, the production of the 3D-printed armrest took only a week — a 94% decrease compared to using conventional manufacturing methods