Fastening Points

Lightweighting with composite materials in the rail industry

31 Jan 2023

bigHead fasteners offer many solutions

Rail industry OEMs face considerable pressures on all fronts. To survive they must greatly improve their reliability and operating performance. In rolling stock manufacture, companies are striving to achieve overall weight reductions of around 30 percent in order to meet their goals in terms of sustainability, operating cost reductions, capacity and efficiency. Vehicle weight reduction will be a significant part of the response to these challenges.

A large part of rail vehicle weight reduction will be determined by the materials and construction methods used, driving the industry to look at new materials and production processes. Two materials that consistently stand out above the rest in ability to satisfy design and structural criteria are fibre-reinforced polymer composite (FRP) materials and honeycomb or foam laminates. Composites made from recycled composites are proliferating making sustainability more apparent for this material.  At bigHead we support this innovation in the rail industry, supplying expertise and a wide range of standard or customised fastening solutions that enable safe, secure and discrete fixing of individual panels or complete modular sub-assemblies.

Working with composites as a new material

When customers move from metal to composites, as a consequence of light-weighting or for reasons of performance or design enhancement, they discover a lack of guidance or knowledge in fastening composites.  Whether they are designing, manufacturing or assembling with composite material this inexperience can be a major hurdle. There is little or no time to experiment and try things out. At bigHead we provide the necessary clarity and guidance. We undertake R&D at our premises on the Cranfield University Technology Park, which, though time consuming and expensive, is fundamental to the creation of optimal solutions for composites which are notoriously prone to non-standardisation. For the customer new to composites we can provide a bridge to the world of fastening, steering it away from the typical focus on joining metal.

bigHead has a solid reputation for delivering ‘engineer to engineer’ advice, with prototyping and thorough testing forming a strong part of our project development service. Our wealth of experience and knowledge has been gained during 50 years working with companies in the rail sector. We understand the challenges facing the designers, the manufacturers and the final assemblers.  Crucially we ensure that the fastening methods adopted are suited to the loads, material characteristics and operating environment of the applications.

A bullet train

Light weighting in the rail sector

bigHead fasteners in rolling stock and infrastructure

bigHead fasteners can be embedded in the composite materials during the lay-up process or surface bonded with adhesive. Both of these discrete and secure solutions facilitate fast and trouble-free mounting and remove the need for secondary assembly processes – helping to reduce manufacturing costs for fabricating lightweight composites.

Working with Tier 1 suppliers to UK and European train builders, bigHeads are being used to fasten everything from simple components to complete ‘pods’ that have been manufactured separately and then assembled into the vehicle structure and connected to its internal services.   Applications for which secure, discrete bigHeads are so well suited include front cabs, passenger and bathroom modules. On the inside of the pods and structures bigHeads are used to fix internal panels, flooring, signage and trim components in position. The fasteners are secured in position utilising various male or female threaded fasteners that allow fixing without the need to drill through or provide access apertures in the composite material. This saves a great deal of time (and cost) in assembly and preserves a smart and attractive finish.

Helping to reduce CO2 emissions

Reducing the weight of new trains is the single most cost-effective intervention the rail industry can make as it seeks to reduce its CO2 emissions, according to the Rail Safety and Standards Board (RSSB). This body estimates that the additional capital costs from moving to light-weight vehicles will give a two-times pay back and more over the lifetime of the train. Using composite materials will enable lightweighting and as more of these materials are formed through recycling used composites.

Get in touch to see how bigHead fasteners and our expert engineers can help with your project.

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