What are the fastening methods for railway fishplates?

As a seasoned supplier of railway fishplates, I've witnessed firsthand the crucial role these components play in the railway infrastructure. Fishplates, also known as joint bars, are used to connect two sections of rail together, ensuring a smooth and continuous track for trains to travel on. In this blog post, I'll delve into the various fastening methods for railway fishplates, providing insights into their advantages, disadvantages, and applications.

Bolted Fastening

One of the most common fastening methods for railway fishplates is the use of bolts. Bolted joints are widely employed due to their simplicity, reliability, and ease of installation. The process involves drilling holes through the fishplate and the rail web, then inserting bolts and tightening them with nuts. This creates a strong mechanical connection between the fishplate and the rail, preventing relative movement and maintaining track alignment.

The advantages of bolted fastening are numerous. Firstly, it provides a high level of clamping force, which helps to distribute the load evenly across the joint and reduces the risk of fatigue failure. Secondly, bolted joints are relatively easy to inspect and maintain. If a bolt becomes loose or damaged, it can be easily replaced without the need for specialized equipment. Additionally, bolted fastening allows for some degree of adjustability, which is useful during track installation and maintenance.

However, bolted fastening also has some limitations. One of the main drawbacks is the potential for bolt loosening due to vibration and dynamic loading. Over time, the constant movement of trains can cause the bolts to gradually loosen, leading to a loss of clamping force and increased wear on the joint. To mitigate this issue, various anti - loosening devices, such as spring washers and locking nuts, are often used. Another limitation is the time and labor required for installation and maintenance. Drilling holes in the rail web can be a time - consuming process, especially in large - scale projects.

Riveted Fastening

Riveted fastening was once a popular method for joining railway fishplates. Rivets are metal pins that are inserted through holes in the fishplate and the rail web and then deformed at the end to create a permanent connection. Riveted joints offer several advantages, including high strength, good fatigue resistance, and a relatively smooth surface finish.

The strength of riveted joints comes from the mechanical interlocking of the rivet and the surrounding materials. When the rivet is deformed, it fills the hole and creates a tight fit, which helps to transfer the load between the fishplate and the rail. Riveted joints are also less susceptible to loosening compared to bolted joints, as the deformation of the rivet creates a permanent connection.

However, riveted fastening has become less common in recent years due to several factors. One of the main disadvantages is the difficulty of installation and removal. Riveting requires specialized equipment and skilled labor, and once a rivet is installed, it can be challenging to remove without damaging the fishplate or the rail. Additionally, riveted joints are not as adjustable as bolted joints, which can be a problem during track maintenance and alignment.

Welded Fastening

Welded fastening is another option for joining railway fishplates. Welding involves melting the metal of the fishplate and the rail together to create a continuous joint. This method offers several advantages, including high strength, excellent fatigue resistance, and a seamless appearance.

Welded joints provide a strong and durable connection between the fishplate and the rail. The fusion of the metals creates a homogenous structure that can withstand high levels of stress and dynamic loading. Welded joints also have a lower risk of loosening compared to bolted or riveted joints, as there are no mechanical fasteners that can come loose.

However, welded fastening also has some challenges. Welding requires specialized equipment and highly skilled welders. The welding process must be carefully controlled to ensure proper fusion and to avoid defects such as porosity, cracks, and lack of penetration. Additionally, welding can introduce residual stresses in the joint, which can lead to premature failure if not properly managed. Welded joints are also less flexible than bolted joints, which can make track maintenance and repair more difficult.

Adhesive Bonding

Adhesive bonding is a relatively new method for fastening railway fishplates. Adhesives are used to bond the fishplate to the rail web, creating a strong and flexible connection. Adhesive bonding offers several advantages, including ease of installation, good vibration damping, and the ability to bond dissimilar materials.

The installation process for adhesive - bonded joints is relatively simple. The surfaces of the fishplate and the rail web are cleaned and prepared, and then the adhesive is applied. The fishplate is then placed in position and held in place until the adhesive cures. Adhesive bonding can be done quickly and with minimal equipment, which makes it suitable for small - scale repairs and maintenance.

Adhesives also have good vibration damping properties, which can help to reduce noise and wear on the joint. Additionally, adhesive bonding allows for the bonding of different materials, such as steel fishplates to aluminum rails, which can be beneficial in certain applications.

However, adhesive bonding also has some limitations. The strength of adhesive joints can be affected by environmental factors such as temperature, humidity, and chemical exposure. Over time, the adhesive may degrade, leading to a loss of bonding strength. Another limitation is the lack of long - term data on the performance of adhesive - bonded joints in railway applications.

Application Considerations

The choice of fastening method for railway fishplates depends on several factors, including the type of railway (e.g., mainline, urban rail transit), the expected traffic volume, the environmental conditions, and the budget.

For mainline railways with high - speed and heavy - haul traffic, bolted or welded fastening is often preferred due to their high strength and durability. Bolted joints are suitable for new track construction and maintenance, as they offer some adjustability. Welded joints are often used in areas where a high - strength, permanent connection is required, such as in long - welded rails.

In urban rail transit systems, such as subways and light rail, the choice of fastening method may be influenced by factors such as noise reduction and ease of maintenance. Adhesive bonding or bolted fastening with anti - loosening devices may be more suitable in these applications, as they can help to reduce noise and vibration and are relatively easy to maintain.

Conclusion

In conclusion, there are several fastening methods available for railway fishplates, each with its own advantages and disadvantages. As a [Company role] in the railway industry, we understand the importance of selecting the right fastening method for each project. Whether you are in need of Galvanized Fishplate for corrosion - resistant applications, Fishplate For Urban Rail Transit tailored to the specific needs of urban systems, or Railway Track Joint solutions for mainline railways, we have the expertise and products to meet your requirements.

If you are interested in learning more about our railway fishplates and the appropriate fastening methods for your project, we encourage you to contact us for a detailed discussion. Our team of experts is ready to assist you in making the best decision for your railway infrastructure needs.

References

• "Fundamentals of Railway Engineering" by John Armstrong
• "Track Design and Maintenance Handbook" by the American Railway Engineering and Maintenance - of - Way Association
• "Adhesive Bonding in Structural Applications" by Robert D. Adams