Rail Fastening System Selection for High-Speed Railway
Rail fastening system is the intermediate parts that connects steel rail to railway sleeper. It is required to be reliable in connection, simple in structure, easy to disassemble, and also needed the properties of elasticity, vibration damping and insulation. Different types of sleepers have different rail fastening system for use with ballast and ballastless tracks. Railway fastening system for wood sleeper includes dog spikes and tie plate. Rail fastening system for concrete sleeper is generally rail clip type and balde-type. The most commonly used types are elastic clip fasteners with SKL, clip, e-clip, Nabla or KPO clamp, etc. generally, rail fastening system is consist of screw spikes, rail bolts and nuts, flat washers, rail clip, gauge block, and rail rubber pads.
The high-speed railway is one of common applications of rail fastening system. There are some unique requirements of rail fastening system in the high-speed railway, such as insulation, vibration reducing performance, and etc. As well known, concrete sleeper is the most widely used among all types of railway sleeper, so we take concrete sleeper as an example.
As for the types of railway fastening system, there are various types according to specific needs. As a trusted railway fastening system manufacturer, AGICO Rail can supply WJ-8, WJ-7, type V and type IV rail fastening system. We also customize railway fasteners as clients ‘requirements.
Requirement of rail fastening system
Due to the weight and rigidity, concrete sleeper has high requirement on clamping force, elasticity and adjustability of rail fastening system. Specifications as follow:
Enough clamping force. Rail fastening system is the guarantee of rail connection between steel rail and railway sleeper. Enough clamping force means that rail base have no longitudinal movement when steel rail bend or move. In another word, the longitudinal resistance of rail fastening system is more than longitudinal resistance of rail base. At the same time, the clamping force should not be too large, otherwise the elasticity of rail fastening system will drop sharply and affect the service life.
Appropriate flexibility. The elasticity of the concrete sleeper is much worse than that of the wooden sleeper, so the elasticity of the concrete sleeper in the vertical and horizontal directions is mainly provided by the rail fasteners. Appropriate elasticity can reduce the pressure from the load to the track bed, reduce the vibration acceleration of the unsprung, and prolong the service life of the components. The elasticity of rail fastening system is mainly provided by components like rail rubber pads and rail clips.
Track gauge and horizontal adjustment amount. The bolt hole spacing and the bearing groove width of the concrete sleeper are constant. When the curved gauge needs to be widened or the rail distance is enlarged due to the rail wear, the rail gauge needs to be adjusted by the rail fastening system. The level of the two rails is also adjusted by rail fasteners during maintenance.
Insulating property. Rail track system generally uses the running rail as the return rail, which requires good insulation properties of rail fastening system and prevents current leakage through the fastener.
Less maintenance. Once the high-speed railway is operated, due to the fast speed and high density, track maintenance can only be carried out within a short blockade. It requires sufficient strength and durability for each component of the railway fastening system.
Noise and vibration reducing performance. As the train speed increases, the orbital dynamic effect increases sharply. Therefore, the rail fastening system is required to have good noise and vibration reduction performance, that is, more flexible cushion plate is required.