What Is The Railway Tie Plate?

The rails are not directly fixed to the sleepers but are instead fixed to them through railway tie plates. Wooden sleepers typically use steel railway tie plates, while concrete sleepers typically use composite material railway tie plates.

This component, which is usually precisely forged from special spring steel or composite materials, has its core function to conduct and buffer the power intelligently. When tens or even hundreds of tons of wheel loads crash onto the rail, the pad, thanks to its meticulously designed elasticity, instantly transforms into an efficient “force disperser”, softening and spreading the massive concentrated impact force, and evenly transmitting it to the wider surface of the sleeper below. This significantly alleviates the stress concentration on the sleeper, effectively preventing fatal damages such as cracking and subsidence. At the same time, it is like a precise “shock absorber”, absorbing the high-frequency vibrations and impact energy between the wheel and the rail, significantly reducing noise and greatly improving the smoothness of train operation and passenger comfort. It is an indispensable “quiet guardian” in the railway system.

1. The design of the tie plates is full of ingenious engineering ideas.

Their surfaces are closely attached to the bottom of the rails, often featuring anti-slip patterns or raised slots to ensure that the rails do not shift under huge lateral forces (such as when a train turns) and firmly “lock” onto the rails. The bottom is shaped according to different types of sleepers (the flat surface of concrete sleepers or the grooves of wooden sleepers) to achieve stable support. Many base plates also integrate or are paired with high-performance elastic pads, like embedding a layer of “rubber spring” between steel and concrete/wood, further enhancing the buffering and insulation performance. In terms of material selection, special spring steel is treated through cold hardening, possessing excellent fatigue resistance and wear resistance characteristics that “get stronger under pressure”; while composite base plates (such as glass fiber reinforced polyamide) are increasingly widely used on high-speed and heavy-load railways due to their advantages of light weight, corrosion resistance, good insulation, and maintenance-free.

2. The main functions of the railway tie plates include:

· 2.1Protecting the sleepers from wear;

·2.2Providing a flat contact surface for the rail base;

·2.3 Preventing rail creep.

2.4 For wooden sleepers, the steel rail tie plate also serves another function, which is to provide the inclination angle (cant) of the rail.

2.4.1 Firstly, it protects the rail from wear. Since the contact pressure between the rail and the sleeper is very high, in order to protect the sleeper, it is necessary to reduce the pressure. For wooden sleepers, since wood can withstand less stress, it is necessary to increase the contact area to distribute the stress. In the picture of the metal pad, the red box outlines the projection of the rail base, and the yellow box outlines the projection of the rail pad. The area of the yellow box is larger than that of the red box. When the area increases, the stress distributed on the sleeper naturally decreases. For concrete sleepers, since concrete can withstand more stress than wood, the demand for stress dispersion is relatively smaller. However, during train operation, due to the unevenness of the rail, the roundness of the wheels, and changes in the strength of the track, the dynamic impact can reach up to twice the weight of the train. Such a strong impact may still damage concrete sleepers. Therefore, composite material railway tie plates are often used on concrete sleepers, which are relatively soft and can alleviate the dynamic impact to a certain extent.

2.4.2 Secondly, it provides a flat contact surface for the rail base. The upper surface of the sleeper is not an absolute plane. Originally, the projection area of the rail base on the sleeper is not large. If the contact surface is not flat, the contact area will be even smaller. Therefore, using the rail pad can provide a flat contact surface, thereby increasing the contact area and reducing the stress.

2.4.3 Thirdly, it prevents rail creep. On the side of the rail base in contact with the sleeper on the metal pad, there are two “steps” (coinciding with the edges of the red box in the picture), so this rail pad is called a Double Shoulder Tie Plate. These two “steps” can prevent the rail from lateral movement. When the metal pad is used in combination with spikes, it cannot provide sufficient longitudinal restraint for the rail, so anti-slip equipment needs to be used in conjunction, which will be explained later. The friction coefficient between the composite material rail tie plate and the rail is greater than that between the concrete sleeper and the rail. Combined with the use of elastic fasteners, it can provide sufficient lateral and longitudinal restraint.

2.4.4 Finally, the metal rail pad also has the function of providing the rail inclination angle. As shown in the picture, the rail is not arranged perpendicular to the sleeper but inclined inward (gauge side) by a certain angle, which can provide a better wheel-rail contact surface. The inclination angle of the rails in North American railways is 1:40. For concrete sleepers, the inclination angle of the rail is integrated into the sleeper; that is, the rail contact surface of the sleeper (Rail Seat) is itself inclined.

Supplier

Luoyang Fonyo Heavy Industries Co., Ltd,founded in 1998,is a manufacturer in railway casting parts.Our factory covers an area of 72,600㎡, with more than 300 employees, 32 technicians, including 5 senior engineers, 11 assistant engineers, and 16 technicians.Our production capacity is 30,000 tons per year. Currently, we mainly produce casting, machining, and assembly for locomotive,railcar,high-speed trains, mining equipment,wind power,etc.
We are the railway parts supply to CRRC(including more than 20 branch companies and subsidiaries of CRRC),Gemac Engineering Machinery,Sanygroup, Citic Heavy Industries,etc. Our products have been exported to Russia, the United States, Germany, Argentina, Japan, France, South Africa,Italy and other countries all over the world.
Contact Information:
Email:sales@railwaypart.com
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