How To Select Contact Method Between Contact Shoe And Third Rail

The third rail on train tracks is the main equipment for transmitting electric energy to the tram. The third rail is generally set along the rail line and is an additional contact rail for the railway system. The third rail power of the train is obtained by contacting the third rail with the current collector extending from the bogie through the sliding shoe.

At present, the third rail system designed by AGICO RAIL for customers mostly adopts steel aluminum composite contact rail as its power receiving system, which is powered by DC750V third rail power supply fed from traction substation. During the operation of the train, the electric energy is continuously transmitted to the locomotive through the sliding of the train current collector by the third rail on train tracks, so as to ensure the safe and normal operation of the third rail train. Since the conductor rail system is a third-rail power supply device without backup, it is greatly affected by meteorological conditions. Therefore, ensuring the reliable operation of the conductor rail system is a necessary condition for the safe and normal operation of the tram track.

With the development of industrial technology, the third rail productions have made great progress in material selection and suspension structure. It is mainly reflected in the selection of composite materials for the third rail, which greatly improves its electrical conductivity and corrosion resistance. The insulation support and protection technology adopt advanced integrated structure.

The third rail on train tracks produced by AGICO RAIL can be divided into three types: top contact current receiving method, bottom contact current receiving method and side contact current receiving method (also called fourth rail current receiving method) according to the different current receiving contact positions. What are the advantages of the three current collection modes and how to choose the current collection mode for different third rail productions?

Top Contact Third Rail

The third rail system with top contact is composed of the third rail, insulator, clamp, protective bracket, protective plate, anti creeper and other components. The current receiving surface of the third rail faces upward, and the current receiving shoe is pressed down to take the current. The contact force of the receiver is adjusted by the pressure of the downward acting spring.

• Advantages: In this way, the current collection is stable and the installation and maintenance are convenient. Due to the transition effect of the end elbow, the current impact in the power-off zone can be reduced.
• Disadvantages: The top contact third rail system can only protect the third rail from the top and the outside of the line, so the protection is not tight enough and the safety is slightly poor. In order to prevent the third rail deaths, the protective cover is usually added above the third rail on train tracks.

Bottom Contact Third Rail

The bottom contact type third rail on train tracks has its head down and is installed on the base through insulating frames, rubber pads, gusset plates, tightening bolts, brackets, etc. The power receiving shoe is in contact with the third rail to fetch flow through the upward lifting force.

• Advantages: The protective cover is directly fixed around the third rail through a rubber pad from the upper part, which is beneficial to prevent the happen of third rail deaths. Less affected by climatic conditions, the third track is not easy to attach debris, dust, ice and snow on the track. In addition, since the bottom force of the third rail train receiver in the lower current receiving mode is opposite to the deflection direction of the third rail, it helps to improve the quality of current receiving.
• Disadvantages: The installation structure of this method is more complicated and the cost is higher.

Side Contact Third Rail

The third rail on train tracks current receiving surface of the side current receiving mode is perpendicular to the top surface of the steel rail, and the third rail train takes the flow through lateral pressure. The structure of the side current receiving system is basically the same as the bottom current receiving system. The main difference is that the side current receiving contact rail system consists of two steel-aluminum composite contact rails, namely the fourth rail. One is a positive pole and the other ACTS as a negative backflow.

• Advantages: The third rail of the side contact current receiving mode is not easy to adhere to debris.
• Disadvantages: The side contact third rail can only be protected from the top and the outside of the line, but there are also the problems of insufficient protection and poor safety.

As for how to select the contact method of the third rail train, customers can consider the current collection performance, mechanical wear, impact on traction power supply system, maintenance cost, system stability, construction difficulty, safety of the third rail protection and engineering investment. AGICO RAIL has a variety of third rail sales, as well as technical support for the design and installation of various third rail systems. Welcome to send inquiries to discuss cooperation.