Elastic Rail Clip
Brief Description :

    Fixing of rails to sleepers can be done either directly or indirectly, by using suitable fastenings. These fastenings are subjected to not only vertical, lateral and longitudinal forces, which are predominantly dynamic in nature, but they are also subjected to vibrations. The traditionally used “Rigid Fastenings” are not able to meet these challenging requirements, especially with higher speed and higher axle loads. Use of ”Elastic Fastening” is a possible solution to this issue. Therefore, elastic fastenings are used in most of the world Railway systems now-a-days.

    Elastic Rail Clip (ERC) is used for fastening the rails with PSC Sleepers. The Elastic Rail Clips used in Indian Railway are mostly Pandrol Type, and therefore many times they are referred as “Pandrol Clips” also.

    This clips is made from Silico Manganese spring steel bar by a process which involves heating it to austenitic range, hot pressing it to the shape and then quenching and annealing.

    Different types of ERCs are used in Indian Railway e.g. ERC MK-II, ERC MK-III, ERC MK-IV, ERC MK-V, Anti-Corrosive, Anti-theft ERC and J-Clip at Glued Joint/Fish Plated Joint/Joggled Fish Plated locations. The RDSO drawing numbers, approximate weight of the clips and typical values of Toe load and Toe deflection for various clips are as under:

    Drawing No. Type of Clip Approx. Weight of Clip (kg) Toe Load Range (kg) Toe Load Deflection (mm) Remarks
    RDSO/T-1892 ERC Round Toe 1.0 645-800 11.4
    RDSO/T-3700 ERC Flat Toe 1.0 645-800 11.4
    RDSO/T-3701 ERC MK-III Flat Toe 0.910 850-1100 13.5
    RDSO/T-3721 ERC MK-II Flat Toe 0.60 700-900 11.2
    RDSO/T-5919 ERC MK-V 1.080 1200-1500 13.5
    RDSO/T-8258 ERC J-Clip 1.000 650 8.5
    RDSO/T-6254 Anti-Theft ERC 0.937 850-1100 13.5

    One of the critical parameter determining the in-service performance of ERC is its’ Toe Load and therefore, toe load measurement at the prescribed frequency is a part of maintenance regime of these fittings.

    The mechanical toe load measuring device consists of a pre-calibrated helical spring having a steel pointer attached to a lever arrangement through a link hanger for gripping elastic rail clip. When the spring is compressed by turning a rotating handle at the top of the device, the toe of the clip gets pulled up and compression of the spring causes a pointer to indicate displacement on a graduated scale. The Toe load (in Kg) exerted by the spring on the toe of the clip is measured by multiplying the displacement of the pointer and the spring constant. The device is supported on three legs, two resting on the sleeper and one on the rail head.

    The Electronic toe load measuring device has a load cell of 2000 kg capacity and an LCD panel integrated with suitable electronic circuitry. This device has got a lever arrangement attached to it in order to grip the toe of an elastic rail clip. When the load cell is compressed by turning a rotating handle, the elastic rail clip gets pulled up. The force applied on load cell is converted into load (in kg.) and displayed directly on LCD.

    Fig. 1: ERC Round Toe
    Fig. 2: ERC MK-III Flat Toe
    Fig. 3: ERC MK-V
    Fig. 4: Anti-Theft ERC
    Fig. 5: ERC J-Clip
Video on fixing of ERC
Video on typical ERC Installation Tool
Video on Mechanical Toe Load Measurement of ERC
Video on Electronic Toe Load Measurement