Tension clamps

The tension clamps are used for flexible fastening of the rail to the sleeper. In Hungary the tension clamps developed by Vossloh Germany are commonly used for all types of running rails: S49/MÁV48, 54E1 (UIC 54) and 60E1 (UIC 60). The tension clamps are produced of spring steel to provide suitable flexibility and resistance against dynamic powers as well as strength at the same time. The rail is firmly but flexibly fastened by the tension clamp which closes on the foot of Vignol rail while sits on a specially shaped plastic heavy duty angle guide and is fixed by a sleeper screw into the sleeper. The rail fastening by tension clamps has the edge over the fastening by rigid clamp plates due to the improved flexibility of the whole structure of fastening through the use of spring steel material and that a tension clamp keeps tight much longer than a clamp plate fixed by bolts with nuts, while its fastening power is strong and stable. Although in some application a rail base plate goes still between the bottom of the rail and the sleeper, considering cost-effectivity, increasing applications on concrete sleepers do no longer use rail base plate but the rail sits on the sleeper by use of plastic rail pad, except for rail tracks laid on wooden sleepers with which rail base plates must still be applied. The Hungarian National Railways uses mostly tension clamps of types SKL3, SKL12 and SKL14, while less commonly are also used SKL1, SKL21 etc. as well.