Abstract
The pulley-type tensioning device subjected to a maximum tension of 34 kN has been developed for 400 km/h high-speed railway. The tensioning device is to maintain the tension variation within 3% of the normal value, irregardless of temperature changes. Field tests shows that the tensioning device had a variation of tension which was as small as 0.6% as temperatures changed from $-5{\sim}7^{\circ}C$. Along with the tensions, we measured its X and Y movements due to the temperature changes. Based on a combination of its X and Y movements, we proposed a new performance index with which we can see if the tensioning device has troubles in operation without tension measurements.
