Tensile fatigue examination of flat rubber-coated tail steel ropes of SAG type
Manufacturing Company for Rubber-Coated Steel Ropes SAG, located in Katowice, Poland. To date, 442 units of such ropes have been delivered to customers altogether. The ropes are operated in shafts of domestic collieries with their depth up to 1,100 m as well as in foreign ones that are as deep as nearly 1,500 m. The total weight of a single, freely suspended rope can sometimes reach even 29,000 kgf. Operation intensity of hoisting machinery depends on shaft depth and can be sometimes as high as 600 cycles per day. Under such operating conditions in the Polish mining industry, the lifetime of SAG ropes ranges from 9 to 15 years with the total number of cycles from 1.4 to 2.75 million. The paper presents progression and results of fatigue examinations on Polish flat rubber-coated tail ropes of SAG type. The tests under vertical (tensile) elongating loads were carried out in the Research and Supervisory Centre of Underground Mining Co. Ltd. (CBiDGP) with use of the fatigue test machine UPDh-l00S. The examined samples of SAG ropes were able to withstand, an average value of N??R = 2,148,000 cycles until fatigue failure.