Study on the Application Safety of Prusik Hitch in Rope Rescue
In order to obtain the quantitative research results of the application safety of the prusik hitch under ultimate strength conditions,understand the possible situation when the hitch fails,and provide theoretical refer-ence and safety suggestions for various emergency rescue teams at all levels to conduct rope rescue operations,12 experiments were set up with different diameters of the main rope and accessory cord and the different number of winding loops.The ultimate static tensile tests were carried out one by one through the tensile testing machine until the Prusik hitch fails.Four typical phenomena of prusik hitch failure were obtained,including rope loop fracture after short distance sliding,rope loop fracture after repeatedly short distance sliding,main rope sheath breaking after short distance sliding and continuous sliding.The results show that the holding effect of the prusik hitch is bet-ter when the diameter difference between the main rope and the accessory cord is bigger and the number of loops is more,and when the 12.5 mm main rope is paired with the 8mm accessory cord and the number of loops is 6,it is the best combination providing the best security.