Non-Destructive Test methods for high-performance synthetic rope

Interest in high performance-synthetic ropes for mine hoisting has increased as mine operators pursue resources at greater depths. One limiting factor for hoisting capacity is the self-weight of steel wire used as the hoist rope. [1) The significanHy higher strength to weight ratio of synthetic rope offers the attractive alternative to enable hoisting a larger payload with a similar size rope and hoisting plant (2). Due to the critical nature of hoist rope service, frequent and reliable inspection methods are required and regulated. Visual inspection and a variety of electromagnetic methods [3) are used to monitor wire rope performance in-situ. Wire ropes have been used for decades in hoisting applications and the data acquired through nondestructive test (NOT) methods can be correlated with a wealth of data and experience to ensure safe and successful operation. For synthetic ropes to be used in a hoisting application a multi-faceted approach is required to ensure the internal and external integrity of the rope. Visual observations made directly by trained inspectors or with cameras and image processing can thoroughly document the external appearance of the rope and any changes that occur. This paper presents two methods to monitor the internal structure of synthetic hoist ropes in service. Marked yarn magnetic principle based and x-ray inspection methods are introduced with cyclic bending test data to demonstrate an ability to detect internal degradation. Either or both methods could be employed in conjunction with visual inspection techniques to provide the real-time data necessary to safely utilize synthetic ropes in critical applications.