Wilson, ML, Van Hout, GJ & Dean, FF 2018, 'Testing the suitability of radio frequency identification cattle tags for tracking block cave progression', in Y Potvin & J Jakubec (eds), Caving 2018: Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 713-724, https://doi.org/10.36487/ACG_rep/1815_55_Wilson (https://papers.acg.uwa.edu.au/p/1815_55_Wilson/) Abstract: Modelling the upward progression of the cave back and the resulting downward flow of rock material within a block cave mine is critical to the safe and productive exploitation of an ore reserve. To this end, there have been many attempts, with varying degrees of success, to develop systems to enable the reliable gathering of information to produce data points of such a density as to assuage the concerns from geotechnical engineers and management. These systems, typically installed in concert with one another, range from the more elaborate and technical such as vast seismic arrays, beacons monitored in near real-time (Cave Tracker System) and active markers installed in the caving column (Smart Marker System), all the way down to surplus marked tyres placed on ground above the cave footprint. This paper discusses the testing of a new system that would combine low-cost, passive, and long-lived markers with unobtrusive, low-maintenance, and relocatable detection hardware. This system would make use of recycled radio frequency identification (RFID) tags (small passive tags which use radio frequency excitation to transmit an identifying number to a detection system) and antennas currently employed by the cattle industry to test their practicality for use in a mining environment and its ability to supplement or replace some currently used technologies that are battery life reliant. After initial design and setup works, several rounds of testing were undertaken from late 2017 through mid-2018. These tests started with deployment of tags directly below the detection hardware for commissioning purposes through to putting tags through full loading and crushing cycles and monitoring their detection rates. The results give confidence that refinement of the design and further testing is warranted with a view to deployment testing on other block cave operations within the Rio Tinto group. Keywords: RFID, caving, instrumentation, monitoring