The rapid crushing technique for the measurement of gas content of coal consists of accelerating the rate of gas desorption
from coal by crushing. This technique allows the determination of gas content in the space of hours rather than days or
weeks as required for the traditional slow desorption technique. The crushing technique is used particularly when gas
content determinations are urgently required for mine safety purposes. The method is now routinely used in underground
coal mines of NSW and to a lesser extent in QLD. Despite the rapidity and efficiency of this method, concerns have been
raised upon the reliability of the method to deliver accurate results. Experience in Australia has shown that there is in fact
some discrepancy in results between gas laboratories using the rapid crush technique. The development of rapid crushing
techniques for seam gas content measurements in Australia and the main causes of variability in the gas content test results
were investigated. The gas laboratories participating in the gas content testing were CSIRO Division of Coal and Energy,
BHP Technical Services and GeoGas Pty. Ltd.