Abstract: A system for recording the use of individually identifiable detonators is described, the system comprising a data log of identified detonators; means to record electronically when a detonator is committed to fire; means to alter the data log to log as consumed a detonator recorded as so committed. A detonator is recorded as committed to fire only either when a detonator is intrinsically and irrevocably committed to fire or when an abort facility is set up in such manner that the system operates to remove the log entry of detonator consumption in the event that an abort signal is given. A method of recording the use of individually identifiable detonators is also described.

Abstract: The present invention relates to a stemming arrangement and stemming method for use in blast holes. A rigid but deformable hollow member is located in a blast hole with its curved shape providing a clearance between opposed wall portions. A stemming material is contained within the curved portion. Detonation of the explosive deforms the hollow member outwardly into contact with the opposed wall portions of the blast hole.