The 'MAGNADET' to provide a safe enhanced protection extraneous currents, electricity and radio detonator was designed electric detonator with against the effects of current leakage, static frequency energy._x000D_
It has found a particular niche in shaft sinking operations and Mount Isa Mines initiated trials of the system in 1983 as part of the design work for the 3000/3500 orebody access shaft._x000D_
Initial surface blasts indicated a number of significant advantages which were confirmed during the bench and concrete phase of the M37 shaft sink. The application of 'MAGNADETS' was later extended to the horadiam phase of the project._x000D_
Details of the exploder capacity calculations for the various M37 round designs are included with the paper.