Communicating through rock
The system provides for groups of in-hole primers to be wirelessly initiated by a firing command that communicates through rock, water and air. This removes the constraints often imposed by the requirement of a physical connection to each primer in a blast.
How wireless initiation works
Low frequency magnetic induction waves are widely used in underground mining for PED (Personal Emergency Device) systems, where communication is one-way from a large surface transmitter to receivers carried by each miner underground.
The WebGen™ system uses a similar approach, where signals are generated by a transmitter and received by each primer prior to a blast. The primers are encoded with their group ID and delay time just prior to charging, this data is ‘stored’ in the primer and detonator respectively.
The primer goes into standby mode soon after charging where it wakes up every few minutes to check for a wake-up signal. If a blast is planned, a wake-up signal goes out to all primers, they are then synchronised and if in the group to be fired will go into armed mode. The firing command is a second unique signal adding an additional layer of security to the system.