That part’s easy, you just mine a tunnel, and then you mine a parallel tunnel 500m away from the first one. Ta-da , 500 metres of solid rock now exists between the two.
Note: mining a tunnel through solid rock can be somewhat difficult if you don’t have the right equipment, YMMV.
But seriously, the amount of dicking around maintaining the loop and the limited abilities of VLF meant that you would quite quickly have to run leaky feeder and bidirectional amps for two way radio, or you’d build a network using fiber and use Wi-Fi. We primarily used the system for remote blasting, and then once technology progressed a bit the initiators were connected via the network instead.
That part’s easy, you just mine a tunnel, and then you mine a parallel tunnel 500m away from the first one. Ta-da , 500 metres of solid rock now exists between the two.
Note: mining a tunnel through solid rock can be somewhat difficult if you don’t have the right equipment, YMMV.
But seriously, the amount of dicking around maintaining the loop and the limited abilities of VLF meant that you would quite quickly have to run leaky feeder and bidirectional amps for two way radio, or you’d build a network using fiber and use Wi-Fi. We primarily used the system for remote blasting, and then once technology progressed a bit the initiators were connected via the network instead.