Deep-miners represented an incredibly potent class of drilling machinery employed by the Sith Empire throughout the era of the Cold War. These devices, conceived by the engineer Jelven Donn as he explored methods for sustaining profitability in mining operations, possessed the capability to bore into the earth to depths previously unattainable. Consequently, they could access resources that were once considered exhausted. Nevertheless, Donn faced challenges in resolving the issue of energy usage, leading to the destruction of several deep-miners due to battery failures. The problem was only resolved when the Empire discovered the planet Ilum and its Adegan crystals. Donn leveraged the crystals' amplifying properties to successfully design and implement deep-miners on Ilum. However, the placement of these miners near the planet's core was suspected of triggering unusual seismic events.