Just add water

Mining for precious metals is an energy intensive and inefficient process. Underground pneumatic drills are powered by huge air compressors that sit kilometers above. Alan Barrows have developed a drill which uses 0.01 per cent of the energy and 60 per cent less water than existing systems. The drill is driven by tap water rather than pressurized air, and pressure to drive the drill is created by a powerpack the size of a fridge. The drill works by circulating water through a closed-loop system using a power pack with an electric motor. Because of the way the drill is engineered no oil is required for lubrication, so water both powers and lubricates the drill. The properties of water demand very high levels of precision engineering, with tolerances of 2μ to 5μ, an order of magnitude more precise than in oil hydraulic drills. Some of the equipment required to manufacture these parts is only usually found in high-end aeronautical and automotive plants.