Waterjet cutting can be traced back to hydraulic mining of coal in the Soviet Union and New Zealand. Water was collected from streams and aimed to wash over a blasted rock face carrying away the loose coal and rock. This method of mining was redeveloped in South African gold mines to remove blasted rock from the work area into a collection drift or tunnel. In the California Gold Country between 1853-1886, pressurized water was first used to excavate soft gold rock from the mining surfaces. The pressurized water allowed the miner to stand further back from the face being washed. This was safer because there was less danger of being covered by a collapsing wall of blasted rock. By early 1900s this method of mining had re ached Prussia and Russia. In these two countries the pressurized water was used to wash blasted coal away.
In the 1930s it was Russia that made the first attempt at actually cutting the rock with the pressurized water. A water cannon was used to generate a pressure of 7000 Bars.
Dr. Norman Franz is regarded as the father of the waterjet. He was the first person who studied the use of ultrahigh-pressure (UHP) water as a cutting tool. The term UHP is defined as more than 30,000 pounds per square inch (psi). Dr. Franz, a forestry engineer, wanted to find new ways to slice thick trees into timber. In the 1950's, Franz first dropped heavy weights onto columns of water, forcing that water through a tiny orifice. He obtained short bursts of very high pressures (often many times higher than are currently in use), and was able to cut wood and other materials. His later studies involved more continuous streams of water, but he found it difficult to obtain high pressures continually. Also, component life was measured in minutes, not weeks or months as it is today.
Dr. Franz never made a production timber cutter. Ironically, today wood cutting is a very minor application for UHP technology. But Franz proved that a focused beam of water at very high velocity had enormous cutting power - a power that could be utilized in applications beyond Dr. Franz's wildest dreams.