History

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The building blocks for the Egyptian pyramids and obelisks were obtained by using hammers and wooden wedges to extract large sections of stone in carefully measured shapes and sizes. The wedges had a hole in the middle for holding and carrying.

Miners from the time of the Roman Empire though the Middle Ages often applied a "fire setting" system to break rock. A rock face was exposed to intense heat followed by a quick dousing with water. The sudden cooling caused the rock to crack and split along natural seams. Sometimes a suspended wooden ram with a hard stone ball on its front was used to open a hole in the center of a rock face, and the face was chipped into it radially.

Gun powder was first used to break rock during the Middle Ages. In 1683 a Saxon named Hemming Hutman used a drill forged of wrought iron with an inset bit of tempered steel to hammer holes in the rock at critical points. The charges placed in the holes broke the rock more effectively than those laid on or near it.

The early history of our country contains many accounts of legendary 'hammer and steel' drillers who were experts at both single and double jacking. Single jacking involved an individual holding and turning the steel with one hand while hitting the steel with a small hammer held in the other hand.

Single jack drilling, circa 1850. (Photo reprinted
courtesy of Compressed Air Magazine.)

Ambidexterity was very helpful for the single jack driller because he could work longer by shifting the hammer from one hand to the other to distribute the work. In double jacking one or two drillers hit a drilling steel with large sledge hammers while a holder turned the steel slightly after each blow. As the hole deepened, the holder substituted longer steels in a way that did not interrupt the driller's disciplined rhythm.

'Down hole' double jacking, early 1800's.	'Up hole' double jacking, early 1800's. (Photos reprinted courtesy of Compressed Air Magazine.)

Since every mechanical advantage gained by drillers was considered desirable, hand drilling was generally abandoned as soon as pneumatic drills were developed. Still some hand drilling methods were retained by prospectors for small budget rock work. Drilling and breaking rock with hand tools is discussed in Forest Service manuals up to 1923, and in prospecting handbooks as recently as 1943.

Some of the older techniques are not applicable today. For example, we consider double jacking unsafe for inexperienced drillers. Since most of today's hand drilling will be done by beginners, we suggest you use either single jacking or modified double jacking, a technique we developed. Both of these methods are safe, effective, and readily learned.