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“Bite-Size Bits of Local, National, and Global History”
Lead in Lawrence County, South Dakota — The American Midwest (Upper Plains)
 

Pneumatic Rock Drill

(Jackleg Drill)

 
 
Pneumatic Rock Drill Marker image. Click for full size.
Photographed By Cosmos Mariner, July 12, 2018
1. Pneumatic Rock Drill Marker
Inscription.  The pneumatic rock drill, also called a jackleg drill, was the most versatile rock drill used at the Homestake Mine and mines worldwide. This drill was used to drill holes that were then loaded with explosives for blasting and to drill holes that were then used for ground support (rock bolts). Compressed air actuated both the rotation and penetration rates of the drill and water was used to both cool the drill bit and remove the cuttings. A special oil was used to lubricate the internal workings of the drill.

The drill was hand-operated and could be moved around the mining areas on a regular basis, sometimes into 3-4 different areas in one shift. The drill and the telescoping leg are two components that could be replaced individually in case of a failure. The drill and leg weigh approximately 135 pounds in total.

Different lengths of drill steel would allow various hole depths to be drilled. A typical drill hole depth for production was 10 feet, with approximately 35-40 holes needed in a 10 foot by 10 foot square face. When blasted this would result in approximately 90-100 tons of ore. Other hole depths were used for rock
Pneumatic Rock Drill Marker (<i>wide view</i>) image. Click for full size.
Photographed By Cosmos Mariner, July 12, 2018
2. Pneumatic Rock Drill Marker (wide view)
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bolts and geologic sampling. Different diameters of drill bits also increased the versatility of the jackleg drill.
 
Erected by Black Hills Mining Museum.
 
Topics. This historical marker is listed in this topic list: Industry & Commerce.
 
Location. 44° 21.131′ N, 103° 45.909′ W. Marker is in Lead, South Dakota, in Lawrence County. Marker is on West Main Street (CanAm Highway) (U.S. 85) west of Julius Street, on the right when traveling west. Marker is located near the sidewalk and adjacent to the subject drill exhibit, on the north side of West Main Street, west of the Homestake Visitor Center. Touch for map. Marker is in this post office area: Lead SD 57754, United States of America. Touch for directions.
 
Other nearby markers. At least 8 other markers are within walking distance of this marker. Homestake Gas-Powered Locomotive (within shouting distance of this marker); The First National (Norwest) Bank (within shouting distance of this marker); Homestake One Ton, End Dump Ore Car (within shouting distance of this marker); Homestake Air Locomotive Number 35 (within shouting distance of this marker); Commonwealth Mine Stamp Mill (within shouting distance of this marker); 1912 Lead City Hall / Homestake General Offices (within shouting distance of this marker); Homestake Slag Buggy
Pneumatic Rock "Jackleg" Drill image. Click for full size.
Photographed By Cosmos Mariner, July 12, 2018
3. Pneumatic Rock "Jackleg" Drill
(within shouting distance of this marker); Homestake Hospital Site (within shouting distance of this marker). Touch for a list and map of all markers in Lead.
 
More about this marker. Marker is a metal plaque, mounted horizontally on a waist-high post.
 
Also see . . .  History of the Jackleg Drill. The jackleg drill is one of the pieces of machinery that allowed miners to increase productivity during the industrial revolution. It changed mining operations by allowing for much more powerful drills. The “jack” portion of the name refers to the common name for any worker that emigrated from Cornwall, England. These workers made up a large percentage of the hard rock workforce during this time because they were the most technically skilled in the field. The “leg” portion of the name refers to the hydraulic leg which is used to change the height of the drill and to provide pressure against the rock face which was being drilled into. (Submitted on August 14, 2018, by Cosmos Mariner of Cape Canaveral, Florida.) 
 
 
Credits. This page was last revised on August 15, 2018. It was originally submitted on August 12, 2018, by Cosmos Mariner of Cape Canaveral, Florida. This page has been viewed 260 times since then and 80 times this year. Photos:   1, 2, 3. submitted on August 14, 2018, by Cosmos Mariner of Cape Canaveral, Florida. • Andrew Ruppenstein was the editor who published this page.

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Jul. 4, 2022