Serpentine Drill Core Section

Serpentine Drill Core Section. . This core section was created in 1934 while boring an air/service shaft for the Idaho-Maryland Mine in Grass Valley, California. The overseer of this demanding project was mining engineer J.B. Newsome. Reputed to be the largest drill core of its type at the time, each 5 ft. diameter by 7 ft. long solid serpentine section weighs around 9-1/2 tons. The drilling was accomplished with a sophisticated combination of core barrel cutter and core puller. As the barrel slowly advanced, every seven feet, the core section would be broken off and removed with the puller. The power to accomplish this was provided by a 100 hp electric motor driving a shaft via a "noiseless" link belt and reduction gear. The entire machine, operator included was continually raised and lowered with its hoisting gear until it reached the final depth of 1125 ft. In 1954 this core section was transported here by the California Forest Service after it was donated to the museum by M.E. Hammill of the Idaho-Maryland Mine Corp. At the same time a similar specimen was donated to the Calaveras County fairgrounds where it remains to this day. . This historical marker was erected by Angels Camp Museum, sponsored by Native Sons of the Golden West in memory of esteemed member Millard Smallin. It is in Angels Camp in Calaveras County California