Historical information
This hollow core bit has hard cutting inserts for drilling into rock. It was used to drill and recover 50mm diameter (most common size) rock cores. The rock cores were assessed by geologists and engineers to provide information for design of structures such as tunnels, dams and underground power stations (eg. McKay Creek Power Station, West Kiewa Power Station). This type of bit was also used where damage to the surrounding rock had to be minimised.
The Diamond Drill Bit,used in the early 1900's, when it was primarily used as a method of sampling rock for ore deposits and oil exploration resulting in a "coring" of rock. The use of "coring" to obtained samples for the SEC Kiewa Hydro Electricity Scheme(1920's onward) was to analyse the core to obtain temperature and rainfall patterns shown by the levels of layered solidified soil(rock). This diamond drill would have been used in the early 1900's to provide a sub strata map of temperature and water patterns (over an long period of time). This was a pre requisite to any decisions about the viability of the region to provide the water needed for a successful hydro electricity scheme.
Significance
This diamond drill for core sampling was at the forefront of the analysis whether to construct a hydro electrical facility in the Kiewa Valley and the adjoining alpine region. The rock core samples produced were assessed by geologists and structural engineers. It was only after extensive core drilling covering the region that solid scientific evidence could be provided to start the "SEC Vic Hydro Electricity Scheme" within its current boundaries.
Physical description
This "diamond" drill bit has eight "teeth" at its cutting edge. The drill creates an 55mm hole in extremely hard rock material to obtain 50mm core samples.. Three quarters down the shank it has thread screw channels to attach the bit to the drill pipe. The coring pipe attaches via screwing it onto this bit. Core samples are the main objective of this tool.