The South Dakota Science and Technology Authority created the Davis Campus at the 4,850-foot level of the former Homestake gold mine. The $15.2 million project began in the summer of 2009, and the campus was completed this month.
First, Sanford Lab technicians dismantled and removed Ray Davis's neutrino detector. Then Sanford Lab staff, many of them former Homestake miners, enlarged the Davis experiment hall for the LUX dark-matter detector, and they created a new experiment hall, the Transition Area, to house the Majorana Detector experiment and to provide a transition for both experiments into a clean laboratory environment. Sanford Lab staff and contractors also applied shotcrete to the campus walls and poured concrete floors. The Sanford Lab Operations Department completed this phase of construction with a single recordable injury.
Ainsworth-Benning Construction of Spearfish, S.D., was the general contractor for outfitting the Davis Campus-an $8 million project in itself that included electricians, plumbers, mechanical contractors, stainless-steel welders and others. Ainsworth-Benning worked two shifts a day-20 to 25 workers per shift-for 11 month, and they completed the project with only one minor recordable injury.
Sanford Lab staff assisted the contractors at every step, including delivering materials to a construction site nearly a mile underground.
Here are some numbers that help tell the story:
- 30,000 (total square feet in the Davis Campus)
- 10,000 (square feet for LUX and Majorana)
- 29 (tons of rebar used construction)
- 525 (yards of concrete poured)
- 2,000 (cubic yards of gravel used to level floors)
- 80,000 (pounds of spiral ductwork)
- 75,000 (pounds of rectangular ductwork)
- 7 (miles of conduit)
- 30 (miles of wire)
- 4,191 (cage trips to the 4,850 Level to deliver supplies and personnel)*
A "cage" is the conveyance used in the 5,000-foot Yates Shaft. The Yates Shaft actually has four separate compartments, each running the length of the shaft. One is for the cage, which looks like an industrial elevator car. The adjacent compartment is for a work deck, and two other compartments have conveyances called "skips," which hoisted rock during mining. The cage itself is just over 6 feet wide and 12 feet deep. Material or equipment too big to be hauled inside the cage-including 30-foot steel beams for the LUX experiment-was slung underneath the cage.