During the summer of 1999, while working nearby in Pocahontas County, I visited the NRAO in Green Bank. I was able to see the construction of the GBT, and took a look at the 140 ft. dish. Here's some of what I saw.
The main building, housing much of the office space and also the control system for the GBT.
Here are some of the control racks for the GBT. These were still being constructed at the time of my visit.
The GBT, under construction, summer, 1999.
A closer look at the GBT construction site
Looking at the main gear drive for the 140 ft. dish.
A closer look at the 140 ft. support system
Looking at the base of the hydraulic rotation system for the 140 ft. dish.
A look at the ball bearing that supports the entire 140 ft. support system. The bearing is supported by a number of very high pressure hydraulic "pads."
The line pressure indicators for each of the support pads. The average pressure is 1500 lbs PSI.
© 2002 Broadcast Engineering Services of Bonny Doon