Transporting parts of the 140-foot telescope to Green Bank
The Green Bank site in West Virginia was chosen for its remoteness from the radio interference of cities. However, on occasion, this remote location has given us some headaches. In this photo from the early 1960s, engineers measure the clearance inside the Droop Mountain tunnel in West Virginia that stood between the steel manufacturers of our 140-foot (43-meter) telescope and Green Bank. This tunnel, and a few other tight spots in Pennsylvania, constrained the size of the polar shaft bearing to 17.5 feet — still the largest steel bearing ever made.