The Cathedral of Immaculate Conception in Albany, N.Y., is currently undergoing an extensive restoration. One of the studies performed to ensure a safe and successful project was determining the impact of operating a scaffolding hoist on the north tower.

Vibration measurements were recorded using an accelerometer and a Hewlett-Packard 3560A two-channel FFT dynamic signal analyzer. The equipment recorded particle accelerations (vibrations) of the masonry and the wood floors on the fourth and sixth levels. Horizontal accelerations were measured perpendicular to the masonry walls, and vertical accelerations were measured on the floors.

Measurements were initially recorded without running the hoist. Other readings were recorded while simulating construction activities with hand tools.

The results of the vibration measurements, in conjunction with the existing condition survey, suggested that the vibrations caused from the operation of the hoist would not damage the overall structure of the tower.