Hydroelectric Dam Shaft Measurement Tool

In the project, the MS1000 high-resolution scanning sonar head was used with a narrow cone beam to profile vertical boreholes. Through the investigation. the size of the liner inserted inside the structure could be determined to prevent rocks from slumping off the shaft wall and getting caught in the hydro turbine. During the process, the working staff installed the sonar head on the fixed frame and leveled it at the same height as the altimeter.

The use of a digital overlay profile scanning system enabled engineers to measure shaft diameters and design bushings. The horizontal contour plot in 1′ increments showed the irregular arrangement of the shafts vertically.

Equipment configuration for vertical rock shaft survey:

– MS1000 sonar processing software 

– MS1000 interface unit with 28VDC and 56VDC power output

– 675kHz high-resolution scanning sonar head with sector or cone transducer

-675kHz frequency altimeter (configured for MS1000 software operation)

– Supporting Kevlar cables for sonar and altimeter (connectors for termination)

-Customized placement device

In addition, the MS 1000 program allows the user to manipulate and display multiple sonar image windows. In this project, the scanning sonar and altimeter were running simultaneously. The altimeter was powered by the 28VDC power supply of the MS 1000 interface unit, and the scanning sonar head was connected to the 56VDC output interface. For this project, the sonar builder customized the corresponding aluminum to accommodate both a high-resolution 675 kHz scanning sonar (with sector/cone sensors) and a 675 kHz altimeter. Mounting tabs allowed the cage to hang vertically or horizontally. To collect the horizontal profile, the builders deployed the placement device vertically by using two lines to avoid rotation. Installation of an altimeter in the deployment recovery enabled verifying the distance from the bottom of the wellbore to each horizontal profile.