Sonar Dome Cutting

When the decommissioned USS Yorktown (CG-48) was to be scrapped, the U.S. Navy wanted to salvage the valuable sonar transducers located in the sonar dome – the bulbous fore section at the tip of its hull. To do so effectively, engineers needed a practical, cost-efficient way to sever the entire dome from the hull with one clean, precisely placed cut to be made while the ship was moored in 30 feet of water. After conventional metal cutting methods were considered and dismissed, CTI was approached to develop a diamond wire sawing plan that would meet the team’s objectives.

CTI began by designing and fabricating a system of guide sheaves that would ultimately draw the diamond cutting wire along a precise path between the sonar dome and the remaining hull. The sheaves were affixed to uprights that were then mounted to a large framework of steel I-beams. Extending up from this frame was a pedestal covered in steel grating that would serve as the wire saw’s work platform once cutting began. The entire structure was designed and built to ensure total safety throughout each phase of the project, and also to minimize the use of costly divers and overhead cranes during the positioning of the framework in the water, during the cutting phase, and finally when the freed sonar dome was pulled from the water.

With the guide system in place, the diamond wire was strung in a continuous circuit through the sheaves and back to the saw perched above the water in front of the ship. Once sawing commenced, the diamond wire was drawn back through the hull, separating the sonar dome and allowing it to set safely onto the steel framework below.

Then, with the saw and pedestal removed, the framework was rigged and pulled away, carrying the sonar dome safely intact for renewal and reuse.