News and information for the worldwide dredging industry

Bookmark and Share Email this page Email Print this page Print

American Using GPS for Rock Placement

By Jarvis Frederick

Project Superintendent

Placing rock armoring on a 2:1 slope is a fairly straightforward task on land, but how about on an underwater slope ranging in depth from 10 feet to 52 feet?

American Construction Company used a clamshell dredge and a three-GPS-system to place filter stone and riprap on a slope of the Blair Waterway in Tacoma, Washington, to prepare it for a future pier. Lyman Burk configured his WinOps dredge positioning software to replace a gyro with three GPS receivers working together to allow real-time positioning of the crane boom and placement of rock to an accuracy of inches. This is the first application of the three-GPS system for real-time positioning, according to Burk.

American used the crane Mukilteo, which has a 50-foot beam on a 120-foot long barge, to spread the rock. The GPS receivers were mounted as far apart as possible: on the center of rotation of the rig, on the deck winch operator’s station near the stern, and on the tip of the boom.

Add your comment:
Edit Module