Deployed trenchless method called spiral wound lining on a Manhattan sewer project to mitigate disruptive effects of conventional open-trench repairs, including allowing the sewer to remain in service during construction.
In the wake of a rise in fatal trenching cave-ins, the federal Occupational Safety and Health Administration has begun a targeted education and enforcement program to try to reverse the trend.
Edwin “Ed” Malzahn, who invented the first compact trenching machine and built his family company into global manufacturer Charles Machine Works on the success of his “Ditch Witch,” died Dec. 11. He was 94.
