Trenchless technology speeds gas line renewals. Anon. Pipeline Gas J., June 1995, 222(6), 23--25.
Recent developments in the use of trenchless technology are reviewed. The main advantages are reduced environmental impact, cost savings, maintaining client goodwill, and minimizing traffic disruption. Some recent projects are described. One by Michigan Consolidated Gas involves replacing 10 000 ft of gas line supplying domestic premises in Dearborn and uses a compact directional boring unit called the Vermeer D-6 Navigator. Another project in Dayton Ohio uses a Vermeer D-24 Navigator for directional boring operations in a residential area. The self-contained design and self-propelled tracks enable this machine to double productivity to five bores a day.