Gas Line Breaks New Ground

Con Edison’s pilot gas line installation program, just completed on 35 Ave., between 163 and 170 Sts., in Flushing, may revolutionize local service by cutting costs and dramatically reducing street construction delays.
This was the program’s first test in Queens and only, the third time the process was used in the United States. Developed in England, the new procedure has been used once in the Bronx and once in Manhattan, but the Queens line is the longest segment to be installed to date.
Under the plan, pedestrian and vehicular traffic was able to move freely during construction along this third-mile stretch, because the usual series of block-long excavation trenches and detours were eliminated.
Called a subline system, Con Edison’s crews were installing a half-inch thick polyethylene tubing inside a 16-inch gas main instead of digging up and replacing the 75-year-old cast iron line.
Con Edison spokesperson Art Cronson said, "Our goals in looking at new technologies is to reduce the capital, operating and maintenance costs of our gas system, preserve the environment, and reduce inconvenience to the public."
Using a "no dig" technique, street crews folded and inserted 1,900 feet of thick plastic tubing into the seven-block long gas line. Street crews not only cut installation costs in half (from $300 to $150 per foot), but they also eliminated the necessity for digging up the entire street. These savings, said Cronson, could ultimately be passed onto Con Edison’s customers.
Using special equipment, the plastic tubing was folded into a "C" shape, lubricated, and then inserted into the gas line, after it had been inspected by closed circuit television and cleaned. Since only a tiny section of the street was opened no extensive street repairs were required, and the job was completed very quickly.