National Geographic : 1951 Oct
53U mlcnara rilnnie, necntel Corporation "Big Buck" Scoops Out a Bed for the Super Inch Contractors spent more than a million dollars on construction equipment for the 34-inch giant pipe line. This 31-ton monster, largest wheel-type trencher ever built, digs a ditch 44 inches wide and 5' feet deep. Scoops like Ferris wheels can gouge out a mile-long trench in a day. set up in these hazard ous areas from scrap iron buried near the pipe line to the pipe it self, and by completing a circuit it serves to stop corrosion. Unless a line break is near the point of deliv ery-that is, just out side a city-the gas stored up under pres sure in the line itself is enough to continue serv ice for some hours, or until the repair has been made. Delivering the "Line Pack" The gas in the line on its way to delivery is known as "line pack," and the larger the pipe the more line pack there is to keep service going. In other words, a large diameter pipe is one device for storing gas, for emergency as well as for regular use. The builders of the new Super Inch line from Texas to California had this fact in mind. It was fortunate that by the middle and late 1920's technical ad vances in steelmaking,* pipe manufacture, and electric welding had reached a point where it was possible to lay and operate strong, high pressure, long-distance, large-diameter pipe lines. The reason is that about the same time reserves of natural gas vast enough to amortize the investment had been dis covered in the Monroe Field of northern Loui siana and the Panhandle Field of Texas. Up to that time pipe lines had been strictly local in nature. Natural * See, in the NATIONAL GEOGRAPHIC MAGAZINE: "Pittsburgh: Workshop of the Titans," July, 1949, and "Steel: Master of Them All," April, 1947, both by Albert W. Atwood.