FRAME BETWEEN 1500 AND 1600 FT. SPAN.
Long span work, employing copper cables, and using the oil-well derricks for support, seemed well to meet these and all other conditions in the most economical fashion. The adoption of long span work effected a large saving in the length of line and wire needed to cover the territory, since air-line routes could be covered in all cases across country, without any care being taken to lay out a pole line which would conform to some general inflexible plan. Moreover, much vertical distance was saved in not having to follow the contour of the country. Incidentally the long span work makes the installation of new pieces of line very easy and simple, and no large amount of material need be kept on hand for expansion purposes.
Where conditions are rapidly changing, as in the present instance, existing lines having to be moved because of the abandonment of wells or re-arrangement as new wells come in amongst the old ones, are easily changed, with but little loss of labor and material. The derricks, 80 feet in height, make ideal supports for long-span construction, and steel frames, heavy enough for the largest size of wire, eventually were made of “scrap” pipe set in cement. Where the derricks were not available, redwood “dead-men” were also used between derricks which were near together, but on opposite sides of rises or hills. The present system of distribution is 72,550 feet, or 13.75 miles, in length, and consists of 70 derricks, 9 frames, and 10 “dead-men,” making the average span about 800 feet. The seven-strand bare copper cables used in this work were furnished under rigid specifications previously described in the “Journal,” by the Standard Underground Cable Company. One will observe from the map and photos that there are many spans 1,500 feet in length, one span of 2,000 feet between derricks and one 2,600 feet from one frame to another. The sags allowed correspond to 60 feet on a 2,000-foot span, and the cables were very small for such work, No. 6 being used for the greatest lengths, which occurs as a neutral on the longest spans. The sizes used are Nos. 2, 4, and 6.
As the cables were suspended high above the ground and good construction was relied upon for safety from breakage, they were used without insulation, and a large saving was thus effected. “Goose-egg” strain insulators, first designed by the writer several years ago, are used to insulate the cables. Copper sleeves were used to splice the cables and to loop them to the insulators.
It is of considerable interest to observe the action of these light cables in a high wind, for even in the most gusty storms there is no whipping action. In the longer spans, the cables hang absolutely parallel and sway in a most deliberate manner from 12 to 25 feet out of line.
HARTWELL NO. ONE.
