Insulated Parallel Circuit with Air Dielectric for Rural Telephone Service

摘要

The need for open wire circuits in rural areas will prevail for the foreseeable future. The use of bare wire for such circuits has many disadvantages which can be offset by using individually insulated wires. In addition, insulated wires would permit changes in design with substantial additional benefits. Field trial data with the insulated wire and new types of support are encouraging to date. Field trials on an increasing scale are progressing. Net increases in first cost because of the present costs of insulating the wires is an obstacle to widespread use of this type of construction in spite of the tangible and intangible benefits in operation and maintenance. While first costs comparisons are not favorable, it is expected that there will be many situations where elimination of hits, improvement in the leakage characteristics, resistance to corrosion and freedom from effects of foliage will easily prove it in over bare wire. Experience in these situations will permit determination of specific information on savings in operation and maintenance. It is clear that the differences in cost are sufficently close that only minor savings in costs of operations and maintenance are needed for insulated wire to be more economical than bare wire on an annual cost basis. (Author)