[Trade Journal]
Publication: Telephone Engineer
Chicago, IL, United States
vol. 45, no. 3, p. 30, col. 1-3
Insulation Kinks
I would like to discuss two items which I believe are quite new and novel. Both of these will help in maintaining good insulation on long lines where leakage is a serious matter during wet weather. One is a dry spot which is both simple and economical. This device was developed by Mr. C. A. Worst who has used the. construction on most of the telephone lines on the Chicago Burlington & Quincy Railroad. Fig. 1 shows the details of this device, and is self-explanatory. It is merely necessary to slot the wooden cob as shown in the drawing and loop the wire up under the insulator. A quantity of cobs can be slotted in any wood-working shop at very little expense and each lineman can be provided with 25 or 50 so that a dry spot can be made when needed.
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| Fig. 1—Dry Spot for Tapping Line of Looping Into Way Stations. |
There is some difference of opinion among telephone engineers as to the merits of dry spots, however where there are a large number of drops such as on dispatching telephone lines, the use of this construction at way stations will materially improve the insulation resistance under wet weather conditions. Instances have come to my attention where it was almost impossible to operate a duplex printer on a simplexed telephone line during wet weather conditions, however after the installation of dry spots at each way station satisfactory printer operation was obtained under the worst conditions of rain and sleet.
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| Fig. 2—Unbreakable Type Insulator |
The cost of the commercially available dry spots has prevented many companies from taking advantage of the improved insulation made possible by their use, however with the method described above, I believe everyone can take advantage of this improvement in line construction.
Another method of improving line insulation makes use of a recently developed non-breakable insulator for use where breakage is severe. Fig. 2 shows one type of insulator recently developed for this purpose. As almost every lineman knows, breakage occurs only in, certain sections along the line, generally at locations where hunters or school children frequently pass. The breakage is seldom more than in 6 or 8 spans so that it is only necessary to equip a few poles. The insulators now on the market have a fairly long life. although the operating conditions are rather severe. Sun and heat are the worst enemies of rubber, however the use of recently developed compounds-should give a life of at least 5 to 10 years. This obviously is many times that of glass in locations where the breakage is bad.
