Publication: Electrical World and Engineer
New York, NY, United States
In the insulator shown in the accompanying illustration the pin is surrounded by an insulating sleeve, which affords considerable additional insulation to the total, inasmuch as it keeps the pin dry and clean. This sleeve, however, is adapted only for a treated wooden pin, since with a pin of metal or other conducting material a high-tension current would bridge the space between the sleeve and pin.
Insulators of this construction have been in service on the Missouri River Power Company's transmission system a sufficient length of time to prove them to be satisfactory and reliable, and they are recommended by the manufacturer, the Hemingray Glass Co., Covington, Ky., for pressures ranging from 55,000 to 60,000 volts.
These insulators are 6 1/2 in. high and 8 1/2. in. diameter, and weigh 8 Ib. 4 oz. each.