One of my favorite insulators, living here in Montana I have always had a special place in my heart for the Big 2 piece power insulators that ran by my home for years delivering power to the Berkley copper mine in Butte. This line started at Canyon Ferry Dam and ran South to Butte, there were two lines that ran side by side called the Canyon Ferry feeder A and Canyon Ferry B Lines, and there were many lines tapped off of these which fed many Mines and small Mining towns along the way, like the Porphyry dyke Cochrane Line, the town of Elkhorn where Hemingray #2 provo’s were used, as well as power to Boulder and Basin Mt just to name a few:

The Design and Development of the line started in 1900, where a special glass insulator was designed by H.M Gerry Jr, chief engineer and manager of the Missouri River Power Co. and designs were sent to and made by the Hemingray Glass Co, Covington Ky. The insulator proper is a three petticoated glass 5 1⁄8” high and 9” in diameter, the special pin extending as near as possible to the wire groove below the insulator, extending up inside the inner petticoat is a tapered glass sleeve 5 ½” in diameter at its lower end , clearing the cross-arm by 1 ¼”, and supported on a 1 ¼” shoulder on the pin. The pin are all seasoned oak. Still further dried and impregnated by boiling in hot paraffin, so that pins themselves stand 100,000 Volts on test. The pins are 12” long above the butts. 1 ½” at the top of thread, which is of standard pitch, the maximum diameter is 2 ½” tapered on a 60-degree angle at the top of this butt, whose diameter is 2” for the pin which fits the cross-arm. The distance between the line cables is 18 inches. The pole lines are 40 Feet apart, and the right of way is entirely cleared of trees, etc. The poles are of Idaho Cedar, 8 inch tops, and in length from 35 to 90 feet, all poles above 75 feet being spliced.

Scan compliments of http:/hemingray.net

In view of the completeness of the drawing and the appearance thereon of all dimensional data, a detailed description of this remarkable insulator is unnecessary, beyond stating that it, together with its tapered glass sleeve, is all glass, non-cemented. It is stated that these insulators have proven to be absolutely reliable when in operation under 50,000 volts, and that the only defect which has occurred in their design rested in the belief that it would have been better to have given more body to the walls supporting the cap of the insulator at the section of the horizontal plane of the top of the pin, where a thickness of seven-eighths of an inch is shown. This belief is held for the reason that several—probably half a dozen—caps have broken off at the point stated, which would indicate slight structural weakness at that point. Were a new lot of insulators to be ordered the only change which would be made in the specification for them would be in the direction of increased strength in the body of the insulator supporting the cap

One further notation: The ratio in which the transformers are wound is 552 1⁄2 to 50,000. The generator voltage was stated to be 630 volts, which would give a line potential of approximately 57,000 volts. The weather was clear, cold, dry and crisp.

Yes now you know where the Coolie Hat came from. The CD 304/310 had some other design changes as the body was more straight and no Neck per say, so that’s how it got its Nick Name “Coolie Hat” Notice the neck area in the following Picture.

The poles are of Idaho cedar, the cross-arms of Oregon fir, the braces and pins of white oak, and the insulators and sleeves of glass. The cross-arms, braces and pins are held in place by means of through bolts. The pins in the top of the poles are of larger size and of greater length than those in the cross-arms, to provide for the greater strains there present. The pins were prepared by being first dried and then treated in paraffine, until all moisture was removed, and were then tested to 60,000 volts.

The circuits are transposed five times, making two complete turns between the generating station and the substation. The switching arrangements are such that the circuits may be operated either singly or in multiple. A telephone circuit is located on one of the lines and gives good results in service. The poles are from thirty-five to seventy-five feet in length, and the pole-tops are from nine to twelve inches in diameter. The poles are set from six to eight feet in the ground, according to height, and the standard spacing is one hundred and ten feet, with a maximum spacing of one hundred and fifty feet, when required by the nature of the ground. Fig. 28 shows the lines through timbered country.

The constructions just described were selected as typical examples of what has been accomplished in the building of high tension transmissions. Several of the lines mentioned have been in regular operation for periods varying from one to three years, and are in no sense experiments, but rather represent successful commercial undertakings. Other interesting and well-known systems might have been described had the limits of this paper permitted a further expansion of the subject.

We are now to the point of considering the very highest-voltage insulators—those which are in use for voltages from 50,000 to 60,000. Fig. 8 shows a glass insulator used by the Missouri River Power Company in Montana, for 55,000 volts. This insulator has been in service since 1901. The insulator is in two parts, one a hood 9 in. in diameter, and the other a sleeve set over the pin. The sleeve, which is open at the top, adds nothing to the dielectric strength of the insulator, its purpose being to protect the wooden pin. Obviously the sleeve would be of little value if a metal pin were used. This type of insulator possesses the advantage of being in two parts which are separable, either of which can be replaced if broken.

This picture was taken around 1904 when the City of Seattle was building the Ceder River powerhouse. The 44 kV pole line in the background was the main line to Seattle that ran along the aqueduct water line from the power plant to Seattle . This line was the first Seattle City Light transmission line. Robin Harison mentioned to me once that early collectors as well as lineman remember seeing large Muncies without bases in service in Seattle in the 1950's and 1960's. These were likely the original Ceder River insulators that were removed in 1907 and later reused in distribution service in Seattle. Sadly no pretty aqua-blue glass Muncies have survived to adorn the poles of Seattle today. Ed Sewell found a whole Muncie top and several more broken ones on a hill above the powerhouse in 1999.

Here is a photograph dated 1987 of Bill Burger digging an outhouse pit that was temporarily not under water due to a drought that year. Rattle Snake Lake is a man made lake in Western Washington in the Cascade Mountains just south of North Bend. This pit and many others at the bottom of this lake were loaded with mostly broken Hemingray Muncies. Note the Muncie top directly below Bill in the mud pile.