What is an insulator??
I started collecting these things because most of the ones I found at the flea market were my favorite color, turquoise, and I thought they were pretty. Little did I know, this insulator collecting thing is really complicated! I had NO IDEA how many different types there were. There are approximately 460 shapes, 2800 different embossings, and almost 9000 color combinations of insulators. And that is just North American glass ones. That doesn’t include foreign or porcelain ones!
The need for the insulator arose out of the discovery of electricity, which in turn led to the invention of the light bulb, telegraph, telephone, and other electricity-oriented innovations. Also, as railroads began crisscrossing the continent, there came the need for signal devices. Electricity had to be moved economically from one place to another to meet the increasing demands generated by these new marvelous inventions.
According to Webster, to insulate means “to separate or cover with a nonconducting material in order to prevent the passage or leakage of electricity, heat, or sound.” Communication and electric line wires in service must be kept as dry as possible in order to function efficiently, and to cut down on loss of current. The wires are kept off of the ground by being strung between poles. But something was needed to keep the wires and (sometimes wet) poles apart. This “something” had to meet three basic needs:
- it must be made of a fast-drying nonconducting material
- it must be able to hold the line wire in place
- it must stay on the pole
This “something” was the insulator. It was developed and improved upon over more than 100 years to meet those basic requirements and:
- it is most commonly made of glass or porcelain
- it has a wire groove to accommodate the line wire
- it has a pinhole which fits onto a pin (which in turn is attached to the crossarm on the pole)
Many shapes evolved to hold the line wire more efficiently or to increase the insulating ability. Larger insulators were developed to meet changing needs as larger heavier wires or higher and higher line voltages were used. In addition, some insulator shapes were designed for special applications. Many insulator companies would patent special shapes, designs or other attributes, even if in reality the invention proved impractical. The different colored insulators could be used when several lines of different companies were on the same cross arm, the lineman could distinguish his line by the color of the insulator. Different currents could also be designated by different colored insulators.
Look at this chart of all of the different colors for Hemingray insulators!
AGEE (circa 1920 – 1940’s)
BROOKFIELD (55 Fulton Street) (circa 1868 – 1888)
CORNING (PYREX) (circa 1868 – present)
DOMINION (circa 1886 – 1898)
FOLEMBRAY (circa 1709 – 1956)
GAYNER (circa 1898 – 1937)
HAMILTON (circa 1884 – 1895)
HAWLEY – (HARLOE) (circa 1889 – 1910)
HEMINGRAY (circa 1848 – 1933)
KERR (circa 1903 – 1991)
LYNCHBURG (circa 1919 – 1925)
S. McKEE (circa 1834 – 1886)
OHIO VALLEY (circa 1881 – 1888 & 1902 – 1905)
OWENS – ILLINOIS (circa 1929 – 1966)
PACIFIC GLASS WORKS (circa 1862 – 1876)
SPRATT (JAMES) (circa 1845 – 1852 & 1854 – 1858)
THAMES (circa 1864 – 1865)
WHITALL TATUM (circa 1806 – 1968)
Material that the insulator is made from:
Nonglass-Nonporcelain (such as rubber, wood, or plastic)
Place of origin:
North America (including Canada and Mexico)
Number of parts:
“Unipart” – any one-piece insulator
“Multipart” – any insulator of two or more separately molded parts, either cemented together during or after manufacture, or used together on the line
Threaded – an insulator with internal screw threads which correspond to matching threads on a pin
Threadless – an insulator without threads and having a smooth pinhole
Good grief! I just thought they were pretty turquoise thingies!
I looked in to this, and you would not believe how many websites there are on this, and how many really dedicated collectors there are!
So here is what I do. I go to the flea market, and when I see pretty ones, I try to buy them for a dollar or so. Then I bring them home. I open my iPad, go to eBay, and plug in the company written on them, and any numbers I find. I see how much it is worth. Then I go put it on the shelf with the other ones, and admire how pretty they look.
Go to Pinterest and search for insulators. You wouldn’t believe what people do with these!
Here is my collection. I have one porcelain insulator:
Here are my Whitall Tatum insulators:
And my favorites, the Hemingrays. Of course, these are apparently plentiful and almost worthless. But they are so pretty!