Just the Insulators

All about my hobby, insulators and other electrical stuff.

[justtheinsulators]

These pictures are a few years old, but I haven’t posted them yet.

Intact telegraph poles are rare around here because AT&T ripped them all out and threw them away, rather than letting them rot in place like usual. Those that are left behind were mostly too rotten to pick up in one piece.

The whole pole top and crossarm in the first picture were good, thanks to a heavy coating of creosote, which gives them that orange-brown color. The pole and top crossarm in the second picture were completely rotten internally. The bottom crossarm was alright, though. I combined the best pieces to get the display you see here!

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Another Hemingray -42 from the Lone Star Insulator Club Potluck, this time in Hemingray Blue with Amber Swirls. The amber and blue combine to make  green.

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Green with envy yet?

I went to the Lone Star Insulator Club’s annual potluck on Saturday, and got a few really cool glass insulators. Here’s a pair of Hemingray - 42s in beautiful true green! There isn’t a single hint of aqua or blue.

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If only this old soldier could talk!

This is the remains of a CD 127, an 1870s era design. I found it beside what was once the Galveston, Harrisburg, and San Antonio Railroad, now owned by Southern Pacific. The GH&SA was completed through to San Antonio on February 5th, 1877. This old glass insulator was part of the first telegraph line along the route, and watched the steam trains of the Sunset Route roar by every day!

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A McLaughlin - 42 glass insulator in sage green, CD 154.

This McLaughlin looks more like a Hemingray - 42 with the square dome! The later Maydwell glass insulators have tall domes, so this isn’t a later mold, and it doesn’t match McLaughlin’s short mold insulators, so how this guy came to be is tough to discern.

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Some subtle shades.

Three Whitall Tatum Co. No. 1 glass insulators, CD 154, in light straw, peach, and pink.

The straw color in the first piece is a result of the sunlight acting on a chemical in the glass called selenium. Selenium was used during and after WWI to save manganese.

Manganese was the first glass decolorizer used. It turned purple in the sunlight, but was not used during WWI because it is an important part of some steels. When only a little manganese was added, the glass turned pink or light purple rather than dark purple.

The insulator in the middle has a little of both. The manganese probably came from recycled older glass, while the selenium was mixed into the new batch. The end result from a little purple and a little straw was an in-between color, peach.

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A crackled Hemingray-42 glass insulator, CD 154, in aqua.

Crackling glass is a process that totally destroys the value of insulators, but this one was done correctly and looked cool enough to warrant the whole $3 I spent on it.

Crackling is caused by heating up glass, then dropping it in water. The glass must be hot enough to stick together so as not to shatter, but still hard enough to crack. Afterwards, the glass is returned to the oven to melt the outside smooth again. If the outside is not melted together, the piece ends up as an insulator-shaped pile of sharp glass shards that loses pieces every time you touch it.

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Long time, no insulators!

A Lynchburg No. 44 glass insulator, CD 154, in light blue aqua.

Lynchburg Glass Corporation started manufacturing insulators in November of 1923. Despite a state-of-the-art factory, the glass was of poor quality and expensive to produce. After many problems and setbacks, the Lynchburg Glass Corporation closed its doors in May of 1925.

During demolition, it was discovered that a mainline gas valve which supplied the factory was installed incorrectly and not fully open, limiting gas flow and thus the heat output of the furnaces. Lynchburg Glass Corporation was doomed from the start!

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GOOOOOOOOOOAAAAAAAALLLLLLLLL!!!!!

A slightly wonky green “gingerbread man” insulator, CD 640. Personally, it reminds me more of the Pilsbury Doughboy than a gingerbread man. These glass insulators are a foreign style, this particular one from a factory in Folebray, France. How it ended up in a Texas antique shop is beyond me.

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A $2 junk shop find. This is an Ohmite model L rheostat, or wire-wound variable resistor. It’s approximately 4″ in diameter and made of unglazed white ceramic.

This one must be pretty old, it’s only rated at 50W and 300V. The new model Ls on the company site are rated at 250W and 1200V.

And yes it still works just fine!

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A set of 3 purple Whitall Tatum Co. No. 1s, CD 154, who have suffered a fatal trepanation!

I didn’t drill these holes, someone else did to make these into a crude tabletop lamp. I’ve always wanted to make my own colorful insulator lamps, but would never buy such pretty insulators to only to destroy them with holes. I got these for cheap and didn’t have to do the awful deed myself!

Don’t get me wrong, insulator art is super cool, but please do some research and make sure it isn’t rare first! There was one bottle digger who crackled 6 clear Hemingray-42s to sell, thinking they were worthless. Little did he know they were the rare MR embossing, worth around $750 EACH! After the crackling, they went for less than $50 apiece.

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A McLaughlin No. 42, in light sage green.

William McLaughlin, (August 12, 1884 - July 17, 1975), was unique in the insulator world, as he was the only major American insulator personality who survived from the golden age of insulator manufacturing to the age of insulator collecting.

William McLaughlin was only 13 when he got a job making insulators in the R. Good glass factory in Valverde, Colorado. He started his own glass company in Vernon, California, in 1920, and sold his business in 1935 to the Crystallite Products Corporation, who continued to make insulators under the name MAYDWELL. Later, when he became a member of the hobby, he proved to be an invaluable source of information about the manufacture, use, and sales of insulators.

The crudeness of this particular insulator, with straw marks and bubbles, the smooth base, and the sage green color are all distinctive traits of the early production runs of McLaughlin Number 42s.

All this and more information can be found in the wonderful free book by John and Carol McDougald, “A History and Guide to North American Glass Pintype Insulators”.

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Today’s lesson: spool insulators, or spools.

Spool insulators, although mechanically strong, cannot stand much voltage. In the past, spools were used on low voltage circuits such as streetlights or other lighting (120 or 240V). They were also used for building feeder drops (~240 to 480V) and sometimes for low voltage distribution wiring (~480 to ~600V).

Nowadays, spools are most often used to insulate neutral lines. If two different utility poles were linked directly by a neutral wire, different ground conditions could cause them to act like terminals of a battery. The resulting current, although small, can strip the protective coating off of metal poles and cause them to rust. The metal parts on wooden poles can be ruined as well, even if the wooden pole itself is not affected.

The overwhelming majority of spool insulators are made of porcelain in brown or grey tones, although greens, blues, yellows, and even reds are sometimes found. Those made of glass are usually clear, but can come in blue, green, aqua, amber, and yellow.

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These five pictures represent the evolution of Hemingray’s “hoopskirt” style glass insulators, starting with the Hemingray 40 (CD 152) and ending with the Hemingray 45 (CD155).

The first picture shows a Hemingray 40, CD 152. This style of insulator was introduced by Hemingray in 1910 as the new standard in telegraph insulators. However, it had its shortcomings and was replaced by the Hemingray 42 in 1921.

The immediate difference between the 40 and the 42 is in the wire groove. A square wire groove and big wire ridges held the wire in place much better than the narrow, round wire groove of the No. 40.

As the 42 matured, the wire groove was revised, widening slightly. The upper wire ridge was also reduced, because most of the line’s stress is from hanging down.

During and after WWII, the Hemingray 42 (and several other insulators) were shortened or redesigned to use less glass. Later molds of model 42s also were given lower wire ridge reinforcement.

A slightly different model, the Hemingray 45, was introduced in 1938 for long-distance telephone lines. The weight of long spans of wire necessitated a robust lower wire groove, to keep heavy ice-covered wire from breaking the glass.

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A beautiful purple glass insulator, a Whitall Tatum Co. No. 1, CD 154.

Whitall Tatum No 1s are among the most affordable of purples, ranging from $25-$35. What makes this one extra interesting to a collector like me is the wavy line on the left.

This wavy line isn’t a crack, but a fold in the glass. Folds can occur if the glass is poured wrong, causing part of it to cool before the rest and then not melting back together again. Whitall Tatum used an automated insulator machine and a rigourous quality check to ensure top of the line flawless insulators, in line with their other glassware products. Although relatively common in other manufacturers, for whom glass insulators were a second-rate product, a flaw of this magnitude in a Whitall Tatum is hard to find.

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A foreigner in disguise!

Although the same style, CD154, as the rest of my collection, this particular glass insulator comes all the way from Spain.

Made by Esperanza S.A. (not sure what S.A. stand for) and marked on the back C.T.N.E (Companía Teléphono Nacíonal de España), this Christmas tree green insulator does a good job of hiding in plain sight.

Fun fact: Different insulator manufacturers use different sources of materials for their glass. Local materials impart certain hues and colors to glass, so much so that unmarked pieces can often be identified by their color alone. This particular shade of green is found in many Western European glass insulators, regardless of style, company, or manufacturing date.

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A 7.5 inch Ohio Brass strain insulator with hand-wound wire hardware, ST-1255.

Also known as a hog’s liver or calf’s liver strain, these styles were used before the advent of modern cap and pin suspension insulators. Early cap and pin suspension insulators had the unfortunate tendency to pull apart, dropping the electrified conductor to the ground.

This style of suspension insulator has the wires passing over each other, compressing the porcelain in the middle rather than pulling it apart. Even if it did break, the entwined loops would prevent the conductor from falling down.

Rated at 11KV and listed in Ohio Brass catalogs from 1914 to 1940, this primitive insulator style enjoyed a relatively long life well into the modern suspension insulator era.