Insulators, aren’t those the glass things that went on the telegraph poles? Yes, they are. But there is a lot more to them than that. There are hundreds of different styles, glass and porcelain, and several thousand collectors. What are all the collectors supposed to do with so many styles to know which ones are one-of-a-kind, and which were made by the thousands? The CD or Consolidate Design system was invented for the purpose of identifying, cataloging, pricing, and comparing insulator designs.
Even though this system was invented in the 1960s when people had only just started collecting insulators, new designs are being added, switched, or merged with other styles. Recently, there has been a debate whether or not to change the small California CD 112 variant to CD 114. These two styles are transposition styles that have a second wire groove (the dip on the side of the insulator) to reduce “crosstalk” of two parallel wires. Crosstalk is when one phone call or telegraph message leaks a tiny bit into the line that it is paralleled to. It helps reduce this when the wires are crossed at intervals along the line.
The CD 112 style was produced in large amounts by many different companies until around the 1920s when it was replaced by the CD 113 which used less glass therefore being less costly. The CD 114, until now, was considered to only be produced by Hemingray Glass Company; one of the main producers of glass insulators in America until 1967 when there was too much competition from porcelain insulator manufacturers. Hemingray also replaced the CD 114 with the CD 113.
The CD 114 is not very much unlike the CD 112. The only major differences are that the CD 114 lacks a lower wire ridge (the protruding ridge below the lower wire groove on the CD 112 insulator) and the dome of the CD 114 can be somewhat of a prism shape in some variants. The California Glass Insulator Company (California) opened in 1912 in Longbeach California, and used sand mined nearby for their glass, which was often a smoke or yellow color that turned a smoky purple-brown when exposed to sunlight for long amounts of time, although they made a wide spectrum of colors such as blue, sage green, plum, and two tones; a mixtures of two colors.
Although the plant was only open for four years, they produced as many insulators as a lot of companies that were open much longer. They made around 15,000 insulators every day. Before they closed in 1916 due to flooding, they produced many styles including the CD 112s. When the company had just started, they used the typical CD 112 design, then they quickly switched to the disputed CD 112-114, because it cost slightly less to produce. Because of this, there are few original CD 112 design Californias. If the later design of the CD 112 is designated CD 114, there will be a listing both for cd 112 (the earlier style) and for 114 (the later more common style) for California. The later style has some characteristics of the CD 112, and some of the 114, leaving it somewhere in between.
Many experienced collectors claim that it is a CD 112, and many others say it’s a 114. Some say that the collectors should not get worked up over the details, and just leave it the way it is. No matter what happens, the California Glass Insulator Company will remain an iconic insulator manufacturer.
Lockhart Bill, Schreiver Beau, Serr Carol, Lindsey Bill. California Glass Insulator Co. 2014, https://sha.org/bottle/pdffiles/CaliforniaGlassInsulatorCo.pdf, Accessed 17, JAN 2017
Meyer, Bill. Insulators Glass & Porcelain. Amber 8 Computer Consultants, 2017 http://www.insulators.info/. Accessed 17, JAN 2017