Classification Systems in the Hobby
The Classification Systems
Glass - N.R. "Woody" Woodward developed a Consolidated Design (CD) system in the 1960s that is used for both North American pintype glass insulators and foreign pintype glass insulators. The system has been expanded to include battery rests, glass spools, nail knobs, guy wire strains, and other miscellaneous glass. For foreign glass insulators, Marilyn Albers has worked with Woody to produce the reference on the subject. For North American glass, Woody published and updated his CD system for many years but now the updates only show up in the price guide published by John and Carol McDougald.
Porcelain - Jack Tod published and updated a guide to porcelain insulators with his Universal numbering (U-number) system. Elton Gish is currently doing this work.
Multipart Insulators - Elton Gish developed a system for identifying multipart insulators (M-numbers) in 1988. The first number of any M-number indicates the number of pieces comprising the insulator (e.g., an M-4380 has four pieces cemented together). Within each grouping, insulators are generally ordered by size (e.g., the M-4380 is larger than the M-4360).
One of the delights of collecting is finding an insulator that has not been previously reported. Certain discoveries are better than others because of how unexpected they are. Fitting the new discovery into the currently existing body of knowledge can sometimes be tricky and involves copyright issues. In any case, it is important to document your discovery and publicize it to the hobby as many collectors have taken pride in doing.
What is the best discovery? These can range from major new designs to trivial differences between insulators. Listed below are what I consider to be the ranking by importance of different discoveries.
Where do new designs fit? Generally it will be up to the copyright holder to decide where additions go. For North American glass insulators, N.R. "Woody" Woodward makes that determination. For certain parts of his Consolidated Design (CD) system, other people make the assignments. Ray Klingensmith assigns CD numbers for threadless insulators. Kevin Lawless developed CD numbers for battery rests and Charlie Irons took over this task when Kevin died. For North American porcelain insulators, Jack Tod developed a Universal (U) numbering system to identify them. Elton Gish currently assigns these numbers since Jack died many years ago. Elton also assigns numbers to multipart insulators (M-numbers). For foreign glass insulators, Marilyn Albers and N.R. Woodward are in charge of this. For foreign porcelain insulators, Marilyn Albers and Jack Tod made the assignments.
There is an organizing system to each of the different classification methods.