1979 >> December >> Porcelain Insulator News  

Porcelain Insulator News
by Jack H. Tod, NIA #13

Reprinted from "INSULATORS - Crown Jewels of the Wire", December 1979, page 28

Dear Jack: 

Reference the egg-type porcelain strain insulator in your Sept. 1979 column (page 27). 

I have seen many egg insulators still in use on 600-volt dc trolley feeder lines and overhead trolley wires in San Francisco. Also some are still in use on Pacific Gas and Electric Co.'s 120-volt service lines in San Francisco. I'm enclosing a couple of photos showing these eggs in use (bottom 2 photos.) 

I'm also enclosing a photo showing Hewlett-type insulators still in use on a 4 KV line in Frisco. Not too many Hewlett-type insulators can be found in San Francisco area anymore. However., in Los Angeles area, there are plenty of them still in service. 
Richard A. Peterson 
Oakland, Cal. 

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Dear Richard: 

Many thanks for the photos and information on the old strain insulators in use in California areas. Many of the old insulators such as these, and even pin types too, are still in use on lines which haven't been rebuilt for a long time. Also, strains such as these are perfectly serviceable, and many utilities would keep them in stock forever and just keep on reusing them as needed. We like to get photos and info about any oldies or unusuals still in service. 

Jack


Dear Jack: 

Note I've moved to Wyoming since I last wrote. But, as before, I still collect glass. 

Your answer to Emma & Tony Almeida in Sept. 1979 issue prompted me to write. I also have a Locke U-784A and Locke U-783 with white glazes. As I will be putting these on my trade list for glass, could you suggest a trade value for them? 

Would any of the following have a trade value high enough to put on my trade list: U-231 No-Name; U-256A with Triangle-M on dome; U-236 embossed "G" on the dome; U-791 with underglaze J-D marking -- all brown and mint? There are some U-414 here (marking unknown), and are these worth going after? 
Tom Kasner 
Casper, Wyoming

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Dear Tom: 

Most of the Hi-Top insulators are very common in brown, and it's just a case of their being tough to locate in white, unless you happen to be in an area where they were used, of course. As uncommon as these whites are in most areas, I'd say a trade value of even $3 would be pushing it. 

As cute as the U-231 is, it's a small, no-name brown--trade value $1 or so. Your U-256A is a zero unmarked, but with Triangle-M marking should have a trade value several $. The U-791 is good only because of the J-D marking -- rather tough to get in any style; suggest trade value of $4 to $5. The U-236 with "G" is about a $3 to $4 trade value. 

The U-414 is a relatively scarce insulator, and nearly, all collections I know of lack it. I've seen them in only one place -- on a line in New Mexico. I bought one remaining specimen from the utility company in Socorro, N.M., plus later found two unbroken ones in a New Mexico dump. They were cataloged by Victor Insulators Inc., Porcelain Products Inc., and Knox Porcelain. I was told by P.P. engineers that the design was a flop regarding lightning, so it was short-lived. The one I have retained has a barely legible Rectangle-V incuse marking on the skirt. 

Due to its scarcity and unusual design, we stuck a $50 estimate on U-414 in the book; however, it just doesn't look that old or spectacular sitting on the shelf, so I doubt it's that good an item. But they probably are worth going after if you can get them. Make sure you allow for postage in swapping these items, a bit on the large and heavy side. 

Jack



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