1978 >> July >> Porcelain Insulator News  

Porcelain Insulator News
by Jack H. Tod

Reprinted from "INSULATORS - Crown Jewels of the Wire", July 1978, page 26

Dear Jack: 

A man sold these two insulators to my father in England last month, saying that they were excavated from a circa-1920 dump. Any info would be appreciated. 

The pin type has an insert which screws out, and this insert is fluted up the sides and over its top for insertion of a wire. Both the insert and outer shell are glazed white except for the three threaded surfaces which are unglazed.
Mike Doyle 
Annandale, Va.

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Dear Mike: 

I can't give you any specific info on your English insulators, since I'm unfamiliar with foreign manufacturers and their products. The double-skirted item (at top) is a common form of shackle insulator much the same as ones made in the U.S. up to current tines. These are for use in dead-ending circuits with a shackle mount on the pole or crossarm. 

The pin type appears to be a form of "dry-spot" insulator, and an interesting one at that. One lead of the bridle-wire pair would be afforded a dry spot on its insulation by running it up over the center insert in the groove provided for it. It would require two of these insulators on the crossarm to dry-spot both wires of the bridle pair. Although there is a U.S. patent on the British "screw-cap" form of dry-spot insulator, I am not aware of any U.S. patent on this particular style you have. I have no easy way to research the English patents. 

Jack


Dear Jack: 

I just traded some glass for a U-940A Imperial plus another triple-petticoat Imperial which I think is an addition to the Universal Style Chart. (See U-940B drawing above.) 

Except for the extra petticoat, this one appears to be essentially identical to the No.3 Imperial shown on page 22 of the 1902 C. S. Knowles catalog (Frank Peters reprint). 

This specimen has a white glaze and is a skirt-rest. It has three handstamp markings as follows: The "crown" trademark marking, the "MANUFACTURED BY ... " marking with "PROCELAIN" error, and a 9-7-98 date. Do you think it merits a new U- number?
David Bethman 
Bellingham, Wash.

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Dear David: 

Yes, this should be added to the Style Chart, and it will be U-940B. Whereas things such as variations in exact crown style or groove widths are real ho-hum situations on modern cable styles, they are important on these early items by Fred Locke, Thomas and Imperial. We want to be able to refer to each specific style (and state of evolution) that was made in the very early days of porcelain pin types. (The above U-940B drawing was made from shadow profile and measured dimensions subsequently sent by David at my request.) 

Jack


Dear Jack: 

Must be about time to write a few lines. Have several interesting items. 

First is this Illinois marking. Haven't access here to many Illinois "map" markings, but this one has the state reversed from all the others, both incuse and underglaze types. Is this an error?

Secondly -- I have, since collecting started, found most of the Victor Insulators, Inc. insulators in only chocolate brown and with the usual markings as in your books. Recently I acquired a half dozen different U- numbers, each with a mottled brown glaze and each one differing widely in coloring -- from rose red mahogany to ochre-brown to "closest to red" brick shade. All have this uncharacteristic incuse marking (above) Note the logo is more nearly square, has rounded corners, a very thick V with a flat instead of pointed bottom. I am wondering if this might be the earliest of the V-I markings and if these are therefore very early V-I production insulators. The varied glazes sure spruced up that corner of the collection.

Lastly -- I had never seen the U-514 until I bought a collection last fall. There were a dozen in a box, all with the metal pins in and in the case upside down. There are five very distinctly different varieties, but all are similar in that they have the same elongated petticoat as the U-514. These are:

  1. CHANCE (u-g), exactly as the U-514 chocolate brown. 
  2. V-I (incuse), exactly like U-518 but with 1" petticoat extension, chocolate brown. 
  3. THOMAS (incuse), exactly like U-511 but with 1-1/8" petticoat extension, chocolate brawn. 
  4. KNOX (r-e), like U-511 but with 1" petticoat extension, sky glaze. 
  5. KNOX (r-e), more like U-512 but with 1" petticoat extension, bright orangey chocolate brown.

This sure is an interesting group. Did the extended petticoat make them a special-use insulator? 

Also added recently a white U-259 Fred Locke, a U-939 Fred Locke, a U-928A, and the U-928 with embossed marking "BOCH'S INSULATOR PAT. APL'D. FOR". 

Really using your new book, too (Electrical Porcelain). A great reference & needed. Good luck at the National.
Lew Hohn
Rochester, N.Y.

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Dear Lew: 

Very sorry, old buddy, but I'm giving you a "D" in geography for turning your Illinois maps on one side or the other to cause the Mississippi River to flow in an east-west direction. The Illinois "map" trademark is as shown here -- and usually appears on specimens correctly oriented. It's not the map which is reversed; it is the number inside it which is. 

I have a number of the old marking stamps used to apply markings on Illinois insulators, including the one used for this specific marking. Both the map outline and the year number (1934 in this case) are glued to the rubber backing of the stamp. Installed through the center of the map and the padded backing is a small channel for insertion of the various catalog numbers (237 here) for making runs of their various insulator styles. Although there was obviously a "normal" manner for inserting these type numerals on a day-to-day basis, they could naturally be inserted either way. Most specimens have the bottom of the catalog numbers at the left side of the map, or at least the ones I've noticed were mostly that way.

Re your V-I insulators, I completely agree with your assessment that these are probably the earliest production in the 1935-1953 span of the company. Most companies quit making the pretty mahogany-type glazes in the 1930's and went to the chocolate brown (the current standard along with sky glaze). I can't recall ever having had or seen many brown V-I insulators other than chocolate brown Yours are certainly unusual in that respect, not to mention the variety of marking.

I would also have agreed with you that your group of insulators with very extended petticoats such as on the U-514 were made for special applications and/or certain customers. The U-514 drawing in the Style Chart was from a chocolate brown CHANCE Specimen I found in the Parkersburg factory dump some years ago. When visiting the KNOX plant several years ago, they were making a run of these insulator styles (with sky glaze), but these had sanded holes instead of threads. The Knox president-manager told me at the time that these were "equipment insulators", so I didn't inquire further then. I had never heard of any other collector specimens of these styles until receiving your report. 

Of course, knowing the answer to your question is better than guessing, so I wrote to A. B. Chance Co. about it. They sent back information which proved we guessed correctly. 

Chance did make these, and it was a special order for Consolidated Edison N.Y. They apparently quoted on these as early as 1958 but believed the first order was probably in 1962, which agrees with the 5-2-62 date of the factory drawing. Their files indicate that Knox was their big competitor on this particular item. 

The Chance drawing SPO-3915 is titled "steel shank insulator", and it is an assembly of the threaded pin type (U-514) with a cemented-in steel shank with machine thread end (5/8-11 threads), washer and nuts. Overall height from end of the shank to top of the insulator ears is 10-1/2".

The insulator itself is part number 350081 with brown glaze, 350082 with white glaze. 

I presume all your specimens have cemented-in steel shanks. Further, I'm guessing your CHANCE ones had threaded holes and that your KNOX ones had sanded holes instead. 

It's a moot point whether the U-514 should be in the Universal Style Chart if it was furnished only with cemented-in pins. As yea have already found, the U-514 reference is very handy for describing these distinctively different pin types when you encounter them.

Lew, I think anyone who latches on to four more very rare items (the F. Locke & Boch items) in one season is guilty of hoggin' the trough. Please move over a bit and let some of the other boys have a chance!

Jack



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