What I consider to be the unipart find of the decade is an odd Fred Locke pin-type that was recently reported. I am admittedly biased when it comes to Fred Locke porcelain, but surely you will agree that this is a great new discovery!

Bob Berry (NIA#1203) managed to acquire this fine jewel at an eastern show last fall. I have assigned it U-339B, since it obviously fits alongside the one-of-a-kind U-339A. The U-339A was dug at the Victor dump back in the 1970's. It has the 1-8 incuse marking on the top of the 1-3/4" loop and a dark tan glaze.

U-339A

Bob's new insulator, U-339B, is a smaller version of U-339A. It has a very pretty rusty-tan glaze and a 3/4" hole in the crown. There is even the number "3/4" neatly scratched to the right of the hole. On the flat surface on top of the insulator is a very strong 1-2 marking. [For details of the Fred Locke markings and U-number drawings for porcelain unipart styles, refer to Jack Tod's book, Porcelain Insulators Guide Book.] U-339B was discovered just after I published the "1992 U-Chart Supplement" (still available for $1 plus long SASE), so it will be added to the next supplement.

I guess that we will never know the reason for the hole in these two styles. The Pittsburg U-339 picked up on the idea many years later, and well after Locke dropped the idea (apparently, this was soon after Fred left the company in 1904). Our best guess is that these were used as "slack wire" insulators, where the cable was threaded through the hole in the insulators, and allowed to hang with a small amount of slack. This would allow the cable to expand and contract with temperature changes. I suspect that these insulators were used indoors at an industrial facility, where the heavy cable was merely supported, rather than held firmly in place with a tie-wire. These insulators would not be suitable for standard outdoor use, where the cable would be free to swing in the wind, resulting in damage to both the cable and the insulator. With the recent discovery of the Etheridge designs, U-376C and U-376D, at various steel mills in Pennsylvania (which were used to support heavy electrical cables inside the buildings), I suspect that the slack wire insulator design may have been superseded by the stronger Etheridge designs. These stronger cable top insulators, which were probably introduced circa 1904, would adjust to changes in cable expansion by allowing the insulator to turn slightly on the unthreaded tubular pin.

U-339B

While doing research for my upcoming book about Fred Locke, I came across a photograph that showed Fred Locke himself standing in front of an outdoor insulator display booth, at an electrical trade show. The year was probably 1904. On the bottom shelf at the front of the booth, was U-339A. and next to that insulator was U-339B! I found this photograph a few months before Bob reported the U-339B specimen. Many other insulators were present in the photograph, some of which have never been found. Unfortunately, you will have to wait until my book is published before you will have the opportunity to see this photograph (along with more than 70 other previously unpublished old photographs). 

At the Kansas City show in April, Rob Lloyd (NIA #3414) loaned me two photographs of a very odd post-type insulator that is owned by Shaun Kotlarsky (NIA #4993). Shaun is a 13 year old collector who does not lack enthusiasm for our hobby. He has over 1,000 insulators in his collection, and he has only been in the hobby since October, 1992!! Shaun's quest for insulators has even taken him to a military surplus store in Ohio, which is where he found this unique post insulator specimen! Who would have thought to look there?! Shaun's insulator has the Lapp marking. Note that this seemingly common insulator has a very unique crown. There are three grooves along the top!! Does anyone know how this insulator was used? What ever the purpose, it must have been very specialized, and very, very expensive considering how much the military spends on toilet seats and hammers these days. 

Lapp post insulator with three conductor 
grooves. (8" tall, 5" diameter crown)

Ken Willick (NIA #3709) and Steve Jones have been digging again in the western New York area. Both of them found similar insulators, which we call "kitsulators", because they did not come assembled ("broken", for those of you who do not remember). Steve's insulator was found with an iron busbar support cemented to the crown. He cautiously cut it off with a hacksaw to reveal that it has a crosstop. Both of these insulator specimens have a beautiful mottled mustard/orange glaze, and the characteristic Thomas "blue-jean seam" inside the bottom skirt. This is a very early Thomas glaze, which dates these insulators to circa 1905. These 3-part, glazeweld insulators are the rare U-954A. As you can see in Steve's photograph, this 5-1/2" tall insulator is dwarfed by his M-389 bottom skirt. Note that the crown is slightly shorter than the U-drawing, which reduces the size of the flat crown side and explains the 3/8" overall shorter height. Steve said that they found other similar smashed insulators that had only one groove in the crown, but he could not find enough pieces for a kitsulator.

U-954A with Thomas "blue-jean seam" and very pretty mottled mustard/orange glaze. Steve also reported finding a Hewlett suspension disk insulator, which has the followlng marking:

It must have been made at the time when the insulator logo marking was being phased out, and the LOCKE marking was first used. He said the LOCKE marking appears to be branded on the surface, rather than under-glaze ink. I suspect that the marking was an iron oxide "ink" applied under the glaze. When the insulator was fired, the iron marking would "burn" though the glaze, thus giving the appearance that it was branded.

Ken also reported two other very interesting insulators. The first one is a white U-39 with the incuse marking 'GLEN' on the top. Only about two of these have been reported before. Ken's insulator was dug in central New York, which is the same general area that the other specimens were found. These were made at Fred Locke's factory at Victor, NY, but we do not know the significance of the marking. If only one specimen had been found, you might suspect that it was marked with a Victor factory employee's name, but the marking must have some other meaning.

Fred Locke insulators: U-39, U-39 'GLEN', U-38

Many of you know that Ken Willick lives in Lima, NY, which is the home of the old Lima Insulator Co. Consequently, Ken is always on the lookout for Lima and early Pinco insulators. At a local household auction, Ken won the bid on a box of insulators. In that box, along with the usual common porcelain, was a new porcelain style, which I have assigned U-133A. Ken graciously sent it to me for close inspection. I firmly believe that it is an early Lima insulator (1904-1908), as the glaze is characteristic of that time period. When I first saw this insulator, I instantly realized that two previously unidentified styles were most certainly made by Lima, too. These are U-30A and U-133. I first saw these two styles at the Rochester National, in 1984. I quickly bought a couple of each thinking that they were Fred Locke insulators; after all, they had nice tan glazes and filed firing rests, just like the early Victor production. Lima insulators do have similar glazes to those made at Victor, but the Lima glaze often has a slight purplish cast. After several years of studying the Lima and Victor glazes, pinhole characteristics and swirl marks inside the bottom skirt of Lima multiparts, I am convinced that Lima products can now be determined with a reasonable degree of certainty.

U-30A, U-133A, U-133  Unmarked insulators made by Lima Insulator Co.  (1904-1908)

Fred Collier (NIA #2933) has a couple of interesting reports. The first one is about two varieties of U-410. which were both made by Pittsburg. In the photograph below. the insulator on the right matches the U-Chart drawing for U-410. The insulator on the left is a slightly larger version. Does anyone realize that U-410 can be found in two sizes? Thanks, Fred, for pointing this out. Either style is rare. so he is probably the only person to have two of these. The one on the left may be the rarer of the two. 

U-410 variant (lift) and typical U-410 (right)

Fred reports a very unusual insulator (see drawing) that we need some help in identifying. It has a chocolate brown glaze and a standard threaded pinhole. He says that the insulator "looks incomplete", and that there is a possibility that it is the top part to a two-part insulator, since there is some flaking around the pinhole, as if it were screwed down against another insulator part or electrical equipment. Due to its odd shape, and since there is no indication that a wire or tie-wire was used in the groove, I suspect that this insulator was not used in the normal manner as a line wire insulator on a crossarm, but rather in some special service, such as can be found around a substation or other such facility. If it were the top part of a two-part insulator, the bottom half would have to be narrow enough to fit inside the extended skirt of this odd insulator. We would appreciate any information that you have regarding the use of this insulator. I am holding off assigning it a U-number, because of the suspected special service, and the possibility that it is not complete.

Odd (incomplete??) insulator.  Do you know how it was used?

I received a report a couple of years ago that keeps getting overlooked when it comes time to write another PIN article. Both Bob Harding (NIA #3746) and David Wilson (NIA #3630) are credited with this report, but Rob Lloyd (NIA #3414) was in on the find, too. 

Bob reported that he and Rob were on an insulator hunting trip in Columbus, OH when they spotted some downed utility poles at a bridge reconstruction site. They picked up some nice power glass and a few U-705's. Rob noticed that some of them had an unusual marking. The insulators have a reddish mahogany glaze with the following "keystone F" marking deeply incuse marked on the skirt:

Dave learned about the find and recovered another marked U-705 for his collection. A week later, Dave returned to the site where he found two more U-705's, but these were incuse marked "FP" on the top firing rest.

We know that the Franklin Porcelain Co. (Norristown, PA) used the "FP" marking, but it is very uncommon to find a marked specimen. The "keystone F" was surely that of Franklin Porcelain Co., too, since both marking types were found on the same insulator style, and at the same location. 

Electric Service Supplies Co. was the sole sales agent for the Franklin Porcelain Co., and they obtained controlling interest in the company soon after Franklin started business. ESSC used a keystone logo in their trade journal ads in the mid to late 1920's.

Dave notes that one of the "FP" marked U-705' s has a squared crown, just like in Jack Tod's U-Chart drawing; however, the other "FP" marked one, and the "keystone F" marked one, have a more rounded crown detail. Bob Stahr (NIA #4186) sent me a copy of the following advertisement from a 1927 issue of "Electrical World". Note that all of the insulators have a squared crown. In 1927, most insulator manufacturers had already changed their insulator designs to rounded edges, which reduces the electrical stress around the insulator (sharp edges provide an arcing point). We might speculate that the "FP" marked specimens with a rounded crown were made later than the squared crown specimens (1927 and later), and maybe they were used as replacements at this location. Since the "keystone F" marked specimens also have rounded crowns, they may have been made even later, and introduced as replacements at this site. Since bridges and rivers tend to attract people, and people like to throw rocks at insulators, this bridge site might have been a prime location for damaged insulators, and the occasional need for insulator replacements. Franklin Porcelain Co. went out of business in either 1928 or 1929.