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CD 251 - Insulator of the Week on Fri, 7 Feb 2008


General term is "Cabletop"

Related Patents

No specific patent for this style found, but some of the NEGMs carry the patent date for a cable patent: Utility Patent 430,296 issued to Samuel Oakman on November 1, 1889


Embossing Types: Hemingray, Lynchburg & NEGM Co

Hemingray: Colors run from shades of aqua and Hemingray blue, to clear; blue tint and ice blue on their later units. There were several embossing variants produced by Hemingray. The three primary variations for style number embossings are: "Hemingray-61", "Hemingray No 1 Cable" and "Hemingray No 61 Cable", with the last two also containing the May 2, 1893 patent date. Base configurations include smooth base, corrugated base, sharp drips and round drips. This style appears to have seen wide use across the country---anyone know of an area where they were used in large quantities?

Here's a great pic of three Hemingray CD 251s in service, with a good example of how they were tied:

Lynchburg: Found mostly in a uniform light shade of aqua with a smooth base or sharp drips. A few have been found with milk swirls. All are marked with the trademark "L" in a circle and "Made in No.1 U.S.A." Lynchburg evidently acquired NEGM molds, as some are found with the NEGM embossing blotted out. I obtained several of these from a city lighting lineman's collection that were picked in the Pasadena, CA, area, along with a couple of aqua Hemingray CD 251s. Any known from other locations?

N.E.G.M. Co.: By far the most colorful of the CD 251s, available in ice blue and several shades of aqua, plus dark blue and gorgeous shades of green, yellow green, emerald green and olive green. Some have been found with amber swirls. Found with smooth or rounded base.


These brief comments on the Insulator of the Week are not intended to be complete and are presented to encourage discussion and additional information from ICON. Now it's your turn to share info and/or post photos of your favorite CD 251s!




Justin Stoudt commented on Thu, 07 Feb 2008

My good friend and hunting partner found a cd 251 Lynchburg on the Virginian RY near Abilene, VA, circa 1976. These were used on the power feeds on the catenary, but have long been removed.

Andrew Gibson commented on Thu, 7 Feb 2008

When did the CD 251 style originate? N.E.G.M. CO. is assumed to be 1899, and the Hemingray versions are obviously from 1893 at the very earliest. The Lynchburg units weren't around until 1923. So presumably the style originated sometime around 1893-1899 or so. I could fairly easily speculate that it was first made by N.E.G.M. CO., and that the CD 250 was an early prototype, though there is obviously no proof of that. As for an end date -- the Hemingray units with Numbers and dots in clear are from the 1930s at the earliest, and I believe the corrugated base versions date from around 1946 or later. So this style saw a fairly long life!

What IS very interesting to me, though, is what is missing (all this was pointed out to me in a discussion I had with someone, so this isn't first hand). The CD 251 showed up in a 1902 Knowles catalog, and is in the 1912 Brookfield catalog as well. Where are the KNOWLES and BROOKFIELD embossed CD 251s? Even better, a close examination of the N.E.G.M. units shows an Elmer ring at the top of the pinhole of some, as well as colors typical of Novelty at least. And there are other N.E.G.M. units that have a RB and appear to have air vents on the inner skirt, typical of Brookfield, as well as in typical Brookfield colors. N.E.G.M. supposedly was only in existence in 1899. But any Elmer production was 1903-1906 or so, and the typical dark aqua Brookfields would have been 1908-1920 or so. If Knowles and Brookfield made the CD 251 (which, from the catalogs, it would seem that they did), could they have made units embossed with the N.E.G.M. name? Why would they have done so, if N.E.G.M. no longer existed? And if they didn't make units with the N.E.G.M. name, where are these Knowles and Brookfield units?

The mold was obviously still around in 1923-1925 when Lynchburg made their units with a N.E.G.M. blotout.

There are so many mysteries when it comes to insulators, and it's so much fun thinking about them!

Brent Burger commented on Thu, 07 Feb 2008

Knowles never MADE insulators, to my knowledge. The Elmer works did a large amount of jobbing for them. This crosses two of the above points, for whatever that is worth. One will also note that Brookfield was lazy or reluctant to mark many of their larger, odd designs in later years. Could this be because they were sold to a jobber like Fred, Knowles, etc., and not directly ? BF marked power glass is uncommon-to-rare, yet they made plenty of unmarked stuff. The CD 200 comes to mind as another popular BF product they did not bother putting their name on.

An observation that can quickly be quashed or verified by the Hemigods, but are there Hemi 251's known with lettering pre-dating the Stamp style ? I cannot picture one in my head, but since these fall outside my interest sphere, I could be off on this one. If they are NOT found with Script or Prismic, then we can date Hemi production to 1901 and later.

I was unaware the Lynchburg units were made from re-used NEGM moulds. Lynchburg did this with a number of already extant moulds, namely from Brookfield. I think Marion Milholland told me that Wee Willie Gayner got his mitts on a bunch of BF equipment upon their demise and passed it on down as needed at Lynchburg, as he had ties there.

These are a cute little cable style. Even for a pony guy, they always caught my attention on lines. I have no specific memories of lines just loaded with them beyond being shown a short stretch up at Fort Bonghit (can't remember the name right now) by Port Townsend by our own Del Quist-o-nator. The 251's on that line were used for secondary drops to the officers' houses - large 1890's houses - and that they were in many colors, indicating some were replaced with later like units. I had no burning desire to play with power for something that really didn't interest me, so 30 vertical feet was as close as I got to them.

Paul Greaves commented on Thu, 7 Feb 2008

Great choice for the insulator of the week! I hope this post isn't too long... but the CD-251s have been sort of a side-specialty of mine for quite a while now. In the process of amassing a number of them, I've noticed some very interesting things about them. Here is a summary I wrote up a while back of the fine details I've noticed in the NEGM variations:

In approximate order of production (I think)...

1. N.E.G.M.CO. (no date). These come in aqua and kind of ho-hum green. They seem to have very sharp threading, much like Pennycuick but no "dot" in the pinhole. The inner skirt is rather thick. They also have a flat-ish base contour, with the base plate mold seam running around the outside of the base-skirt boundary. The aqua ones are a dead ringer in glass character for a lot of NEGM stuff, such as the signals you see so often. Plain light-ish aqua often with a fair number of pinhead bubbles. The green ones are pretty scarce in my experience. Perhaps these are the ones made during the 1899 time frame when the NEGM company was listed in the city directory?

2. N.E.G.M.CO. // "PAT.JUNE.17.1890" I have one of these that has all the same features as the undated ones. Same flatish base, same thick inner skirt. But it has normal "half-round" in section threads, and a circle at the top of the pinhole that could be Elmer. The glass color is a very light aqua, a color I've not seen often in this CD. I've only seen two of these for sure, and a third possible one on ebay (I wasn't willing to outbid for it).

3. N.E.G.M.CO. // "PAT.JUNE.17.1890" Same embossing, but inner skirt is a bit thinner, with a very flat bottom contour. The actual base is thicker and more rounded in contour than the above ones, also with the base plate mold seam running around the outside of the base-skirt boundary. Threads normal, with a distinct ring at the top. Sure looks like classic Elmer production to me... on top of that, the colors range from lt. green to the classic yellow greens you see Novelty stuff come in. I just realized I don't own an aqua one of these, if they exist they are unusual.

4. N.E.G.M.CO. // "PAT.JUNE.17.1890" This variation seems to have had the base part of the mold re-worked. The base profile is rounded on the outside, and sharp on the inside. They also have a fine line going around the base just above where the rounded base profile joins up to the lower outer skirt... I think the mold was modified by attaching a metal extension to the lower section, and then machining it to include the base curve, giving it the classic "rounded base" profile that certain Brookfields come in. The side mold lines curve under the base to join the sharp inner edge. So, as you might guess, I think Brookfield made them. The inner skirt looks like typical Brookfield, but not terribly distinctive either. Sometimes they show evidence of 4 tiny "points" which I take to be the air vents, but they are barely there. It is distinctly not the same as the type #3 above. Glass color is typically dark to medium aquas, often with green swirls, and ranging to solid green. I have one specimen that is a lighter aqua.

5. N.E.G.M.CO. // "PAT.JUNE.17.1890" This is interesting. The base is rounded with mold line curving under to meet the sharp inner edge same as above. But there is no faint line running around the outside just above where the rounded base profile joins the lower skirt. Also, the NEGM name is embossed in large letters, about the same size as what you see in the date. Color is still dark aqua ranging toward green, compatible with typical later Brookfield production. I think one or more of the molds wore out, requiring making some new molds from scratch. Incidentally, some of type #4 do show signs of heavy mold deterioration and repair.

6. Lynchburg, with NEGM blotout. Just to complete the story, these are clearly re-worked molds from the above, with the Lynchburg re-engraving. No doubt as to who made them, since they were kind enough to say so.

So what is up with all this? NEGM was supposedly 1899, Elmer stuff was 1903-1906 or so, and Brookfield continued to 1921. The molds were clearly still around in 1923 when Lynchburg re-engraved them, and that is a long time.

There is also the catalog evidence... they are shown in the 1902 Knowles catalog, and the 1912 Brookfield catalogs. Lynchburg must have gotten the molds when they acquired the surplus Brookfield equipment. And Hemingray made them for years... they were apparently a popular style, they're not rare. And if some of the NEGM's are not Brookfield or Knowles related, then where are those? Are we to believe Hemingray sold scads of them, but neither Brookfield nor Knowles ever got any orders? I really think they did sell them, but they were marked N.E.G.M.CO.

Again, it's a pretty interesting story, I just wish I really understood the why's of it all. I find it hard to believe that NEGM really lasted that long, but style #5 really intrigues me. Why would Brookfield re-engrave the molds with the NEGM name if they didn't exist as a company at the time? Of course I could be all wrong here, but man, the evidence is pretty compelling... Oh well, the mysteries keep this hobby interesting.

Incidentally, I have seen many other CD's that show similar Novelty to Brookfield transitions. A quick summary of other molds that seem to have "transitioned" from Elmer/Novelty to Brookfield with a mold line evident across the base:

CD178 Santa Ana (the very latest ones unmarked) CD256 Manhattan (the Brookfield ones seem to always be short ones) CD292 "Patent June 17 1890" CD280 Prism CD162 Star (mold shows heavy re-working overall)

There may be others as well where the embossing was erased or the mold was re-worked to the extent that they were not easily identified. I have a few other examples that I am suspicious that Brookfield used old Novelty molds but ended up not modified to include the mold line across base feature. I am judging by color mostly, and fairly worn looking molds. No proof there, however.

A few other things that seem to have something to contribute to the story...

CD267 NEGM's with the June 17 1890 date seem to have Elmer/Novelty characteristics. I have never examined the NEGM without the date to see if it has Pennycuick features, it would be interesting if it did. Apparently at least some of the Brookfield made CD267 (No 4 Cable) have the Rounded base with features that indicate a re-worked mold, but I have not examined enough of these to have an opinion.

CD202 "K" also comes in both "Pennycuick characteristics" and "Elmer/Novelty characteristics".

There may well be several phases of Elmer production to make things more difficult. Possibilities include Sterling/Harloe, Novelty, and the post-Novelty company (same factory, but I forget their name).

I think there is still a lot to be learned in this area, and an interesting story yet to be told.

Bob Stahr commented on Thu, 7 Feb 2008

Of interest in establishing the timelines of the CD 251 I offer the follwing from my research files:

NEGM of Boston was incorporated in July of 1898 in New Hampshire. NEGM's plant was located in Somerville, MA NEGM was destroyed by fire in January of 1900.

Novelty Glass Co. was incorporated on February of 1901 Novelty Glass Co. was closed in January of 1904 as a result of a labor strike and a lawsuit with Brookfield Elmer Glass Co. purchased Novelty in January of 1904 (this was the old owners of Novelty avoiding the lawsuit) Novelty Glass Co. (what was left on paper) lost it's lawsuit with Brookfield in September 1904 Elmer Glass Co. was sold to Brookfield by August of 1907.

The earliest reference I have to the CD 251 is from the 1906 Central Electric catalog. It depicts several Knowles/Novelty/Elmer pieces such as CD 199, 251, 253, 266, 267, 285, 292, etc.

I don't have a copy of the Knowles catalog handy so I don't know if it is in there.

The earliest reference I have to Hemingray selling the CD 251 is in the 1912 Central Electric catalog.

Mike Martin commented on Thu, 14 Feb 2008

This style insulator was fairly widely used here in the Louisville area on the old city fire alarm system, now abandoned, although some of the insulators and wires are still in the air. I have never seen them in any other style besides clear and had no idea until I saw the pictures that they were ever made in colors. There is a pole a few miles from me that still has a clear with no wire attached mounted on an iron "L" bracket. I have also seen them used to support heavy power conductors on a brick wall at an old industrial complex on west main street in Louisville, but they are gone now.

Bob Berry commented on Thu, 14 Feb 2008

Couple more pictures: [1]

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