Antique glass insulators glossary
A Glossary of insulator terms
- ANSI - Abbreviation for American National Standards Institute
- Baby Battleford - Nickname for CD 734.8.
- Baby Columbia - Nickname for CD 262.
- Baby Signal - Nickname for CD 160.
- Baby Teapot - Nickname for CD 791.
- Baby Wade - Nickname for CD 721 and CD 722.
- Ballerina - Nickname for CD 298.
- Barclay - Nickname for CD 150.
- Base - The bottom of an insulator; generally what the insulator would rest on if placed on a flat surface.
- Bat Ears - Nickname for CD 321 and U-389.
- BE - Abbreviation for Base Embossed. Used to denote that there is embossing on the base of the insulator.
- Beal's - Nickname for CD 309.
- Beehive - Nickname for CD 145. May also refer to the Canadian "Beehive" CD 143, as well as porcelain U-132 through U-153 and U-157 through U-160.
- Bell Chambers - Nickname for CD 317.5 which was used in conjunction with the Wing Chambers CD 124.5.
- Big Mouth - Nickname for CD 128.4.
- Bird Feeders - Nickname for Battery Rest Insulators.
- Blackburn - Nickname for CD 141.6.
- Blob Top - Nickname for CD 126.
- Blotted Out Embossing - Old embossing on a mould which has been partially removed. However there are traces of the old embossing still visible. Not to be confused with "ghost embossing".
- Boat Anchor - Nickname for large, heavy multi-part porcelain insulators, such as the M-4800 which weighs 55 pounds.
- Boch - Nickname for U-928 and U-928A.
- Boston Cable - Nickname for CD 266, U-408, and U-408A.
- Bracket - A wooden or metal mounting device designed to fit in the pinhole of an insulator, and attach it to a (normally) vertical surface such as a pole or the side of a building.
- Braille - Nickname for the CD 113 from Canada that has dots on the skirt which appear like braille.
- Brass Bushing - A threaded brass insert that was inserted into the pinhole while the glass was still molten. This created perfect threads to assure uniform contact with the pin and protect against pin expansion. Sometimes referred to as a liner or thimble.
- Bullet - Nickname for several styles, including CD 132, CD 133 and CD 133.4.
- Burbrook - Nickname for CD 149.
- Bushing - A cylindrical insulator with external ribs on one end, usually mounted on a transformer and used to insulate high voltage leads.
- Button Mould - A three piece mould with a "button" high on the crown.
- Buzby - Nickname for CD 141.8.
- Cable - A large diameter line wire that often rests in the saddle groove.
- Cable Insulator - A larger insulator with a saddle groove designed to support a heavy cable.
- Canadian Boston - Nickname for CD 136.4.
- Candlestick - Nickname for CD 317. Used in conjunction with the Chambers Companion CD 132.4.
- Carnival Glass - Carnival glass is a coating which is applied as a liquid. It is sprayed onto hot glass at approximately 1100 F. The liquid carrier evaporates with the heat and the result is a deposit of a metallic coating on the glass. The colour can range from a dull orange brown on some Hemingray insulators, to a bright "marigold" carnival on many of the Pyrex pieces.
- Casting - Seldom-used form of making wet process porcelain insulators where a difficult shape is desired. Thick clay slip is poured into a plaster mould. The plaster mould absorbs the excess water leaving a semi-dry clay body.
- Castle - Nickname for CD 206.
- CB - Corrugated Base
- CD - Consolidated Design Number (a cataloguing system)
- Chambers Companion - Nickname for CD 132.4. Used in conjunction with the Candlestick CD 317.
- Chester - Nickname for CD 123.2.
- Chicago Diamond Groove - Nickname for CD 135.
- CIC - Canadian Insulator Collector
- CJ - Crown Jewels
- Claw - Nickname for CD 109.5, CD 206.5, and U-184. May also be referred to as "Harloe's Claw".
- Cleat - Refers to various styles of porcelain house wiring insulators often composed of two porcelain halves used to clamp two or three low voltage wires in separate grooves.
- Climax - Nickname for CD 184.
- CM - Marking found on certain insulators specially designed for high frequency (30,000 cycles per second) long distance telephone lines called carrier-circuits.
- Cobalt Blob - Nickname for CD 140.5.
- Columbia - Nickname for several styles, including CD 262, CD 263 and CD 264.
- Combination - Nickname for M-2795 (Combined glass and porcelain).
- Combination Safety - Nickname for CD 139.
- Confederate Egg - Nickname for CD 701.6 and U-970.
- Coolie Hat - Nickname for CD 304; sometimes simply referred to as "Coolie".
- Corkscrew - Nickname for the large CD 110.6 and the small CD 110.5.
- CREB - Crown Embossed Brookfield.
- Cross-top - Refers to insulators with two top cable grooves that cross perpendicular to one another. This feature can be found on CD 141, CD 204, CD 208, CD 244, U-432, U-432A, U-923 to U-923E, U-927A, U-927B, U-942, U-954A, U-954B, U-954C, U-958, M-2105, and M-2111.
- Crown - The section of the insulator from the upper wire ridge to the dome.
- CS - Marking found on certain insulators (CD 128) specially designed for high frequency (30,000 cycles per second) long distance telephone lines called carrier-circuits. The "C" stands for Carrier-circuit application and the "S" denotes the insulator was intended to be used on a Steel pin.
- CSA - Marking on CD 128. The "C" stands for Carrier-circuit application and the "S" denotes the insulator was intended to be used on a Steel pin. The "A" has no known meaning. These insulators were made of boro-silicate glass such as Pyrex glass.
- CSC - Marking on CD 128. The "C" stands for Carrier-circuit application and the "S" denotes the insulator was intended to be used on a Steel pin. The second "C" has no known meaning. These insulators were made of soda-lime glass.
- CSO - Marking on CD 128. The "C" stands for Carrier-circuit application and the "S" denotes the insulator was intended to be used on a Steel pin. The "O" has no known meaning. These insulators were made of soda-lime glass.
- Cutter - Nickname for CD 1038. This is a non-pintype insulator. A porcelain version of this also exists.
- CW - Marking found on certain insulators specially designed for high frequency (30,000 cycles per second) long distance telephone lines called carrier-circuits. The "C" stands for Carrier-current application and the "W" denotes the insulator was intended to be used on a wooden pin. This designation was intended for CD 122.4 but no insulators were ever marked with "CW".
- Dome - The top part of the insulator. Also used as an embossing location designator when written as (Dome) and used to indicate the embossing that follows is on the dome.
- Door Knob - Nickname for CD 175.
- Double Petticoat - An insulator with two petticoats: the outer skirt counts as one and the inner skirt counts as a second.
- DP - Double Petticoat.
- Drip Points - Small projections on the base of the insulator believed to help water "drip" off the insulator. There are many size and shape variations, but most can be described as "round" (hemispherical beads about the size of a BB) noted as RDP, or "sharp" (conical shaped projections about 1/8" in diameter) noted as SDP.
- Dry Process - A porcelain manufacturing process where granulated clay particles are pressure moulded into the desired shape.
- Dry Spot Insulator - Nickname for CD 182, U-188, and U-173 through U-175.
- Duplex - Nickname for CD 187, CD 188, and U-81 through U-85.
- Eaves Trough - Feature around the outer edge of the top skirt of Fred Locke styles U-969, M-2335, M-2335A, M-2785, M-2795, M-2796 which collects and channels rain water to one or two spouts.
- Edison -Nickname for CD 285 and U-356.
- Embossed - A marking technique used on all insulators where the mould is punched or engraved, resulting in raised letters or other markings on the insulator. This method is used to mark all glass insulators and is one of several methods used to mark porcelain insulators.
- Fog Insulator - Broad term for any insulator designed to cope with contamination problems such as fog bells, fog bowls, fog types, etc.
- Foree Bain - Nickname for CD 144.
- Forestry Insulator - Refers to several styles of small donut-shaped porcelain insulators used to suspend telegraph lines through a forest to a fire lookout tower. Most styles are composed of two halves with a large hole in the centre. The overall shape of this insulator can be hexagonal, round, or oval.
- Frogs Eyes - Nickname for CD 230.
- Glaze-filled - Fusing process patented by John Boch similar to glaze-welding. Glaze-filling is different in that extra glaze is poured between the inverted porcelain shells and fired in that position so that the extra glaze flows down and fills all of the gaps between the porcelain shells.
- Glaze-weld - A porcelain manufacturing technique where two or more shells of porcelain are glazed and fired together allowing the glaze to fuse the parts as a single unit.
- Ice Cream Cone -Nickname for CD 160.7.
- Incuse - A marking technique used on porcelain insulators where the insulator is struck with a metal stamp while the porcelain is still in a plastic state before glazing or firing. This is by far the most common porcelain marking technique. The marking is actually recessed into the insulator.
- Inner Shell - This is the bottom section of a multi-part Insulator. This is the section that is usually threaded for a pin.
- Intermediate Shell - This refers to the centre section of a three part multi-part or the two middle sections of a four part multi-part. These can also be referred to as Top, second, third and bottom.
- ISC - Abbreviation for Inner Skirt Chip.
- JD-Blue - A distinctive light blue glaze used on Jeffery-Dewitt insulators.
- Johnson & Watson - Nickname for CD 109.7.
- Jumbo -Nickname for CD 140.
- Keg - Nickname for several styles, including CD 112, CD 113 and sometimes CD 114.
- Kitsulator - An insulator repaired by cementing good pieces from one or more broken insulators to form one whole insulator. Note that these should be marked as repaired if they are sold.
- Knob - Small cylindrical insulator used to secure house wiring or the cylindrical member projecting out from the insulator body for tying the line wire.
- KPP - Abbreviation for Kerr Packaging Products.
- Lily Shell - Nickname for the beautiful flared shape of the skirts on some early multi-parts which are similar in shape to a lily flower.
- Line Wire - The main wire that the insulator is designed to support. The line wire is attached to the insulator with a tie wire and generally rests in the saddle groove or wire groove of the insulator.
- Link Strain Insulator - This serves the same purpose as the strain insulator except it is designed to allow linking of additional insulators (similar to suspension disks) for protection at higher voltages were it is desired to insulate horizontal spans or dead-ending of feeder wires. The link strain insulator is commonly referred to as "hog liver" or "pork liver" because of its odd shape.
- Liquid Insulator - Nickname for CD 180.
- Locke Cross Top - Nickname for CD 204.
- Loop - Nickname for uni-part porcelain insulators U-396 to U-400B.
- LRB - Abbreviation for Lightning Rod Ball.
- LRI -Abbreviation for Lightning Rod Insulator.
- LRO -Abbreviation for Lightning Rod Ornament.
- M - Abbreviation for Mint. Used to describe the condition of an insulator.
- M-number - An M-number is used to identify different shapes of multi-part porcelain insulators, regardless of manufacturer or style number. An example of this notation is "M-2140".
- Mad Hatter - Nickname for CD 134.6. May also be referred to as the "Philadelphia Mad Hatter".
- Manhattan - Nickname for CD 256.
- Mershon - Nickname for CD 288 or U-945. The glass version may have either one or three ridges, and the latter is referred to as the "Three Ridge Mershon". The porcelain version is very rare.
- Mickey Mouse - Nickname for CD 257 and U-395.
- Miller Twin Pin - Nickname for CD 138.9. May also be referred to as the "Twin Pin". It was named after the original owners of the piece, Stewart and Isabelle Miller.
- Mine Insulator - Nickname for CD 185 and U-97 through U-100.
- MLOB - Abbreviation for Mould Line Over the Base. This is when the mould line comes down the skirt and crosses over the base to the inside of the outer skirt.
- Montana - Nickname for CD 248 along with two CD 311 sleeves.
- See also: Stacker
- Muncie - Nickname for CD 303. May also be used to refer to the smaller 7" CD 302.
- Mushroom - Nickname for CD 176.
- NDP - Abbreviation for No Drip Points. Used to describe the type of base the insulator has. A historical term; the preferred notation for this is SB.
- NE - Abbreviation for No Embossing. Used to indicate that there is no embossing at all on the insulator.
- NN - Abbreviation for No Name. Used to indicate that there is no manufacturer marking on the insulator.
- O'Brien - Nickname for CD 119.
- Patent-top - Any of various insulator styles which have a specially designed top to eliminate the need for a tie wire. Also "self-tying", "slot-top", and "tieless". Examples are CD 109.5, CD 109.7, U-181, U-183, U-184, U-185, U-186, and U-187.
- Peacock Mickey - Nickname for CD 257 in Electric Blue. This name started early in the hobby, and has stuck, even though the insulator is not Peacock Blue.
- Pennycuick - This term is used to describe insulators produced with James Pennycuick's patent. These insulators has several unique characteristics. They have very sharp angular threads and a pointed projection in the center of the top of the pinhole. They are often crude and heavy, unmarked, and generally are light blue-aqua in color. They are found in a number of CDs such as 102, 104, 112, 121, 126, 127, 133, 134, 138.2, 145, 146.4, 149, 170 and 170.1.
- Petticoat Rest - Unglazed surface on the bottom of the extended petticoat used for a firing rest. If the rest was glazed it would be fused to the kiln tray.
- Pilgrim Hat - Nickname for CD 160.6.
- Pin-Post - Nickname for U-425, U-425A, and U-425B.
- Pluto - Nickname for CD 181.
- Pogo - Nickname for U-582 through U-593.
- Pomona - Nickname for CD 244.
- Pony - Nickname for a number of smaller styles of insulators. These styles include CD 102, CD 106 and others.
- Pork Liver - Nickname for a link strain insulator made by Ohio Brass. It is also referred to as "Hog Liver". The name refers to its odd shape.
- Ram's Head - Nickname for CD 109.9. Similar to the Claw.
- Ramshorn - An iron rod with one end inserted in the insulator (either rubber, composition, or metal-clad glass) and the other end shaped like a ram's horn. The conductor is secured to the insulator by threading it through the opposing "horns".
- Ranson - Nickname for U-183.
- Redlands Insulator - Nickname for a triple petticoat insulator design made famous in the late 1890's when used on a power line in Redlands, CA. These insulators are U-746 and U-935.
- Roman Helmet - Nickname for several styles, including CD 258, CD 259, CD 260, and U-377 through U-389.
- RR - Abbreviation for Rainbow Riders (Trading Post). For more information about this insulator magazine, see the Rainbow Riders Trading Post listing.
- Santa Ana - Nickname for CD 178.
- SCA - Abbreviation for Sun Coloured Amethyst; a light purple colour. Glass containing small amounts of manganese when exposed to ultraviolet rays (i.e. the sun) over time will turn a light purple colour.
- Screw-Top Boston - Nickname for CD 158.9.
- SDP - Abbreviation for Sharp Drip Points. Used to describe the type of base the insulator has. Sharp Drip Points are conical shaped projections about 1/8" in diameter on the base.
- Teapot - Nickname for CD 790 and U-990.
- Teardrop Pony - Nickname for CD 109. May also be referred to as the "Chicago Teardrop Pony".
- Teat Rest - A firing rest on the base of the insulator skirt. The firing area is usually unglazed. A firing rest developed by Ohio Brass composed of four small raised teats on the crown. When the insulator was glazed all over and fired upside-down, the insulator was broken off the firing surface, leaving four small white spots on the crown.
- U-number - A U number is used to identify different shapes of unipart porcelain insulators, regardless of manufacturer or style number. An example of this notation is "U-123".
- Wade - Nickname for the "Dot-Dash Wade" CD 723 and the "Smooth Wade" CD 723.3.
- Washboard - Nickname for CD 739.5.
- WDP - Abbreviation for Wedge Drip Points. Used to describe the type of base the insulator has.
- Wet Process - A porcelain manufacturing process where the insulator is formed from clay in the plastic state. This process generally provides much higher quality insulators by greatly reducing the air trapped in the clay.
- Whittle Mould - Used to describe the surface erosion of a mould that creates almost a leathery or reptile scale look to the surface of the glass. This term is usually used by bottle collectors who refer to old bottles blown into wooden moulds. Some Canadian CD 143's have this 'whittle mould' characteristic.
- Wing Chambers - Nickname for CD 124.5. Used in conjunction with the Bell Chambers CD 317.5.
- Wire Groove - The square or concave section between the wire ridges on the side of the insulator that holds the line wire.
- Wire Ridge - A ring of glass around the insulator above and below the wire groove designed to help support the line wire and the tie wire.