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Electrical History of Knob and Tube Wiring to Modern Alternative




In the late 1890s, Thomas Edison’s ground-breaking work in the field of electricity was ready to be shared with the world. To transfer electricity for the very first time in North America, a 4000 V transmission line went alive on the 3rd of June, 1889. It stretched to a distance of 13 miles. The period of 1920-1935 is marked as the bloom of electricity, during this period of time nearly 70% of America’s residential areas were connected to the grid stations. The foremost technology used to convey electricity and to share the luxury of electricity with the citizens’ Electrical History of Knob and Tube Wiring system was adopted.

Knob and tube wiring

Knob and tube wiring is considered the foremost approach to conduct electricity. Though being century-old, the knob and tube wiring approach is still functional in some of the houses in North America.

Materials Used

Ceramic knobs

Ceramic knobs were ceramic cylinders that were directly nailed into the walls or the floor joists. They served as a secure and permanent anchor. Protected it from excessive tension, from combustion, and aided in changing direction.

Ceramic tubes

Ceramic tubes helped to separate wire from the wooden frame. Also kept the wire from compression.

Ceramic cleats

These blocked shaped pieces were also used for a similar purpose as that of knobs.

Ceramic bushings

Whenever wire was needed to ender on a metallic box, ceramic bushing protected it from short-circuiting.


Whenever two or more wires were to be passed under or over another wire, these flexible woven looms were used. These sleeves were added as additional protection.

Advantages and disadvantages of the knob and tube wiring

Being the foremost approach, it has its own pros and cons. Advantages and disadvantages are described in detail below


It was the foremost and ground-breaking approach of Electrical History of Knob and Tube Wiring; at that time, it had the following advantages as compared to other available options.

  • In the early 1900 period, it was the least effective of all the available options. For several decades, knob and tube wiring, armored cables, metal junction boxes, and conduit were the only available options for the electricians to choose from. Conduits, flexible armored cables, etc. were considered to be of better efficiency and quality but were a lot more expensive. Knob and tube wiring method allowed to wire entire building at very cheaper rates so persisted.
  • Porcelain parts had an infinite life span and were best suited to carry high voltage surges to far distances.
  • It was also the safest way to conduct electricity if used within the current-carrying capacity.


Although a ground-breaking approach it was. But eventually several of its cons were discovered.

Following are some of the disadvantages

  • As safety is concerned, the grounding conductor was never used in it.
  • Wasn’t able to confine the switching to the hot conductor
  • Inline splicing was held in the wall without any junction boxes.
  • With the passage of time, the cost of electrician labor overweighed the cost of the materials used in electrical wiring. Hence, the knob and tube wiring system lost the advantage of being the most cost-effective approach.
  • It required an extensive and complex wiring diagram.
  • Installing the knob and tube wiring required an immense amount of time.
  • Installing knob and tube wiring required extremely skillful hands, hence electricians started to charge more for knob and tube wiring system.
  • Currently, the pre-installed knob, and tube wiring system has grown less efficient as the metal wire degraded over time.
  • With degraded ancient wire, knob and tube system now pose a great risk.
  • Many insurance companies deny the insurance of the houses with this ancient knob and tube system installed for electricity conductance in houses.

Modern Alternative: Copper Wire

As the world advanced and technology overwhelmed in this modern era, the knob and tube system went out of the game, and several modern techniques, technologies, and materials cast this system into the shadows of extinction.  Now highly efficient copper wires, fire and corrosion-proof insulating, heavy-duty plastic junction boxes, and power switches, etc. made it extremely easy, convenient, cheap, and risk-free.

Advantages and Disadvantages of Copper Wire

Following are some pros and cons of using copper wires.



In terms of conductivity, copper ranks 2nd to silver. As compared to other abundantly available metals, copper can easily deal with great amounts and loads of electricity.

Heat resistance

Copper wire has the highest resistance to heat as well.


They are also very resistant to corrosion


Being extremely ductile and malleable, wires thinner than strands of human hair can be made and can be easily bent without breaking.


Small charges of Electricity

Some modern devices require extremely small charges of electricity. Amount this minute, copper is unable to deal with. Using copper wire for such delicate devices may burn the devices. As copper cannot control electrical surges.


Extremely susceptible to electromagnetic interference, the copper wire may lead to the failure of some devices, especially communication devices.

The current copper wiring system is way ahead of the ancient knob and tube wiring system.

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Sophia James is a writer at The News Engine; writing content on different niches like world, technology, lifestyle and news. I have a keen mind interest when it comes to exploring the most valuable stories out there. I believes in the idea that this world is filled with information that can benefit us in a variety of ways. Seeking knowledge is the most valuable act we can do as a author. The more we know, the better we can make our lives. I will continue to bring new interesting topics for you, keep an eye out!

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