What was used Before K&T Wire?

Railroads

Active member
Hi everyone, I was wondering if there ever existed installations that used two bare conductors separated by porcelain insulators to light switches run down the walls of older houses? I've seen something like this in old movies but can't figure out what it was called or what part of the world it was used?

Robert
 

BMyrkle

Subscriber
Re: What was used before K&T wire?

Supposedly knob and tube is the oldest standardized form of electric wiring, with commercial electrical codes for it being written as early as the 1880s.

Everything before that was one-off, custom wiring; or done to local codes that weren't yet standardized.
 

pegasuspinto

Active member
Re: What was used before K&T wire?

I think if you look at knob and tube, the insulation isn't required for it to work. Ceramic and open space provide all insulation needed. The insulation was added later to make it safer, then once the insulation was reliable, the wire was quickly put into one cable and buried in the walls.
 

Railroads

Active member
Re: What was used before K&T wire?

I wonder if in days gone past one could have kept the K&T feel but used modern single core insulated conductors like those available now? Think along the lines of restoration work and wanting to keep a building as close to original as possible.

Robert
 

slip knot

Subscriber
Re: What was used before K&T wire?

We got a house that the K&T is exactly that way, insulated single conductor. K&T itself was pretty safe. its the joinery that gets a bit sketchy. I've redone the connections but the wiring is still mostly original K&T.
 

pegasuspinto

Active member
Re: What was used before K&T wire?

As far as I know, knob-n-tube is still in code and can be repaired in grandfathered installations. Can't be used in new or remodel. I suspect there may be exceptions for some kind of historical reproduction type work.
 

Birken Vogt

Email NOT Working
Re: What was used before K&T wire?

Insurance may also have a problem with K&T, not that it was not good to begin with but what is left is usually in poor condition and hacked.
 

Frank DeWitt

Subscriber
Re: What was used before K&T wire?

The Coolsprings power museum wired there gift shop with new knob and tube. It is well done and looks great.
 

Ozlander

New member
Re: What was used before K&T wire?

Insurance may also have a problem with K&T, not that it was not good to begin with but what is left is usually in poor condition and hacked.
What was not good about it? :shrug:

Got some in my house, under the upstairs floor, above the living room ceiling. 14 gage wire separated by 18 inches on a 15 amp breaker powering 3 60 watt blubs. I could have replaced it at one time, a lot of hassle.
 

Birken Vogt

Email NOT Working
Re: What was used before K&T wire?

I think it is fine too but here is what has typically happened to it:

1. It got nails driven into it.
2. It got insulated over with crumpled newspaper, back in the day.
3. It got insulated over with fluffy cellulose, the kind that the flame proofing died away.
4. Hacks that do not know how to solder spliced it poorly.
5. The insulation began to crumble.
6. Bed frames and the like got tossed on top of it in the fluffy cellulose attic, and it got walked all over, stretched and kinked.

After 70+ years of service, I would not insure it either if it was my money. I do not mind it where I can see it (crawl space, short rise to interior wall outlets) but insulated walls and attics make me nervous.
 

dependable

New member
Re: What was used before K&T wire?

I was renting an apartment once in a big old house that had been divided in to several apartments. had to go to the basement to get something my gf had stored there, and I noticed the main feed to the building was still open wire on white porcelain insulators. That was in the mid '80s.
 

Birken Vogt

Email NOT Working
Re: What was used before K&T wire?

That is interesting, I have never seen anything resembling K&T in any size larger than #12 or #10 maybe. Does anyone have any pictures of larger open wire services like this?
 

Railroads

Active member
Re: What was used before K&T wire?

I second that request. Would love to see pictures of open wire service wire?

Robert
 

dependable

New member
Re: What was used before K&T wire?

I second that request. Would love to see pictures of open wire service wire?

Robert
If I had a time machine and a digital camera, be happy to oblige.

On the other hand, I might find myself too preoccupied with the gal I had at that time to document the wiring. Haha.

However I do remember thinking "this is not good" and that was before I knew much about utilities, or anything else for that matter, it was around 35 years ago.

It might have been only 10 or 12G, I may have misspoken, it was not the main feed in, but what was distributing power from the service though the building.. along the beams in the basement, on old white porcelain insulators.
 

Combustor

Member
Re: What was used before K&T wire?

Until the early 1960's cable in Australia, (and most of the world?) was the cotton covered, gutta percha insulated stuff in red or black, and was run in roof space and wall cavities using porcelain cleat insulators. They were say 2 inches long, an inch wide and 1/4" thick, used in pairs to sandwich the wires with a single screw through the middle. Recall wiring several houses for 32 volt lighting for friends at the age of 16. All fairly simple stuff. Sounds much like that recalled by "dependable". Regards,
Combustor.
 

Birken Vogt

Email NOT Working
Re: What was used before K&T wire?

I've seen the pair insulators saved from some demolition somewhere but never seen them installed.
 
Re: What was used before K&T wire?

I helped clean out an old school building that was built in 1885, and I salvaged a couple wooden cleats (which I soon sold).

From a friend's site: "Porcelain wiring cleats were not used in the very early days of house wiring. They simply strung insulated-covered wires along the walls using wooden knobs and blocks of wood to attach the wires and ran them to the center of the room to drop a light down from the ceiling. Houses often only had one light bulb per room and only the important rooms had a need for expensive light bulbs. It was more of a novelty. Electricity quickly caught on and prices of bulbs, wiring, and electric power dropped allowing more and more people to afford the luxury of electric light. Wooden cleats, knobs, light bulb holders, and other wooden electrical devices were widely used and often resulted in fires from the early use of electricity. In less than 10 years it became obvious that electric power and light bulbs were something more than a fad. By 1891, the insurance companies refused to tolerate wooden wiring devices because of the fire hazard. Porcelain wiring devices had to be used to get insurance. The produced a huge demand for porcelain wiring devices with several manufacturers offering to meet the demand. The National Board of Fire Underwriters founded the Underwriters' Laboratories, Inc. (UL) in 1894 to formulate safety standards for the industry and in 1897, the first National Electrical Code was published." (http://www.r-infinity.com/Cleats/)
 

Frank DeWitt

Subscriber
I have been fortunate to find a couple of pieces of wood wire mold (one from a guy on this forum). Two pieces. The one that goes against the wall has two grooves in it. The second piece is a fancy wood cover. A lot of porcalan fixtures have slots that match the wire mold.
 
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