1930s Wiring.

Yes can be interesting, have you yet found any "American 2 way light switching" Seems popular in ex army buildings.


Uses standard two way, three terminal switches. Live and neutral connected to "L1" and "L2" at each switch, lamp connected between the two common terminals.

Works fine and saves material, but is rather dangerous since 50% of the time BOTH lamp terminals are live when the lamp is off.

Particularly useful when a socket outlet exists or is required at each switch position, with live and neutral already present very little extra wire required.

Also used for long tunnels with the lights switched in sections.


Prohibited in the UK since it is a switched neutral.

Fine for 220 volt lights connected to a three phase, wire system at 127/220 volts, since BOTH sides are live it does not matter which wire is switched.

Fine at ELV.


In America they call it "[insert name of next state or city] switching" Obviously WE do not do it like that, but the primitives over in [other place] know no better.


Another armed forces special is three phase for small installations, I have seen a hut with a three phase 40 amp supply. Four twin 13 amp sockets on each phase.

When I was little we lived in a place that was an old army Nissan hut the owner lived in the nice end we had the mingy end. For reasons I don't know the place was called casbah yes really I remembethere was no earthing the wash machine used to bite when the hearer was on. The sockets were a mix of 2 5 and 13 amp  oh and we had mice lots of mice

A casbah is the Arabic word for something like a large fort or castle, or a walled town, and in  jokey way for some UK folk who did national service in the middle east became a way to refer to the safety of the camp,  when "back inside the fort"  at the end of a patrol or whatever. 

Presumably being a home in a Nissen Hut, of the army type, that was the joke.

My late scout leader did his service in that part of the world shortly after the war, and had a number of these strange ways to refer to things, as I suspect many of his generation did.


Mike.

In the post war housing shortage in the UK and overseas, there was a move to encourage the use of Nissen huts as housing, they were cheap, effectively free if left over from the war, durable, fire resistant, and easy to dismantle and re-assemble.


They never proved popular with the residents being considered "a hut and not a house"


If regularly painted or otherwise treated against rust they last almost forever.

I remember as a boy Nissen huts being used for fruit packing on fruit farms in Kent in the 50s.


Two things to note here:


1. The high level post for the overhead electrical supply in the static image.


2. The officer getting in the way of construction in the cine film clip.

https://nissens.co.uk/


Z.

Seems they were easy enough to put up  im guessing those men had done it all before since they seemed to know exactly.what to do. Ours was between 2 farmers fields but beyond that I don't know of the history of why it was there. I've never heard of the American lighting wiring system sounds down right dangerouse  I 5hink it would be lethal on a 240 or 220 volt supply but probably just about acceptable on 110 or 127 volts. Bearing in mind how technically advanced the yanks are there electrics seem really bad  shame really

BOTH lamp terminals are live when the lamp is off.

And what's worse is that they used ES rather than BC lampholders - so traditionally one of the terminals was the easily accessible outer "ring" contact and so too the cap of lamp itself could be live when changing it until it was fully unscrewed.

  - Andy.

The earlier described way of wiring a two way lighting circuit, is not "allowed" in the USA but is regrettably common. In New York it might be called "A California 3 way" and IN California it might be known as "A redneck 3 way" or in any urban area the system might be called "farm 3 way"

"American 2 way switching" is a mildly rude term applied by UK electricians who discover the system used over here. Controlling the same lamp from two positions is known as 3 way switching in America.


Not to be confused with "3 way bulbs" a type of filament lamp with two different  wattage filaments, in order that three different lighting levels may be selected by use of the smaller filament, the larger filament, or both together.

The desired light output was usually selected by a 4 position rotary switch built into the lamp holder, this limited use to table lamps, floor standard lamps and the like within easy reach.

The special lamp holders were available built into ceiling mounted lights, with a wall mounted switch.

Used to be popular in America and are still widely used, with both the original twin filament style or low energy equivalents available.

Also used in the UK but never a mass market item, 230 volt 3 way lamps are no longer available AFAIK.


Common wattages were 40/60/100 watt or 60/100160 watt, with a special 3 contact screw base. Or 100/150/250 watt with a special 3 contact large screw base.

There also existed a version with two filaments of very different wattages, such as 15 watt and 200 watts for night lighting in hospitals etc. These only gave two usefully different lighting levels, the difference 200 watts and 215 watts being insignificant.

Zoomup:

Nice brown circular M.E.M. bakelite tumbler light switches.

Covers removeable without the use of a tool?

Jaymack