The big difference in the electric terminology and installation regulations and practice in each country!

[Cbelectrics]

in domestics, we generally use twin& earth cable. :
View attachment 51089
hot wire we call line(brown) . neutral (Blue), and what you would call the ground wire, we call it "circuit protective conductor (cpc). OH, and due to some silly farts back in the 1970's all our cable is metric.

that's a start

Actually a good thing that was introduced. Was to avoid massive blunders happening in the scientific community where conversions would be made from old imperial measurements to metric. Everything from engineering/satellite's/chemistry (all relatable to electrics).

 

[telectrix]

rubbish. if i see a measurement in inches, i can visualise it. if in cm, then i need to work out 25.4 = 1", so,say, a 25 measurement is stated, but it does not tally. it's 10" less a bit. also,e.g. my tappets on my van engine should be 10 thou. i set at 0.25mm and they rattle.

 

[Cbelectrics]

rubbish. if i see a measurement in inches, i can visualise it. if in cm, then i need to work out 25.4 = 1", so,say, a 25 measurement is stated, but it does not tally. it's 10" less a bit. also,e.g. my tappets on my van engine should be 10 thou. i set at 0.25mm and they rattle.

You and what you are talking about is at the very bottom of the ladder so to speak and you seem to have no understanding of how imperial v metric effects the world around you.

When you start venturing across the fields of physics for instance everything is relatable from a small piece of wire in a satellite to numbers you can’t even count in distances for instance. When you start using physics at the level of powers, conversions matter and mistakes can be made quite easily. When calculating the number of brain pathways in medicine it matters, engineering computer chips it matters.

Scientific units mass (kg) for instance can be a pound of pork scratchings but it can also be used to calculate how to get a spaceship out of orbit. So you have to have harmonised measurements across the board for reasons other than your spanner in a tool box.

 

[littlespark]

Maybe we’re at an advantage, us older members who learned about metric at school, but still had old imperial parents.
We were taught both, and the conversion processes.


You can see how imperial lengths came into being… an inch was the width of your thumb… a hand was basically the width of your hand… used for measuring horses… a foot being self explanatory,
In those days we weren’t building massive skyscrapers, sending rockets to the moon or looking at micron sized particles through a microscope…
We didn’t need that level of definition, so we didn’t use it.


If an engineer or an architect can’t tell the difference between feet and metres, then they’re in the wrong job…

 

[Cbelectrics]

Maybe we’re at an advantage, us older members who learned about metric at school, but still had old imperial parents.
We were taught both, and the conversion processes.


You can see how imperial lengths came into being… an inch was the width of your thumb… a hand was basically the width of your hand… used for measuring horses… a foot being self explanatory,
In those days we weren’t building massive skyscrapers, sending rockets to the moon or looking at micron sized particles through a microscope…
We didn’t need that level of definition, so we didn’t use it.


If an engineer or an architect can’t tell the difference between feet and metres, then they’re in the wrong job…

Totally agree but it still happens.

Here’s a list of some interesting stuff that has gone wrong over the years.

Great miscalculations: The French railway error and 10 others

The discovery by the French railway company that 2,000 new trains are too wide for many platforms is embarrassing, but far from the first mistake of its kind.

www.bbc.com

 

[Cbelectrics]

Double entry . See happens to the best of us.

 

[littlespark]

I’ve had a quick read, and see an awful lot of “could be the reason” or “one theory” or whatever.
Nothing 100% to say that confusion between metric and imperial was definately THE only factor.

There’s one in there about Big Ben the bell being built…. (Whew!). Way before metric was taken up…
And of course, the media- even bbc- can embellish the truth somewhat to make their articles seem more important.

 

[Cbelectrics]

I’ve had a quick read, and see an awful lot of “could be the reason” or “one theory” or whatever.
Nothing 100% to say that confusion between metric and imperial was definately THE only factor.

There’s one in there about Big Ben the bell being built…. (Whew!). Way before metric was taken up…
And of course, the media- even bbc- can embellish the truth somewhat to make their articles seem more important.

That was just an example, think it’s just lazy source confirmation and editing to cover their arse writing the article. The nasa issue was factually correct. So too was a flight from canada and running out of fuel.

Many other factual examples as well as theoretical ones.

 

[brianmoooore]

One thing I don't understand is why it's still almost impossible to find a tape measure in the UK that doesn't have imperial measurements on it alongside the metric ones, some 50+ years after we 'went metric'. A tape measure that you can't use either way up dives me nuts.

 

[pc1966]

I think it is for cheapness, so they can sell the same model to both old and young customers, and in the USA, etc, where metric is still a bit of a novelty.

 

[brianmoooore]

I checked out every tape on offer at the recent Exeter Elex/Toolfair, and found just all metric one - a 5m Stanley, although another supplier sais they would be selling them in the UK 'soon'.

 

[nicebutdim]

One thing I don't understand is why it's still almost impossible to find a tape measure in the UK that doesn't have imperial measurements on it alongside the metric ones, some 50+ years after we 'went metric'. A tape measure that you can't use either way up dives me nuts.

I know a few people who bought metric only tapes and generally they regretted doing so.

Milwaukee make a couple, which is ironic for a brand that used to be American.

 

[brianmoooore]

I've brought them back from Europe for about the last 30 years, but now, as a result of Covid restrictions and now an extremely aged dog, I've been unable to leave the country for the last three and a half years, and my stock has run out.
I brought back three in 2019, and what I thought was the second one, broke the end of the tape about a month ago. Couldn't find the third one anywhere, hence the search at Toolfair.
About a week and a half ago, while looking for something else, I came across an almost pristine all metric tape - just the bit with the measurements on, neatly coiled up, on a shelf, bound up with green/yellow PVC tape. In an instant, it all came back to me. Tape #2 had been a dud, with the spring securing post breaking after about a week of use, and the one that had just failed was #3 out of 3.
I had totally forgotten that I had saved the nearly new tape, so a few minutes later I had fitted it into #3, and am back in business again with a tape I like the 'feel' of (unlike the new Stanley, which has a very wide tape.)