I've been working in the aircraft business for over 20 years and it's only recently we've begun to accomodate napoleonic units. Aircraft I've worked with, the B-52, B-1, F-15, F-16 and F-18 are all dimensioned in inches. For the B-52 it's a lot of inches. Someone, probably named Wright, long ago decided to only use inches. We also have an interesting unit called the mug. This arose when it was found desirable to use slug-feet in some calculations, but not handy to convert to feet. The mug was then defined such that one mug-inch = one slug-foot. This is not the same as the napoleonic ''metre-slug''. Outside our structural dynamics department the mug is unheard of. That's O.K., we didn't invent it for other folks. The important thing is for the engineers to know what they are doing, not what units they use.
I don't think most socialist countries stick to basic napoleonic units in everyday life either. I doubt that anyone measures their tire pressure in N/m^2, do they? Do they use a ''customary'' napoleonic unit, maybe the bar?
I put a microwave oven over my cookstove the other day and in the process ran some 12 AWG wire from the breaker box. Two conductor-insulated, plus ground-bare, solid, to be precise. If I were in the United Kingdom, would I have run 2.05 m/m wire? I probably would have needed a permit from the Empire of Uropa too, I suppose.
Here are some interesting napoleonic values. I recently was asked if we could carry a weapon which uses N.A.T.O. standard 356 m/m suspension hooks. That struck me as strange that a designer would pick 356 m/m, rather than, say 350 m/m, so before I responded that we only have 14'' and 30'' suspension available, I did a quick conversion and found 356 m/m is 14''. Note also that N.A.T.O. 5.56 m/m, 7.62 m/m, and 12.7 m/m ammunition are really .22 cal., .30 cal., and .50 cal. They are using common units, they just don't know it.
<<
I doubt that anyone measures their tire pressure in N/m^2, do they? Do they use a ''customary'' napoleonic unit, maybe the bar?
>>
1 N/m^2 is also called a Pascal (Pa).
I have seen pressure gauges in both bars and in kPa. The 1 bar (which is 100kPa) is listed by the International Bureau for Weights and Measures as a "non-SI unit currently accepted for use with the International System".
Bud
Re: B-52, B-1, F-15, F-16, & F-18
July 26 2004, 8:41 AM
<<
"non-SI unit currently accepted for use with the International System".
>>
Translation: We'd like to abolish it eventually because it doesn't fit in mathematically, but we'll have to tolerate it for now because no one would stop using it if we told them to, and that would make us look bad.
SteveH
Re: B-52, B-1, F-15, F-16, & F-18
July 26 2004, 2:51 PM
<<I have seen pressure gauges in both bars and in kPa>>
Erm, the ones in petrol stations up and down the land are either big Lb/sq in little kg/cm2 or lb/sqin and bar.
My car documentation has it in imperial and then 3 different metric equivlents (that made me titter!)