Whenever I'm discussing the pros and cons of the US moving fully onto the Metric system (which I favor BTW), the subject of 'slugs' will inevitably enter the conversation at one point or another ;-)
Note that I worked 14 years for the American division of a British company back in the 60's and 70's. This proved interesting as British standards were officially in place, but we were still working in the US building equipment for mostly a domestic market and having to deal with local suppliers and contractors. Of course, since the British were still using 'Imperial' units at the time (for some reason we were never allowed to say 'English' units), this wasn't a real problem. But it did present some interesting situations. Such as the fact that they were still using the so-called 'Imperial' standard drawing standards where paper sizes were based on a factor of 11 x 15 inches. This worked out to the following sizes:
[tt]
D (Detail) = 11 x 15
LD (Large Detail) = 15 x 22
IMP (Imperial) = 22 x 30
DE (Double Elephant) = 30 x 44
ANT (Antiquarian) = 30 x (as long as needed)[/tt]
When we brought CAD into the company in 1977 and started to set-up templates so that we could plot our drawings (this was in the days of pen plotting and we used our pre-printed drawing sheets as stock) we noticed that all of the title blocks were different proportions. So we went to our paper supplier to propose a common master template and it was then that they informed us of how much money we had been wasting all these years because we were using non-standard sizes as they had to custom cut our paper from larger stock. So they suggested that we go to standard ANSI sized drawing sheets, but this was based on 8 1/2 x 11, which when extrapolated out to what would then be a 'D' sized drawing, it was only 22 x 34, pretty small compared to our old 'DE' size. Note that we couldn't go to 'E' size paper as that's 34 x 44 and all of our file drawers were designed to take 30 x 44 size sheets (note that ANT's were stored rolled-up in tubes). So we compromised and used Architectural size paper instead which was based on 9 x 12 so at least our new 'D' size would be 24 x 36 (ANT's remained unchanged).
Anyway, I was still working there when the United Kingdom started to transition to the Metric or SI system. Note that they insisted on referring to it as 'decimalization' and of course they also had to convert their monetary system as well, which seemed to occupy the minds of most of the Brits that I knew more then anything else. Of course since the US already had a decimal-based monetary system (if you leave out 'quarters' which owe their existence to before fractional coinage when Spanish Doubloons were sort of the de facto standard in the world and since they were sterling silver it was relatively easy to cut them into smaller denominations which is where the term 'Pieces of Eight' came from cutting Doubloons, usually in half or in quarters, hence where we also got the term '2-bits' meaning 25 cents). Anyway, since we didn't have any monetary issues we just stat back and watched our co-workers in the UK hassle with this. They had a company newspaper which was published worldwide and so were able to keep up with progress of all this. Of course they eventually got around to converting to the Metric system itself in the Drawing office, but we were allowed to continue on our marry way since we were still a US-based operation doing mostly a domestic business.
Of course, I can go back even further to when I was in engineering school and as our campus was bisected by a US highway that just so happened separated the science buildings (chemistry, physics, etc) on one side of the highway while the engineering buildings were on the other. Since most of the science classes were using metric units and engineering was still locked in to Imperial units, the joke on campus was that the highway not only divided the campus, it was also the demarcation between a modern versus an antiquated view of how the world worked, at least unit-wise. As the university has grown and the make-up of the student body is now including more and more foreign students, I understand that the use of the metric system in engineering is becoming the general norm. Besides, being in Michigan, many of their graduates are going to work for either one of the major automotive OEM's or for many of their suppliers, so teaching in the metric units only makes sense (not sure what the norm is for civil engineers and forestry majors though).
Anyway, sorry for the rant, but the US officially moving to the metric system is long overdue.
And here's a bit of trivia for you. The United States never actually adopted the Imperial system as the basis for our weights and measures. Back when these sorts of issues were first being debated by the newly formed United States Congress, when the subject did come up it was Thomas Jefferson who proposed that we adopt the Metric system, which was just starting to gain traction in France, but Alexander Hamilton objected on the grounds that the British still ruled the seas and therefore had a big influence on global commerce and how business was conducted and he felt that adopting the new Metric system would be an affront to them and so Congress did what it does best, nothing. It just never got around to making anything official, however shortly after the Civil War, the US recognized the Metric system as being a legal and valid system acceptable in commerce and trade, and while this did not constitute it being officially adopted by the US, it did make it legal for anyone in America to use it, if they wished to do so.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
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