Dave Platt Half Tone

[Wayne_H]

Guys, I totally agree!

Having trained in mechanical engineering in the 70's, it was all imperial units. Then Australia "went metric" in the late 70's. It was a no-no to mix units.

I used the mixed UofM for consistency(?) with the question Bluejets asked, which was based on the original article he referenced. Regardless of the (mixed) units, it enabled a direct comparison which we all understood

The brain is a remarkable thing!

[bluejets]

I second after quite many years in the "Imperial world", what I have learned is to not mix them in the same project, it's like when switch between languages...You can't think in one language and speak an other. Might be easier when you are born in a bilingual ...
What confuses me is that the imperial system have the "choice of fractional or decimal" especially in mechanical workshops.

Assumed initially it was g/sq cm...... then the penny dropped.
Doesn't bother me in the workshop when machining my engines though.
Work quite happily between the two.
Even on the worksite as a leckky, I always used a tape measure with metric one side and imperial on the other.
Others wouldn't go near it and it also meant no one would pinch it either.

[Martin]

About 30 years ago, I helped install a manufacturing line at a company that made insulating foam boards. There was a catalogue that specified the insulating properties of the various types of board in units of BTU per square metre of area per inch thickness per degree centigrade of temperature difference on the two sides of the board. And then there were explanatory footnotes giving modification factors depending on whether the boards were in contact with brick, plasterboard or 'still air'!

I asked them why they had such a mish-mash of units, and they told me it was 'industry standard'!

Another place I attended as a contractor was making paving slabs one metre long by two feet wide - which made them difficult to lay, other than in the most boring straight-line patterns. They had switched from three feet long to one metre because they wanted to 'go metric', but it was more difficult to modify the machine to alter the width of the slabs, so they were stuck at two feet. They put '1000 mm X 610 mm' in the sales brochure, because metric!

[bluejets]

There was a catalogue that specified the insulating properties of the various types of board in units of BTU per square metre of area per inch thickness per degree centigrade of temperature difference on the two sides of the board. And then there were explanatory footnotes giving modification factors depending on whether the boards were in contact with brick, plasterboard or 'still air'!

Brings back memories of the calculations we used to have to do for cold rooms, air con and the like.
Never thought I'd ever make it initially as it was all correspondence back then.
Internet wasn't even in the back of their minds.
Questions were written out and sent away, wait for two weeks for an answer.

[Spike S]

Slightly away from the DP Half Tone (I remember it well) topic but at least aviation-related:

Having only recently then come to terms with UK coinage decimalisation, I was confronted by a major conflict of mixed units when detached ‘somewhere in (W) Germany’ back in the 1980s. We were operating some distance from base and needed fuel to be able to return, so had to call into Fassberg to top up the tanks. It was enough of a trial flying to Imperial units using maps with ground elevation in Metres but the fuel replenishment made my brain hurt for a while. Aircraft fuel gauges and tank capacities were calibrated in Litres but the ancient bowser we were offered delivered in US Gallons and the docket required payment in Deuchmarks. That got us home but I was then required to account for the transaction in £Sterling at the current Exchange Rate. All pre-GPS and smartphones but fortunately the Air Course Plotter device can also be made to work as a circular slide rule.
The brain is (usually) a remarkably agile device but I was reminded of the pilot's old standby retort:
“I’m so b*** confused, I don’t know whether to scratch my watch or wind my backside”.

[Wayne_H]

Then there was the Gimli Glider, a 767 that landed "dead stick" on a dissused runway turned drag strip after running out of fuel, in Canada back in 1983.
https://www.google.com/search?q=Gimli+G ... e&ie=UTF-8

Oh yes, then there is the Dave Platt Half Tone

Using my imperial knife and my dual-units steel ruler, I have cut all the bits out of coloured metric foam . Tailplane & fin+rudder are finished complete with bamboo stiffeners, fuse sides are ready to join & wing top skins are the next wing related task.