The whole factory workforce managed mixed measures.
A few weeks ago, when talking about recent changes from pounds to kilos and feet and inches to metres and millimetres, with the attendant problems it produces for older folks, I recalled a situation in the 1960s where the whole factory workforce managed mixed measures.
In 1963, while working at the Tyne Board Factory at Willington Quay, making chipboard, we had two production lines making two different sizes of board in five types of thickness. Timber logs were bought by cubic fathoms (6ft3) and turned into woodchips to make the chipboard. One size of board was weighed off via a scale recording kilograms. The other was weighed off on a pounds and ounces scale. Thickness was measured in millimetres. Batches of boards were made to specific densities, measured in pounds per cubic foot. Factory output was measured in cubic metres and boards were sold by the cubic foot.
People got used to remembering such things as how many boards 8′ x 4′ x 15mm@ 36lbs/ft3 made a cubic metre and what weight in metre3 could go on a wagon. Straight line graphs helped with conversion if the memory was bad.
Today I don’t try to visualise a size in mm. I just look at a tape measure.