There have been three major Weights and Measures Acts in recent
times (1963, 1976 and 1985) all gradually abolishing various units, as well
re-defining the standards. All the Apothecaries' measures are now gone, and of
the Troy measures, only the ounce remains. The legislation decreed that -
From the 1st October 1995, for economic, public health, public safety and administrative purposes, only metric units were to be allowed EXCEPT that -
- pounds and ounces for weighing of goods sold from bulk.
- pints and fluid ounces for beer, cider, waters, lemonades and fruit juices in RETURNABLE containers.
- therms for gas supply.
- fathoms for marine navigation.
could be used until 31st December 1999.
The following could continue to be used WITHOUT time limit -
- miles, yards, feet and inches for road traffic signs and related measurements of speed and distance.
- pints for dispensing draught beer and cider, and for milk in RETURNABLE containers.
- acres for land registration purposes.
- troy ounces for transactions in precious metals.
Sports were exempt from all of this, but most of them have (voluntarily) changed their relevant regulations into statements of equivalent metric measures.
That was how the legislation was framed. In common usage the 'old' units are still very apparent.
Some other dates of note
1950 The Hodgson Report
was published which, after arguing all the points for and against, favoured a change to metric.
1963 Weights and Measures Act
defined the basic measures of the 'yard' and the 'pound' in terms of the 'metre' and the 'kilogram'. Many of the old imperial measures were abolished (drachm, scruple, minim, chaldron, quarter, rod, pole, perch, and a few more)
1971 Currency was Decimalised
1985 Weights and Measures Act
abolished several more imperial measures for purposes of trade, and defined the 'gallon' in terms of the 'liter'.
Thus, all the measures had been metricated even if the public hadn't!