The white heat cools

We review the events that followed the announcement in May 1965 of a change of Government policy on the adoption of metric weights and measures.

Our article last week examined the consequences of the failure to follow through the change in policy in 1965 on measurement units. This week we look at some of the events up to 1980, the year that the Government abandoned attempts to achieve a planned and orderly transition to a single, simple, rational and universal system of measurement for the UK. We then look at the years of waste and confusion that followed.

For a personal, ‘eye-witness’ account of this period, readers may be interested in the article written by the last Director of the UK Metrication Board, Jim Humble OBE, which may be found here:

Metric Britain before 1965

It is often said the usage of measures in a country is never entirely customary or metric, but a mixture of the two, with the proportions depending on how far the transition has progressed. This is illustrated by examples of metric use in the UK before 1965:

  • The teaching of science in schools, colleges and universities was metric, using the centimetre gram second system (cgs).
  • The teaching of engineering was a mixture of Imperial for civil and mechanical engineering and metric, using the metre kilogram second ampere (MKSA) system, for electrical engineering.
  • Electrical energy was sold by the kWh, although gas was sold by the therm (equal to 100 000 British thermal units).
  • Engine sizes were specified in metric: cubic cm (or cc) for motorcycles and litres for cars.
  • The Met Office had been using metric internally since 1914. Celsius temperatures, then known as centigrade, started appearing in public forecasts in 1962.
  • The scales on nautical charts issued by the Hydrographic Office were metric.
  • Roll film had been designated in metric since the early 1900s, namely 8, 16 and 35 mm.
  • Before FM and digital, radio stations were known by the wavelength in metres of their transmissions. Some readers may remember the BBC’s Light Programme on long wave, 1500 m.
  • For mapping, the Ordnance Survey had adopted a metric national grid in 1940.

Although they may not have realised it, the British had already begun their transition to metric measures long before 1965.

Initial enthusiasm

In November 1965, major sectors of British industry approved a policy statement that urged British firms to regard the traditional screw thread systems – Whitworth, BA and BSF – as obsolescent, and to make the internationally-agreed ISO metric thread as their first choice (with the ISO Inch (unified) thread as second choice) for all future designs. Industry had thereby signalled its intention to move from focusing on pound-inch markets to metric ones.

A year later, a Parliamentary Standing Committee on Metrication was appointed.

By 1967, the British Standards Institution (BSI) had recommended that the UK adopt the modern version of the metric systrem known as SI, one of the first countries to do so, and the Department of Education and Science (DES) had published guidance for the change to metric units in education. The construction industry issued its timetable for the changeover, which was then followed successfully. In this year, also, the adoption of international paper sizes (A4 and so on) started and the UK Hydrographic Office began the conversion of depths on charts to metres.

1968 saw the establishment of the UK Metrication Board to co-ordinate this voluntary activity – it had been recognised by the Government, belatedly, that the metric changeover would need a helping hand if it was to extend successfully beyond industry. The Royal Society, the BSI and the DES all published guidance on issues related to the adoption of the metric system. In 1969, the metric system became obligatory for the dispensing of medicines.

However, in 1970, the first cloud appeared on the horizon when the Minister for Transport announced that speed limits would not be made metric in 1973 as had originally been proposed – the cost was estimated at £2 million!

In 1971, the introduction of decimal currency went ahead as planned.

In 1972, a Government White Paper on metrication said that the changeover should take place in a well-ordered and regulated manner. At this time, the metric transition had the support of the minister responsible for trade.

In the same year, the Government began negotiations to join the European Economic Community (EEC), knowing that entry would carry with it an obligation to adopt the Community’s measurement system – ‘let there be one measure’ should have been a principle familiar to UK negotiators. Membership of the EEC was supported by a referendum in 1975.

Momentum lost

Another cloud appeared in the early 1970’s – a widespread reluctance in manufacturing industry to fund the changeover. Target dates were frequently missed. Some companies opted for a US takeover to avoid the investment that the changeover would require. Despite the approach of industry to the Government in 1965, many companies did not believe that one day they would face the choice of going metric or going out of business.

However, many of the plans laid in the late 1960’s did appear to be coming to fruition. Teaching of maths in primary schools went metric in 1974, the Ordnance Survey began issuing Landranger maps to 1:50 000 scale to replace the “one inch” series, Royal Mail adopted metric measures for postal tariffs, and a large number of packaged goods, including tea, sugar, rice, flour and soft drinks, began to appear in rational metric packaging.

It was not until 1977, that the shortcomings of the Government’s favoured voluntary approach became apparent. Jim Humble relates how a major carpet retailer found commercial advantage in reverting to sales by the square yard because these prices appeared to customers to be 20% cheaper than those in metric. Metrication of carpet sales entered into a full-scale reverse. Retail associations pressed the government for cut-off dates for imperial pricing of a wide range of products, but to no avail. With a General Election approaching, the Government lost its nerve, and the changeover stalled.

It was left to a new government, taking office in 1979, to kill off the Metrication Board and limit further metrication to what could be achieved voluntarily. The message was clear – plans for a well-ordered and regulated transition had been abandoned.

The aftermath

Fifteen years of drift followed. The very British mess that resulted is described in UKMA’s publication, available for download here:, and is summarised in our last article. Worse, pre-packed groceries were often in metric packaging, but loose fruit and veg was weighed and priced everywhere in Imperial. Visitors to Britain could be forgiven for thinking that here was a first world country with a third world approach to measurement units. And school pupils must have wondered how their maths teaching related to their lives outside the school gate.

At this time, manufacturing industry saw a decline in Britain’s competitiveness, caused partly by the failure to complete the metric transition.

Metric countries such as Brazil, China and Russia were increasing their share of world trade, and, of course, the UK could not isolate itself from these changes. Many Commonwealth countries, once export markets for Britain, had pressed on with metrication, some following the 1965 announcement, and by 1995, for example, Australia, India, Malaysia, New Zealand and South Africa had substantially completed the transition. Canada, despite the 8900 km long border with the US, had converted its road signs.

One by one, big (Imperial) names in British industry succumbed to foreign-owned (metric) competition. For example:
for cars, BLMC, later the Rover Group then MG Rover gave way to Nissan, Toyota, Honda, Peugeot, VW and BMW (now makers of the Mini);
for lorries, Foden, Leyland and Bedford gave way to Mercedes, DAF, MAN and Renault;
for buses, Leyland and Guy gave way to Volvo and Scania;
for aircraft, BAC and its successor, British Aerospace, gave way to Airbus.
And so on for a myriad of smaller companies. Manufacturing survived, albeit often by foreign-owned companies. But the focus of the UK economy had moved from manufacturing to services.

One of the areas hardest hit was the West Midlands, represented in Parliament in the 1960s by John Horner who had put the question to the President of the Board of Trade that had produced the auspicious reply fifty years ago.

Our final article in this series will look at the short burst of activity between 1995 and 2000 and the long period of stagnation that has followed.

13 thoughts on “The white heat cools”

  1. It’s the fear people have of change that holds back the completion of metric conversion. I remember in the early-mid 1960s the first tentative proposals for the construction industry in the UK to convert – and at the time (and hard to believe today), I was actually opposed to such conversion – I was very happy with my feet and inches, thank you very much! I emigrated to Canada in 1966 – primarily because of economic conditions in the UK at the time, but also, even if so very slightly, Canada still used imperial, and there were no signs that was going to change.

    Then at the end of 1970 I got transferred to South Africa, just as it was starting its transition to SI. I was thus forced to learn SI PDQ – and found that, actually, I rather liked it! I have been a strong metric supporter ever since, and now see that the fear of change was rather irrational. If we can only find a way to persuade the British public, but perhaps more so British politicians, that there is nothing to be afraid of in converting to SI, and so much to be gained in doing so, completion of the transition to the metric system would be quickly accomplished, and everyone would wonder what all the fuss was about.


  2. I think the problem is at once deeper and more complex than JF-L suggests. It is no longer a question of conversion, since the majority of people, including the older generation, use both systems – often interchangeably and even in the same sentence. A standard response of imperialists is that people are happy with the “one country, two systems” approach (pace Deng Xiao Ping) and use the units that they find most appropriate to the particular task. Thus, for example, feet for measuring a floor, millimetres for copper pipes.

    The task is not to persuade people to use metric. Most people often do. The task is to persuade people to stop mixing the systems, to stop using imperial and to use exclusively metric. This is a much more difficult argument to win – not least because people are so used to the muddle that they do not realise it is a muddle.

    It does not help to bang on about conversion of industry, export markets etc. That was an argument of the 1960s and 70s. Most people know all that, and have moved on.


  3. Like John-Frewen-Lord, I too was in South Africa when that country was converting to the metric system. Unlike the United Kingdom, the South African authorities realised that as long as dual units were permitted, the conversion process would be self-defeating because substantial numbers of people would not use the new system. On the other hand, a safety mechanism had to be built in to the conversion process to prevent exploitation of the weaker members of the population by unscrupulous merchants.

    South Africa adopted a very successful conversion to decimal currency starting in 1961. In that year the Rand replaced the pound with R2 = £1 and 10c replacing 1/-. The new notes and coins (apart from the 1/2 c and 1c coins) were almost identical to the old coins (apart from van Riebeeck’s head replacing the Queen’s head reflecting South Africa’s new republican status). Four years later (between 1965 and 1968), by which time the bulk of the population (both literate and illiterate) were used to rands and cents, the old coins and notes were replaced with smaller lighter coins and notes but the R2 note (formerly the pound note) disappeared from circulation. Ten years after that (about 1977) a new R2 note was reintroduced by which time all memories of the old £sd system had vanished (except in the history books!). The South African metrication process followed a similar pattern. In both cases there were rigid controls to ensure that the man in the street (especially those who were illiterate) was not exploited by the changes.

    The British Government however seems to have been trying to please everybody resulting in the mess that we see today.


  4. @Martin Vlietstra
    Perhaps, unlike the apartheid South African government, the British government see no benefit in forcibly sweeping away culture and heritage links with the UK.


  5. Again Charlie P uses “culture” as an excuse. See me comments on the article “Crazy acres”.


  6. Charlie P also uses inflammatory phrases such as ‘forcibly sweeping away’ culture and, yesterday on ’50 years on’, ‘compulsorily abolishing’ imperial. Perhaps the comparison he wishes to make is with IS destroying historical sites in the Middle East! I don’t think anybody would seriously argue that, for example, the decimalisation of the currency was an imposition forced upon an unwilling British public. It was a changeover rationally planned for, with all necessary contingencies in place, and then properly carried out. So why is the goal of modernising and harmonising the UK’s weights and measures such a dreadful thing to wish for? The answer of course is that it is not. No one in their right might would set out to have the current confusion of measurement units seen in the UK. It is not a desirable situation to be in.


  7. @Charlie P:

    Two things:

    1. Every country in the world sets and enforces a single measurement system (the metric system, except the USA, which hangs on to old units), regardless of what may be its ‘culture’. The UK should be no different.

    2. The metric system is very much part of British culture. John Wilkins of the Royal Society devised a decimal measurement unit almost equal to today’s metre in 1668, while more SI units are named after British scientists than any other country.


  8. @Charlie P,
    I understand that there are some potential issues about South Africa did a number of things. But Australia and New Zealand were a bit more “forceful” than the UK about metrication, and they seem to be a lot more metric, but also have considered their culture. They have certainly metricated a lot more successfully than the UK. For that matter, so has Canada. Of major nations, only the US is less metric.

    Odd since we rebelled against your rule, that we are more locked into antiquated measure than even you.


  9. @Alex
    I wasn’t using the word “culture” as an excuse for anything. I was using it literally.

    Facts are facts. The SA government approach was to legislate against the use of imperial measures. That is, they forcibly swept away their use. That sounds like the approach that is being advocated here. Let’s call a spade a spade.

    Decimalisation was ruthless, yes. People objected to it, yes. Traders ripped the public off in the aftermath, yes. However, the saving grace was that the pound sterling was retained at exactly the same value. All that changed was that the penny was redefined as 1/100th rather than as 1/240th of a pound. The sixpence, shilling and two-shilling pieces were retained with exactly the same value as before: 1/40th, 1/20th and 1/10th of a pound. So the language was not seriously impacted – the quid remained as the quid. Absolute an total metrication (as advocated here) is a whole different ballgame.

    And what is it about the UK weights and measures that are not modernised or harmonised? The UK has used SI for years, where it wants to and where it needs to. What we are talking about now is forcing the use of metric measures into areas where they aren’t needed and where they aren’t wanted – for no sound logical reason.

    @John Frewen-Lord
    1. The UK already enforces the metric system where it is required to and where it wants to. What more do you want them to do?

    2. That the British played a large part in the development of the metric system does not automatically mean that the British people have already accepted it as part of their tradition and culture in place of the measurement units that are part of their tradition and culture. First they need to adopt them in applications where they currently prefer to use the traditional units. That will take at least two more generations as I see it.

    @John Steele
    The imperial system as used in the UK wasn’t implemented until after the USA was created. The USA didn’t adopt it for the same reasons that SA wanted to sweep it away.


  10. “It is often said the usage of measures in a country is never entirely customary or metric, but a mixture of the two.”
    So true. Sadly, so true. I comment from the perspective of well into my fourth decade as resident in Japan.
    Japan has adopted to express only in metric system, but not change the actual size thereof. For instance, the “sake” bottle has usually 1.8 litre in capacity (in retail stores) that is equal to 1 “shoh”.” The US occupation from 1945 led, by fits and starts to imposition of the metric measurement system.
    Other examples of traditional units can be found in the construction industry. And of course tyre sizes are a total USCS/metric mishmash.
    Bottom line is that Britons love the past. For proof, look at comments in say the Daily Telegraph whenever this topic is raised. While politicians can see the logic of completing the change to metric measurement, they realise that it would be political suicide.
    While I support the campaign for full metrication, bottom line is that this is an exercise in frustration. We are talking of decades, even centuries before Britain will change.


  11. I looked up the UK Horse Racing website the other day and came across their Frequently Asked Questions section.
    Their unbelievably anachronistic website included this information on weight:
    “The Imperial System is the official measurement system used in the United Kingdom, despite the best efforts of our leaders who wish to drive us headlong into Europe. This system is still used daily by everyday people. This system is actually easy to understand and follow as there are just a few simple units to deal with. If you think that this system is unworkable then please do recall that the greatest engineering projects, including putting a man on the moon, was used using this system.”
    I don’t think UK Horse Racing is aware of the May 1965 change of Government policy on the adoption of metric weights and measures or any “white heat” that was being produced at the time.
    I doubt if they even realise that we’re now in the twenty first century. No wonder horse racing in the UK is in trouble.


  12. Charlie P has made a slick debating point about the apartheid South African government and metrication. However, Australia, New Zealand and Ireland also made the change to metric measures, so his point, though slick, is hardly profound.

    As for culture, the use of Arabic numerals in place of Roman numerals has enhanced our mathematical culture, the development of electricity is something we would not be without, ditto the internet and a whole host of new inventions that have revolutionised our lives. The metric system is another development that makes life a little easier. It’s not something that should be feared.


  13. As one of the USA’s primary architects of rocketry, Dr Wernher von Braun would have made his seminal calculations using metric units whilst still working in Germany.

    There’s none blinder than those that don’t want to see …


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