Decimal changeover lessons

Following on from last week’s informative article about the UK’s introduction of decimal currency, we look at some of the features contributing to that success and draw comparisons with the changeover to metric measures.

The introduction of decimal currency saw an early acceptance of the need, initial hesitancy in implementation, then a century of dreaming up excuses for not proceeding. Finally, a decisive push showed conversion to be straight-forward, and in retrospect it is difficult to understand why it had been thought problematic for so long. A ten-minute film on decimalisation from 1970 featured someone who said, “We have been since 1828 getting to the introduction of a decimal coinage, and we shall be the last major country in the world to go over, although we were one of the first to start thinking about it.”

The introduction of decimal currency featured:

  • Good contingency planning
  • An intensive public information campaign for 2 years before D-Day
  • Clear explanation of changes and benefits
  • Plenty of information supplied to key stakeholders, including retailers, businesses, teachers and the general public
  • Widespread publicity – use of different media, including television and radio, and distribution of a large number of booklets and leaflets
  • Smooth and efficient changeover after years of co-ordinated and detailed planning
  • Clear cut-off date
  • Rapid and compulsory changeover
  • Clean Break changeover philosophy

The changeovers to decimal currency and to metric measures share some features. For example, both bring the benefit of the simplicity of using decimals, rather than factors of 12 and 20 for currency or 12, 3 and 1760 for both length and distance. But whereas the change of currency affected only part of the UK economy, the full benefits of metrication will come when all sectors of the economy use a single, simple measurement system with which everyone is familiar. And with many sectors involved, there could be no ‘M-day’. Each would proceed at the pace it found most convenient and practical. For many, without a helping hand from government, that pace was very slow indeed. In 1965, perhaps 10% of the UK economy was metric, including science and the teaching of science in schools and universities. Today, that figure is probably around 90% – but it has taken 55 years to get there.

However, a key factor in both projects has been the support of government. For the currency changeover, government was totally committed, and supported all the features listed above. For the metric changeover, the Government was showing lack of interest as early as 1970 when the Transport Minister announced, “… the Government have however decided that speed limits will not be made metric in 1973 and have no alternative date in mind.” Thereafter, government involvement tended to be half-hearted, before ceasing completely.

The last word goes to Prime Minister Harold Wilson, who began this story. He is reported to have said that leading a political party is like driving a coach full of passengers. All the while you are going forward, everyone is fairly happy. As soon as you stop, many passengers will leave the coach and form groups to discuss where to go next, or wander off to admire the scenery. Perhaps this applies also to the currency and metric changeovers. With currency, the coach accelerated steadily and was travelling at its maximum speed on ‘D-day’, arriving at its destination shortly afterwards. For the metric changeover, the driver parked the coach in a lay-by shortly after setting off. All the passengers eventually left it, most walking to their destinations, some waiting by the roadside considering what to do next, and a few turning back. Then, many years later, the driver said the coach had run out of fuel and there was no money to buy more.  

8 thoughts on “Decimal changeover lessons”

  1. Can you seriously imagine the present UK government doing any of things in that bullet point list?


  2. It’s true that there could never have been one M-Day for everything in the UK to switch over to metric units, but many sectors have had their own M-Days, where it was desirable to make the switch in a timely fashion. Experience has repeatedly shown, that the most effective metrication programmes have been those that were carried out in short timescales, and which used M-Days to coordinate the change quickly.
    5 May 1975 – British Rail switched to metric units for loads, capacities, tare weights and brake force for all rail traffic.
    29 September 1975 – The Post Office switched to metric units for all postal weight tariffs.
    4 June 1976 – All returns for the Agricultural Census were required to be in metric units for the first time.

    Of course, the elephant in the room is the one big M-Day that has yet to be scheduled. Despite initially being announced over 50 years ago, the switchover of UK road speed limits to metric units has still not been given a definite date. Ireland’s M-Day for this was 20 January 2005, and Australia’s was 1 July 1974 (see ). All we can be sure of is that each passing day is bringing us one day nearer to our road speed limits M-Day.

    Liked by 1 person

  3. Yesterday, the Government announced a £700 million spend to help education recover from Covid: £300 million for a ‘recovery premium’, £200 million for tutoring, and £200 million for summer schools. The spending on any one of these three programmes would cover the cost of the metric conversion of all the UK’s highway speed limit signs and get the changeover of distance signs off to a flying start. Which would in turn eliminate the need to teach inches, feet, yards and miles in schools, to teach conversions using factors of 12, 3 and 1760 (as mentioned in the article) and to teach the 11 times and 12 times tables (yes, I am not joking!). Thereby saving at least a similar sum every year, not just this year, but for ever. It would also save motorists a few hundred pounds every time they buy a new car as the UK is the only country that drives on the left and requires miles on the odometer, adding to the price.
    Will it happen? Not until people realize the current muddle is making them poorer. In the meantime, our politicians rush to defend Roman and medieval measurements on road traffic signs while ignoring the fact that the alternative, both simpler and more logical, was originally suggested over 350 years ago by the first Secretary of the Royal Society.


  4. As long as the Tories are pushing the myth of the EU as the enemy, finishing metrication in the UK has little hope.
    Of course, if Scotland breaks away and gets the green light to join the EU, they will undoubtedly convert their road signs to metric for many reasons. That will add pressure on England (starting with the north) to save themselves and rejoin the EU (but without all the special concessions that the UK had previously), so that could finally trigger the changeover.


  5. What a shame that British politicians did not learn from the success of decimalisation and apply lessons learnt from the decimalisation project to metrication. Metrication in the UK has been slow, chaotic and erratic. Ministers blamed the European Union for metrication regulations instead of making the case for them on their own merits. Hence there was a perception that they were applied by stealth and imposed by the EU despite the fact that British ministers agreed to them in the Council of Ministers and the UK was committed to going metric when the British joined the European Economic Community, forerunner of the European Union, in 1973. Little information was supplied to the general public or to businesses to explain the changes and how they would benefit from them.
    On metrication, the British did the equivalent of leaving old money in circulation. There is a widespread misconception that imperial conversions are helpful. It just encourages people to pay attention to the imperial units they are used to and ignore the metric units. One classic example of this is the conversion of body height and weight to imperial units. While the NHS uses metric units internally for body height and weight, most Britons still express their height and weight in imperial units. Officially, the only imperial units still in use are the mile, yard, foot and inch for road signs, the pint for draught beer and doorstep milk and the troy ounce for precious metals. However, unofficial usage of imperial units is widespread in the UK.
    Other major Commonwealth countries such as South Africa and Australia made the successful transition to a decimal currency and to the metric system. The UK also succeeded with decimalisation so it is surprising that we did not learn the lessons from the successful decimalisation of the pound or the successful metrication projects of other countries. We can still learn those lessons. We had to wait over a century from conception to implementation to complete decimalisation. Let’s hope that we will not have to wait as long to complete metrication.


  6. @Ronnie Cohen
    Totally agree.
    Even in Canada, which is hobbled in its metrication efforts by being next door to the USA and its biggest trading partner, completely eliminated “miles”, “miles per hour”, and “degrees Fahrenheit” by converting road signs and dropping “Fahrenheit” from all media in favor of “Celsius”. I never hear a Canadian use “miles” or “mph” or “degrees Fahrenheit” since they dropped those all the way back in the 70’s. This means an entire generation of Canadians has grown up thinking only in terms of kilometers, kilometers per hour, and Celsius.
    If the Canadians can see such success despite the huge drag on them from the USA next door, the UK could have easily discarded every vestige of Imperial back in the 60’s if it had chosen to.

    Liked by 1 person

  7. I remember D-Day well.
    The decimalisation plan included a Shoppers’ Table – a chart to compare decimal and £sd amounts, displayed in all shops and issued in pocket-sized format to every address in the UK. From Feb 15, 1971, shops could trade either as decimal shops or as £sd shops for a limited period. In decimal shops one could present old currency in multiples of six old pence and change would be in decimal. In £sd shops one could present new currency in multiples of 2·5p and receive change in £sd. These were the lowest common amounts compatible with both systems. Larger denominations of either type could be used in either shop.
    British Rail decided to go decimal one day early, Feb 14. The reason was that on a Sunday much less happened and there were far fewer transactions, so this was an easier day to perform the conversion. As far as I remember this went smoothly.
    Some shops displayed dual pricing but many more did not; by Feb 15 they were displaying prices in decimal only, avoiding cluttered labels. If customers wanted to compare old and new prices, the Shoppers’ Table was available. These were the shops where the changeover went most smoothly.
    My own first occasion of “shopping” in decimal on Feb 15 was during mid-morning break at the college canteen, which was fully and unashamedly operating in decimal. By lunch time I had spent all my old £sd coins.
    Some bus operators decided it better to delay the change to decimal trading. They reckoned they were a special case; they handled large amounts of small change and it would take a while for this to give way to decimal. They declared they would not change over until Feb 21. These turned out to be the organisations that had the most problems. In practice, most passengers had used up their old coinage by the end of Feb 15, and were irritated when they tried to pay their fares, only to receive in change £sd coins which they were trying to get rid of. The situation became worse as the week progressed. There became a general shortage of £sd coinage, and the buses could not even provide enough £sd coins for change for passengers, though the fare structure and ticket machines were still in £sd. Things became increasingly chaotic and change given amounted to little more than negotiated guesswork. Everyone was very relieved when Feb 21 arrived and the buses could go properly decimal like everyone else.
    OK, it is easy to look back and be wise after the event. But there is a lesson there, is there not!
    It is a pity that some people in our government cannot learn from past successess, let alone past failures.


  8. Maybe the lesson is do a lot of prep and education, then change over in one fell swoop everywhere (unless a special sector is not widely used and has special issues).

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: