The Arthur Doodson story

One day there will be many more famous people sporting the surname Doodson. However, for now arguably the most famous and influential Doodson was Arthur Thomas Doodson, who has more direct and indirect references on the web than any other (with the possible exception of Mike Doodson, the motor sport journalist) - a few of the links are listed below.

Arthur Doodson, who died in 1968, was great-uncle of the author of most of the pages on this web site, and sadly I was only 9 years old when he passed on. I only have a very vague memory of him, mostly based on a black and white photo (see at left) of myself and "Uncle Arthur" playing with a football in our back garden when I was about five years old.

Arthur was based for more or less the whole of his illustrious career at Bidston Observatory, now home to the Proudman Oceanographic Laboratory [
link to web site]. He was director of the Liverpool Observatory and Tidal Institute, precursor to the Proudman, until his retirement in 1961. There's a biography page about him on their site too.

Tide predictions and annual tide tables were produced at the Observatory in the 1920s, calculated by hand, using already well-documented (if rather complicated!) methods. Arthur was tremendously able in these calculations, having proved to be an excellent and enthusiastic mathematician in his youth, proving himself in 1912 with a 1st Class Honours BSc in Chemistry and Mathematics (despite becoming profoundly deaf during the course of the under-graduate studies), and an MSc in 1914. An early practical application for Arthur's expertise came in the form of calculations of the trajectory of shells used by the Army during the Great War.

Early tide-predicting machines were in use at Bidston in the 1920s, but Arthur wanted to improve them. Initially he made small adjustments and eventually his understanding of them enabled him to take the design to new levels of sophistication.

In 1949 the Doodson-Légé Tide Predicting Machine, arguably Arthur's greatest achievement, was installed at the Observatory (there's a photo of it,
click here to see). This represents one of the closing chapters in the pre-computerised era - using numerous precision-engineered cogs and wheels the machine was able to predict tides anywhere in the world, and did so until it was superseded by computerised tide prediction in the late 1960s. The machine. now displayed in the Proudman Institute, represents the fruits of theoretical and practical work done by Arthur and others in the mathematics and physics of tide prediction. While today's computer programs are able to predict tides far more quickly, the tide predicting machine - which may have take a day and a half for each set of a year's calculations for a particular location - they use pretty much the same calculations and variables that Arthur built into the design of his machine. The Proudman Institute sells a descendent of the Doodson-Légé in a Windows program called POLTIPS, that produces tide tables for anywhere in the UK, more or less instantly.

The tide predicting machine supplied tide tables for places throughout the world, but its (and Arthur's) moment of glory came when it was used in the planning of the Normandy landings on D-Day. In due course Arthur was awarded the CBE for his work on tide prediction, receiving the honour from Queen Elizabeth II in 1956.

Arthur was also involved in a number of projects for the British government, including one that investigated devastating floods that killed 14 people in basements in central London in January 1928 - see Some believe that Arthur coined the term "storm surge" as part of this work.

Internet Links related to Arthur Doodson

Update November 2007: Wikipedia entry!
Someone finally got round to adding a
Wikipedia entry on Arthur's work on tidal prediction. It's definitely focussed on his analytical work and doesn't give much more about his life, but it's great that he's recognised in Wikipedia.

Flaybrick Memorial Gardens, Bidston - Arthur was buried there after his death in 1968. This site has a page showing an extraordinary collection of photos and documents relating to Arthur's life, including a photo of Arthur outside Buckingham Palace after receiving his CBE, with his wife, Elsie, and son, Thomas, standing with him.

The Tidal Glossary on the web site of Australia's National Hydrographic Authority [link] has the following definition: "Doodson's number: A six digit number, with each digit describing a different characteristic of tide according to a system developed by Doodson in 1921." Fancy that! Imagine having a number (or six of them) named after you! That puts Arthur alongside such luminaries as Avogadro and Planck. And no, I can't remember what either Avogadro's number or Planck's constant were, to my shame.

A number of references on the internet to Arthur and his works have sadly disappeared, but here are some extracts that you may find interesting:

Tides and Tidal Prediction - there used to be the following explanation on the web site of Linden Software Ltd [dead link], a company making software for predicting tides: "... Like most hand-waving explanations this simple description of the tides conceals a torrent of mathematics. For further information consult the classic reference: Admiralty Manual of Tides, HMSO London 1941, Doodson AT and Warburg HD."

More references to Doodson numbers in tide prediction software: In this case by Stormy Weather Software [dead link] - their site used to have this explanation: "All Doodson numbers (s, h, p, N and p') are corrected by adding {Species x ( -s +h )} (Species being 0 for long term, 1 for diurnals, .... 6 for sixth diurnals); this facilitates conversion from Tau (lunar day) to UTC in later calculations." Any the wiser?

A computer named after Arthur: There used to be a server called "" at Center for Ocean-Atmospheric Prediction Studies, Tallahassee, USA.

You want more? For more stuff about Arthur's work on tides, simply go to Google and type in "Doodson tide" into the search field (click here to do just that automatically).

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