05/12/2021

008 – Target practice – 1909, 1927

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Aeroplanes are interesting toys but are of no military value. Ferdinand Foch, French Marchal

Arthur Pollen, a writer who specialised in naval matters, attended a Royal Navy gunnery exercise off Malta in 1900.  He was surprised to see that the accuracy was quite poor, even from just a mile the number of hits proved to be minimal.  Pollen surmised that some form of calculator might be designed to evaluate the relative motion of a ship during the time delay while a shell travelled towards a target.  It should then be possible to calculate the direction and elevation gunners should use.

Lord Kelvin, then considered to be Britain’s top scientist, proposed to Arthur Pollen that his brother, James Thomson, had a differential analyser that might be investigated as a potential solution to develop a fire control system for the Royal Navy.

Pollen worked with Thomson within the Linotype Company attempting to design a plotting device that captured the relative motions, including the addition of a gyroscope to eliminate the movement of the host ship.  However at the time a solution proved elusive.

In 1909 Pollen founded the Argo Company and developed the Argo system which some claim to be the first electrically-powered mechanical analogue computer. 

Subsequently Frederic Dreyer who had been a naval lieutenant on Pollen’s naval liaison team produced his own approach, the Dreyer Fire Control System.  With better military connections he secured most of the market.

In WWI the British defeat at the naval battle of Jutland was to some degree blamed upon the shortcomings of the Dreyer system.  It had delivered a poor performance, but it was not entirely clear if this failure was more about bad tactical manoeuvres.

In 1926 a Royal Commission granted Pollen £30,000 in compensation for Dreyer’s plagiarism – one of the many legal actions to routinely punctuate the progress of the computer market.

Carl Norden was Dutch, though born in Java and educated at ETH Zürich in Switzerland.  He moved to the USA in 1904 where he worked at Sperry on gyroscopes and bombsights. 

He set up his own business in 1920 where he cooperated with the US Navy to come up with the Norden bombsight in 1927. 

It was not just a visual device, it used a gyroscope to take over and manage the automatic pilot to ensure a stable bomb run.  The sight had a telescope and a series of motors and gyroscopes to retain the sight on a fixed point below. 

A small analogue computer required manual entries of altitude, ground speed and any wind speed, and from these calculated the release point.  Some of these manual factors were later improved by linking the sight with radar.

A German spy, Herman Lang, working in the Norden factory managed to acquire the details of the design in 1938.

Carl Zeiss produced the Lotfernrohr 7 version as a result and this was used by the Luftwaffe.

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