The word ‘camouflage’ naturally conjures up the idea of hiding something from view by blending it in with its background. But how do you hide something as large as a battleship? The answer is: you don’t. Instead, you disguise it in such a way as to fool potential attackers as to its shape, speed and direction.
At least, that was the idea of two very different people who each claimed to come up with the idea for protecting vessels from predatory U-boats during World War I. But did it work? According to a new academic study, yes and no.
With German U-boats scoring increasing success against British shipping by September 1914, John Graham Kerr, Regius Professor of Zoology at the University of Glasgow, took inspiration from the animal kingdom when thinking of ways of protecting marine craft from marauding submarines.
His interest in naval camouflage had been piqued after being present at the opening of the Kiel canal in 1895 where he observed German and French naval vessels painted in battleship grey, in contrast to the prevailing livery of British warships of black hull, white superstructure and yellow funnels.
Kerr had also become friendly with American artist Abbot Handerson Thayer after they met in England in the 1890s. By then Thayer, also a keen amateur naturalist, had long been studying what he termed ‘concealing colouration’ in animals, particularly the fact that animals often had darkish colouration on top with white undersides which tended, at a distance, to counteract the effect of sunshine from above and shadow below.
Thayer took the idea to the US Navy; the Navy Department showed no interest, but he took out a patent with his fellow artist and collaborator, Gerome Bush, (‘Process of treating the outsides of ships, etc, for making them less visible’ US Patent No 715,013 (1902)) to protect his idea nonetheless.
Thayer also proposed a form of ‘disruptive’ colouration, that Kerr was to take on enthusiastically, taking inspiration from animals such as zebras and giraffes.
In a letter to First Lord of the Admiralty, Winston Churchill, on September 24, 1914, Kerr explained his ideas for camouflaging ships. There are three ways one could proceed, he said:
- Use of colour to make an object blend into its background. This was not much use to a large animal, let alone an object as large as a ship.
- ‘Compensating shading’ as per Thayer, such that it ‘should be constantly borne in mind in painting the upper works of ships’, with all areas of deep shadow being painted white, including the big guns, which should be grey on top, shading to white on the undersides of their barrels.
- A scheme of ‘parti-colouring’ to break up the outline of the ship: ‘It is essential to break up the regularity of outline, and this can easily be effected by strongly contrasting shades. The same applies to the surface, generally – a continuous uniform shade renders it conspicuous. This can be counteracted by breaking up the surface with violently contrasting pigments. A giraffe or zebra or jaguar looks extraordinarily conspicuous in a museum, but in nature, when not moving, is wonderfully difficult to pick up, especially at twilight. The same principle should be made use of in painting ships.’
The Admiralty instituted a trial of Kerr’s ideas as General Order: ‘Visibility of ships – method of diminishing’. But the counter-shading aspect was largely ignored due to the expertise required to execute it satisfactorily.
By the time Kerr wrote again in the summer of 1915 offering technical assistance, Churchill had moved on and the Admiralty replied that they had decided that the most efficient scheme was to paint all warships a uniform grey. And there the matter rested until 1917.
Obfuscation
Kerr’s was an academic approach, taking examples from nature, and was an outsider in naval circles. Norman Wilkinson was an artist but, crucially, he had the advantage of also being a serving officer in the Royal Navy.
Wilkinson proposed a scheme of disruptive camouflage using ‘masses of strongly contrasting colour’, which became known as ‘dazzle’, to make identification of the class of ship and its size, speed and heading more difficult for an attacker.
The calculations involved for a submarine commander were already tricky enough: the closer the approach to a target, the easier a potential hit, but also the higher the chances of detection.
At greater distance, more accuracy in determining the size, speed and heading of the target was required. The skill and experience of a U-boat captain was also an important factor in achieving a successful hit, but anything that could make that task even a little harder might save lives and vessels.
Wilkinson’s connections ensured that his ideas were accepted by the Admiralty, leading to the formation of a ‘Dazzle Section’. There were several aspects of dazzle camouflage.
Apart from breaking up the outline of a vessel generally to render identification of its type and size more difficult, the main features were bold patterns at the bow and stern to break up their profile and cause confusion as to which was which; curves within the patterns to give a false impression of a bow wave (thus disguising the speed and heading); and patterns on the funnels to disguise their true angle (the smokestacks leaned astern).
There is still debate about how effective dazzle camouflage was and, if it did have an effect, the degree to which each of its many facets was a contributing factor.
Modern assessment
A recent paper by Lovell, Sharman and Meese (Dazzle Camouflage: Benefits and Problems Revealed, Royal Society Open Science, Vol 11, Issue 12, December 2024) has attempted to analyse this question scientifically. They used five camouflage patterns and a control, uniform grey, pattern.
Two patterns were Kerr (parti-coloured) and Wilkinson (Mauretania dazzle) designs and three the authors’ own. The latter concentrated on the principle of texture gradient: which, the authors explain, ‘are the smooth changes in the retinal image of element size, shape and density that derive from perspective projection when viewing a textured planar surface at a slant.’
In other words, a regular pattern of, say, circles on a plane surface, but with the circles gradually diminishing in size from one side to the other, would result in the false perspective of the edge with the smaller circles appearing further away than the other. Two designs of this nature, and a ‘simplified dazzle’ pattern (modified from Wilkinson) using the texture gradient concept, were used.
Camouflage periscope view
Subjects with varying sailing experience were recruited to view static ‘periscope view’ images of the ships on screen, rotated randomly, and asked to show on an accompanying diagram their perceived heading of the ship. Two main effects were found.
One, the authors denominated ‘twist’, which is the perceived difference in heading from the actual with respect to the east-west axis; the result dazzle was supposed to effect.
The other, the authors termed ‘hysteresis’, or ‘horizon bias’ whereby, on headings between 60-120 degrees away from the horizon (east-west), there was a tendency for perception to be ‘pulled’ towards the horizon. These two effects could be additive or conflictive, depending on circumstances.
Hysteresis was found to have a much greater effect than twist, although twist reduced hysteresis. Twist was greatest with the texture gradient patterns, the least effect being from the Kerr pattern. In torpedo-firing simulations, the researchers found that twist gave more protection to longer ships at greater speed and where hysteresis was low.
An interesting finding was that hysteresis decreased with sailing experience so, while twist was shown to provide, of itself, relatively small protection, its effect would be increased the more experienced the attacker.
A Royal Commission after the war determined that Wilkinson was the inventor of dazzle camouflage, to the detriment of Kerr’s (and Thayer’s) earlier work. That controversy rumbles on.
As to its effectiveness, perhaps the last word should be from the eyewitness account of a U-boat captain, quoted in Camouflage, by Tim Newark, (Thames & Hudson / Imperial War Museum, 2007): ‘It was not until she was within half a mile that I could make out she was one ship [not several] steering a course at right angles, crossing from starboard to port. The dark painted stripes on her after part made her stern appear her bow, and a broad cut of green paint amidships looked like a patch of water. The weather was bright and visibility good; this was the best camouflage I have ever seen.’
- David Baker is an independent optometrist.
Acknowledgements
My thanks to Professor Tim Meese and Professor Leon Davies, both of Aston University; and Dr George Lovell of Abertay University, for their assistance.
