Ship’s stripes dazzle a king
QUESTION Why did the Royal Navy’s Kil class sloops have zebra stripes?
This striped colour scheme was the Royal Navy’s first foray into camouflage.
in the early 19th century, Britain started adopting camouflage to conceal troops. The Light infantry, brought in by General sir John Moore, were issued with dark green jackets in place of traditional red.
The idea is said to have been adopted from marines in the American War of independence who wore green jackets that made them hard to see in forests.
The British adopted khaki in india from 1848 and by the end of the second Boer War it was general issue to all soldiers.
in World War i, the Royal Flying Corps adopted brown and green camouflage after finding it made aircraft harder for enemy pilots to see from above.
The number of ships being destroyed by U-boats had reached a critical level and the Admiralty was desperate to reverse this. stripes in contrasting colours broke up the outline of the Kil class sloops, which was supposed to make them harder to detect through the periscope of a U-boat.
The colour scheme was known as Dazzle, supposedly coined by George V in 1917. in a demonstration where he looked at a model through a periscope, the King, an experienced sailor and former Royal Navy officer, confused the direction in which the model was moving because of the disruptive pattern. he is supposed to have said he was dazzled by it.
Kil class sloops were based on a whaling ship design. Each had a name of a village or town in scotland and ireland starting with Kil, eg Kilbirnie and Kildare.
Out of a planned 80, 55 boats were built for anti-submarine duty, but only 35 had entered operational service by the end of World War i.
As well as having a main armament of a 4in naval gun, they were equipped with hydrophones to detect U-boats and depth charges with which to attack them. They had a crew of 57 and a top speed of 13 knots. After the war, 48 were sold as whaling or coastal cargo transportation.
As well as stripes, the Navy experimented with wavy lines and swirls in a range of blues, greys and purples.
Dazzle was reintroduced for convoy escorts in World War ii, especially in the North Atlantic where grey skies and dark waves made visibility poor. Today’s Royal Navy ships are a uniform grey: Dark Admiralty Grey or Light Admiralty Grey, colours 632 and 697 in the British standard colour chart.
Bob Cubitt, Northampton.
QUESTION Aside from humans, what animals have the greatest range of vocal calls?
TOOThED whales, such as dolphins and porpoises, have a much greater vocal range than humans.
Their eyesight is poor compared to us, so they rely on sound more than any other sense to navigate their world.
Consequently, they have evolved a distinct, complex and unique acoustic anatomy that enables them to see and feel with sound.
They can distinguish small differences in the frequency or pitch of sound waves and can hear and generate low-frequency sounds below 20hz as well as highfrequency sounds of up to 150,000hz, well beyond the range of our hearing.
The borders of human hearing are 20 to 19,000hz. A man’s speech has a frequency from 85 to 155hz, while a woman’s is 165 to 255hz.
Toothed whales produce sounds using their larynx as well as air sacs near their blowhole. They produce low-frequency pulses for long-range communication and high-frequency echolocation clicks.
Dolphins whistle almost constantly while porpoises communicate in high-frequency clicks around the 130,000 kilohertz mark. For us to hear a porpoise click, you would have to slow it down 100 times.
Joseph Harrison, St Andrews, Fife.
QUESTION Why hasn’t the 800 square mile Bir Tawil between Egypt and Sudan been claimed by either country?
AssERTiNG ownership over land is at the root of many of the world’s problems, yet the presence of unclaimed Bir Tawil, a trapezoid of rocky desert between sudan and Egypt, is the story of a battle not to occupy a territory.
The dispute arises from the British colonial administration and two maps drawn up to define the boundaries of Egypt and former Anglo-Egyptian sudan.
The first is from 1899 and provides a 770-mile straight line across the desert. This is the border Egypt would like to keep because it gives Bar Tawil to sudan, but puts the valuable 8,000squaremiles of hala’ib Triangle on its side.
The second map was drawn up in 1902. it is mostly straight, but towards the coast begins to change course, giving a tongue of land along the Nile to sudan.
This comprises the Wadi halfa salient and the hala’ib Triangle. The map designers considered them ethnically and geographically linked to sudan.
Using the same logic, a southwards bulge in the map scooped Bir Tawil into Egypt because it was used for grazing by the Ababda, a nomadic tribe that lives in the south of the country.
The 1902 borders were not disputed until the early 1990s when sudan granted oil exploration permits for the hala’ib Triangle. Egypt responded by occupying the area and claiming its right to defend the 1899 border. it claimed the hala’ib Triangle and disowned Bir Tawil.
Bir Tawil, which means tall well, had become ever more unwanted after a drought dried up the well, effectively ruining any agricultural value it had.
As the world’s only unclaimed piece of land, it has become the focus of nation builders, with disputes arising between a variety of would-be kings, emirs and presidents of Bir Tawil. Laurence Rees, Monmouth.