With no trees, trenches, or other terrain to cover, the open ocean was a particularly dangerous battlefield for aircraft and watercraft in the 20th century. Ships sat on ducks that could be seen from a distance, and these ships could easily see – and aim – approaching aircraft. So the military developed smoke barriers to hide their armed forces.
According to PortandTerminal.com, an early version of smoke control resulted in hundreds of gallons of oil being funneled through a ship’s combustion chamber, creating massive clouds of smoke that poured out of the chimneys. This type of smoke screen was occasionally used during World War I, but it took too much oil ̵
Towards the end of the war, the military had come across a more promising alternative: titanium tetrachloride. While the yellow liquid could attack metal and seriously irritate your eyes and lungs, it could also create an impressive curtain of thick white smoke that looks a bit like the colossal north wall game of Thrones.
How Popular mechanics According to reports, titanium tetrachloride is likely to be responsible for the smoke protection seen in the footage below. The video was shot by the US Army Engineering Division in 1923 and shows a US biplane emitting smoke near a battleship, with the caption “The Air Service may put up a smoke curtain to protect the bomber.” Battle Not On – He was part of a series of experiments led by Army Brigadier General William Mitchell to prove that the Air Force could rival the might of the Navy. The ship was likely either the USS Virginia or the USS New Jersey.
Although smoke grilles were a clever innovation at the time, advances in technology have since made them unnecessary and ineffective. Radar and infrared devices are not fooled by smoke and allow the Air Force to fire missiles from a distance. And if you need to hide the whereabouts of your vehicle, you can disrupt your enemy’s radar.
[h/t Popular Mechanics]