By James Patton
|Wing Cmdr. F.A. Brock|
Being experienced with explosives, in October 1914 Frank Brock volunteered for the artillery. A month later he was transferred to the navy, then became a flight lieutenant in the Royal Naval Air Service (RNAS) in January 1915. Although he was a civilian pilot, he never flew for the RNAS; instead he founded and headed up the Royal Navy Experimental Station at Stratford, located in London’s East End. On 1 April 1918, the RNAS and the Royal Flying Corps (RFC) were combined to form the Royal Air Force, and Brock was appointed to the newly created rank of wing commander.
During the First World War he is known for the invention of several devices and processes. Among these are:
The Dover or Deck flare, which was a one-million-candle-power incendiary device. These were used to protect cross-Channel steamers from U-boat attack by washing out a periscope’s field of vision.
Colored glass filters, which improved clarity in cameras, binoculars, periscopes, and optical signaling devices by removing less useful colors. These were a sort of simple precursor to modern infrared devices.
Brock is probably best known for his work in developing artificial smoke and fog. This research resulted in two different products. On the small scale he developed chlorosulfonic acid bombs, a substance which when discharged into the air, fuses with atmospheric water to form a dense, opaque, and highly acidic fog. Brock used this technology in the E-float device which could help a merchant ship screen itself from a following U-boat. Modern smoke grenades have also used Brock’s technology.
Brock also developed a process for large-scale production of artificial fog for use by ships. A generator tube was attached to the exhaust of the ship’s engines or boilers. This device was partly filled with water, which was heated by surface contact with the exhaust pipe or stack. Into this water was discharged a steady flow of calcium phosphate, which the heat converted to phosphoric acid. This was injected into the exhaust plume where it combined with atmospheric water to produce a dense and highly corrosive fog. Like all forms of gas release, the atmospheric conditions had to be right to prevent the fog from enveloping the ship itself.
|Marines & Sailors Storm the Zeebrugge Mole from HMS Vindictive|
This system was employed by the Navy at the raid on Zeebrugge, Belgium on 22–23 April 1918. Brock was present on the cruiser HMS Vindictive to supervise the fog production. Likely bored, he decided to go and find a German fire direction station so he could study their technology. Like one of Henry Morgan’s pirates, Brock went ashore armed with a Webley revolver (some say two) and a cutlass. He was never seen again.