Carl Norden’s bombsight was one of the most closely guarded military secrets of World War II. In fact, the U.S. military deemed the sight so important that it required the men who used it to guard its secrecy with their lives. Such an important technological breakthrough would normally earn its creator sizeable financial gains. This was not the case for Carl Norden, however. Sensing how important his invention would be to the U.S. war effort, he sold the rights to the government for just one dollar.
- Norden patented control systems for launching aerial torpedoes from ships. He also designed robot flying bombs, radio-controlled target planes, and catapults and arresting gear used on aircraft carriers.
- In 1921, Norden began work on an instrument which could drop bombs from an aircraft and hit targets on land and sea, and in 1928 developed a bomb-timing device.
- Norden developed a gyrostabilized automatic pilot to combat pilot’s problems maintaining constant airspeed and altitude.
- He developed the Norden bombsight that was used during World War II, the Korean War, and for photoreconnaissance missions during the Cold War.
Carl Lukas Norden was born on April 23rd, 1880 in the Dutch colony of Semerang, Java (now Indonesia), the third of five children. Following the death of his father in 1885, the family returned to Holland, then moved to Dresden, Germany in 1893. In 1896, he began a three-year apprenticeship in a Swiss machine shop, after which he entered the world-famous Zurich Federal Polytechnic School. He graduated as a mechanical engineer in 1904 and came to America.
Norden worked for two years for the Worthington Pump and Machine Company in Brooklyn and from 1906 to 1911 at the J. H. Lidgerwood Manufacturing Company before moving to the Sperry Gyroscope Company. Elmer Sperry hired Norden to help design the first gyrostabilizer for large ships produced in the United States. While at Sperry, Norden married and brought to America Else Fehring, who he had met years earlier in Zurich. In 1915, Norden left the Sperry company to set up his own business, but continued to work on Sperry’s marine stabilizer contracts until 1917.
Norden won several patents on control systems for launching aerial torpedoes from ships. He also designed and furnished many instruments and devices for the U.S. Navy. Some of these devices included robot flying bombs, radio-controlled target planes, and the catapults and arresting gear used on aircraft carriers. He also worked on a control system for aircraft, with others, which proved to be a precursor of the automatic pilot.
In 1921, Norden began work on an instrument which could drop bombs from an aircraft and hit targets on land or sea. In 1923, Norden and Theodore H. Barth teamed up as partners and, over the next four years, Norden worked on the bombsight in Zurich while Barth assembled the parts in the U.S. In 1928, they incorporated their company as Carl L. Norden, Inc., with an order for two precision bombsights. Barth became the president and Norden took on the engineering work. In the first year the company developed a new bombsight with a timing mechanism to indicate the time to release the bomb.
In 1931, Norden demonstrated to the Navy a much improved bombsight in a test against the hulk of the heavy cruiser, Pittsburgh. Its accuracy so impressed Navy officials that they promptly ordered forty sights. The Army Air Corps also placed its own order.
The Air Corps, in 1935, installed Norden bombsights in Martin B-10s of the 7th and 19th Bomb Groups to develop the tactics of high-altitude, precision, daylight bombing. The first day of testing saw the B-10s coming within 520 feet of the targets from altitudes of 12,000 to 15,000 feet. By the end of the tests, the bombs were hitting within 164 feet of the targets.
To guide bombs on target with acceptable accuracy requires an aircraft to correct for drift while maintaining a constant altitude and airspeed. Even minor fluctuations can cause a miss, and the greater the altitude, the greater the potential for error. To overcome this problem, Norden devised a gyrostabilized automatic pilot. On the approach to the target, the autopilot would be turned on to reduce turbulence and “overcontrolling” by the pilot. The bombardier would take over and keep the cross hairs of the sight centered on the target. At the critical moment, the bombs were released and a green light in the cockpit would flash in the cockpit, informing the pilot that the bombs were gone and he could resume control of the aircraft.
In the succeeding years, the bombsight was improved. The ultimate model, designated the Mark XV, was a complex assemblage of more than 2,000 cams, gears, mirrors, lenses, and other components. With it, the pilot would have to maintain a fixed speed and altitude for only 15 to 20 seconds. Technically, the sight could place a bomb inside a 100-foot circle from four miles up. But, the bombardiers claimed that it could “put a bomb in a pickle barrel from 20,000 feet.”
At the beginning of 1941, the Carl L. Norden factory had planned an output of 800 bombsights a month, but the Japanese attack on Pearl Harbor caused immediate expansion of the facilities and production. By the end of 1943, the company was turning out nearly 2,000 Norden sights monthly. So valuable were the secrets of the sight’s manufacture that the plants were some of the most carefully guarded installations of the war. Norden himself was always accompanied by two bodyguards. Bombardiers were required to swear an oath to destroy any bombsight which had the potential to fall into enemy hands and bombsights were always covered on the ground and not unwrapped until the plane was airborne.
The compant halted production of the bombsight in September 1945, after producing 43,292 of the units. The Army Air Force had procured all except 6,500 of the sights, which went to the Navy. The military used the Norden bombsight during the Korean War and on Strategic Air Command’s photo reconnaissance and mapping missions in the early years of Cold War.
Norden was a quiet and unassuming man who was proud that the bombsight could be used for strategically striking military targets, while minimizing collateral damage to surrounding civilian populations and structures such as churches, schools, and homes. One interesting fact is that Norden did not make money on the bombsight during the war; instead he sold his rights to the sight to the government for one dollar. Carl Norden returned to Switzerland shortly after World War II and died there in 1965.
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