Heinrich Mohaupt

from Wikipedia, the free encyclopedia

Wolfdieter Hans-Jochem Mohaupt , called Heinrich Mohaupt , in the USA Henry (Hans) Mohaupt (born August 16, 1915 in Egg ZH ; † May 20, 2001 in Santa Barbara ) was a Swiss-American inventor . He was one of the first to recognize the value of the lining effect on shaped charges . The exploitation of this effect led to the development of new armor-piercing ammunition during World War II . He then continued his inventiveness in the field of oil and gas production.

Life

childhood and education

Heinrich Mohaupt was born on August 16, 1915 in Egg ZH. His parents were Flora Mathilde and Berthold Mohaupt. Heinrich had a sister who was four years older, the Deziré Liselotte. Berthold Mohaupt was born in Breslau in Germany ; he was naturalized with his two children on May 30, 1918. The family moved several times during Heinrich's childhood: Egg ZH (until 1915), Cham ZG (1916), Höngg (1917–1920) and then Zurich .

After finishing secondary school , Mohaupt completed vocational training as an electrical mechanic in Zurich. He completed the compulsory basic training ( recruit school ) in the Swiss Army in 1935. In 1936 he enrolled in the Matura class at the Minerva Institute in Zurich . In December 1936 Mohaupt had to drop out of school due to health and financial problems. He took up a job as a technical chemist .

Shaped charge for the military

Mohaupt was interested in explosives, with which he experimented in his laboratory in Zurich. He applied for his first patent on a manufacturing process for nitroglycerin on August 5, 1935.

In late 1935, Mohaupt observed the effect of the shaped charge with a metallic lining during an explosive test: the hollow charge focuses the explosive energy and deforms the metallic lining into a very fast beam of metal, which penetrates an obstacle. Mohaupt recognized the potential of his discovery, because he made several applications to buy explosives and to carry out experiments on a larger scale, on the grounds that he wanted to offer his invention to the Swiss army. This means he was possibly a little earlier than the Austrian Franz Rudolf Thomanek , who observed this effect on February 4, 1938 at the Aviation Research Institute in Braunschweig and also recognized the potential for military applications. However, the date of Mohaupt's discovery is controversial. While Thomanek's events can be well substantiated by documents, Mohaupt's only depend on his retrospective reports, which he wrote in 1966. Because of the limited diagnostic resources, it was initially difficult for Mohaupt to fully understand his discovery; some of his early designs show arrangements that would hinder the generation of the metal beam.

At the request of the military engineering department of the Swiss Army , Mohaupt demonstrated the effectiveness of his invention on September 16, 1938. Since no patent had yet been issued, Mohaupt was not allowed to reveal any details. The Swiss authorities were not interested in Mohaupt's invention; they assumed that due to the high kinetic energy only mass bullets are suitable as anti-tank weapons.

In late 1937 the United Kingdom learned of Mohaupt's attempts; In the spring of 1939 it was shown in Zurich for representatives of the British Royal Arsenal . The British suspected the already known shaped charge effect behind the invention, so the license fee demanded by Mohaupt seemed too high to them. They ended the negotiations, but did their own research in the field.

In January 1939, the United States learned of Mohaupt's experiments through military channels; Correspondence also took place in July, but the US was also unwilling to pay the requested $ 25,000.

Heinrich and his father Berthold, who was also an inventor in the field of ammunition, had connections to the French weapons engineer and entrepreneur Edgar Brandt . Heinrich left Zurich on October 26, 1939 to follow his father to Paris . After several attempts, the two Mohaupts, with Brandt's support, succeeded in recognizing the patent filed on November 9, 1939 under the number FR919818. In return, Brandt got exclusive rights to market the patent in France. From October 1939 promising tests and further developments took place. Demonstrations of the developed rifle grenades took place on February 18, 1940 in Bourges and on June 10, 1940 in Satory near Versailles . After the collapse of the French resistance in the German campaign in the west and the conclusion of the armistice at Compiègne on June 22, 1940, tests and production preparations were relocated to the unoccupied zone in Pau . The Vichy regime allowed Brandt to share developments with the Americans.

Projectile with shaped charge, Mohaupt's patent from 1941

Mohaupt was supposed to drive the development in the USA further, but he first had to wait a while in Portugal until his immigration papers were ready. He finally arrived in the United States on October 18, 1940. Shortly after his entry, a demonstration took place on the Aberdeen Proving Ground . The French envoy Paul Delalande, who arrived a few weeks earlier, was able to organize this in advance. The explosive charges were manufactured by the chemical company DuPont , which from then on played an important role in the development and production of shaped charges. After Mohaupt demonstrated his grenades, the US was ready to secure the rights. When Mohaupt disclosed the principle, the US argued that the shaped charge effect itself was already known. It was agreed on a significantly lower license fee.

The 30 mm rifle grenade offered by Mohaupt could penetrate about 5 cm of armor steel. On this basis, the Army developed the 60 mm M10 rifle grenade with a penetration rate of around 10 cm. The M10, developed in early 1941, weighed over 700 grams and was so heavy that it damaged the rifle when it was fired and endangered the shooter. Coincidentally, a portable rocket launcher was developed by the Army in parallel to the M10. The rocket-propelled M10 warhead and the rocket launcher proved to be a groundbreaking combination and became known as the bazooka .

On June 4, 1941, the project was given a high degree of secrecy , so that Mohaupt, as a foreigner, was no longer allowed to participate directly. Since most of the knowledge transfer had already taken place, this had no serious impact on the project. Mohaupt was also active as a consultant for the Army. Independently, he continued to research various configurations of the shaped charge and the insert. Mohaupt patented the improvements he had made in 1942. He took US citizenship and served from May 28, 1943 to May 15, 1945 with a special contract in the US Army that allowed him to work at DuPont.

Oil and gas industry

After the war he went to Europe for a short time and worked for the United States Navy on his return . In October 1946, Mohaupt been shareholders of the company Well Explosives Company (1948 Welex Jet Services renamed) and moved from Washington, DC to Fort Worth to. There he tried to improve the perforation of oil and gas wells using shaped charges. The perforation allows the raw material to be extracted from the source to enter the otherwise sealed bore. The process was successful and prevailed.

Mohaupt sold his Welex company shares in 1954 and devoted himself to other applications in borehole stimulation . He was President of Petroleum Tool Research, Inc. and commercialized a new process called Vibro-Frac . The company Servo-Dynamics , which he founded in 1980, developed processes known as Dynamic Gas Pulse Loading (DGPL) and STRESSFRAC in the field of high energy gas fracturing .

Private life

Shortly after the end of the war, Mohaupt married Hazell White; the marriage was divorced in 1946. From about 1947 to 1950 he lived in Fort Worth , Texas , where he married his second wife Barbara. From 1951 to 1957 he lived in Pasadena and from 1959 in Santa Barbara , where he died on May 20, 2001.

literature

  • Henri Habegger: Edgar William Brandt, Berthold (father) and Heinrich (son) Mohaupt in: Bulletin Association of the Swiss Army Museum , No. 1 2015: [5]
  • Donald R. Kennedy: History of the Shaped Charge Effect , 1983 [6]
  • Syd Levine: A Brief History of Lined Shaped Charge Perforators , 2010, based on: Douglas W. Hilchie: Wireline: a history of the well logging and perforating business in the oil fields , 1990 [7]
  • Gordon L. Rottman : The Bazooka , Osprey Publishing , 2012, ISBN 9781849088015
  • American Oil & Gas Historical Society: Downhole Bazooka [8]
  • Technical Manual TM 9-1300-214: Military Explosives , Department of the Army technical manual, September 1984 [9]
  • Constance McLaughlin Green , Harry C. Thomson, Peter C. Roots: The Ordnance Department: Planning Munitions for War , Washington, 1955, Office of the Chief of Military History, Department of the Army, [10] [11]
  • GlobalSecurity.org : Bazooka Anti-Tank Rocket Launcher [12]

Individual evidence

  1. ↑ a b c d Habegger: Father and Son Mohaupt, 2015, p. 41
  2. ^ Kennedy: History of the Shaped Charge Effect , 1983, p. 9
  3. ↑ Habegger: Father and Son Mohaupt , 2015, pp. 41–42
  4. ^ Kennedy: History of the Shaped Charge Effect , 1983, p. 9
  5. ↑ Kennedy: History of the Shaped Charge Effect , 1983, p. 20
  6. ↑ Kennedy: History of the Shaped Charge Effect , 1983, p. 21
  7. ↑ Habegger: Father and Son Mohaupt , 2015, pp. 42–43
  8. ↑ Kennedy: History of the Shaped Charge Effect , 1983, pp. 10, 21
  9. ↑ Green et al: The Ordnance Department , 1955, p. 212
  10. ^ Green et al.: The Ordnance Department , 1955, pp. 212-213
  11. ↑ Habegger: Father and Son Mohaupt , 2015, p. 43
  12. ↑ Kennedy: History of the Shaped Charge Effect , 1983, pp. 21-22
  13. ^ Green et al: The Ordnance Department , 1955, p. 213
  14. ↑ Mark J. Reardon : Bazooka in: A History of Innovation: US Army Adaptation in War and Peace , Center of Military History (US Army), 2010, ISBN 978-0-160-86722-4 , p. 75 [1]
  15. ^ Gordon L. Rottman : The Book of Gun Trivia: Essential Firepower Facts , Verlag Osprey Publishing, 2013, ISBN 9781782006206 , p. 12 [2]
  16. ^ Rottman: The Bazooka , 2012, p. 12
  17. ↑ Kennedy: History of the Shaped Charge Effect , 1983, p. 11
  18. ^ Kennedy: History of the Shaped Charge Effect , 1983, pp. 11-12
  19. ↑ Kennedy: History of the Shaped Charge Effect , 1983, p. 22
  20. ↑ Habegger: Father and Son Mohaupt , 2015, pp. 44–45
  21. ↑ a b c d Levine: A Brief History of Lined Shaped Charge Perforators , 2010
  22. ^ Pacific Oil World , Volume 52, 1959, Petroleum Publishers, p. 16
  23. ↑ Syd Levine: Propellant Type HEGF Devices , 2010, [3]
  24. ^ Servo-Dynamics, Inc .: Company Background [4]
  25. ↑ Habegger: Father and Son Mohaupt , 2015, p. 44
personal data
SURNAME Mohaupt, Heinrich
ALTERNATIVE NAMES Mohaupt, Wolfdieter Hans-Jochem; Mohaupt, Henry Hans
BRIEF DESCRIPTION Swiss American inventor
DATE OF BIRTH August 16, 1915
PLACE OF BIRTH Egg ZH
DATE OF DEATH May 20, 2001
Place of death Santa Barbara