Some origins of German jet power
 
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End of World War II
 
  End of World War II
  By the time the second World War had ended, the Germans had achieved many firsts in the field of air-breathing jet engine and gas turbine technology. Atlthough this technology was by no means confined to an aerontautical sphere, it was here that the greatest effort was made and, amongst other achievements, accounted for the world’s first turbojet-and pulsejet-powered aircraft and the first jet fighters, bombers and flying bombs going into production and operational service. Additionally, the Germans flew the world’s first jet helicopter and ramjet missiles. It is proposed here to review some of the more salient events in German work proceding the operational debut of Luftwaffe aircraft in 1944, subsequent events being already recorded elswhere in some measure.
  Although, eventually, the Germans worked on vritually every type of jet, gas-turbine and hybrid engine (not to mention rocket motors), the prime types were the turbojet, pulse-jet and ramjet engine.
  History
  In Germany, the idea of extracting power from hot, expanding gases by means of a turbine wheel (essential to the turbojet) went back at least to 1877 when Joseph Wertheim was granted a patent covering an Atmospheric Gas Engine in which a mixture of gas and air was to be exploded in a turbine. Although many ideas followed, it was not until 1908 that the first German gas turbine, Hans Holzwarth’s constant-volume type, was actually built. Two decades then passed before H. Oestrich at the Bramo engine company made jet propulsion studies but initially rejected such ideas for the speeds than in view.
  At the same time, early experimenters were obtaining unpromising results due largely to the lack of heat-resisting materials which would permit operating temperatures high enough to give the desired effinciency.
  Breakthrough
  The breakthrough for the turbojet began in the early 1930’s when Hans von Ohain began studying the problem. Curiously enough, he did not have a comprehensive picture of the previous studies of other pioneers (including Frank Whittle) despite a search through patents made in 1934, but he was in a position to have a model built around 1935 to demonstrate the turbojet principle.
 
Drawing Whittle patent, 1930
Whittle patent from 1930 shows a jet engine wiht axial compressor followed by a centrifugal flow-stage. The whittle development resulted in the Gloster E.28/39 flown for the first time on may 15, 1941.
 
  In the meantime, Paul Schmidt obtained patents and government support for work on the pulse-jet (1931). Karl Leist had patented a scheme for a turboprop engine (1934) and Helmut Walter had initiated studies of the ramjet and suggested a turbojet with afterburning (1934).
 
Schelp, Whittle, Ohain, Bentele
Left to right: Helmut Schelp, Sir Frank Whittle, Dr. Hans-Joachim von Ohain and Dr. Maz Bentele during a meeting on 4 May 1978 at the Air Force Museum in Dayton, Ohio.
 
  HeS 1
  With the exhausting of his personal funds, von Ohain was fortunate early in 1936 to obtain the backing of the Ernst Heinkel AG and he left the University of Göttingen to begin work on the first demonstration turbojet, the HeS 1, at Rostock-Marienehe.
 
Drawing of HeS 1
Drawing of the HeS 1.
 
  Making extensive use of sheet-metal, the HeS 1 had a centrifugal compressor, annular combustion chamber and radial inflow turbine. With a static thrust of about 250 kp (551 lb), this engine was succesfully bench-tested in april 1937 and work on the first flight engine, HeS 3, was put in hand.
 
Hans von Ohain with HeS 3A
Dr. Hans-Joachim Pabst von Ohain standing beside the HeS 3A jet engine in the Deutsches Museum.
 
  Turboprop and ramjet
  Contemporary with these events were the facilities set up under H. Wagner at the Junkers airframe works to study the turboprop and the desing made by Helmut Weinrich and Wolf Tommsdorf for a counter-rotating turboprop and ramjet missile respectively. However, apart form Walter’s ramjet work and Schmidt’s pulsejet work, there was no official or government backing for jet propulsion at that time.
  Programme
  That Germany eventually had an extensive jet propulsion programma at all was due to the early efforts of a few men within the German Air Ministry’s Technical Office. In august 1937, Helmut Schelp was sent to the research secton of the Technical Office and given charge of the pulsejet and ramjet projects of Schmidt and Walter but he made no headway there with his chief enthusiasm for gas turbines and turbojests and he had moved by september 1938 to the engine development section of the Technical Office.
  Here he found an ally in Hans A. Mauch who has inspected von Ohain’s early wordk (the HeS 3 was bench-running by then) and had conferred with the Junkers airframe company on its turboprop studies. It was decided, however, not to back officially either the later company or Heinkel since Mauch at least felt that such radical developments as jet engines could not be entrusted to airframe companies. On the other hand, approaches to engine companies, such as BMW, Bramo, Daimler-Benz and the Junkers engine devision with a view to developing a turbojet engine were greeted with little or no enthusiasme. Partly, the companies considered solutions to the great technical problems involved to be far in the future and they were already immersed in the problems of getting reliable piston engines of high power into production for a Luftwaffe clamouring to increase its potential.