Hellmuth Walter (26 August 1900 – 16 December 1980) was a German

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considerin ...

who pioneered research into

rocket engine A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accorda ...

s and gas turbines. His most noteworthy contributions were rocket motors for the

Messerschmitt Me 163 The Messerschmitt Me 163 Komet is a rocket-powered interceptor aircraft primarily designed and produced by the German aircraft manufacturer Messerschmitt. It is the only operational rocket-powered fighter aircraft in history as well as ...

and Bachem Ba 349

interceptor aircraft An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are ...

, so-called ''Starthilfe'' jettisonable rocket propulsion units used for a variety of

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German '' Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the '' Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabt ...

aircraft during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, and a revolutionary new propulsion system for

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s known as

air-independent propulsion Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel). AIP can augment or replace th ...

(AIP).

Early life

Walter began training as a

machinist A machinist is a tradesperson or trained professional who not only operates machine tools, but also has the knowledge of tooling and materials required to create set ups on machine tools such as milling machines, grinders, lathes, and drilling ...

in 1917 in

Hamburg Hamburg (, ; nds, label=Hamburg German, Low Saxon, Hamborg ), officially the Free and Hanseatic City of Hamburg (german: Freie und Hansestadt Hamburg; nds, label=Low Saxon, Friee un Hansestadt Hamborg),. is the List of cities in Germany by popul ...

and in 1921 commenced studies in

mechanical engineering Mechanical engineering is the study of physical machines that may involve force and movement. It is an engineering branch that combines engineering physics and mathematics principles with materials science, to design, analyze, manufacture, ...

at the

Technical University of Berlin The Technical University of Berlin (official name both in English and german: link=no, Technische Universität Berlin, also known as TU Berlin and Berlin Institute of Technology) is a public research university located in Berlin, Germany. It was ...

. He left before completing these studies, however, in order to take up a position at the Stettiner Maschinenbau AG Vulcan, a major

shipyard A shipyard, also called a dockyard or boatyard, is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance ...

. Walter's experience with marine engines here led him to become interested in overcoming some of the limitations of the

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal co ...

. He reasoned that an

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy b ...

source already rich with

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

would not require an external supply of oxygen (from the

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A ...

or from tanks). This would have obvious advantages for powering submarines and

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, ...

es. Research suggested that

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ...

was a suitable monopropellant fuel—in the presence of a suitable

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

it would break down into oxygen and

steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporizatio ...

at high

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

. The

heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...

of the reaction would cause the oxygen and steam to expand, and this could be used as a source of

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country a ...

. Walter also realised that another fuel could be injected into this hot mixture of gases to provide

combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combus ...

and therefore more power. He

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

ed this idea in 1925.

Entrepreneur

After working for some time at the Germaniawerft shipyard in

Kiel Kiel () is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 246,243 (2021). Kiel lies approximately north of Hamburg. Due to its geographic location in the southeast of the Jutland ...

, Walter branched out on his own in 1934 to form his own company, Hellmuth Walter Kommanditgesellschaft (''HWK'', or ''Walter-Werke''), to further

research and development Research and development (R&D or R+D), known in Europe as research and technological development (RTD), is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existi ...

of his ideas. That same year, he made a proposal to the ''Oberkommando der

Kriegsmarine The (, ) was the navy of Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war (1919–1935) of the Weimar Republic. The was one of three official branches, along with the a ...

'' (OKM – Naval High Command) suggesting that a submarine powered by one of these engines would have considerable speed advantages over the conventional combination of diesel engine(s) for surface running and electric motor(s) while submerged. The proposal was met with much scepticism, but Walter persisted, and in 1937 showed his plans to

Karl Dönitz Karl Dönitz (sometimes spelled Doenitz; ; 16 September 1891 24 December 1980) was a German admiral who briefly succeeded Adolf Hitler as head of state in May 1945, holding the position until the dissolution of the Flensburg Government fo ...

, who was able to assist in obtaining a contract to produce a prototype. Construction started in 1939 on a small research submarine designated the V-80. When it was launched in 1940, the submarine demonstrated a top speed of 23 knots submerged, twice that of any submarine in the world at the time. Despite these spectacular results, problems with the production, supply, and safe handling of hydrogen peroxide prevented wide-scale implementation of Walter's revolutionary engine. In the end, only a handful of German Type XVII submarines were built using this engine, and none saw combat.

Rocket engines

At the same time that Walter was developing submarine engines, he was also applying his ideas to rocketry. The high-pressure gas mixture created by the rapid decomposition of hydrogen peroxide could not only be used in a

turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating ...

, but if simply directed out of a

nozzle A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe. A nozzle is often a pipe or tube of varying cross sectional area, ...

, created considerable

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that ...

. Wernher von Braun's rocketry team working at Peenemünde expressed interest in Walter's ideas, and in 1936 began a programme of installing Walter rockets into

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

. The experimental results obtained by von Braun created interest among Germany's aircraft manufacturers, including

Heinkel Heinkel Flugzeugwerke () was a German aircraft manufacturing company founded by and named after Ernst Heinkel. It is noted for producing bomber aircraft for the Luftwaffe in World War II and for important contributions to high-speed flight, with ...

and

Messerschmitt Messerschmitt AG () was a German share-ownership limited, aircraft manufacturing corporation named after its chief designer Willy Messerschmitt from mid-July 1938 onwards, and known primarily for its World War II fighter aircraft, in parti ...

, and in 1939, the Heinkel He 176 became the first aircraft to fly on liquid-fuelled rocket power alone. This type of engine went on to become the cornerstone of the Messerschmitt Me 163 rocket-powered fighter, when married to

Alexander Lippisch Alexander Martin Lippisch (November 2, 1894 – February 11, 1976) was a German aeronautical engineer, a pioneer of aerodynamics who made important contributions to the understanding of tailless aircraft, delta wings and the ground effect, and ...

's revolutionary

airframe The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system. Airframe design is a field of aerospa ...

design. Throughout the course of

, Walter's aircraft engines became increasingly powerful and refined. The original design of simply decomposing hydrogen peroxide was soon changed to its use as an oxidizer (much like

dinitrogen tetroxide Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium ...

would be used later) when combined with a hydrazine/methanol true rocket fuel designated

C-Stoff C-Stoff (; "substance C") was a reductant used in bipropellant rocket fuels (as a fuel itself) developed by Hellmuth Walter Kommanditgesellschaft in Germany during World War II. It was developed for use with T-Stoff (a high-test peroxide) as an o ...

, into the hot, high-pressure gases, and in later, never-deployed developments, a second, 400 kg (880 lb) thrust "cruising" combustion chamber, nicknamed a ''Marschofen'', was added below the main chamber to allow for more precise control of the engine. Versions of this engine were intended to power a variety of aircraft design proposals and

missile In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocket ...

projects and was also licence-built in

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

(see HWK 109-509). Another Walter engine was used to assist heavily laden aircraft to take off (

JATO JATO (acronym for jet-assisted take-off) is a type of assisted take-off for helping overloaded aircraft into the air by providing additional thrust in the form of small rockets. The term ''JATO'' is used interchangeably with the (more specifi ...

or RATO). When the rockets' fuel had run out, they would separate from the aircraft and return to the ground by

parachute A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, w ...

for refurbishment and re-use (see Walther HWK 109-500). In 1945, Walter was awarded the

Knight's Cross Knight's Cross ( German language ''Ritterkreuz'') refers to a distinguishing grade or level of various orders that often denotes bravery and leadership on the battlefield. Most frequently the term Knight's Cross is used to refer to the Knight's ...

for his wartime service. Walter was captured by a British Army unit named

T-Force T-Force was the operational arm of a joint US Army–British Army mission to secure German scientific and industrial technology before it could be destroyed by retreating German forces or looters during the final stages of the Second World War ...

following a 60-mile advance behind German lines to prevent his research falling into the hands of the advancing Russians. His factory was then investigated by

30 Assault Unit No. 30 Commando, from 1943 to 1946 known as 30 Assault Unit, was a British Commando unit during the Second World War, originally formed to gather intelligence. History Formation In a 2012 documentary Dieppe Uncovered, Canadian Professor David O ...

, a unit of Royal Marines which had been established by ''

James Bond The ''James Bond'' series focuses on a fictional British Secret Service agent created in 1953 by writer Ian Fleming, who featured him in twelve novels and two short-story collections. Since Fleming's death in 1964, eight other authors hav ...

'' author

Ian Fleming Ian Lancaster Fleming (28 May 1908 – 12 August 1964) was a British writer who is best known for his postwar ''James Bond'' series of spy novels. Fleming came from a wealthy family connected to the merchant bank Robert Fleming & Co., an ...

Post-war career

The end of the war saw all of his research materials confiscated by the British military and Walter and his colleagues taken to the UK to work for the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...

. With Walter's co-operation, one of the German submarines using his drive, the U-1407 was raised from where it had been scuttled and re-commissioned as HMS ''Meteorite''. The Royal Navy constructed two more submarines using AIP engines before abandoning research in this direction in favour of

nuclear power Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced b ...

. Allowed to return to Germany in 1948, Walter worked for the Paul Seifert Engine Works. In 1950 he emigrated to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

and joined the Worthington Pump Corporation of Harrison, New Jersey, eventually becoming vice president of research and development. In 1956 he founded the company Hellmuth Walter GmbH in Kiel, and in 1967 constructed a civilian submarine, STINT, with Walter propulsion.

Notes

References

* * *

External links

*
"The Hellmuth Walter Website"
{{DEFAULTSORT:Walter, Hellmuth 1900 births 1980 deaths Engineers from Schleswig-Holstein German rocket scientists German emigrants to the United States Recipients of the Knights Cross of the War Merit Cross People from Wedel