Born: 1910-03-03. Died: 1943-08-17.
Had Thiel remained alive, development of a simplified 25 metric ton thrust engine for the V-2 probably would have been completed in time for production versions of the missile.
Wikipedia: Dr Walter Thiel (born March 3, 1910 Breslau - dued August 18, 1943 Karlshagen, near Peenemünde) was a German rocket scientist. Walter Thiel provided the decisive ideas for the A4 rocket engine and his research enabled rockets to head towards space.
Walter Erich Oskar Thiel was born on March, 3, 1910 in the Silesian city of Breslau, as second son of Oskar Thiel (civil servant at the German Post) and Elsa Thiel. 1929 Walter Thiel passes all Abitur exams with the highest possible grade A. After his Abitur he studied chemistry at the Polytechnical College in Breslau. Due to his excellent work he was exempt from study fees as of the third semester.
In summer semester of 1931 he passed the preliminary examination with excellence. In winter semester 1933 he passed all 7 diploma exams with the highest possible grade A and he became Dipl.-Ing. (chem.). In 1934 his thesis “Über die Addition von Verbindungen mit stark polarer Kohlenstoff-Halogenbindung an ungesättigte Kohlen-Wasserstoffe“ received the highest possible honor (summa cum laude). He became Dr.-Ing. (chem.). His doctorate was confirmed on November 8, 1934 in Breslau (source: Walter Thiel’s doctorate).
Thiel's Professor in Breslau recommended Thiel to the Research Institute of the German army ordnance office of under-secretary Prof. Karl Erich Schumann at the University of Berlin. Thiel’s previous findings had technological applicability and therefore he was able to continue his fundamental research in a leading position. Late 1934 or early 1935 Thiel became research instructor at Reichswehrministerium. Schumann accompanied many diploma theses and dissertations, including that of Wernher von Braun, who completed his dissertation in 1934. The contacts between the testing ground in Kummersdorf and Schumann’s Institute was close, the eastern part of the site in Kummersdorf served as an experimental base for Schumann’s institutes, in the west a group of scientists around Major Walter Dornberger carried out their experiments. Here Thiel got to know Walter Dornberger and Wernher von Braun.
In autumn of 1936 Dornberger asked Thiel to move from fundamental research to Wa Prüf 11 at Kummersdorf’s western testing ground. All topics regarding the engine were assigned to Thiel, and he had to further advance the propulsion, which he managed in a very short time. In his paper “Empirische und theoretische Grundlagen zur Neuberechnung von Öfen und Versuchsdaten, Schießplatz Kummersdorf Vers. West“, that he presented on April 27, 1937, Thiel introduces developments that lead to decisive changes, including a shortening of the oven and an optimization of the injection nozzle. Furthermore, Thiel continued to research different fuel mixtures for the rocket engines.
In 1937 the first scientists moved from Kummersdorf to Peenemünde. As the test stations were not ready yet, Thiel and his team stayed in Kummersdorf until 1940. After transferring from Kummersdorf to the Peenemünde Army Research Center in the summer of 1940, Thiel became deputy director of the Peenemünde HVP Organization under von Braun. In 1940 many new scientists were recruited in order to speed up the R&D of the A4. Chemist Gerhard Heller became a very important co-worker of Thiel. They also established private contacts. Other colleagues of Thiel at the development unit, who later followed von Braun to Fort Bliss (USA) as the first 118 paperclip engineers, included: Hermann M. Bedürftig, Konrad Dannenberg, Werner Dobrick, Hans Fichtner, Werner Gengelbach, Hans J. Lindenmayr, Dr. William A. Mrazek, Kurt E. Patt, Gerhard H. Reisig, Walther J. Riedel (Riedel III), Ludwig Roth, Helmut Zoike.
The scientists’ hard and intense work on the A4 project was crowned with the first successful launch from test station VII on October 3, 1942. The rocket flew 190 km in the targeted direction and it reached a height of 85 km. The top-speed was 1,322 m/s. As the A4 was now showing military qualities, the NS leadership was demanding immediate implementation in war. Mass production replaced science, although the whole unit was still immature. There were many launch failures after October 3, 1942. In 1943 Thiel and many fellow scientists and researchers were very exhausted and unhappy in Peenemünde. Work overload, pressure to succeed and the changeover from a research unit to a production facility started to take its toll on the scientists. Thiel refused to declare the rocket engine ready for mass production. In a letter to von Braun, sent during a trip to a health farm, Thiel described the Aggregat 4: “…where it is more of a complicated lab product than a mass item….”. Thiel formulated his protest by handing in his resignation orally on August 17, 1943. He planned to get his professorship at a university. Dornberger rejected his resignation.
During the following night from August 17 to August 18, 1943 the Royal Air Force launched a bombing raid of Peenemünde, Operation Hydra. The Thiel family died in a slit trench in front of their home in Karlshagen. It is very likely that a bomb hit the slit trench directly. Thiel and his family (wife Martha, daughter Sigrid and son Siegfried) were buried at the war cemetery in Karlshagen. Martin Schilling replaced Thiel.
On 29 October 1944, Thiel was posthumously awarded the Knight's Cross of the War Merit Cross with Swords.
Thiel’s accomplishments were not forgotten. In 1970 a moon crater is named after him. It is located on the dark side of the moon and it is not visible from earth. (Coordinates: 40° 42’ N / 134° 30’ W, mean diameter: 32.0 km). In addition, Thiel was one of the first pioneers to be inducted in the “Space Hall of Fame” in Alamogordo, New Mexico, USA in 1976.
Aggregate series Development
Based on the film cooling ('veil cooling') solution identified by colleague Moritz Pöhlmann at Peenemünde, Thiel designed annular rings of tiny perforations to inject unburnt fuel through the chamber walls at the throat for evaporative cooling to prevent V-2 rocket nozzle erosion.
By September 15, 1941, Thiel officially declared the basic eighteen-pot design of the A-4 motor finished.
Earlier in the Spring of 1941, Thiel began investigating nitric acid and diesel oil to be used as the fuel for the 30-ton-thrust A-8 .
Then on December 18, 1941, Thiel documented the initial A-9/A-10 motor design of six combustion chambers into one common nozzle in Secret Command Document 1496/41.
By the middle of August 1943, Dr Thiel declared that the A-4 developmental problems preclude mass production, recommended the project be abandoned.
Thiel also designed the motor for the Wasserfall anti-aircraft missile.
Joint German Army-Air Force rocket research station opened at Peenemünde on the Baltic Sea. The Army Ordnance rocket program under Capt. Walter Dornberger moved 90 of its staff from Kummersdorf. Thiel and five staff working on V-2 rocket engine development remained at Kummersdorf until the summer of 1940, when the test stands at Peenemuende were finally completed..
The engine delivered 18 months after design started was so compact, that the length of the A4 could be cut in half. Walter Thiel, a gifted and systematic researcher, was responsible for the engine design. He had great difficulties in obtaining stable combustion, and preventing burn-through of the chamber walls. Various injector patterns were studied in a 1.5 tonne thrust chamber. His research finally reduced the combustion chamber length from 2 m to 30 cm, while the exhaust velocity was increased from 2000 m/s to 2100 m/s, and eventually reached 2280 m/s. However the reduction in the cooling area of the chamber also increased problems in preventing hot spots and burn through. This was finally solved by using a conical throat exit and a mixing chamber ahead of the burning chamber. The 1.5 tonne thrust engine was initially run at 15 bar pressure, versus the 50 bar desired. But whenever the combustion chamber pressure was increased, burn-throughs occurred, as well as forcing increases in the mass of the pumps and tanks. Therefore finally the decision was taken to leave the chamber pressure at 15 bar.
The next step was to make a 4.5 tonne thrust by clustering three of the 1.5 tonne engines as preburners. However Thiel still had burn-throughs in test runs. Poehlmann suggested the use of film cooling, which finally solved the problem. For the 25 tonne thrust engine, Thiel simply used 18 x 1.5 tonne thrust chambers, feeding a common mixing chamber. This was on the test stand in early 1939.
Saenger's advanced rocketry work was so secret that Von Braun was not even aware of it until one of his team, looking for a new method of rocket ignition, heard of its existence. Von Braun, Walter Thiel, and Rudolf Hermann were finally given a tour of Saenger's advanced facilities at Trauen.
Throughout the early 1940's Thiel and his team sought to produce a single chamber 25 tonne thrust engine in place of the kludged prototype engine that used 18 separate 1.5 tf chambers. They managed to demonstrate a 60 second burn time in the 18-chamber design, but the engine itself was considered too complicated to fabricate in production, requiring thousands of hand-assembled tubes to introduce fuel and oxidiser into the chamber. Thiel sought to replace these thousands of tubes with a simpler injection system - rows of simple bored holes on a flat injector plate at the head of the chamber. Beck at the Technische Hochschule in Dresden developed a ring-pattern injector that worked well in subscale engines. But the design proved unstable in the 25 tf engine. Therefore, it was decided to stick with the 18-head chamber for V-2 production.
With only four months to go before Degenkolb's mandated production of 900 missiles per month, the engineers declare the missile is not ready for production. A workable engine has been developed, but it is complex, suitable for prototypes only, and the engineers involved do not have the experience to turn it into something designed for mass production. Continuous changes on the engine also affect other parts of the rocket, resulting in drawing changes simultaneous with the effort to mass-produce detailed parts. Thiel and his team declare that in fact development of the A4 can never be finished before the war's end. They recommend that plans to put it into production should be stopped. Thiel, at the verge of a nervous breakdown, led this engineering 'revolt', although Rees was the spokesman. They declare they would stop work at Peenemuende and retire to the university. Von Braun argued against this position, demanding that production continue. Dornberger suffered a crisis of confidence in the rocket team as a result of this fight, but decided to continue trying to get the missile in production and fielded with the Germany Army.
The Royal Air Force attacked Germany's Peenemünde Rocket Research Center, causing heavy damage and delaying V-weapon program by months.
With the V-2 development program already in crisis, the Allies launch a massive bombing raid against Peenemuende. On that evening test pilot Hanna Reitsch was visiting the launch site. At 23:30 the air raid siren sounded. 600 British bombers drop 1500 tonnes of ordnance on the launch centre. However many bombs fell in the ocean around the peninsula, or buried themselves harmlessly in sand dunes. The resident area was hardest hit, while the Luftwaffe station at Peenemuende West was not touched. 47 British bombers were shot down - they were told before the raid that this was the most important mission of the war, and that their commanders would accept a 50% loss rate. 735 people were killed in the raid on the ground, including 178 of the 4000 inhabitants of the residential area. A large number of the foreign slave workers in the Trassenheide concentration camp barracks were also killed.
After the tremendous raid the rocket team wander around the devastated facility, half-clothed, the buildings bathed in a weird light and everything covered in fine sand, as if flour was dropped over everything. Thiel and Walther - the two leading rocket engineers in Germany - were killed in the raid, and virtually all major facilities were damaged. The saving grace was that the soft sand of Peenemuende attenuated the blast of many bombs. Nine bombs hit the main assembly hall, but while there was splinter damage to some of the machine tools, there was no decisive hit that would prevent production from continuing. It was estimated that operations could resume in 4 to 6 weeks.
The raid was not unexpected. The high altitude contrails of the V-2 test launches were called 'frozen lightning' and could be seen from Sweden on clear days. The location and purpose of Peenemuende appeared in a crossword puzzle in a illustrated magazine published in central Germany in early 1943. British reconnaissance flights to locate the launch facilities had been recognised for what they were.
This raid, together with the bombing of V-2 production lines at the Zeppelinwerke in Friedrichshafen and the Raxwerke in Wiener Neustadt convinced Saur to reduce the V-2 production rate goal to 900 per month.