Walter J.H. Riedel
From The Space Library
 Walter J.H. Riedel circa 1942 | |
| Birth Name | Walter Julius Hermann Riedel |
|---|---|
| Birth Date | December 5th 1902 |
| Birth Place | Königswusterhausen, Germany |
| Date of Death | May 15th 1968 |
| Place of Death | Berlin |
| Occupation | Engineer |
| Nationality | German, British |
| Notable Works | RAK-7 rocket car, V-2 rocket, A-3 and A-5 missile |
Contents |
Early Life
Walter Julius Hermann "Papa" Riedel was born in 1902 in Königswusterhausen, near Berlin Germany. His parents were Julius Wilhelm and Margarete Emma Riedel. From 1921 - 1927 he was employed as a civil engineer working for Mamag and Wolf, and Netter and Jacobi.
Heylandt and Valier
In 1927 he joined the A.G. Fuer Industriegasverwertung as a designer and engineer. He was assigned by his boss, Paul Heylandt, to be an assistant to the early rocket pioneer Max Valier, a role which he took from January 1930 until Valier's death in May 1930.
During those few months Riedel worked side by side with Valier and Arthur Rudolph as they created ever more powerful liquid fuel rocket engines. Over a four day period at the end of January 1930 Valier's engine increased in thrust from 300gm to 2,150gm. After a brief interlude Valier, Riedel and Rudolph increased the thrust in March 1930 to 8,000gm. On March 22nd 1930 the engine was installed in Valier's experimental rocket car the Rak 6, which was renamed the Rak 7. Valier was able to drive the car around a track for 22 minutes. By April 14th the engine was putting out 28kg thrust. The car was put around a test track for nearly 10 minutes and Riedel later wrote, "April 17 and 19 1930...These dates should be noted because they are of some historic importance. Indeed, it was the first time that a rocket propulsion with liquid propellants was demonstrated in Germany..."
On May 17th 1930 Riedel was operating the valves on an engine test using kerosene instead of alcohol as the fuel. Despite an earlier problem with the engine, Valier pushed ahead with another test against the protests of Riedel. The kerosene and liquid oxygen created a slurry in the engine nozzle and when the gelatinous mixture fell into the exhaust plume the engine exploded. Valier was mortally wounded and Riedel could do nothing more than catch him as he fell. Riedel was only six feet away from Valier and was partly protected by a low wall. Valier's death was the first high-profile accident involving a fatality with a liquid fuel rocket.
Work continued with Riedel, Heylandt and Arthur Rudolph at the Heylandt factory in Berlin-Britz after Valier's death. A larger car was built and tested at Tempelhof airport. It had a cylindrical fuel tank at front, a small nitrogen pressurisation system and a large spherical oxygen tank in rear. Rudolph later stated that Riedel "designed the entire system of the rocket car, I was responsible for the new injection system."
In 1931 or 1932 Riedel and Rudolph proposed and then built sophisticated cooling systems for their rocket engine, first using a water "jacket" and then regeneratively cycling the fuel around the combustion chamber.
Riedel may have briefly become a member of the VfR but the VfR and Valier's team didn't share common goals for very long. Valier was mostly interested in demonstrating rocket propulsion to the public by building rocket cars, planes and even sleds, using any kind of rocket including black powder or pressurised carbon dioxide. It was only in early 1930 that Valier turned to liquid propellants and it was Riedel who showed him the way forward.
Peterson reports that in March 1933 Riedel voted for the National Socialist Party.[1] This would have been within a few weeks of the Heylandt company being given a contract by the German Army to build a sophisticated liquid fuel rocket system with instrumentation, steady thrust and automatic valves. Riedel completed this project by the end of 1933 and fulfilled all of the Army's specific requests.
Kummersdorf
In 1934 long after the death of Valier, Riedel and Arthur Rudolph were still increasing the thrust from their liquid rockets when Walter Dornberger head of the German Army's rocket division recruited Riedel to come and join Wernher von Braun at Kummersdorf. He transferred from the Heylandt Company to Kummersdorf on January 15th 1934.[2] For a short time the entire German Army rocket team was comprised of just three men, Von Braun, Papa Riedel and a mechanic named Heinz Grünow.
When Riedel first arrived at Kummersdorf Von Braun had spent a year building his own liquid fuelled rocket but whereas Riedel had been building his system to run on a test stand, Von Braun was building a rocket to fly. This first iteration of Von Braun's design was known as the A-1. The ignition system was unreliable and the A-1 exploded multiple times. Von Braun and Riedel turned to a new design which incorporated many of the fuel tank, pressurization, valve and ignition systems designed by Riedel at Heylandt. The Army apparently paid for much of this technology to be transferred to Kummersdorf. This hybrid of Riedel and Von Braun components became known as the A-3 and with some further modification, the A-5, a missile which was essentially a highly successful miniature testbed version of the V-2.
In 1936 Von Braun had the idea to create a rocket propulsion system for a small aircraft. The requirement for this system was a hydrogen peroxide powered turbo-pump to push the propellants into the combustion chamber. Although it never flew, it gave both Von Braun and Riedel experience with HTP turbo pumps which Riedel later cited as proof that Max Valier had been correct to work on rockets for aircraft.
Peenemünde and the V-2
In 1937 Riedel became chief designer of the V-2 missile. In October 1942 he became Chief engineer on the V-2 production. In this role he was to fall prey to a political struggle between Dornberger and Von Braun. The former was becoming frustrated with the slow pace of development and propulsion engineer Walter Thiel blamed Riedel's department. Von Braun moved Riedel aside and by the summer of 1943 he was made special assistant to Von Braun in charge of monitoring production timelines for the V-2.[3] After the bombing of Peenemunde, when Thiel was killed, another role was found for Riedel; he was sent to survey a potential location for an underground construction site for rockets near Ebensee in Austria. Peterson also reports that Riedel "temporarily transferred there to assist in the work." The site later became a notorious concentration camp where military hardware was constructed, but no rockets came from Ebensee.
Post War Capture
On May 14th 1945 Riedel may have been located in a jail cell in Saalfeld where he was being held by U.S. Counter Intelligence. Some local people had directed the Americans to Riedel in the town of Leutenberg and accused him of making a bacteriological weapon. When Riedel tried to explain to his interrogators that what they were looking at was a valve for a surface to air missile they didn't believe him. When he lost his temper he was roughed up. It is not entirely clear if this anecdotal story was about "Papa" Riedel, who was frequently mixed up by later writers with Walther Riedel, another rocket pioneer who also worked on the V-2 before moving to California to work for North American Aviation.[4]
It is believed that "Papa" Riedel was interrogated in the United States at the end of the war.
After assisting with V-2 rocket launches for the British at Cuxhaven, as part of Project Backfire, "Papa" briefly worked in 1946 at Eugen Sanger's Raketentechnisches Forschungsinstitut in Trauen.
Employment in England
In March 1947 Papa Riedel was offered employment at the Royal Aircraft Establishment at Farnborough England where he worked until moving over to the associated Rocket Propulsion Establishment at Westcott in Buckinghamshire in 1948. Riedel was granted British citizenship on November 18th 1953 and was sworn in on 30th November with an oath of allegiance to Queen Elizabeth II. His occupation was listed as "Temporary Civil Servant". He and his wife Else and their daughter were living in Aylesbury, Buckinghamshire at this time.
Late Life and Legacy
Riedel remained working at Westcott until his death which happened while visiting his sister in East Berlin on May 15th 1968. In his obituary in the Journal of the British Interplanetary Society it was reported that he had worked on both liquid and solid fuel rockets at Westcott. It is known for certain that he wrote a damage analysis for the British solid fuel Cuckoo II rocket engine when it was being used as a second stage for the Black Knight rocket.
In 1953 he wrote of his experiences with Valier in an article for the journal Weltraumfahrt.
In 1956 writing in the Journal of the British Interplanetary Society Wernher von Braun stated, "Hardly a rivet or washer in our experimental A-3, A-5, A-9, and particularly the A-4 can have escaped his personal scrutiny."[5]
A technical study of his work from 1930 to 1942 was translated into English in 2005 and published by the Rolls Royce Historical Society.[6] In that document Riedel explained how many of the principle components of the A-3 propulsion system came from the research he had conducted with Valier, and remained virtually unchanged when applied to the V-2. This contention was supported by later research conducted in 2007 by Dr Olaf Przybilski at the Dresden Technical University.[7]
In a letter written just before his death he stated, "For personal reasons I have severed my connections related to rocket and space exploration. I also do not wish to be mentioned in any way with the beginnings of the missile"[8]
Footnotes
- ^ Engineering Consent: Peenemunde, National Socialism, And The V-2 Missile - Michael Brian Petersen (2005)
- ^ Wernher von Braun's Aggregat 2 - Olaf Przybilski (Luft- und Raumfahrt 3/2007)
- ^ Von Braun - Dreamer of Space, Michael J. Neufeld (Knopf 2007)
- ^ The Rocket Team - Frederick I. Ordway III and Mitchell Sharpe (Apogee 2003)
- ^ Reminiscences of German Rocketry - Wernher von Braun - JBIS Vol 15 No 3 May-June 1956
- ^ Rocket Developments With Liquid Propellants - W.H.J. Riedel (Rolls Royce Heritage Trust TS07 2005)
- ^ Wernher von Braun's Aggregat 2 - Olaf Przybilski (Luft- und Raumfahrt 3/2007)
- ^ Ibid.
