After arriving in Germany in 1934, it was found that PVWS had only research sites in the shipbuilding sector, where the researcher himself had to make a financial contribution to the research. As Shields did not have any extra money, this was not possible (in addition, the value of his grant was significantly reduced due to the massive inflation). The only option offered to him was to continue research into the stability of bed material in watercourses (
Geschiebebewegung). This investigation was initiated by Franz Eisner, who had committed suicide in 1933 because he had been expelled from his position by the Nazis. Shields was given the office of Eisner (Eisner had committed suicide in this office) and he was assigned two assistants. Shields continued to work on the investigation that had been initiated before him by Hans Kramer and Hugh John Casey (both also American bursals in Germany). Since Shields as a mechanical engineer had no background knowledge in this, he had to make it his own first. His promoter was Dr. Ing. Adolf Ludin, a convinced
Nazi with a dislike of Americans. Fortunately, he had nothing to do with him in his daily work. He only met Ludin twice, at the start of the research and at his PhD. Because he had to finish this extra master's degree, he got into financial difficulties and had to look for a job. He couldn't find a job in Berlin. Finally, he found a job at a steelworks in the
Saarland area of Germany. He worked here in the summer of 1935. In the autumn of 1935 he was able to continue his research at PVWS somewhat after hassle and by the spring of 1936 the research was completed and the manuscript of his dissertation was completed. After some minor improvements, the dissertation was submitted to the Berlin TH in May 1936 and his promoter, prof. Ludin. On 30 June it was (oral) exam; Prof. Ludin listened to his presentation without any comment. Right after the presentation, Ludin only gave some derogatory remarks and left. Shields never spoke to him again. Shields did not even have a copy of the dissertation, which he had lent to one of the examiners. A few days later, he received a message that his dissertation had been assessed with a “Gut” (a 7 on scale 1 to 10). Shields was disappointed with this result and wanted to go home as soon as possible. It was customary at that time for a dissertation to appear in print only after it was defended. The director of PVWS, Prof. Seifert, promised to send Shields 200 copies of the dissertation; Shields, however, was never allowed to receive it. In this dissertation, Shields presented a graph for the stability of sand and gravel in currents based on a dimensionless number (later called the
Shields parameter, as well as a formula for calculating that stability and a sand transport formula, the
Shields formula. These results are an important basis of current knowledge in the field of sediment transport.{{cite book {{cite journal He still had a few obligations to PVWS. At this time, he managed to do some research with Dr. Weinbaum on the wave resistance on ship hulls. This was the research he actually came to Berlin for. ==His later career==