The “Seesen Quadriga” under the magnifying glass TU Braunschweig graduate wins the promotional prize of the Society for Construction History

His findings could be groundbreaking for many restoration projects: Now, the master’s thesis of Braunschweig civil engineering graduate Julian Leonard Rudolph has been awarded the promotional prize of the Society for Construction History. His thesis “The Model Figure Group of the Braunschweig Quadriga of 1890” deals with historical joining techniques for copper plates in large sculptures and examines these using the so-called “Seesen Quadriga” as an example.

The work of Julian Leonard Rudolph is characterized by the fact that it rediscovers forgotten techniques of copper metal processing, classifies them historically and compares them for the first time. The focus is on master smith Georg Howaldt’s joining technique of the Brunswick quadriga, which he examines on the basis of the so-called “Seesen Quadriga”. It is a scaled-down copy of the sculpture built for the 1893 World’s Fair in Chicago, USA, by Howaldt’s student Bode. The latter had already worked on the first Braunschweig Quadriga. The Seesen Quadriga is the last surviving original using Howaldt’s technique.

Hidden construction method investigated

“In 2020, the Institute for Preservation of Structures (ibt) investigated the structural safety of a scaled replica of the Braunschweig Quadriga from 1893. In his master’s thesis, which has now received an award, Mr. Rudolph worked on the background of building technology history with remarkable initiative and technical depth, which is also important for research on many similar works of art. ibt congratulates him on this more than deserved award”, ibt director Professor Klaus Thiele is pleased to say. And Nicole Parlow, member of the jury of the Society for Construction History, emphasizes: “With his work, Julian Rudolph pays special attention to sheet metal sculptures, which have been rather neglected until now, by addressing the often hidden method of construction.”

Originally, large sculptures were cast. When this was no longer economical due to weight and material costs, sculptures were made from copper plates, which were often joined to a substructure with rivets or an interlocking soldering technique. Georg Howaldt from Braunschweig had developed a new joining technique for large sculptures, in which the driven copper sheets were screwed together on copper rails. The screws were pre-drilled with countersinking of the screw heads. The protruding screw heads were then filed off, creating a flat and smooth surface so that the position of the copper plates could only be seen up close. For his master’s thesis, Rudolph conducted his own series of tests to recreate these connections based on Howaldt’s historical construction method. In doing so, he demonstrated that the seams were very strong. Based on this series of tests, the stability of the figures could be recalculated even more precisely in a 3D model.

Figures made of copper sheets

The knowledge gained about the various joining techniques and their effects on stability can be groundbreaking for future restoration projects. In the case of large sculptures, several joining techniques for the copper plates are sometimes used simultaneously: for example, during an inspection of the Hermann Monument in the Teutoburg Forest, Rudolph showed the local project managers a variety of different techniques used there.

As part of the research, the civil engineer also visited master blacksmith Achim Kühn, one of the last of his profession who can produce large sculptures from copper sheets. Kühn reconstructed parts of the Apollon chariot group and the Pegasus on the Berlin Schauspielhaus in the 1970s. From him, Rudolph was able to learn first-hand how the huge figures were driven from copper sheets and what difficulties had to be mastered in the process.

Julian Leonard Rudolph now works in an engineering office in Braunschweig, where he also spends a lot of time working in the field of restoration and monument protection. In the future, the TU graduate will be working in particular for the local test engineer on the regular inspection of the stability of the current so-called Third Quadriga on the Braunschweiger Schloss.

The promotional prize of the Society for Construction History

With the biennial prize for young scientists, which is endowed with 1,000 euros, the Society honors outstanding theses and dissertations. The theses must have been completed no more than three years before the deadline for submission. This year the prize committee of the society consisted of the two chairmen, Prof. Dr.-Ing. Stefan M. Holzer (Zurich) and Dr. Christoph Rauhut (Berlin), and three members appointed by the general meeting, Prof. Dr. Andreas Kahlow (Potsdam), Dipl.-Ing. (FH) Nicole Parlow (Berlin) and assoc. Prof. Dr.-Ing. Christiane Weber (Innsbruck).

The Society for Construction History, founded in 2013, currently brings together around 175 architects, civil engineers, monument conservators, and historians of architecture, technology, art and science who work at universities, in offices and in monument offices in Germany, Austria and Switzerland.