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Kunsthaus Zürich

Measures undertaken on the
back side

Substitution of the corroded static elements such as reinforcements, anchors and screws (on the back side) with high-alloy chloride-resistant metal devices.
The major works on the back side of The Gates of Hell began in August.  Michael Salzgeber and Samuel Zubler, two engineers of Firma Wetter, were put in charge with the planning and execution, in collaboration with the restorer Joseph Ineichen.
 
Instead of working on the actual poured bronze figures, this stage of the project was dedicated mainly to the substitution of the original and now fully corroded static elements such as the reinforcements and anchors.
In the past months a new support structure made of high-grade metal has been planned and built.  In addition to the narrowly defined material requirements and the precise execution and mounting, the support structure needed to meet another set of important criteria:  it needed to be such as to allow for an additional frame to be easily installed in order for the Gates to safely travel to the Royal Academy in London.

Full view of the back side before the restoration.  Strongly corroded, original support structure and screws made of iron.  The bearing capacity of the elements in the lower section is put at risk, in part due to thorough rusting. (Photo:  F. Forrer, Editing:  P. Schwindel)
Full view of the back side before the restoration. Strongly corroded, original support structure and screws made of iron. The bearing capacity of the elements in the lower section is put at risk, in part due to thorough rusting.
(Photo: F. Forrer, Editing: P. Schwindel)