Holkham Hall

Investigating Marble statues in Holkham Hall, Norfolk - using NDT

Structural investigative specialist, GBG, has been commissioned by Skillington Workshop Limited to undertake surveys of a number of marble statues - including Lucius Verus, Apollo, Satyr with Pigskin and Dionysus - at Holkham Hall in Norfolk.

The surveys were designed to identify any metal pins which had been used to repair the statues, prior to carry out a conservation programme. In the case of Lucius Verus, an iron pin had been used to fix a replacement base to the statue. This had corroded and caused a large section of the marble to spall, thus revealing the pin.

According to Dr. David Carrington of Skillington Workshop: 'We wanted to draw upon specialist non-destructive testing expertise to assess the depth of the corroded pin and also to identify any similar repairs within this and the other statues.'

GBG's engineers used NDT Techniques normally associated with structural investigation to investigate the statues. Each part of the statues to be surveyed was scanned using a metal detector, followed by impulse radar. UPV was used to provide information on the condition of the marble.

Dr. Carrington: 'The information provided by GBG's report was very useful. It revealed the length of the corroded pin, which then allowed us to accurately plan its removal and replacement with stainless steel fixings. We were also unsure whether there were corroded iron fixings in any of the other statues: their survey has confirmed that it is only the Lucius Verus statue that is of immediate concern. This information has influenced our approach to the repair works.'