History meets science to reveal hidden secrets

Ms Birte Koehler, a senior object conservator at the Heritage Conservation Centre, with a centuries-old wooden book stand that underwent a CT scan at the Singapore General Hospital yesterday.
Ms Birte Koehler, a senior object conservator at the Heritage Conservation Centre, with a centuries-old wooden book stand that underwent a CT scan at the Singapore General Hospital yesterday.ST PHOTO: JONATHAN CHOO

Heritage board and SGH team up to conduct CT scans on museum artefacts

It was a meeting of history and science yesterday, when the Singapore General Hospital (SGH) took in a very special "patient" - a centuries-old wooden book stand - for a medical scan.

The National Heritage Board (NHB) has teamed up with the hospital to conduct computed tomography (CT) scans on such museum artefacts.

Since September last year, conservators from the Heritage Conservation Centre (HCC), an institution of NHB, have used SGH's CT imaging machines to study three museum artefacts: a tortoise shell gong, a sealed ceramic jar and a wooden book stand or lectern.

These scans have given the centre's conservators an in-depth look and analysis of the objects, said Mr Kenneth Yeo, 54, a principal radiographer at SGH who helped spearhead the collaboration.

The idea is to see how an item is constructed, or if it is damaged, for instance.

While conservators have used the hospital's X-ray machines since 2014, it is only since last year that they have experimented with the hospital's CT scan machines, he noted.

ADVANTAGE OF SCANS

That's the advantage, you don't have to open up the objects to see what is inside them.

MR KENNETH YEO, a principal radiographer at SGH who helped spearhead the collaboration.

Unlike X-ray images, CT scans are three-dimensional, like a "virtual cake" which can be cut up and analysed "slice by slice", explained Mr Yeo, who was speaking at a media showcase of the scanning sessions yesterday.

"That's the advantage, you don't have to open up the objects to see what is inside them," he added.

Conservators - professionals who repair and preserve cultural items - use information from this cross-sectional analysis to understand how an artefact is constructed and what type of material it is composed of. This is key information that could be used in research, or for advising on conservation methods.

Such diagnostic imaging technology is already used by large museums overseas, which have dedicated imaging devices to analyse artefacts, said Ms Birte Koehler, 48, a senior object conservator at the HCC.

But as the local centre does not have such machines, being able to leverage on the hospital's existing machines and staff has been a boon, she noted.

"These are very expensive machines... we are quite happy to have this collaboration," she said.

Yesterday, a wooden lectern from the Asian Civilisations Museum's collection was scanned, and results showed that it was constructed from a single block of wood, said Ms Koehler. This would be compared with findings from ongoing research about lecterns in the region, she noted.

"We can see how it all eventually fits into the bigger picture," said Ms Koehler.

Previous scans have also uncovered new details about the artefacts. For example, a scan of a sealed ceramic jar in September last year showed that there was a metal ring within the jar, said Mr Damian Lizun, 42, a conservator of paintings from the HCC.

Another CT scan of a tortoise shell gong last year revealed the exact location of crack lines within the shell, he noted.

HCC conservators will continue to use the hospital's imaging facilities for at least two more years under a new agreement with the hospital. This is part of an ongoing initiative by NHB to strengthen the nation's conservation expertise.

A version of this article appeared in the print edition of The Sunday Times on October 07, 2018, with the headline 'History meets science to reveal hidden secrets'. Print Edition | Subscribe