Liverpool Conservation Technologies
Measuring Instruments
Liverpool Conservation Technologies
An in-depth look at the way in which the Range 7 3D Digitiser is currently being used at Liverpool Conservation Technologies, UK.
An Egyptian Bennu-Bird captured in 3D
Amongst the many items on display in the new Ancient Worlds gallery at World Museum Liverpool are some fragile Egyptian figure-moulds. Figure moulds were used for making shapes, in this case, of the Egyptian bennu-bird (a heron or phoenix). The carved limestone tablets were made and used in about 664-332 BC.
The Bennu-bird serves as the Egyptian correspondence to the phoenix, and is said to be the soul of the Sun-God Ra. According to ancient Egyptian myth, the Bennu had created itself from a fire that was burned on a holy tree in one of the sacred precincts of the temple of Ra. The Bennu was pictured as a grey, purple, blue, or white heron with a long beak and a two-feathered crest. (Depicted left). The Book of the Dead says, “I am the Bennu bird, the Heart Soul of Ra, the Guide of the Gods to the Tuat."
Before the figure-moulds were installed in the gallery in November 2008, Conservation Technologies at National Museums Liverpool used a Konica Minolta Sensing Range 7 close-range 3D laser scanning system to digitally record the surfaces of the moulds to sub-millimetre accuracy and create highly accurate 3D computer models of the pieces. The data from one of the computer models was inverted using specialist software and a plaster model of the bird created using a 3D printer.
Photos can be mapped onto the 3D surfaces created by laser scanning.
A Partially Excavated Roman Helmet
In 2000 the Hallaton Fieldwork Group and University of Leicester Archaeological Services discovered a large collection of Roman artefacts in southeast Leicestershire. Most of the items discovered date to just before the Roman Conquest. The site of the find proved to be an internationally important ritual site dating to the generations before, during and after the Roman Conquest of Britain in the 1st century AD. Amongst the 5,000 silver and gold coins, jewellery and many other objects found, archaeologists discovered a unique Roman parade helmet with silver and gilt decoration, which would have been worn by a very high ranking cavalry officer in the Roman army.
The helmet was purchased by Leicestershire County Council with Heritage Lottery Funding and will feature in an exhibition at Harborough Museum opening in Autumn 2009. It is currently in London at the British Museum undergoing excavation, documentation and conservation work. The work is expected to take up to four years to complete. Detailed excavation of the helmet has so far revealed the image of an emperor on horseback on one cheek piece.
Conservators at the British Museum asked Conservation Technologies at National Museums Liverpool to scan the helmet to provide a 3D document of the find during excavation and conservation. Conservation Technologies used a portable, non-contact Konica Minolta Range 7 close range laser scanning system to produce a highly accurate 3D computer model of the partially exposed helmet.
The images above were the result of the laser scanning work undertaken on the Roman Helmet, showing the high level of detail recorded, utilising the unique features of the Range 7 3D Digitiser
3D Recording of Bronze Plaques from the Samuel Smith Memorial
In 1909 the then Lord Mayor of Liverpool unveiled a memorial to the life of Samuel Smith in Liverpool’s Sefton Park. The memorial is an 18m high red granite obelisk with a drinking fountain in the base. On the plinth of the memorial are four bronze plaques detailing aspects of Samuel Smith’s life as a trader, politician and philanthropist. The plaques were made in 1909 by the sculptor Charles John Allen.
In 1987, two of the four bronze plaques were stolen. Shortly afterwards, the remaining two plaques were removed and put into storage for safe keeping. The memorial was restored in 2008: the plaques were brought out of storage and Conservation Technologies at National Museums Liverpool was commissioned by Liverpool City Council to undertake conservation of the existing plaques and reconstruction of the missing plaques. Working from archive photographs, Conservation Technologies staff sculpted models of the missing plaques in clay. The models were then used by Castle Fine Arts Foundry in North Wales to cast the ‘new’ bronze plaques.
All four plaques were then scanned by Conservation Technologies using a Konica Minolta Sensing Range 7 laser scanning system to provide highly accurate 3D records; this will allow straightforward reproduction of any missing or damaged pieces in the future, should this become necessary, eliminating the need to produce models in clay by hand. Once fully documented in 3D, the plaques were re-installed on the monument by Conservation Technologies in Autumn 2008.
