Go back to article: A sustainable storage solution for the Science Museum Group
Preventive conservation storage issues
Storage issues for an extraordinary collection of science objects are complicated by both size and multiplicity of materials of many of the objects. Objects such as a 1918 Ammonia Refrigeration Compressor, a station gas meter and the first hovercraft, are large and robust and can withstand less than ideal environmental storage conditions. Many of the other 35,000 objects stored at Wroughton are made with materials which are vulnerable to light exposure, duration and wavelength; particulates; smoke and gaseous pollution; insect and rodent pests; and varying levels and fluctuations of temperature and RH. Many of the objects in storage at Wroughton are large and robust, such as the following example images:
Lightfoot Ammonia Refrigeration Compressor from Union Cold Storage, Alexandra Dock, Liverpool 1982-355
Watford’s town hall-style gas station meter; 1979-818
SR-N1, the world’s first hovercraft, built in 1959;1968-540
Objects such as in the following images are not inconsiderable in size but are made from materials which can fade, are tempting to insect and other pests and can react disastrously to changes, especially in RH:
Model of the clipper ship Stonehouse, built in 1871
Three-wheeled motor car supplied in kit form by Karl Benz and assembled in 1888 by Emile Roger, engineer and designer
1936 Wurlitzer Simplex multi-selector juke box model 41
While it is true that greater damage and deterioration to the museum collection could come from fire, flood, accident, theft, vandalism and conflict, occurrences of these are far less likely due to site location and preventive measures.
While damage from light intensity and duration within the hangars is eliminated by excluding all light except during occupation, the levels of RH and temperature (hereafter T) within the hangars do not meet the museums’ own agreed recommendations for best practice collections care for robust objects (RH 35–65±20 per cent; T 16oC–24oC±3oC (Brain and Burden, 2011)). Through the annual assessment of storage spaces, the issues of incorrect T and RH and pest management have been highlighted by the conservation and collections care team. All issues are a result of the ageing structures which were never intended either to still be in use or to be used to store objects of cultural significance. Pests – birds, particularly jackdaws and pigeons, and rats, mice and rabbits – find their way into the hangars through holes at the top and bottom of the corroding hangar doors. Unless food or nesting material is present, little damage is done to the objects by rodents. However, bird excrement can damage surface finishes so preventive measures such as covering vulnerable objects with Tyvek sheeting are undertaken. Moths and mould flourish under favourable conditions of high RH and warm T but the hangars are rarely warm; however, outbreaks of both moth and mould have occurred, especially in road vehicles with fabric and leather interiors.
In fact, serendipitously, the cold temperatures could slow down the rate of deterioration in materials. Research has shown that organic material such as paper decays more slowly at temperatures under 12oC (Burge, 2014; Michalski, 2002; Wilson, 1995). It is the associated high RH levels in the hangars that cause most of the deterioration to the collection, whether objects are composed of organic or inorganic materials, or both. It is therefore the issue of controlling humidity that was the primary concern that any new storage facility needed to address.
Component DOI: http://dx.doi.org/10.15180/150405/003