Conservation in Australia, Past Present and Future: Preprints from the AICCM National Conference, 19 – 21 October 2011 Canberra
Abstract
The Sydney Harbour Bridge is an internationally recognized Australian landmark. The distinctive ‘coat hangers’ of the bridge also served as rails for four cranes to traverse the structure. These cranes were used for construction of the arches between 1928 and 1932, and then for maintenance of the bridge until they were decommissioned in 1997. Heritage approval for their removal from the bridge was conditional on the conservation of two representative examples, with at least one to be put on permanent public display. The remaining two cranes were scrapped.
In recognition of the national significance of the bridge, the history and folklore surrounding its construction and maintenance, including its never-ending painting, the National Museum of Australia (NMA) acquired one of the remaining cranes from the NSW Roads and Traffic Authority (RTA) in 2007. This example was ‘conserved’ for the RTA by International Conservation Services (ICS) according to a treatment plan designed by the NMA and ICS to retain as much of the original fabric as possible, including its many layers of lead paint. By contrast, the second remaining crane, intended for outdoor display in a public park below the bridge, was ‘restored’. The works, which included sandblasting and repainting with a modern non-lead paint, were undertaken to allow the materials to withstand permanent outdoor exposure.
In mid-2011, despite already owning one of the two remaining cranes, the NMA received the second on loan from the RTA in order to display it in the external forecourt of the Museum. The decision was taken not to display the Museum’s own minimally conserved crane because the need for further treatment to comply with health and safety regulations associated with lead paint and other parts of the structure would have seriously compromised important aspects of the historic and technical significance for which it had been acquired and conserved.
This paper is an account of both treatment approaches and the rationale underlying them.