|Siding Spring Observatory Asbestos Remediation (Building & Engineering Services)
Client: ANU & Anglo-Australian Observatory
Location: Coonabarabran, NSW
The Anglo-Australian Observatory (AAO) on top of Siding Spring Mountain in the Warrumbungle Range near Coonabarabran is an internationally respected facility undertaking state of the art astronomical research. It also serves as a major tourist drawcard for Coonabarabran and the surrounding area. While the Siding Spring mountain site hosts a plethora of telescopes operated by a number of organisations, the AAO operates the two largest telescopes being the visually impressive Anglo-Australian Telescope (AAT) that dominates the mountain skyline, and the smaller UK Schmidt Telescope (UKST). Those telescopes are supported by a number of other facilities including a large and very well equipped mechanical workshop run by the Australian National University.
The AAO was built in the 1970s and is subject to regular upgrades and ongoing maintenance to provide astronomers with state of the art capabilities, as well as to preserve and extend the life of this major Australian scientific asset. The latest maintenance review confirmed the fact that some of the buildings that comprise the Observatory, like many others built around the same time, were partly constructed with materials containing asbestos. These materials are the external cladding of the AAT building, the roof and façade of the ANU workshop building, fibro roof sheeting, fire doors, a small amount of pipe lagging, lift brake shoes and small sections of roof waterproofing membrane.
A report by an asbestos consultant found that the asbestos materials used in external facades and sunscreens had deteriorated to the point that they posed a health risk to observatory staff and the wider environment. A decision was made to replace the materials with non-asbestos alternatives.
G.E. Shaw & Associates was contracted to remove approximately 7,000 sq m of galbestos sheeting and a further 500 sq m of Super 6 sheeting, together with some minor installations of asbestos pipe lagging and asbestos-impregnated roof membrane.
While many construction projects claim to be unique, this project was truly one of a kind.
Superficially, the project appears to be straight forward, but it involved a combination of elements that, taken together, made this one of the most challenging projects ever undertaken by the company.
These elements included:
- Logistical challenges created by the remoteness of the site, and lack of ready access to the structural engineer (located in Dubbo) and cost planner (located in Canberra) whose input was vital to the success of the project;
- The exposed location on top of the highest mountain in the Warrumbungle Range. The site is regularly subjected to truly awful weather conditions including high winds and snow and ice storms over winter, which is precisely when the project was undertaken.
- The nature of the material being handled (asbestos). While bonded asbestos is generally straightforward to handle, the Galbestos sheeting at the AAO had deteriorated to such an extent that the project’s consulting Occupational Hygienist deemed that it had to be treated as friable asbestos with all of the added complication that that brought to the project in terms of procedures, methodologies and safeguards;
- The size of the sheets being handled - approx 10m in length - a difficult materials handling challenge even without the added complication of the asbestos content and exposed and windy location;
- The requirement that the main telescope building remain fully functional throughout the project. This required the implementation of much greater occupant protection measures including creating temporary access ways, extensive air quality monitoring and pressurisation of the building to prevent any fibres that may have been released when sheets were being handled, being drawn into the building’s air inlet;
- Removal of the vertically-deployed asbestos sheeting form the AAT telescope required work to be performed at heights of up to 27m. As a workman was killed during the original construction of the building from this height, “working at height” safety was of paramount importance that required development and implementation of much tighter than usual work methods. Again, sheet size, asbestos content and exposed location all compounded the difficulty.
- The requirement that the power supply to the entire Observatory Site be maintained without interruption. This created an OH&S issue in the main plantroom during roof removal and replacement, due to the presence of exposed 22kV connections where the incoming feeder main was terminated and metered.
Despite the challenges, the project was completed under budget, within the agreed program, and with a perfect safety and client satisfaction record.
The project was nominated for a Master Buildiers Association Award in the demanding category of Projects Exhibiting Technical Difficulty or Innovation.