The almost 90-year-old Sydney Harbour Bridge will be getting a 21st century makeover thanks to a new collaboration among Australia’s Nuclear Science and Technology Organisation (ANSTO), Australian universities and the NSW Government.
According to a recent press release, the project has been awarded an ARC linkage grant of approximately AU$ 858,000 over 3 years.
What is the Project?
The project will develop a new laser-based large-scale cleaning method for corroded metal and dirt-encrusted surfaces in inaccessible areas on the bridge.
The technology uses a new class of powerful industrial ultrafast lasers which reduce heat load to a structure, reducing energy costs and deliver long-term conservation outcomes.
The new techniques, which will be using robotics, will offer improved safety and economic benefits in building maintenance as well as scrap reduction for the marine, automotive and aircraft industries.
Who are involved?
ANSTO will undertake stress assessments to materials using X-rays and nuclear techniques at Lucas Heights.
It is one of Australia’s largest public research organisations and is widely recognised as an international player in the field of nuclear science and technology.
The Australian National University (ANU) is leading the project. According to their Professor, this is the first time a laser cleaning process such as this is being used on such a large-scale.
Other universities helping with the project are the University of Sydney and the University of Canberra.
The Sydney Harbour Bridge is approaching its 90th Anniversary. Current work involves sandblasting dirt, rust and the existing lead-based paint and applying lead-free paint to protect the structure.
As reported, a different approach is needed for 7.2 kilometres of tightly confined tunnels, which are inaccessible to humans and sandblasting creates too much dust.
In contrast, powerful ultra-short pulse lasers can be used with minimal dust and waste for cleaning.
In this project, the team will analyse mechanical properties of laser-treated steel and granite for fatigue resistance, roughness, understanding the microstructure, and distribution of stresses.
Benefits to be gained
Laser cleaning has been used widely to remove contamination from historic architecture when traditional methods are not viable.
The conservation strategy includes the development of a practical robotic system to undertake inspections, carry out cleaning, re-paint and remove waste.
The long term goal of developing effective laser removal processes and reconditioning has the potential to maintain the integrity and original views of the bridge.
Furthermore, the new laser techniques will prevent detrimental damage to the cleaned surfaces.
These damages include residual stresses, micro-cracking or roughening, which decreases structural performance and surface integrity.
The team is excited to utilise nuclear science and expertise to help develop technology that will help maintain Sydney Harbour Bridge, which is an iconic image of Sydney and of Australia as a whole.