A collaboration between Australia’s Nuclear Science and Technology Organisation (ANSTO), Australian universities, and the NSW Government will see the 90-year-old Harbour Bridge receive a new maintenance “makeover”.
Through the $858,000 three-year project, new laser-based, large-scale cleaning methods will be developed 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 use robotics, will offer improved safety and economic benefits in building maintenance as well as scrap reduction for the marine, automotive and aircraft industries.
ANSTO will undertake stress assessments to materials using X-rays and nuclear techniques at Lucas Heights.
Leader at the Australian Centre for Neutron Scattering, Dr Jamie Schulz, said, “This is a big, challenging cleaning job that we are happy to be involved with.
The Australia National University (ANU) is leading the project, with ANU Professor Andrei Rode said this is the first time a laser cleaning process like this has been used on such a large-scale.
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.
ANSTO’s Dr Anna Paradowska said that ANSTO is well placed to assist with this work.
“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.”
Importantly, the new laser techniques will prevent detrimental damage to the cleaned surfaces, such as residual stresses, micro-cracking or roughening that decreases structural performance and surface integrity.
Laser cleaning has been used widely to remove contamination from historic architecture when traditional methods are not viable.
“We are very excited to utilise nuclear science and expertise to help develop technology that will help maintain Sydney Harbour Bridge – an iconic image of Sydney, and Australia itself!,” Dr Paradowska said.