Dive crews on the floating platform used as a base for their cleaning operation. Pictures: KIM EISZELE
AN underwater project on a scale not seen in Tasmania is under way to protect one of the state's most valuable assets – the 48-year-old Tasman Bridge.
A team of professional divers is working under difficult conditions to wrap protective jackets around the steel piles that support the bridge in a $2 million, three-year project designed to prolong the bridge's life.
Department of Infrastructure Energy and Resources Infrastructure Services manager Shane Gregory said the project was a first for Tasmania.
"As a state we haven't done this before. It's been done in other places in the world, but not here," Mr Gregory said.
"The Tasman Bridge is the most valuable asset on Tasmanian roads and would be a significant cost to replace," he said.
"Maintenance is everything. You have to look after it. Just like a weatherboard house, you have to paint it regularly."
The project was part of ongoing maintenance work that would ensure the bridge achieved its designated lifespan of 100 years and beyond, he said.
"I have every expectation that it would survive longer than that."
The pile jackets, made in Victoria, are impregnated with a heavy-duty marine grease on the inside of rubber material that is tightened to each pile with steel fasteners.
A specialist team of seven experienced, qualified divers have been in the water for up to 10 hours a day blasting 50 years of barnacles, grime and seaweed off the piles before the jackets can be attached.
Tasmanian commercial diving company Subsea Access is doing the work.
Owner Adam Stephens said his crew of seven divers included former army men who had served in Afghanistan and divers who work on oil rigs.
"They are a very, very good crew," Mr Stephens said.
Divers climb down a steep ladder off the rolling barge deck into the water attached to a thick umbilical cord, which contains audio, video, air and light cabling.
A fully rigged rescue or standby diver is always on deck in case there are problems.
Divers wear a harness clipped to a rope around the pile to keep them from being washed away by the strong currents under the bridge.
They are in constant audio and visual contact with dive supervisor Luke Martin, who never takes his eyes off the computer screen inside the barge office.
The divers' helmets have lights to help them see in the murky swirling water.
The high-pressure 8000psi water blaster they use to get the barnacles off the pile creates its own share of muck underwater.
jennifer.crawley@news.com.au
Anda sedang membaca artikel tentang
Bridge divers' work piles up
Dengan url
http://kembangtrotoar.blogspot.com/2013/04/bridge-divers-work-piles-up.html
Anda boleh menyebar luaskannya atau mengcopy paste-nya
Bridge divers' work piles up
namun jangan lupa untuk meletakkan link
sebagai sumbernya
0 komentar:
Posting Komentar