Crawler crane a cut above the rest as tower 'sliced up like cake'
The tallest crawler crane ever used on a Hong Kong demolition project is helping to bring down a 148-metre chimney piece by piece, after it was sliced like a cake.
The innovative method to get rid of the chimney at the abandoned Kwai Chung Incineration Plant was devised to reduce the noise and dust caused by the more common methods of implosion or mechanical crushing.
It is part of a HK$190 million project by the Civil Engineering and Development Department to demolish the plant next to the Tsing Kwai Highway, near the Rambler Channel.
The main block and other buildings of the plant, which closed in 1997, were knocked down in June.
The department said removal of the chimney, which is as tall as a 50-floor building, was the most challenging part of the project. It said the chimney is being cut from the top down into small ring segments which are then broken up at ground level.
To help with the job, the department has hired the crawler crane - so-called because it moves around on tracks like a tank or bulldozer - from Singapore. It has a 600-tonne lifting capacity and an arm that can extend to 168 metres.
'The method is just like cutting a cake. It's safer, more environment-friendly and more efficient,' said Ip Kwai-hang, deputy head of the department's civil engineering office.
Workers use remote-controlled cutting machines to cut horizontally through the structure.
The chimney will be dismantled into about 60 ring segments of various sizes, ranging from 1.4 metres to 3.5 metres high and weighing 25 to 180 tonnes each. After being crushed, some of the concrete will be recycled as sub-base, granular bedding material and ingredients in paving blocks. The demolition work, which started a month ago, is estimated to be completed by the end of the year.
Ip said the department had used the same method to dismantle a 60-metre chimney in Kennedy Road last year.
'Compared with conventional ways, this method is much safer because it greatly reduces the amount of working at high level,' he said.
After the chimney is removed, the department will clean up underground pollutants. The whole project is planned to be completed by 2013 or 2014.
