By Colin Foreman
Brokk demolition units have made their debut in Singapore on a major upgrade project at Changi Airport’s Terminal 2. The machines have allowed consultants to stay on track with round the clock work in a ‘live’ airport terminal building.
Demolition by robotics|~|robots_m.jpg|~|Brokk demolition units were able to perform key tasks far more quickly than human beings could have.|~|Changi Terminal 2 is undergoing a major retrofitting and upgrade project, which includes a complete rebuild of the building’s frontage facia. It was initially envisaged that for the demolition of the concrete and cladding façade over two storeys and the roof, plus interior walls, contractors would rely on conventional jackhammers.
However, as a result of the restrictive night-time only working hours in the ‘live’ operational airport terminal building, together with concerns about noise and dust pollution, an alternative solution was necessary if the critical 30 month deadline was to be met.
Demolition sub-contractor Choon Construction Pte Ltd therefore introduced its first remote operated electro-hydraulic demolition ‘robot’ from Brokk AB, a Brokk 180, for its Singapore debut.
So successful was the unit that two further units, a top of the range Brokk 330 and a Brokk 90 were also ordered through local distributor RCD Pte Ltd.
Starting at the east end of the terminal building, demolition and rebuilding has been split into six packages, each covering the approximately 50 m frontage over the terminal building. Demolition also includes interior walls, raised floors and escalator ‘wells’.
Initial trials using the Brokk 180 with a concrete crusher, delivered two months into the contract, proved it was able to break down a 3m x 3m x 0.25m brick wall in just 15 minutes — a quarter of the time it would take six to eight men with conventional tools.
Further, the Brokk ‘robot’ also reduced dust, noise pollution and vibration, all of which are important features for a ‘live’ business environment.
According to Choon Construction director, Tommy Lim, the Brokk ensured the flexibility of ‘round the clock’ working compared with the previous 12pm – 5am working hours.
“This allowed us to catch up on the lost time of the first couple of months,’ he said.
The middle of the range Brokk 180 has proved to be the ideal size for the Changi project with its low weight, high capacity and good accessibility characteristics. A track width that can be adjusted down to 780 mm ensures excellent manoeuvrability in exceptionally confined spaces.
For demolishing the major structural elements at the front of the building, however, Choon recognised the need for the larger ‘top of the range’ Brokk 330.
With concrete thicknesses of between 400-550 mm with pre-cast concrete slabs and cast in-situ wall thicknesses of 300 mm, the Brokk 330 is being used to remove the roof and two storey façade.
Considered to be the world’s highest capacity remote controlled demolition machine, the Brokk 330 can be equipped with a variety of tools weighing up to 550 kg. It is ideal for heavy demolition projects where high capacity and short demolition times are the deciding factors.
The Brokk demolition units all feature excellent reach facilities — the 330 has a reach of up to 6.5 m, the 180 has a 5.1 m reach when using the extra telescopic facility and the smaller Brokk 90 can reach an impressive 3.6 m — ensuring a major advantage in the often confined and difficult access work areas.
But according to Tommy Lim, another major advantage is the labour saving; just one man using the remote control is required. Remote operation of the Brokk units means that the operator with a good overview of the task in hand can stand a safe distance from the working area and falling debris.
All three Brokk units feature a comprehensive range of attachments, including grappler, bucket and breaker, providing additional versatility for a wide range of demolition applications.
Typically, the Brokk 330 attachments include a CC560 concrete crusher with a 555 mm jaw opening and a 510kN concrete shearing capacity; a 250 l (0.25 m³) bucket; and a SBC850 breaker with an 800 joule output force.
All in all, using the Brokk machines, allowed the contractors to make up valuable lost time and keep the project on track.||**||