Two purpose-configured Liebherr luffing jib cranes have been put to work at a 40-storey tower in Singapore's Central Business District. The Liebherr 355 HC-L 18/32 Litronic cranes, which are owned by rental company Ho Lee Machinery, have been configured by the Takenaka Corporation to climb in stages of six storeys. Located in Singapore's Market Street, the project has been named CapitaGreen, and will provide additional office space in an area densely populated with high-rise towers.

As part of a design-and-build agreement, Takenaka Corporation devised a 20 per cent saving in construction time, reducing the expected completion period from 40 months to 32 months. The 40-storey tower is being built using steel. The luffing jib cranes are being jacked up six storeys at a time to ensure that the growth of the frame and the construction of the lift shafts and floor shafts remain synchronised.

"The construction is very fast, and the site is working 24 hours a day," said Benjamin Tan, managing director of Ho Lee Machinery. "In our discussions with the contractor, it was decided that it would be logistically easier to jack the cranes up six storeys at a time, and that is why we decided to invest in these two new 355 HC-L units."

The masts of Liebherr's HC-L range come with an option of either standard or reinforced elements. Reinforced frame masts offer superior free-standing height. "Only Liebherr supplies cranes in Singapore that can be configured in this way," said Tan. "The cranes are not located in the lift shafts, but are placed in the voids next to the lift bank, allowing the contractor to progress faster with the steel erecting." CapitaGreen is being built on the site of the old Market Street Car Park, and when completed, will reach a height of 248m.