As the super-projects extend Dubai’s concrete boundary out along Sheikh Zayed Road and into the desert, so scores of plots within the older boundary are under development, mostly for new apartment towers.
Filling the gaps poses challenges for contracting firms. Some relate to the construction itself, but many are centred on working in confined spaces, managing relations with neighbours, and ‘just-in-time’ logistics.
Liebherr luffing jib cranes are said to be playing a central role in the “space race”, enabling work to be carried out on sites where there is little or no room for tower cranes to operate.
Two Liebherr 112 HC-L luffing jib cranes are at the heart of a 41-storey hotel apartment block project located on Sheikh Zayed Road. Golden Sands Tower has another six storeys to go to reach its design height, and is scheduled for completion in early 2007.
For project manager, Nashat Louis, of main contractor Al Shafar General Contracting, the luffing jib cranes are part of the answer to the very tight constraints he faces in terms of space.
“Site access is not easy at all,” he said, “We have to operate in a small space with no ground yard. Everything has to be brought in on a ‘just-in-time’ basis from a busy road.”
He adds: “When we have completed the tower, we will face an even bigger challenge in using a large area of the space we do have to build the multi-storey car park.”
With occupied residential blocks situated very close on either side of the site, together with an upmarket hotel close by, work is restricted from six in the morning to six in the evening.
Al Shafar crane engineer Anton Wanis says: “These twin cranes are the vitally important part of the job and the only way to carry it out when you have just 60m between the two neighbouring buildings.”
Concrete is pumped from the ground and the cranes used to handle all materials, from concrete for internal columns to steel and fixtures and fittings.
Able to slew through 360 degrees with a load at a radius of 8m, the cranes are able to overlap, says Liebherr.
Every 10m, or three floors, the cranes need to be raised. Three 2.5t saddle beams are used: one on which the cranes sits and a second higher up to hold it steady. The third saddle beam is available to be installed in preparation for lifting the crane.
Raising the crane takes just over a day: 24 hours to disengage the saddle beam and about three hours to lift the crane, a job carried out by the second crane. Wanis has a 12-man team dedicated to the cranes.
Wanis says that effective operations in a confined area are not the only reason for going down the luffing jib crane route. He is responsible for a second construction project – a four-tower job on Jumeirah Beach Residence. Craning operations are split 50-50 between four tower and four luffing jib cranes.
“We have four external cranes and four internal climbing cranes and here the issue is one of cost,” he said, “The internal climbing cranes were used because we can make a very big saving on costs.”
Wanis is already looking ahead to the completion of the Golden Sands Tower project and decommissioning of the two luffing jib cranes, the final act in the logistical exercise to beat the space issue. He is already planning what he added would be a very difficult job.
Two derrick cranes – one large and one small – will be hauled into place. The large crane will lower the luffing jib cranes to the ground. Then it will be disassembled and the smaller crane used to lower it down. Finally, the small derrick crane will be dismantled and brought to earth via the site passenger lift.
For project manager, Louis, site issues are not the only ones which have impacted the programme of work. The booming construction market in Dubai poses its own challenges. Skills shortages are an issue for him, as for other construction firms. He says, “I can see both the positive side of the construction boom and the negative. It is clear that this vibrant market is improving the economy of Dubai and the lives of many people in Dubai but I also have to deal with the situation where we needed certain skills and we went to India but we were unable to find what we needed, so it is a problem.”
See also the story “Luffer solves space problem” posted on November 24.
