Marr Contracting has erected what it claims is the world's largest luffing jib tower crane. Sydney, Australia-based Marr put up its new 330 tonne capacity Favelle Favco M2480D in Doha Qatar. IC contributor Brent Stacey went to see it.
"Bigger than Texas" is a popular phrase used around the world to describe extraordinarily large items. It has long been a benchmark description to help give true scale both to projects and machines. What then would be a suitable phrase for the amount of work that has been completed over the last ten years and is still going on in parts of the Middle East? The sheer scale of work among the members of the Gulf Cooperation Council (GCC) could be confidently described as "out of this world."
When IC had the opportunity late in 2008 to inspect a Waste to Energy plant being constructed by Keppel Seghers, near Doha, Qatar, it might not have been a surprise to look up at the largest luffing tower crane in the world and to see The Men from Marr's signage down the sides of the machinery deck.
The M2480D is the latest offering in the heavy lift range of tower cranes from Sydney, Australia-based Marr Contractors. The new heavy lift luffer built by Favelle Favco has a 330 tonne capacity at 14.5 m radius and can free stand up to 80 m. On a 4.3 metre-square tower the M2480D needs a ground area of 4 metres-square when erected on starter legs, or about the same area as two family cars parked side by side. The crane can also be set on a grillage or mounted on rails.
Comparing M2480D load charts against large mobile cranes reveals many areas where the big Favco out lifts 600 tonne capacity crawler cranes. These large crawlers can occupy 10 times more ground area than the new heavy duty tower crane.
With a 55 tonne winch and maximum hook speed of 95 m/min, the M2480D is a fast crane. It can operate safely in wind speeds up to 20 m/sec. That is more than twice the allowable wind speed that large mobile cranes can legally work in. On projects where wind velocity affects the amount of useable crane time, large gains in time productivity are possible by using the giant tower crane.
On the job
The heavy lifting M2480D is working on what will be the world's largest fully integrated waste to energy (WTE) project, an AUD$1.8 billion (US$1.2 billion) greenfield development. Design and construction is by leading WTE technology company Keppel Seghers. It will be the first waste treatment facility in the Middle East and represents a forward thinking step from the Qatari Government.
Integrated waste management is designed to maximise recovery of resources and energy from waste and to reduce the volume of waste that goes to landfill by sorting, composting and recycling. In conjunction with the electricity and fertiliser produced through the Kyoto ratified process, recyclable materials, including metal, plastic and glass are recovered in the sorting phase and sold on to recyclers, generating another revenue stream. Power generated by the plant in excess of its own requirements can be sold back into the power grid.
The project is for the Qatar Government and is being constructed near Mesaieed, adjoining the Al Wakrah industrial zone on the outskirts of Doha, where there is more than $600 billion-worth of construction work underway. The facility will be capable of processing more than 1,550 tonnes of waste a day.
The Marr's crane was engaged by the Singapore-based Keppel Seghers, which has established a regional office for the Middle East in Qatar. It has won other projects in the region, including a water treatment plant and a facilities maintenance expertise contract for Doha International Airport.
Keith Holden, Keppel Seghers construction manager, says he has been more than impressed by the big Favco's capabilities. With a career spanning more than 40 years working around the world on large scale projects, he cites the minimal amount of site space required and precision in placing heavy loads as the crane's most impressive features. "We can place large elements with millimetre precision. There is no discernable movement when the crane stops hoisting through flex in the crane. It allows our fitters the best opportunities for precise alignments," Holden says.
Holden also comments on the crane's operating speed. Loads up to 110 tonnes are handled on the two-fall hook, as opposed to, for example, a large crawler crane, which would be operating with up to 10 parts of rope. "We are not losing time waiting for the hook to come back down to our riggers. With comparable winch speeds, the Favco operating in two falls is remarkably quick. And we can pre-assemble at ground level. Our water cooled grate units weigh 74 tonnes and they went in at 46 m radius," Holden continues.
The M2480D was transported from Australia on a specially chartered ship, giving Marr's complete control of the operation. In comparison to a large crawler crane, total weight and size of components allows for easy transporting. The heaviest single component is the front half of the split machinery deck at 29.4 tonnes.
Erection took 10 days, including the assembly of the tower sections and a lot of lost time due to high winds, dust storms and extreme heat. A 250 tonne capacity Kobelco crawler already on site was used to erect the crane. Given that the temperature was around 55 degrees and it was the first time the crane had been assembled, Simon Marr thinks that time could be halved for the next project.
The choice of the M2480D for this project was a direct result of the need to manage heavy lifts. A 120 tonne boiler unit was the largest scheduled task. That was combined with the congestion that would be caused by small working areas in multiple locations. The heavy duty tower crane can not only complete the largest and most difficult of lifts from the one location, it can also do so under the attentive eye of the crane operators supplied by Marr Contracting. On this site with such a multitude of nationalities, communication by universally recognised hand signals, plus radio communication, adds another margin of safety to the job.
The M2480D is the third crane in a heavy duty series of machines designed by Marr Contractors in conjunction with Favelle Favco. Simon Marr explains the company's large investment in heavy lifting construction tower cranes, "Our modern fleet of tower cranes, including the three large Favcos is the core of our business. We have seen the need for cranes capable of both heavy lifts and general site work in areas where there is not the room to set up conventional cranes. Many people are now seeing outside the traditional square, and seeing how both site congestion can be eliminated and construction programmes shortened using heavy lift tower cranes."
The philosophy behind Marr Contractors is no-nonsense, as it has been since inception in 1926 when the company built the first of its mobile cranes in Sydney. Marr's is now a third generation family company that likes to get on with the job and rarely makes public statements.
The range of cranes from the massive M2480D down to the M40R recovery crane have all been developed with careful consideration for applications.
The M1280D and M1680D are the other two heavy lift cranes in the Marr's fleet. These cranes have 50 tonne winches and both can achieve hook heights of 170 m freestanding before lateral ties into a structure are needed. These cranes have been used in a number of industrial and construction applications where establishment area was limited.
Hydroelectric power stations, oil refineries and Melbourne's famous MCG sporting arena are some of the jobs these big cranes have helped complete. At the time of writing in early January 2009 the M1680D was operating mounted on rails on a 2 km wharf project in the very North West of Australia.
The Integrated Domestic Solid Waste Management Centre under construction in Doha could be a good indicator for the immediate future for construction projects. Sustainable environmental projects, for example, water and waste treatment, along with wind energy projects and clean fuel technology may be where many in the crane industry will find work over the coming years as high rise residential and commercial developments slow down in line with the depressed world economy.
Favelle Favco M2480D
Lifting capacity: 330 tonnes @ 14.4 m radius with 36.9 m boom
Maximum boom length: 92.7 m
Maximum lift at maximum radius: 20.6 tonnes @ 91.3 m
Maximum freestanding hook height: 170 m
Line pull: 55 tonnes, high speed winch
Winch speed: 95.5 m/min
Heaviest component: Machinery deck front piece, including slew drive, pins and handrails 29.4 tonnes
Tail swing radius: 11.9 m
Can be static mounted, rail mounted, or self climbing