Heavy lifting, projects and mobile crane hire group Sarens South Africa is to take delivery of the largest capacity hydraulic crane available in southern Africa, the Demag AC 650, this month. It is a nine-axle, 720-t crane, equipped with 160-t counterweight, 96-m luffing jib, a lifting height of 140 m and a 60-m main boom.

Although the company will inherit the crane from Sarens Belgium, Sarens South Africa chief operating officer Peter Yaman says that a new hydraulic crane of this capacity would cost in the order of R50-million.

The 720-t crane offers an enhanced capacity and longer reach. It incorporates separate fly jib components for additional reach, which can be offset by 20 or 40 degrees. The crane will therefore be able to complete higher-reach and longer-radius jobs and will have the option of lifting larger components. Yaman says that smaller components, which have previously been lifted separately, can be preassembled on the ground and elevated as a single piece. This is time efficient and safer because it increases the amount of work done at ground level.

Yaman says that while the 720-t hydraulic crane has not been imported for specific projects, Sarens South Africa anticipates its use in larger petrochemical projects, which require the lifting of heavier vessels and are more challenging in terms of reach and radius, as well as construction and windmill projects.

Prior to the delivery of the 720-t crane, the largest cranes available in South Africa have been 500-t hydraulic cranes and 800-t crawler cranes. While crawler cranes are able to lift heavier components than hydraulic cranes, they are more expensive to hire and take a couple of days to set up. Hydraulic cranes are ideal for once-off lifts and have a set-up time of only three to four hours if operated in the main boom configuration. Yaman says that Sarens South Africa sees an opening in the market for a larger capacity hydraulic crane, which slots into gap between the biggest hydraulic and crawler cranes currently available.

He says that there are foreseeable challenges in operating a crane of this capacity, including the logistics of getting the 160-t counterweight to site. Fifteen to 16 trailers are required to transport the crane and its components to and from its destination, which can be anywhere from Cape Town to Zambia. There are also strict regulations regarding road transport within South Africa, which limits the load that can be carried on trailers. This means that a greater number of trailers are required for the transportation of the crane and its outriggers may need to be removed and carried separately to reduce the total road-travelling weight.

Sarens South Africa managing director Martin Verzijl says that another challenge lies in the fact that the mobile crane hire business is extremely diverse and each project will have its own requirements and circumstances. These include varying site restrictions and ground pressures, which have to be able to withstand the load of the crane.

Yaman says that the skills shortage in South Africa also affects the functioning of a crane of this capacity. Sarens South Africa has an on-site training facility for crane operators. Senior operators that have worked with 400-t or 500-t cranes will be developed by experts brought in from Europe who have four to five years experience operating 720-t hydraulic cranes. Yaman says that one does not want to limit the capacity of the hydraulic crane by not having access to the qualified people required for its operation.


http://www.engineeringnews.co.za/article/mobile-crane-hire-group-takes-delivery-of-largest-capacity-hydraulic-crane-2009-04-24