Undertaking a heavy lift is not a case of ‘one size fits all’ but rather about selecting the most appropriate lifting solution for a given project or contract. This is according to Johnson Crane Hire, which boasts a heavy lifting capacity unmatched on the continent.
“Ultimately, a successful heavy lift is determined by the technical expertise of the heavy lift supplier. Johnson Crane Hire has a breadth of resident knowledge that enables it to provide best practice heavy lift solutions in a turnkey project approach that includes rigging and transportation,” says James Robinson, heavy lift manager for the crawler cranes and projects division at Johnson Crane Hire. “We are able to offer flexibility in terms of heavy lifting solutions because we operate a crawler crane fleet and a hydraulic mobile crane fleet as well as alternative lifting solutions.”
Robinson points out that the three largest cranes in the Johnson Crane Hire fleet are its 750 ton and 600 ton lattice crawlers and its most recent addition – a 750 ton truck mounted lattice mobile unit. “This level of heavy lifting capacity provides continuity and shows our level of commitment to the market by providing them with access to an unequalled combination of heavy lifting capacity and technical expertise.”
Robinson cautions that there is a critical need to recognise that a lattice boom crawler crane offers a vastly greater lifting capacity when compared to mobile hydraulic crane lifting capacities. It is not uncommon to find people making the mistake of comparing one with the other as the nomenclature can be very misleading.
As an example, Robinson points out that the 250 ton lattice boom crawler competes against a heavy lift 400 ton hydraulic mobile crane. These machines have equivalent lifting capacity, but this not obvious to those that do not understand the differences between lattice boom machines and mobile cranes. The nomenclature should not be used as the manner in which to differentiate between capacities and capabilities.
“In explanation, a hydraulically operated mobile crane’s lift capacity is rated on what is referred to as the load moment. Most hydraulic cranes are rated at their capacity at 3 metres, whereas the rating for a lattice boom crane is based on a larger load moment, which can be anywhere between 7 to 14 metres and this capacity is based on its structural integrity. In essence, a lattice boom crawler crane is capable of performing far heavier lifts and offers greater flexibility in terms of its application because of its pick and carry capability,” he says.
There are distinct limits with regard to the amount of counterweight that can be placed on a hydraulic mobile crane and this is where a crawler crane excels. The lattice boom configuration allows for the attachment of an additional counterweight most often referred to as the super-lift ballast. Crawler cranes are able to increase their load moment by balancing the load to be lifted against the super lift ballast.
Johnson Crane Hire has a ten year history in the crawler crane market and has amassed a number of impressive lifts, including a recent heavy lift at Zimplats. “We were contracted to remove an old mill weighing 225 tons, with a radius of 31 metres, and to replace it with a new one weighing 170 tons. We then brought in an LR 1600-2 (600 ton) crawler crane from Europe to perform this work. The crane is now part of our permanent fleet,” Robinson says.
Johnson Crane Hire also used the LR 1750 (750 ton) crawler crane to lift a 280 ton tippler in Mozambique for the Nacala port upgrade project. A notable feat achieved by the team was the lifting of the 280 ton assembly in one execution. The company is also actively involved in heavy lifts for the major expansion underway at a diamond mine in South Africa. A recent lift at this mine required the lifting of a 110 ton structure with luffer and full super lift configuration at a 55 metre radius. There are additional lifts planned for equipment of 200 tons at 35 metres in the same configuration.
On all lifts, the company provides a full pre-lift feasibility study that includes computer simulated drawings, generating method statements, full risk assessments and load studies. Operation of the well maintained crawler fleet is supported by an experienced technical team with in-depth knowledge.
Safety in the complex operation of heavy lifts is paramount. “Adherence to safe operation comprises a number of critical elements. Firstly, our machines are current technology and well maintained, and our operators are skilled and comprehensively trained. In addition, we implement carefully documented and implemented safety systems, which comply with all industry safety standards. This is complemented by the risk assessments conducted before each lift. We are justifiably proud of the fact that safety as a culture is ingrained in every Johnson Crane Hire employee,” says Robinson. Safety in fact forms part of the company’s holistic lifting package, referred to as the ‘SMART’ (Safety, Maintenance, Availability, Reliability and Total cost effectiveness) philosophy.
Johnson Crane Hire has an acknowledged track record in delivering fit for purpose heavy lift solutions for the power, petrochemical, refinery, industrial, mining and civil infrastructure industries, throughout Africa.