Several very large potential dragline contracts are close to being signed with major coal groups in South Africa and Australia, those in the industry have been telling IM. But these kinds of decisions take a lot of time. The hold ups are issues unrelated to the potential suppliers, which for the largest models only includes Caterpillar, P&H and OMZ/Uralmash. The delays are linked to issues like obtaining long-range access to power supply and site leasing resolution and not least the enormous initial cost. In the past, there has been something of a hot market for the global supply of idled, pre-owned draglines, where they are disassembled, relocated and reassembled: at huge cost but still well short of the capital expenses of a new machine. This supply route it seems, however, is virtually gone, with a few exceptions. This includes a rare 46 m class 8200 machine that is being relocated from Canada to Australia.
Caterpillar has been wowing exhibition attendees with a huge model of the 8750 dragline in CAT yellow, photographed by IM Editor Paul Moore at the recent Exposibram show in Brazil. This machine has a potential bucket volume of 129 m3 and boom length of 132.5 m. Until now, draglines all over the world have been fitted with geared drive system motors only. Siemens and Caterpillar (then Bucyrus) jointly developed a gearless AC drive system known as Simine DRAG. The first system to be employed is in the Shenhua Zhungeer coal mine in China on an 8750, though draglines already in use can potentially be retrofitted with the system. P&H Mining has its new 9000 C-Series which has an industry-leading operating radius and a new four-chord boom design. The flagship model is the P&H 9020C. The range was designed using computer analysis, whereby the company optimised the geometry of the A-frame, mast, and boom combination for maximum weight utilisation, structural integrity, and dynamic performance.
