Since the mid ’90s Lampson has been moving face shovels, draglines and excavators for mining companies across Australia. The process typically involves loading, transporting across mine sites then unloading these 800 to 1500 tonne machines.
The first shovel moved by Lampson was a shovel nicknamed “Rocky” at Ravensworth Coal Mine in the New South Wales’ Hunter Valley. This little yellow machine walked onto a pair of brand-new 18 axle Goldhofer platforms for a trip across a mine-owned bridge and into other parts of the coal mine.
At that point the face shovel was ready for an overhaul, so it was not up to the walk and the Self-Propelled Modular Transporter (SPMT) avoided the need for laying the power cables for electricity from one end of the pit to the other. The longer trailer length spread out the concentrated track-load to allow safe passage across the concrete bridge – and with this successful project the now common term “Digger Move” was created.
The ’90s was an exciting period for invention. Also at that time the first Dragline was relocated on Lampson’s crawler transporters – it was a concept the Lampson manager at the time, Phil Lunn, had envisaged for years.
The opportunity came from BHP Gregory Coal Mine in Queensland’s Bowen Basin, which required two used machines to be relocated for the growing Blackwater Coal Mine. The 2550 tonne Marion 8050 Dragline was raised by jacks to allow removal of the tub and walking shoes then careful installation of three Lampson Crawler Transporters (CT). The CTs are the tracks from the massive Lampson Transi-Lift cranes. They were operated by personnel positioned between each of the four sets of V8 engines and followed instructions via radio and video screens. The path between the mines was lightly graded or otherwise pushed out or filled as required to allow passage of the crawlers with dragline on top, with a ground bearing pressure of 160 kilopascal (kPa).
The following development of the Dragline Relocation System involved three CT-2000s and a walk-on transport frame that did not require any disassembly of draglines before loading. This arrangement has since been used many times and it significantly minimises the amount of ground preparation required due to the low bearing area of the 2.4-metre-wide crawler transporter tracks. The speed of travel is also a constant six times faster than dragline self-propulsion, meaning the amount of downtime is reduced before it is back to moving overburden again.
The current day transport of diggers in Queensland and New South Wales requires multiple relocations per month. In one shift a 20-axle trailer moves a typical 600-tonne excavator with just a few experienced personnel. These trailers are also used to move modules or other oversized loads onto barges, around sites or during fabrication. The combination of Goldhofer’s wide deck, 1.6m axle spacing and 45-tonne per axle capacity solve many transport problems; with optional power packs these self-propelled trailers will remain a handy tool and continue to deliver loads without a scratch.