By Anthony Donovan
Draglines have long been considered the lowest cost per ton method for overburden removal in coal mine applications, and Bucyrus has been a leading force in the evolution of these majestic excavators. Entering this area of the earthmoving business in 1910, Bucyrus has since developed first-rate proficiency in the design, manufacture, relocation, and repair of draglines. Today, there are more than 300 Bucyrus draglines in operation, accounting for a significant portion of the world’s overburden removal at major coal mines across the globe.
Despite the advantages offered by the latest dragline models, the initial capital outlay and time it takes to build a new machine can lead mine owners to explore other alternatives. A leading coal producer and power generator, Luminant, found itself in a similar scenario during the planning phase of its new mine, located near Kosse, Texas. They wanted to use draglines for overburden removal, but they were looking for less capital intensive alternatives that could also reduce the required manufacturing time to acquire a new dragline. The agreed-upon solution became the purchase of two pre-owned draglines, a Bucyrus 8200 model and a Bucyrus 1570W model. Both would require complete rebuilds and they would have to be transported great distances. Wanting to ensure that both machines would again operate as reliably and productively as they did upon their original commissioning in the 1970s, Luminant solicited the expertise of the draglines’ original equipment manufacturer (OEM), Bucyrus, to manage the complex projects.
Moving and Refurbishing the 8200
The Bucyrus 8200 model currently owned and operated by Luminant was originally commissioned at a now inactive coal mine, located near the West Virginia border in Pigeon Roost, Ky. The machine needed to be transported more than 1,100 miles to its new home in Texas and it would require substantial electrical and mechanical upgrades. This project would be no small feat, even for Bucyrus.
The move required approximately 120 truck loads, most of which were designated as oversize and/or overweight loads, to transport the behemoth excavator. The disassembly commenced with the lowering of the boom and mast, which were then cut into large sections to facilitate economical shipping. Next, the ballast was removed, totaling 1.1 million lb for this particular Bucyrus 8200 dragline. Weather sensitive components, consisting of the motors and generator sets, were removed and secured as well. This enabled the roof and wall sections of the machinery house to be detached, allowing easy access to the remaining components.
The A-leg structure, hoist and drag drums, gear cases, shoes, walking cams, and additional deck positioned hardware were then removed from the machine. Once all deck installed components were removed, the machine was “separated,” meaning the revolving frame was lifted up, creating a 5 ft space between the tub and the revolving frame, allowing for the removal of the dragline’s racks, rails and rollers. The revolving frame was then cut into the largest economically viable pieces for shipping purposes. Concluding the disassembly process, every dragline piece was sand-blasted, primed, and painted. The total time to disassemble and relocate the Bucyrus 8200 dragline to the designated field assembly site in Kosse was four months.
Once on site, Bucyrus began a comprehensive upgrade to bring the dragline to top operating condition. The Bucyrus field services crew, with their expert knowledge of dragline components, systems, and structure performed structural repair and added 6-ft deck extensions to both sides of the dragline’s revolving frame. A new and larger tub (base) was also manufactured and provided by the Bucyrus facility in Kilgore, Texas, which is located about 150 miles from Kosse. Lastly, Bucyrus performed a complete electrical upgrade on the 8200 dragline, including all necessary rewiring. The Bucyrus 8200 dragline was completely refurbished and given new life, with the expectation of many more years of operation.
Moving the 1570W
The Bucyrus 1570W model dragline was smaller than the Bucyrus 8200 model and was originally commissioned at a coal mine in Kellerman, Ala., which is about 650 miles from Kosse. Despite the size and distance differences, the 1570W dragline relocation would again require precise project management as well as cooperation between Bucyrus field services and Luminant personnel.
Bucyrus field services performed minor structural repair on the 1570W, repositioned the boom,