African Mining November 2019 | Page 65

CRADLE TO GRAVE  the winches was a mere three weeks. It cost the mine about R80 000 to rebuild a single winch and it had to rebuild about 150 winches a month. In addition to their short lifespan, the scraper winches had constant leakage between the clutch drums and gearbox section, occasional overheating, and decibel and vibration levels signifi cantly outside of the acceptable ranges. According to Jurie Reichel, a consultant at Lubrication Engineers (LE), the company suggested that the mine test its Almagard 1 000T TRANSPORTED OVER 1 000KM Five Caterpillar 793D mining trucks with a payload of 200t each were recently transported from Kumba Iron Ore’s Sishen mine in the Northern Cape province of South Africa to the Port of Durban and then onwards to Australia. ALE was chosen to act as the single point of contact for the transportation of these trucks over more than 1 000km across South Africa; an operation spanning fi ve months. ALE is a transportation company that specialises in moving abnormal loads. The project began in Sishen, where the fi rst three trucks were loaded onto three 12-axle Goldhofer trailers widened to 4.3m, using the hydraulics of the trailers themselves. Two prime movers provided the traction for each mining truck. The mine then ran a trial of the Almagard on four of its scraper winches, with excellent results. The four winches used in the trial ran for a year with no breakages or leaks and are still operational over two and a half years later. The initial trial was so successful that the mine extended its used of the Almagard to another trial on 20 additional scraper winches.  If a suitable route could not have been found, then the bodies and chassis would need to have been split. In this case, time- consuming reconstruction would have been needed at the Port of Durban or the fi nal destination. The travelled route required ALE to obtain a wide range of permits. Exemption permits for the transport of abnormal loads were required from the local department of transport for each of the four provinces the convoy passed through. This work included the identifi cation and clearance of the route itself; the establishment of the structural integrity of bridges along the route; authorisation from each municipality the convoy travelled through; liaising with telecoms providers to arrange the lifting of telephone lines and liaising with power companies to lift or de-energise power lines. Upon arrival at the Port of Durban, all three mining trucks were unloaded by lowering the trailers and were then driven onto a ro-ro vessel bound for Australia. The entire journey was then repeated with a further two mining trucks, which were then loaded onto a breakbulk vessel with the ship’s gear. The trucks are now en route to Australia for use on a range of mining projects.  The trucks’ laden height of 6.8m was a major challenge during the project due to many overhead restrictions along the route. ALE identifi ed a route that could accommodate passage at this height, thus allowing each vehicle to be transported as a complete unit. Vari-Purpose Lubricant (3752 and 3750) as an alternative lubrication option for the scraper winches. ALE recently transported fi ve Caterpillar 793D mining trucks from the Northern Cape province to Australia. www. africanmining.co.za African Mining Publication African Mining African Mining  November 2019  63