Mammoet has moved a 690-tonne rock crusher and a conveyor from the top of Graniterock’s A R Wilson quarry in Aromas, California to a new location further down in the mine.
Challenges along the 1.2 km route included 8-10 percent gradients, as well as significant quantities of mud – the result of several days’ rain. SPMTs provided the necessary traction to cope with the conditions and terrain.
Due to its length, the 152 m conveyor had to be dismantled into four sections before it could be moved. Each section was jacked up and moved on SPMTs. A 450-ton (408.2 tonne) gantry crane helped to position the old conveyor sections over a new conveyor. Both were then connected to form a single larger unit.
The crusher was transported on SPMTs in one piece, which meant that it could remain active until just hours before the move. This significantly reduced downtime as well as avoiding unnecessary wear and tear on the machine.
Mammoet said: “The rock crusher is one of only two rubberised crushers in the world (it has rubber wheels and is drivable), and is the only crusher currently in use. The [A R Wilson] quarry has been in operation since 1900, and by relocating the crusher, another 100 years of operation is expected.”