A conveying system of any type requires primary and secondary crushing systems and or conveyor belt feeder/breakers to load them as well. This is the function of the crushing component of the IPCC. For hard rock applications, this will often be a gyratory crusher, but for soft rock, it will be a lower profile sizer or roll crusher. 8411 Underground mine service and support workers. Underground mine service and support workers perform a range of duties related to the operation of orepasses, chutes and conveyor systems, the construction and support of underground structures, passages and roadways, and the supply of materials and supplies to support underground mining.