Abstract: The method and apparatus for mapping mine excavation or tunnel entry conditions by mounting an array of sensors on a vehicle some of which provide knowledge of the vehicle location in the entry and others of which provide knowledge of entry conditions and by interpreting data collected from the sensors, a map can be generated of the entry strata for a given vehicle location in the entry. This map can be compared with similarly generated maps to indicate changes in the entry condition.

Abstract: A thermal dryer used to dry wet material includes a drying chamber and a storage bin. Material is transferred from the storage bin onto a movable support means positioned within the drying chamber. A furnace supplies hot gas to the drying chamber and the gas passes over the movable support means to dry the wet material positioned thereon. The temperature of the gas that has been passed over the wet material is automatically maintained at a preselected temperature by controlling the amount of wet material on the movable support means. The temperature of the gas that has been passed over the support means is controlled independently of the temperature of the gas supplied by the furnace. The amount of wet material in the storage bin is automatically maintained below a preselected amount by controlling the temperature of the hot gas supplied by the furnace to the drying chamber. When the amount of wet material exceeds the preselected amount, the temperature of the hot gas supplied by the furnace is increased.