Figs. 158 and 159 show the conveyor for draining purposes in connection with a coal-washing plant. The head end of the conveyor being fitted with a perforated plate, allows the water to at once escape, whilst the coal is conveyed to the further end. The conveyor has a slight upward incline ; thus should any water remain with the coal, it will tend to run back towards the feed end where it can escape through the perforations