channel sections each channel sections is composed of two side walls 12 12 39 having a somewhat sigma shaped cross sectional profile rigidly interconnected as by welding to a horizontal floor plate 13 the floor plates 13 and side walls 12 12 39 of the channel sections combine to form an upper and lower passageway along which a scraper chain assembly is moved this scraper chain assembly is entrained around drums or sprockets not shown disposed at the ends of the conveyor and is circulated by driving one or both drums or sprockets the upper traction run 14 of the assembly moves along the upper passageway i e along the upper surfaces of the plates 13 while the lower return run of the assembly moves along the lower passageway i e beneath the under surfaces of the plates 13 the transport of material is effected by the upper traction run 14 of the assembly moving along the upper surfaces 13 of the plates 13 as shown in fig1 the scraper chain assembly can be of the type having two round or oval linked chains 15 running alongside walls 12 12 39 with scraper elements attached between the chains 15 and spaced apart along the path of movement the assembly can however be of the type employing one or two chains running along the central region of the plates 13 and again attached to spaced apart scraper elements the lower passageway denoted 16 along which the lower return run of the scraper chain.