on web 10b upon which the roller like elements 14a run and which also serves to position the load bearing conveyor chain stretch transversely of the track section as more fully described in the above said u s pat no 4 358 010 also as described in said patent the conveyor chain has laterally extending wings 14b which share the load with roller elements 14a and which serve to stabilize the chain portion upwardly open slot 10c has lateral recesses 10e designed to receive and guide the projecting wing elements during longitudinal movement of the conveyor chain the track section side portions 10a extending downwardly from the ends of connecting web 10b terminate in longitudinally extending footing flanges 10f with substantial coplanar bottom faces adapted to rest on a common support such as a transverse support beam 18 these downwardly projecting leg flanges project laterally in both directions from the leg portions of the composite track section and are spaced apart for convenience in extrusion molding between the side portions a guide slot 10g is formed which accommodates the return conveyor chain stretch 16 as shown this downwardly open guide slot includes laterally extending side recesses or slots 10h which slidably receive support and guide the wing elements of the conveyor chain return stretch 16 adjacent and immediately above the outwardly projecting legs of the footing flanges 10f are slots 10k opening outwardly along opposite faces of the track section side portions and it is these slots which are used in the improved method of mounting the track sections as illustrated in fig1 and 2 this improved means includes striking up from the web of the transverse support beam 18 two spaced retainer tabs or lugs 20 which are spaced apart and are elevated above the face.