There are three principal conveyor constructions. The recommended arrangement is with the drive at the head end and the carrying and return strands well supported (see fig. 3.1).Note the catenary sag at the head which should be equal to at least 3% of the span over which the chain is suspended. Other methods of supporting the return run are roller support (fig. 3.2) and Wear or guide shoes (fig. 3.3). Supported carrying and return with catenary is preferred as the catenary will ensure correct chain and sprocket engagement and more importantly reduce chain joint wear as minimum tension and flexing is applied.