This standard specifies the safety requirements for support units when used as specified by the manufacturer or his authorised representative. Examples of support units are frame supports, chock supports, shield supports, paired frames and push-pull support systems including the components of advancing and anchoring devices which provide support functions. This part of the standard excludes fixing elements on the conveyor, coal-winning equipment, power set legs and rams, valves, hydraulic and electro-hydraulic control units, lighting and signalling facilities and other ancillary equipment.NOTE Some components are dealt with in other parts of this standard.T