12.3.7 Duty Classification
There is no formal duty classification for supporting structures, but manufacturers commonly refer to light duty and heavy duty or similar terms to indicate the intended duty as follows:
Light duty - infrequent use, manually operated lifting appliance, loads usually below the marked SWL. Also commonly known as economy, junior or lightweight.
Heavy duty - frequent use, manual or power operated lifting appliance, high proportion of loads up to the marked SWL, applications where a more robust structure is required. Also commonly known as colossus, robust or senior.