Historical
SAE J 1305-2007 (SAE J1305-2007)
Two-Block Warning and Limit Systems in Lifting Crane Service
The purpose of this SAE Recommended Practice is to establish the minimum performance requirements of devices which signal and/or automatically prevent two-blocking. This SAE Recommended practice applies to cranes in lifting crane service which are equipped with two-block warning and/or limit systems.
Society of Automotive Engineers [sae]