Definition(s)
Counterweight
Weight used to supplement the weight of the machine in providing stability for lifting working loads and usually attached to the rear of the revolving upper-structure.
Source: API RP 2D, Operation and Maintenance of Offshore Cranes, Sixth Edition, May 2007. Global Standards
Source: API RP 2D, Operation and Maintenance of Offshore Cranes, Seventh Edition, December 2014. Global Standards