It can be fitted to a mast or a kingpost, when it is called a mast derrick, or to the side of a ship's superstructure, when it is called a screen derrick.
Ingakwazi nokufakwa kwikumkani yezithuba xa ibizwa ngokuba sisilenge okanye emacaleni enqanawa ukuxhobisa isakhiwo esi xa ibizwa ngokuba ngumboniso-silenge.