Derrick--Main features:                                                        Specification (Clickhere)

(1)The mast (derrick) type is generally classified as A type, K type, tower type and mast type etc.
(2)A type mast, its leg section is rectangular or triangle shape, with better loading capacity and      stability, connected with pins between sections, installed at low level and erected or lowered      down integrally by drawworks and A-frame.
(3)K type mast, namely front opening mast, its transverse section is a shape truss structure, its      both sides are composed of several pieces or segments, its back is rigid frame or pole system      of truss, connected with pins or bolts between segments and members, may be installed at low      level and erected or lowered down integrally by drawworks or hydraulic cylinder, has the      advantages of convenient installation and teardown, excellent rigidity.
(4)Conforming to API Spec 4F, marked with API .