US Patent 10329788 Drilling rig

A method of assembling a drilling rig may include aligning a trailer with a drilling rig support structure, the trailer carrying a mast and the drilling rig support structure including a step-down substructure. A first end of the mast may be positioned over the drilling rig support structure and arms may be extended from the mast to the drilling rig support structure so that the drilling rig support structure supports the first end of the mast. The mast may translate along a length of the drilling rig support structure. The mast may be coupled to the drilling rig support structure.