| 摘要 |
<p>A derrick apparatus for a drilling machine (10), the apparatus comprising a fixed structure (48, 50) for supporting drill equipment (14, 16), wherein the fixed structure (48, 50) has a generally prismatic shape with a generally constant cross-section along the vertical extent of the fixed structure (48, 50), and wherein the fixed structure (48, 50) comprises supporting beams (48, 50) about outer parts of the fixed structure and a void extending across the internal width of the fixed structure (48, 50).</p> |
