| 摘要 |
PURPOSE:To improve stable performance of a petroleum excavating device, by a method wherein the surrounding of a derrick erected on a column is covered with a cylindrical cover. CONSTITUTION:A deck house 2 is built on a column 1, and a derrick 3 is built on the deck house 2. A cylindrical cover 4 is installed around the derrick 3 for covering. This causes the flow of the air to be prevented from turbulence for smoothing, and reduces production of a wind load, resulting in improvement of stable performance of a petroleum excavating device. |
