| 摘要 |
<p>A drilling ship is maintained over a deep sea well in a drilling position defined by an inner circle and an outer circle having the well as their center. The ship is connected to a set of anchors fastened to the sea bed and adapted, when the ship is subjected to the action of external forces tending to change its position and of not more than a predetermined magnitude, to restrain the ship from moving beyond the confines of the inner circle. The ship is equipped with a set of adjustable propellers adapted, in conjunction with the anchors, to position the ship within the confines of the outer circle when the external forces acting on the ship to change its position exceed the predetermined magnitude. The operation of the propellers is controlled by a computer to which values are fed which are determined by detectors of the position of the ship and of external forces acting upon it.</p> |
