| 摘要 |
PURPOSE:To perform efficient excavation even if there is a change in the depth of water, by a method wherein a ladder is divided into an arm part and a hand part, and an angle of a cutter with the sea bottom is held at a specified value through the converse motion of a second hydraulic cylinder in linkage with expansion and contraction of a first hydraulic cylinder. CONSTITUTION:A ladder 3 is vertically rotatably mounted to a ship hull 1 through a trunnion 2, the ladder 3 is divided into an arm part 8 and a hand part 9, and the hand part 9 is vertically rockably positioned. When the ladder 3, which is under an excavating work on the deep sea bottom, is lifted up by means of a crane on a ship, a first hydraulic cylinder 11 is contracted by the arm part 8, a second hydraulic cylinder 12 is conversely expanded in linkage with the motion of the first hydraulic cylinder 11, the hand part 9 is moved in parallel as it is bent by means of the second hydraulic cylinder 12, resulting in maintenance of a specified angle of the cutter 4 with the sea bottom. Further, the ship hull 1 is moved to a shallow sea bottom, and with the cutter 4 rotated, the sea bottom is excavated. |
