| 摘要 |
PURPOSE:To hold a ladder at an optimum angle irrespective of the depth of water, by a method wherein a grooved slit is provided in the longitudinal direction of an enclosed long boxform ladder, and a trunnion for supporting the ladder is mounted so that it is slidable and stationarily positioned in the grooved slit. CONSTITUTION:An enclosed long boxform ladder 3 is vertically rockably secured to a ship hull 1 through a trunnion 2. A cutter 4 is rotatably mounted to the forward end of the ladder 3, the cutter 4 is driven by a driving device 5 installed to the upper part of the ladder 3, and earth excavated by the cutter 4 is conveyed to the surface through a suction pipe 7. The ladder 3 has a slit 8 formed in the longitudinal direction thereof, grooves 9 are provided in the slit, and this enables sliding and fixing of the trunnion 2. This enables the maintenance of a specified angle of the ladder with the sea bottom irrespective of the depth of water, and improvement of excavation efficiency and operability of the ladder. |
