| 摘要 |
PURPOSE:To improve working efficiency, by a method wherein a weight, having less resistance in water against water in a vertical direction, is moved vertically to perform levelling of ripraps. CONSTITUTION:A weight 1 of mesh structure having a number of through-spaces in a vertical direction is hung down by means of wire ropes 4 hung down from a crane 3 on a working ship 2. Thereafter, the weight 1 vertically is moved in water to level ripraps 5. This causes water to vertically pass through throughspaces in the weight 1 to reduce resistance against water, and enables the use of the weight having a levelling area wider than that of a conventional weight, resulting in improving working efficiency. |
