摘要 |
PROBLEM TO BE SOLVED: To provide a sink-and-float type fence capable of considerably shortening the time required for sinking a sinkable float to a depth which allows a small-sized management boat to navigate. SOLUTION: A sinkable float 18(B) is composed of: a sinkable float for water passage and boat passage 18(B-1) having a length such that the sinkable float 18(B-1) can sink to a width and a depth which allow a small-sized management boat to pass through; and a sinkable float dedicated to water passage 18(B-2) for securing a desired amount of water passage by the total length of the length of the sinkable float 18(B-1) and the length of the sinkable float 18(B-2). The sinkable float for water passage and boat passage 18(B-1) and the sinkable float dedicated to water passage 18(B-2) communicate with each other via a communication valve 28. An air supply hose 29 from an air supply machine 6 on the land is connected to the sinkable float for water passage and boat passage 18(B-1). An exhaust valve 30 is provided on the sinkable float for water passage and boat passage 18(B-1). COPYRIGHT: (C)2013,JPO&INPIT |