PURPOSE: To reduce reaction due to the tensile load of mooring devices by attaching the mooring devices on submarine base members and attaching the mooring devices and a main body of film type wave spending revetment through damper mechanisms.
CONSTITUTION: Base members 2 are buried in a submarine T and secured. Then, the ends of mooring devices 4 are connected to connecting parts 2a formed on the upper parts of the base members 2. The mooring device 4 comprises a chain 5 with their ends respectively attached to the base member 2 and a main body of film type wave spending revetment 3 and a damper mechanism 6 provided in the intermediate part of the chain 5 and imposing its tensile force when tension is applied to the chain 5. Then, the moving energy of the film type wave spending revetment transmitted to the main body 3 thereof is absorbed by the damper mechanisms 6 and its reaction is transmitted to the base members 2. Reaction produced in the base members 2 is reduced, so that a small size of components of the device can be realized.