KAISHO MARU Trailing Suction Hopper Dredger with Spilt Oil Recovery Devices
KAISHO MARU is a trailing suction hopper dredger with spilt oil recovery devices. The vessel is engaged daily in capital dredging or maintenance dredging around Kan-Mon strait area between Honshu and Kyushu. Once an oil spilt accident occurs in the coastal area of Japan, the vessel will serve as an oil recovery vessel to minimize the environmental damage by oil pollution.
Features
1. One center drag ladder with a pair of wide drag-heads is provided in the aft end well to dredge thin layer soil, keeping a straight course of drag heads up to a dredging depth of 18 m. Two (2) recycle pumps are equipped with main dredge pumps to return upper thin layer of hopper loaded muddy water to the drag-heads, which increases hopper loading efficiency and decreases sea surface turbidity due to overflow of muddy water.
2. Two (2) electric motor driven azimuth type fixed pitch nozzle propellers are provided for dredge course keeping and easy maneuvering. Power is supplied by two main generators through 3.3 kVA high voltage electric distribution system. The system also drives such essential motors as dredge and recycle pumps, drag-ladder winch, and bow thruster.
3. Two (2) oil recover equipment mounted ship-side, and two (2) throw-in type oil recovery equipment are on board. The latter work together with I-type floating boom, which collect spilt oil to the equipment. Oil recovery tanks are located at both sides of the mud hopper.
4. The controls of dredging, oil recovering, etc. are performed automatically from the wheel house. Computer system is employed to control and monitor the operation, and record operating condition log data which supports the decisions associated with the maintenance of the equipment.
5. To carry out the highly efficient dredging, fuzzy control system is applied. The system is to optimize vessel speed, dredge pump and recycle pump revolution, and pressure of swell compensator of the drag-head to maximize the hopper loaded material.
6. LAN (Local Area Network) system using optical fiber cables is provided for multiple data transfer which enables operation with central control and monitoring from the wheel house.
PRINCIPAL PARTICULARS
Length (o.a.) ... 103.02 m
Length (b.p.) ... 96.00 m
Breadth (mld.) ... 17.40 m
Depth (mld.) ... 7.20 m
Draft (mld.) ... 5.70 m
Gross tonnage ... 4,663
Deadweight ... 3,768 T
Propulsion motor ... Electric motor: Nishishiba Electric Co., Ltd.
Rated output ... 1,500 kW x 1,200 rpm
Speed (max. trial) ... 13.6 knots
(service) ... 12.6 knots
Complement ... 35
Classification ... JG, Greater Coasting Service (International Voyage)
Dredge pump ... 5,000 m3/h x 2 sets
Recycle pump ... 2,500 m3/h x 2 sets
Loading capacity (Mud hopper capacity) ... 2,000 m3
(Oil collecting tank) ... 1,500 m3
