This is a twin screw, twin engine drive, twin drag head, single deck, forecastle, full steel welding, streamline, round bilge, self-propelled 3000 m³ trailing suction hopper dredger with bulbous bow.

The dredger is mainly used for dredging and recreation project in coastal area and sailing in greater coastal area.

The vessel and its equipment are designed for full operation and the following conditions:

Air conditioner and Central Cooling system design conditions reference to related chapter:

Maximum outside temperature 40°C

Minimum outside temperature -19°C

Engine room temperature 45°C

Maximurn sea water temperature 32°C

Minimum sea water temperature 1°C

Relative humidity 90% 35°C

Maximum current 4 knots

Maximum wind speed 20m/s

Maximum wave height 3m

Wave period 6s

1.1.3 Navigation area and working place

The dredger can sail in greater coastal area and dredge in coastal area (within 20 miles from coast).

1.1.4 Classification And Rules

(1) class notation

The vessel is constructed under special supervision of CCS, and acquires certification notation asbelow:

* CSAD Trailing Suction Hopper Dredger; Greater Coastal Service; Dredging Within Coastal

Area; Ice Class B

* CSMD

Twin trailing suction pipe dredging operation, two inboard dredge pumps are used for hopper loading and hopper self-emptying.

(1) Two inboard dredge pumps are located in independent pump room in front of the hopper, both are driven by frequency conversion motors via gear boxes.

(2) Capable to dump the soil to the sea bed through two rows or in total 12 conical bottom doors.

(3) Two energy-releasing boxes are arranged in hopper, used for releasing the energy to accelerate the settling or mud during loading.

(4) Capable of pumping the soil from the hopper to shore by means of single inboard dredge pump or the double inboard dredge pumps working is series.

(5) Capable of pumping the soil from the hopper for rainbow by means of single inboard dredge pump or the double inboard dredge pumps working in series

(6) The dragheads are provided with pressure water jets and double demountable trailing teeth for loosening comact soil.

(7) Capable of diluting the hopper load at selected hopper spaces by means of jet water to facilitate unloading of the spoil during dumping and during pumping ashore. And the pressure of single jet water can reach 0.7MPa, and when two high pressure water jets are working in series pressure can reach 1.4MPa.

(8) Each bottom door is operated by a hydraulic cylinder, remote controlled from the wheelhouse.

(9) The hopper has a coaming, and an anti-splash plate over the full length or hopper is arranged.

(10) Two cylindrical type overflows are installed, operated by hydraulic cylinder, remote controlled from the wheelhouse, continuously adjusting from capacity or 2100 m³ to maximum 3000 m³.

(11) Each of the twin controllable pitch propellers is driven by a non-reversible diesel engine through a reduction gearbox. And the propellers are fitted in nozzles.

(12) The dredger has two flap rudders, which can enhance the rudder efficiency and reduce the turning circ1e.

(13) Propulsion engines also drive AC shaft generators supplying electric power to:

Two AC electric motors for high pressure water jet drive

Two AC inboard dredge pump motors

Hydraulic pump station

Living use

One AC electric motor or bow thruster (not for use when dredging

(14) One electrically driven bow thruster or 300kW, remote controlled from the wheelhouse to improve maneuverability.

(15) Single person remote control in wheel house

Propulsion control system

Suction pipe / dredge pump control system

(16) Accommodation rooms with air conditioner at the aft part on the deck are available for 26 people.

(17) A forecastle is arranged at the fore part of the main deck, the frequency converter room, hydraulic pump station and rigging store are located.

(18) Each side of the vessel is arranged for a full closed type of life boat, which capacity is for 26 people,

(19) One deck crane or 10t @ 14m lifting arm and one deck crane or 10t @ 11m are arranged at hopper coaming area to facilitate deck equipment repairs, handling of heavy weights and equipment repair in dredge pump room.

(20) The fore peak tank is arranged as trim tank in order to reduce the vessel's trim in light ship condition or partly loaded condition.

Dredging depth below light waterline (i.e. ship empty with 10% stores and water in

Total capacity of fuel oil (service tanks and settling tanks excluded)

At dredging draft, the dead weigh is about 4540 ton.

1.6.1 Dredging characteristic

The vessel shall be designed to dredge ilt, clay, silty fine sand, medium sand and coarse sand technical request is as blow:

Density = 1.95t / m³ (fill water in stoma)

Density = 2.65t / m³ dry sand

Coarse sand d50% = 0.50 mm

1.6.2 Hopper loading

When dredging fine and meduim sand, effective loading time calculated is about 64 mibutes when twin trailing dredging, trailing pipe 45O and dredging is 25 meters (hopper capacity is about 3000 m³, density is about 1400kg / m³). Loading time described above is basics on the condition that mean concentration or loading spoil is 22% and average overflow loss is 16%.

1.6.3 Purnping ashore

Two inboard dredge pumps working in series pump the fine and medium sand described above (hopper capacity is about 3000 m³ density is about 1400 kg / m³) ashore through a pipeline with 3000 meters long, the time is calculated at approx. 65 minutes. The time is based on the condition that pipe diameter is 600mm and the elevation is 6m.While pumping ashore, usabIe power or each inboard dredge pump shaft end is about 1200kW.

1.7.1 Speed

(1) Free speed

The ship with a freshly painted hull, at a mean molded draft 5.20 m, in smooth deep sea

water, an unrestricted channel width and a wind force not exceeding Beaufort scale 2, will have A free speed of 12.0 knots at the two engines with the maximum continuous rating power.

Should the conditions of the vessel and / or the weather differ, a suitable calculation shall be made to present the results in accordance with the above stated conditions.

(2) Dredging speed

At the dredging condition with loaded ship at a mean draft of 5.20 m, a dredging depth 25 m, with both trailing suction pipes, the vessel's speed will be approx. 6.0 Knots through the water, i.e.2.0 knots bottom speed with 4.0 knots counter current. In this condition the resistance force for each drag head will be about 78kN.

If you are interested, please contact Kriesels Shipbroker B.V..