What certificates do dredgers need?

Dredger is also a seagoing ship, which needs competency certificate and four certificates. Rake suction type must be trained for at least three months to obtain the above certificate.

Dredger, responsible for dredging the river so that other ships can pass smoothly. It is also a sharp weapon for blowing sand and filling the sea.

The task of dredger is to carry out underwater earthwork construction, specifically: to dig deep, widen and clean up existing waterways and ports; Digging new waterways, ports and canals; Dredge the foundation trenches of hydraulic structures such as docks, shiplocks, etc., and throw the dredged sediment into the deep sea or fill in the land depressions for land reclamation. It is a sharp weapon for blowing sand and filling the sea.

Rake suction dredger is a kind of suction dredger. It sucks mud by rakes placed on both sides or at the tail of the hull, and works by sucking mud and sailing at the same time. The trailing suction dredger is flexible, efficient and resistant to wind and waves, which is suitable for working in coastal ports, wide river surfaces and ship anchorages.

Cutter suction dredger is a kind of ship widely used in tidal flat dredging engineering. It uses the rotary cutter device around the front suction pipe to cut and stir the sediment at the bottom of the river, and then uses the powerful pump force to transport the distorted sediment to the sediment accumulation field through the suction pipe. Its dredging, transportation and unloading processes can be completed continuously at one time.

It is a dredger with high efficiency and low cost, and it is a good underwater excavation machinery. The total length refers to the total length of the hull plus the extended length of the cutter suction frame. The dredging pump is directly driven by the main engine, and the reamer head is driven by the motor or hydraulic mechanism, and the dredging efficiency is set to 30% of the discharge weight. According to Archimedes principle, the suction depth of single-stage dredging pump is actually less than 28M, and intermediate relay pump is needed to achieve deeper suction depth. Relay pump does not need a high lift, although it has the same discharge weight as dredging pump, but its power can be greatly reduced, so relay pump is generally powered by high-voltage motor or hydraulic mechanism under water. The maximum sand absorption capacity of the primary relay pump is only 55M. To deepen, it is necessary to increase the pressure head of the relay pump and increase the power consumption. The relationship between the displacement of the general suction pump and the power of the main engine is about 1.5 ~ 2 times. For example, the power of the main engine is 1200PS, and the displacement of the oil suction pump is about1200 *1.5 =1800m3. In addition to the scale, the specifications of articulated dredger should also provide M3/ Newton displacement and pressure head. The dredging volume is generally between 20% and 30% of the displacement. The suction pipe diameter and outlet pipe diameter of dredging pump shall also be provided. This is more complete. Cutter suction ship shall be equipped with working ship, which is responsible for anchoring and anchoring. In the process of sales, attention should be paid to spare parts: ① whether the work boat is provided together. (2) How many discharge pipes. (3) there should be four working anchors, at least two and anchor floats. (4) positioning pile with and without guide pin.

Cutter suction dredgers can be divided into self-propelled and non-self-propelled types: the former, like the Whale, ranks first in Asia and third in the world in terms of installed power and dredging capacity; The latter is like Tianqi.