Dredge Drag Head

picture info	Dredge Drag Head {{unreferenced, date=July 2018 A dredge drag head is used by a trailing suction hopper dredger to collect sand from the sea floor. The dredge drag head is a steel structure that is connected to the dredger by a suction pipe. Supported by the gantries and by using hydraulic winches the dredge drag head and suction pipe are let down onto the sea bottom in order to suck a mixture of water and sand. In order to dredge in waves, the suction pipe is suspended from special davit Boat suspended from radial davits; the boat is mechanically lowered Gravity multi-pivot on Scandinavia'' file:Bossoir a gravité.jpg, Gravity Roller Davit file:Davits-starbrd.png, Gravity multi-pivot davit holding rescue vessel on North Sea ferr ...s, which operate with heave compensation to ensure that the drag head nozzles stay in contact with the sea bed. The control of mixture of water and sand is done by a so-called dredge drag head visor. The visor controls the amount of water that enters along with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Trailing Suction Hopper Dredger A trailing suction hopper dredger is a ship that has a full sailing capacity used to maintain navigable waterways, deepening the maritime canals that are threatened to become silted, to construct new land elsewhere or to replace sand eroded by storms or wave action on the beaches. This is made possible by large powerful pumps and engines able to suck sand, clay, silt and gravel. Operation Properties A trailing suction hopper dredger is self-loading/unloading and sometimes equipped with a pressurized discharging system. Loading From the side of the ship one or two suction pipes descend to the bottom of the seabed. On the end of the pipe a so-called trailing drag head is connected. This head is comparable to a large vacuum cleaner and is trailed along the seabed. In the head there are nozzles connected to a high pressure water installation that are capable of loosening the material on the seabed. Due to lower pressure in the pipe, the material will be sucked inward and discharged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Dredge Drag Head {{unreferenced, date=July 2018 A dredge drag head is used by a trailing suction hopper dredger to collect sand from the sea floor. The dredge drag head is a steel structure that is connected to the dredger by a suction pipe. Supported by the gantries and by using hydraulic winches the dredge drag head and suction pipe are let down onto the sea bottom in order to suck a mixture of water and sand. In order to dredge in waves, the suction pipe is suspended from special davit Boat suspended from radial davits; the boat is mechanically lowered Gravity multi-pivot on Scandinavia'' file:Bossoir a gravité.jpg, Gravity Roller Davit file:Davits-starbrd.png, Gravity multi-pivot davit holding rescue vessel on North Sea ferr ...s, which operate with heave compensation to ensure that the drag head nozzles stay in contact with the sea bed. The control of mixture of water and sand is done by a so-called dredge drag head visor. The visor controls the amount of water that enters along with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Davit Boat suspended from radial davits; the boat is mechanically lowered Gravity multi-pivot on Scandinavia'' file:Bossoir a gravité.jpg, Gravity Roller Davit file:Davits-starbrd.png, Gravity multi-pivot davit holding rescue vessel on North Sea ferry file:Freefall lifeboat.JPG, Freefall lifeboat on the ''Spring Aeolian'' file:Frapping line.jpg, Frapping line Labeled Tricing Gripe Steps to launch davit Roller Gravity Davit A davit (pronounced "dayvit" or see Wiktionary) is any of various crane-like devices used on a ship for supporting, raising, and lowering equipment such as boats and anchors. Davit systems are most often used to lower an emergency lifeboat to the embarkation level to be boarded. The lifeboat davit has falls (now made of wire, historically of manila rope) that are used to lower the lifeboat into the water. Davits can also be used as man-overboard safety devices to retrieve personnel from the water. The maintaining and operation of davits is all under jurisdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]