Cutter excavator
A cutter dredger or cutter suction dredger is usually a dredger with or without its own drive, with which solid material is removed from the bottom of the water.
Working method
Behind the cutting head there is a suction mouth which is connected to one or more centrifugal pumps via a suction line . The loosened rock is sucked in by the negative pressure at the suction opening and pumped ashore via a gooseneck and floating pipes. Some excavators also have facilities to load barges lying alongside .
At the bow of the ship, the cutting head device and the suction pipe are attached to a lowerable frame (usually a so-called A-frame). For physical reasons, the first centrifugal pump is usually located directly behind the suction mouth; the hydraulically driven so-called underwater pump. One or two additional pumps are then located on the deck of the cutter suction dredger, depending on the performance. On the aft ship are two lowerable stilts (stilts) with which the ship is anchored to the bottom of the water. One post goes straight through the ship, the other post is attached to the pile wagon, which can be moved up to six meters lengthways. The ship can move sideways around this post with the anchors deployed on port and starboard and thus work on a segment of a circle. The pile wagon pushes the ship forward. When the pile wagon has reached the end of its lane, the second pile is lowered, the pile in the pile wagon is pulled up again and moved back to its starting position. Then drop the main post and pull up the auxiliary post. Now you can edit a new area. Anchoring with piles is no longer technically possible for suction dredgers with particularly large excavation depths (such as the Pirat X from Johann Bunte Bauunternehmung ). The piles are replaced by several anchors, which are brought together in a Christmas tree on the aft ship .
Cutter dredgers are used to deepen fairways and to mine minerals. Since the material is harder, it is not possible to use hopper excavators . Since most cutter excavators do not have their own drive, they are towed to their destination.
Technical specifications
Below are the technical data of the self-propelled cutter excavator Ursa from Royal Boskalis Westminster BV
- Length 115.83 m above sea level A. Length of hull 104.1 m
- Width 20.0 m
- Draft 5.10 m
- Max. Excavation depth 25.0 m
- total installed capacity 15,871 kW, of which
- Cutting head drive 3,960 kW
- Suction pump 2,200 kW
- Unloading pump 7,400 kW
- Drive 7,400 kW
Web links
Individual evidence
- ↑ Different Types of Dredgers Used in the Maritime Industry. In: Marine Insight. July 29, 2019, accessed August 31, 2019 .