Floating Hydraulic Excavators
The floating hydraulic excavator can be assembled using a number of (coupling) pontoons, with or without spud poles, on which a standard hydraulic excavator will be positioned. The advantage of this combination is that the excavator will also be available for land-based dry earthmoving activities. The disadvantages are that stability would only be provided when a sufficiently large pontoon has been used and that the spud poles cannot absorb any horizontal forces.
Another formation of the floating hydraulic excavator is the fixed combination of the excavator’s upper structure and a special pontoon carrying the slewing ring. An example of this type of dredger is the Amphidredge, which was developed in The Netherlands in the 1970s. Using specially designed legs, this machine is able to stabilise itself, even when positioned on very soft muddy and silty foundations. This machine can even crawl into or out of the water using its own legs.
A number of elevator barges are often used to transport the dredged material; they carry it to an easily accessible on-shore location. These barges are then unloaded using a second hydraulic excavator, a land-based machine with a long boom. To transport the dredged material, tipper trucks with a watertight dump body could then be used.
At this point, it is also possible to process the dredged material in a soil treatment plant for environmental purposes.