An excavation tool for making ground excavations for panels and diaphragms includes at least one rotary excavation drum. At least one frame is adapted to support the excavation drum. At least one pump is adapted for suction of an excavation fluid. A brushless electric motor is adapted to put in rotation the at least one excavation drum. At least one mechanical reducer is operationally connected to the electric motor and the at least one excavation drum. The electric motor is installed in the frame and coaxial to the at least one excavation drum. The at least one mechanical reducer is coaxial to the electric motor and the at least one excavation drum. The at least one mechanical reducer is adapted to transfer rotary motion from the electric motor to the at least one excavation drum.

The invention relates to a diaphragm wall cutter for cutting a cutting trench in the ground, comprising a cutting frame, at least one rotatably drivable cutting wheel which is mounted on an lower side of the cutting frame, a suction nozzle, which is arranged in the region of the at least one cutting wheel and is provided with at least one suction opening, and a suction pump which is configured for suctioning slurry from the cutting trench during cutting via the suction nozzle, the suction pump being connected to the suction nozzle via a suction line. According to the invention, it is provided that at least one filling port is provided for filling the suction pump and the suction line with a liquid when the suction line is shut-off, wherein the suction line and the suction pump are filled with liquid for starting the suction pump.

The invention relates to a cutter head for removing a mixture comprising water and solid materials from a water bottom, comprising rotating blades each provided with cutting means on a leading edge thereof, said cutter head being rotatably coupled to a tube for transporting said mixture, the shape of the leading edge of said rotating blades being defined by substantially fitting a rounded cone with a rotation axis, wherein each rotating blade at a middle part is coupled to a connecting ring and at a top part is linked to a top part of another rotating blade. The cutter head is characterized in that the rotation axis of said blades is substantially aligned with a rotation axis of said ring; in that a trailing edge of part at least one of said blades is positioned closer to said rotation axis than a leading edge of said blades so as to provide a suction function towards said tube upon rotation of said cutter head; and in that said blades as viewed from said top part at a bottom part of said blades extend to a position beyond said connecting ring. A preferred embodiment comprises a method for using the cutter head according to the invention.

A cutterhead for dredging water-bed material from a body of water. The cutterhead comprises a shroud presenting a front margin for receiving water-bed material into an interior space of the shroud. The shroud additionally includes a port from which water-bed material can be removed from the interior space of the shroud. The cutterhead additionally comprises a rotatable cutterbar at least partially received within the interior space of the shroud. The cutterhead further comprises a debris guard positioned between the cutterbar and the port. The debris guard is operable to filter the water-bed material removed from the shroud through the port. At least a portion of the debris guard that faces the cutterbar includes a concave shape.

A cutterhead for dredging water-bed material from a body of water. The cutterhead comprises a shroud presenting a front margin for receiving water-bed material into an interior space of the shroud. The shroud additionally includes a port from which water-bed material can be removed from the interior space of the shroud. The cutterhead additionally comprises a rotatable cutterbar at least partially received within the interior space of the shroud. The cutterhead further comprises a debris guard positioned between the cutterbar and the port. The debris guard is operable to filter the water-bed material removed from the shroud through the port. At least a portion of the debris guard that faces the cutterbar includes a concave shape.

An excavation apparatus is disclosed. The excavation apparatus includes a chassis having a length that extends from a front end to a rear end of the chassis. The chassis also has a width oriented perpendicular to the length. A boom is pivotally attached to the rear end of the chassis. A cutting component mounted to the boom. A shroud structure at least partially covers the cutting component. A source of vacuum is in fluid communication with an interior of the shroud structure for drawing air containing dust from the interior of the shroud structure. A filter filters the air drawn from the interior of the shroud structure by the source of vacuum. A dust barrier projects downwardly from the shroud structure and extends along at least a portion of a perimeter of the shroud structure. The dust barrier has a construction that is pervious to debris generated by the cutting component and that provides gradually reduced restriction to inward air flow through the dust barrier as the dust barrier extends downwardly from the shroud structure.