Patent ID: 8893408
Filing Date: 2014-11-25
Classification: E02F

Abstract:
1. An underwater excavation apparatus comprising means for providing a flow of underwater fluid comprising a hollow body having at least one first inlet portion comprising at least one respective first inlet, at least one second inlet portion comprising at least one respective second inlet and at least one outlet portion, the at least one first and second inlet portions being substantially symmetrically disposed around a first axis extending from the outlet portion, the at least one first and second inlets being opposed to one another, at least one pair of impellers rotatably mounted coaxially in the hollow body and means for driving the impellers, wherein, in use, the driving means cause the impellers to be driven in contrary rotating directions, and at least one means for moving the underwater excavation apparatus during excavation comprising at least one first and at least one second moving means, the at least one first and second moving means being provided above the respective at least one first and second inlet portions for counteracting reactive torque of the underwater excavation apparatus, wherein the at least one first and second moving means each comprises at least one further impeller mounted for rotation in a common plane of rotation, the common plane of rotation being coincident with the first axis and with a second axis which extends between the first and second inlets and which perpendicularly intersects the first axis.