An earth removal and sand mining system is provided, comprising a modular floating platform having an elongated U-shaped open channel defining an operating area; a gantry positioned above the operating area, wherein the gantry includes a crane and trolley operable along a predefined path within the operating area; a hoist extending from the trolley; and a pump operatively suspended from the trolley, wherein the pump includes a slurry discharge hose. The platform includes an adjustable drag line connected to the pump to provide maximum control over the pump position for efficient operation.

A device for launching subsurface mining vehicle into a water mass from a docking well of a floating vessel, and/or recovering said vehicle from the water mass is disclosed. The device comprises a docking frame that is hinge mounted to the vessel, and that comprises first mining vehicle engaging means for guiding the mining vehicle along a longitudinal direction of the frame into the water. The docking frame operatively engages with drive means for tilting the frame in a vertical plane between a substantially horizontal mining vehicle docking position and a substantially vertical mining vehicle launching or recovery position. The device further comprises third engaging means for guiding the mining vehicle when the vehicle extends at least partly underneath a base of the vessel. The device allows lowering or recovering subsurface mining vehicle in a controlled manner.

A deep-sea ore hydraulic lifting system with a deep-sea single high-pressure silo feeding device, comprises a water injection pump, a water injection riser, a deep-sea single high-pressure silo feeding device, a lifting riser, a dewatering device and a pipeline. The water injection pump and the dewatering device are fixed on a mining ship. The water injection pump is connected to the deep-sea single high-pressure silo feeding device through the water injection riser. The deep-sea single high-pressure silo feeding device is connected to the dewatering device through the lifting riser. The water injection pump is connected to the dewatering device through the pipeline. Seawater is pumped into the water injection riser by the water injection pump, then ore is fed into a high-pressure hydraulic pipeline by the deep-sea single high-pressure silo feeding device to be mixed with the seawater, and an obtained ore and seawater mixture is lifted.

Dredging apparatus systems and methods are disclosed herein. In an embodiment, a dredging apparatus includes a float assembly, a support frame, and a suction head assembly. The float assembly is configured to float on the surface of a liquid. The support frame is connected to the float assembly. The suction head assembly is movably supported with respect to the float assembly by the support frame. The support frame is tiltable with respect to the float assembly between a first position and a second position.

A method of underwater trenching including providing an apparatus having a floating platform having an opening therein, a frame placed on the floating platform, a guide pipe inserted through the tower, a steel coiled high-pressure flexible hose attached to a high-pressure water pump, and a power source. Positioning the apparatus such that the opening is positioned over an area of water in which the sand under the water needs to be trenched. Lowering the guide pipe until an end of the guide pipe reaches the sand under the water. Inserting the hose through the guide pipe. Activating the water pump to induce until the sand begins to come up from around the pipe underneath a surface of the water indicating a sinkhole has been formed. Removing the guide pipe to collapse the sink hole to create the trench.