Underwater Excavation Tool

Abstract

An underwater excavating tool can generate a downward directed jet of water from a propeller in a main thruster body connected to a surface vessel by an umbilical. The umbilical can include an outer armored sheath that supports an underwater weight of the excavating apparatus, a data cable carrying signals from a controller unit on a surface vessel, and a power cable that supplies electrical power to operate the propeller and other functions of the excavating apparatus. One or more of the orientation, position, and rotation of the main thruster body can be controlled remotely by adjusting two or more positional thrusters mounted radially on the main thruster body. Remote control can be provided using the signals carried via the data cable. Related systems, apparatus, methods, and/or articles are also described.

1 . A system comprising:
 a control and power unit configured to be carried on a surface vessel;   an umbilical comprising at least one electrical power cable, at least one data cable, and a weight-bearing outer sheath, the umbilical configured to be connected at a first end to a winch on the surface vessel and having a second end, the electrical power cable carrying high voltage electricity from the control and power unit, the data cable carrying signals to and from the control and power unit; and   an underwater excavation tool comprising:
 a main thruster body comprising an inlet disposed at a top end of the main thruster body and an outlet disposed at a bottom end and a central axis running from the top end to the bottom end; 
 an umbilical junction located on the central axis and connected to the second end of the umbilical such that a weight of the underwater excavation tool is supported by the weight-bearing outer sheath; 
 a plurality of power packs each comprising an electrical motor and a positional thruster hydraulic fluid pump and one or more main thruster hydraulic fluid pumps driven by the electrical motor; 
 a power junction that receives power from the electrical power cable and distributes the electrical power to the electrical motors in each of the plurality of power packs; 
 a hydraulic motor that receives pressurized hydraulic fluid from the one or more main thruster hydraulic fluid pumps of each of the plurality of power packs; 
 a main thruster propeller mounted about the central axis within the main thruster body and driven in a single radial direction by the main hydraulic motor; 
 a plurality of adjustable positional thrusters mounted on the main thruster body and each supplied with pressurized hydraulic fluid from the positional thruster hydraulic fluid pump of one of the plurality of power packs, each thruster comprising a thruster propeller that produces thrust, the plurality of adjustable positional thrusters acting in response to signals received from the control and power unit via the data cable to provide thrust at one or more angles relative to the main axis to maintain one or more of a desired orientation, position, and rotation of the main thruster body and to provide rotational thrust to counter torque produced by rotation of the main thruster propeller. 
   
   
   
       2 . A system as in  claim 1 , comprising four adjustable positional thrusters and four power packs. 
   
   
       3 . A system as in  claim 1  in which there is only one main thruster propeller. 
   
   
       4 . A system as in  claim 1 , further comprising a second main thruster propeller mounted about the central axis within the main thruster body and driven in the same single radial direction by the main hydraulic motor. 
   
   
       5 . An apparatus comprising:
 a main thruster body comprising an inlet for water intake and an outlet through which water is discharged;   an umbilical junction that is integral to the main thruster body and configured to connect to an umbilical at a first end of the umbilical, the umbilical connecting at a second end to a surface vessel such that an outer armored sheath of the umbilical supports an underwater weight of the apparatus, the umbilical further providing electrical power to the apparatus via an electrical cable that runs from the surface vessel to the apparatus within the outer armored sheath;   a main thruster propeller housed within the main thruster body and powered by the electrical power to generate a flow of water in through the inlet and out through the outlet; and   two or more adjustable positional thrusters mounted on the main thruster body, each thruster comprising a thruster propeller that produces thrust to counteract torque produced by rotation of the main thruster propeller within the main thruster body and to maintain one or more of a desired orientation, position, and rotation, of the main thruster body.   
   
   
       6 . An apparatus as in  claim 5 , further comprising a connection module mounted to the main thruster body, the connection module comprising an electrical connection configured to connect to the electrical cable within the umbilical to provide the electrical power to the apparatus from a power supply on the surface vessel; and a data connection configured to connect to a data cable within the umbilical to transmit data and commands between the apparatus and a controller module on the surface vessel. 
   
   
       7 . An apparatus as in  claim 5 , further comprising an electric motor that is supplied with electrical power via the electrical cable, a main thruster hydraulic fluid pump that is driven by the electric motor, and a main hydraulic motor that is supplied with pressurized hydraulic fluid from the main hydraulic fluid pump and that drives the main thruster propeller. 
   
   
       8 . An apparatus as in  claim 5 , wherein the main thruster body comprises a central passage leading between the inlet and the outlet, the central passage being rotationally symmetrical about a central axis, and wherein the main thruster propeller is disposed within the central passage and rotates about the central axis. 
   
   
       9 . An apparatus as in  claim 8 , wherein the main thruster propeller can rotate in only one radial direction about the central axis. 
   
   
       10 . An apparatus as in  claim 5 , comprising exactly four adjustable positional thrusters. 
   
   
       11 . An apparatus as in  claim 5 , further comprising two main hydraulic motors that drive the main thruster propeller, four positional thrusters, four electric motors, four positional thruster fluid pumps, and eight main thruster fluid pumps, wherein one of the four motors, one of the four positional thruster fluid pumps, and two of the eight main thruster fluid pumps are housed in one of four power packs secured outboard of the main thruster body, the electric motor of each power pack driving the one positional thruster fluid pump of the power pack that provides pressurized hydraulic fluid to drive one of the four positional thrusters and also driving the two main thruster fluid pumps of the power pack that provide pressurized hydraulic fluid to the two main hydraulic motors. 
   
   
       12 . An apparatus as in  claim 5 , further comprising one or more surveying devices mounted on the main thruster body. 
   
   
       13 . An apparatus as in  claim 12 , wherein the surveying devices comprise one or more of a multibeam sonar unit, an obstacle avoidance sonar unit, and a video camera. 
   
   
       14 . An apparatus as in  claim 5 , further comprising an interlock that causes shutdown of the main thruster propeller if rotation of the main thruster body beyond a threshold angle about the umbilical is detected. 
   
   
       15 . An apparatus as in  claim 5 , further comprising one or more sensors that monitor one or more parameters selected from a group consisting of: input and output pressure of the adjustable positional thrusters, input and output pressure of the main thruster body, pressure of one or more auxiliary hydraulics systems, ambient water pressure, differential pressure between the main thruster body inlet and ambient water pressure, differential pressure between the main thruster body outlet and ambient water pressure, rotation of the main thruster body about the umbilical, and position and orientation of the main thruster body. 
   
   
       16 . An apparatus as in  claim 5 , further comprising the power supply that is connected to a surface vessel power source and that comprises one or more electrical transformers that provide a stepped up high voltage current to the at least one electrical cable in the umbilical. 
   
   
       17 . A method comprising:
 generating a downward directed jet of water from a single propeller in a main thruster body of an excavating apparatus whose underwater weight is supported by an umbilical connected to a surface vessel, the umbilical comprising an outer armored sheath that supports the underwater weight, a data cable carrying signals from a controller unit on a surface vessel, and a power cable that supplies electrical power to operate the single propeller and other functions of the excavating apparatus; and   controlling one or more of the orientation, position, and rotation of the main thruster body by adjusting two or more positional thrusters that are mounted on the main thruster body, the controlling occurring remotely via the signals carried via the data cable.   
   
   
       18 . A method as in  claim 17 , further comprising driving the single propeller by one or more main hydraulic motors that are provided with pressurized hydraulic fluid from one or more main thruster fluid pumps that are driven by one or more electric motors powered by the electric power. 
   
   
       19 . A method as in  claim 17 , wherein the electrical power supplied by the power cable powers one or more electric motors that drive at least one main thruster hydraulic fluid pump that drives the single propeller and two or more positional thruster hydraulic fluid pumps that drive the two or more positional thrusters. 
   
   
       20 . A method as in  claim 17 , further comprising transmitting data from one or more sensors on the excavating apparatus to the controller unit via the data cable, the one or more sensors monitoring one or more parameters selected from a group consisting of: input and output pressure of the adjustable positional thrusters, input and output pressure of the main thruster body, pressure of one or more auxiliary hydraulics systems, ambient water pressure, differential pressure between the main thruster body inlet and ambient water pressure, differential pressure between the main thruster body outlet and ambient water pressure, rotation of the main thruster body about the umbilical, and position and orientation of the main thruster body. 
   
   
       21 . A method as in  claim 17 , wherein the controller unit commands an automatic shutdown of the single propeller if rotation of the main thruster body beyond a threshold angle about the umbilical is detected by a rotational sensor on the excavating apparatus.