Abstract:
The present invention is directed toward system for the detection of a condition present in the hull of a marine asset disposed in a marine environment. The system comprises a plurality of transmitter disposed adjacent the marine asset for delivery of delivery of electrical current to the marine environment toward the marine asset. The system may include a sensor array for measuring fluid current and electro-magnetic fields. In a preferred embodiment, each end of the sensor array is affixed to a survey vessel that travels alongside the marine asset.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Field of the Invention 
         [0002]    The present invention is directed toward a system for detection of a condition in the hull of a marine asset, such as damage thereto. 
         [0003]    Description of the Related Art 
         [0004]    Maintenance of marine assets, particularly large ones, is an expensive and arduous task. The task is particularly made more difficult for marine assets that primarily operate in a corrosive salt water environment. Due to the environment and other factors, conditions commonly develop on the assets, particularly on the hull. Examples of such conditions can range from corrosion and scratches due to wear and tear to more serious structural conditions that, if left unrepaired, could catastrophically compromise the asset. The consequences can be severe and include damage to the marine asset itself and loss of cargo. Further, loss of cargo that is potentially harmful to the environment, such as petrochemicals, can immensely impact the ecosystem and coastal communities. 
         [0005]    Accordingly, great efforts are taken to preserve the integrity of the surfaces of the marine assets that interact with the marine environment. These efforts include coating the marine asset with durable or corrosion resistant materials. Nonetheless, while such efforts may slow the development of conditions, vigilantly investigating the state of the marine asset remains vital to ensure its integrity. In fact, inclusion of coatings and other preventative measures often requires inspection of the measures themselves. For example, scratches in a corrosion resistant paint, if left unaddressed, can increase in severity and result of a failure of the corrosion prevention system. However, inspecting marine assets is an arduous and expensive process, particularly in the largest of marine assets, such as transoceanic freighters, that have substantially large hulls. Often, teams of coordinated divers must be employed to inspect those portions of the hull beneath the marine surface. 
         [0006]    Therefore, what is needed in the art is a system for detecting conditions present in the hull of marine assets in a manner that is fast, efficient and cost-effective. Such a system may involve disposition of transmitters in an area surrounding the marine asset. The transmitters may deliver electric current into the marine environment. With the use of sensors, which may be dragged under the marine asset by way of survey boats, a two dimensional or three dimensional map of the magnetic field emitted by the vessel can be created. Disturbances or anomalies in the magnetic field can be used to locate and identify conditions in the marine asset. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is directed toward a system for the detection of a condition in the hull of a marine asset disposed in a marine environment. As described herein, such a condition may be, for example, mars; scratches in the coating, paint or surface of the hull; structural damage; superficial damage; and any other occurrence the presence of which affects the state or integrity of the hull. An embodiment of the system comprises transmitters disposed in the marine environment adjacent the marine asset in a configuration at least partially surrounding the marine asset. The transmitters are structured for delivery of electrical current to the marine environment at least partially toward the marine asset. Accordingly, the electrical current interacts with the hull of the marine asset. A sensor array is disposed and transported below the marine asset, some distance from the hull, by way of a pair of survey vessels that travel alongside the marine asset. 
         [0008]    The sensor array comprises at least one sensor for detection of properties of the marine environment, which may include fluid current information, electrical current information or information pertaining to the magnetic field. Data gathered from the sensors may then be processed to create a multi-dimensional image of the electromagnetic field lines as they intersect with the hull of the ship. Accordingly, irregularities in the field may be indicative of the location of the presence of a condition in the hull. 
         [0009]    These and other objects, features and advantages of the present invention will become clearer when the drawings as well as the detailed description are taken into consideration. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which: 
           [0011]      FIG. 1  is a top-down schematic view of an embodiment of the system. 
           [0012]      FIG. 2  is a perspective view of the system of  FIG. 1 . 
           [0013]      FIG. 3  is a top-down schematic view of an embodiment of the system. 
           [0014]      FIG. 4  is a rear schematic view of the embodiment of  FIG. 3 . 
           [0015]      FIG. 5  is a schematic representation of a model of electromagnetic fields created using data gathered by the system. 
       
    
    
       [0016]    Like reference numerals refer to like parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. As used herein, “or” means “and/or” unless expressly stated otherwise. Furthermore, the use of the singular includes the plural unless specifically stated otherwise, and use of the term “including” as well as other forms, such as “includes,” and “included,” shall not be considered limiting. 
         [0018]    As represented in the accompanying drawings, the present invention is directed to a system for detection of a condition  4  present in the hull  111  of a marine asset. As used herein, “condition” includes mars; scratches in the coating, paint or surface of the hull; structural damage; superficial damage; and any other occurrence the presence of which affects the state or integrity of the hull, and which is beneficial to detect so as to facilitate repair. 
         [0019]    With reference to  FIG. 1 , an embodiment of the system  1  comprises transmitters  10 ,  20 ,  30  disposed adjacent a marine asset  110 , which may be, by way of example, a ship, boat, barge, or any other vessel or structure deployed in a marine environment. A first transmitter  10  is disposed approximately equidistant from a second transmitter  20  and third transmitter  30 . However, in other conceived embodiments the relationship may not be equidistant. The first transistor array  10  may also comprise a power source for providing electrical current to other elements of the system  1  as described herein. The second transmitter  20  and third transmitter  30  are each disposed on an opposing side of the marine asset  110 , such that the marine asset  110  is located between the second and third transmitters  20 ,  30 . 
         [0020]    With further reference to  FIG. 1 , the second and third transmitters  20 ,  30  are attached to the first transmitter  10  by way of a pair of current carrying members  21 ,  31  supported by buoyant members  50 . Accordingly, the first transmitter  10  may also act as a power source for the second and third transmitters  20 ,  30 . Further, the first transmitter  10  may be disposed in a current carrying relationship with the marine asset  110  by at least one cable  60  that may transport alternating current or direct current. 
         [0021]    The transmitters  10 ,  20 ,  30  deliver electrical current  2 , which may be in the form or forms that includes direct current (DC), alternating current (AC), or both, to the marine environment in which the marine asset  110  is situated. AC current produced by the transmitters  10 ,  20 ,  30  may be in the range of 8 to 1000 Hz. The DC current may be rectified current from AC current in the range of 8 to 1000 Hz or in the galvanic/harmonic frequency domain. Additionally, in the event that the system  1  directs both AC and DC current into the marine environment, the DC current may be switched on and off at a set interval to avoid resonance with the AC current. 
         [0022]    In addition, in at least one embodiment, the first transmitter  10  produces a different type of current for propagation into the marine environment from that of the second and third transmitters  20 ,  30 . In other words, the first transmitter  10  may produce alternating current and the second and third transmitters  20 ,  30  may produce direct current. Alternatively, the first transmitter  10  may produce direct current and the second and third transmitters  20 ,  30  may produce alternating current. 
         [0023]    The embodiment of  FIG. 2  serves to illustrate further components of the system  1 . Each of the transmitters  10 ,  20 ,  30  as represented in  FIG. 2  comprise a transmission member  13 ,  23 ,  33  disposed at or near the surface of the marine environment. Accordingly, the transmission members  13 ,  23 ,  33  may comprise a buoyant construction to facilitate such disposition. 
         [0024]    The transmission members  13 ,  23 ,  33  of  FIG. 2  further comprise anchors  12 ,  22 ,  32  affixed to the marine environment. Further, the anchors  12 ,  22 ,  32  may be affixed to a floor of the marine environment. The anchors  12 ,  22 ,  32  serve to restrict movement of the transmission members  13 ,  23 ,  33  within the marine environment so as to retain them in their relative positioning as described above. Accordingly, each anchor  12 ,  22 ,  32  may be connected to the respective transmission members  13 ,  23 ,  33  by way of a connecting member  14 ,  24 ,  34 , which may be a cord, cable or any other sufficient structure. In at least one embodiment, at least one connecting member  14 ,  24 ,  34  is structured to carry electrical current supplied by the respective transmission member  13 ,  23 ,  33 . At least one conductive member  15 ,  25 ,  35  is disposed on the respective connecting member  14 ,  24 ,  34 . The conductive member or members  15 ,  25 ,  35  is structured for delivery of electrical current to the marine environment at least partially toward the marine asset  110 . In at least one embodiment, each transmitter  10 ,  20 ,  30  comprises a plurality of conductive members  15 ,  25 ,  35  disposed in spaced relation along at least a portion of the respective connecting member or members  14 ,  24 ,  34 . In addition, the conductive members  25 ,  35  of the second and third transmitters  20 ,  30  may have sufficient surface area or other structure for delivery of electrical current of 20 milliamps per square meter on the hull  111  of the marine asset  110 . Similarly, the conductive member or members  15  of the first transmitter  10  may have sufficient surface area or other structure for delivery of electrical current of 30 milliamps per square meter on the hull  111  of the marine asset  110   
         [0025]    In addition, in the system of  FIG. 2  the first transmitter is disposed in a current transferring relationship relative the marine asset  110 . This may be achieved by way of at least one cable  60 . In another embodiment, two cables  60  may be used, with the one being configured to transmit alternating current and the other being configured to transmit direct current. 
         [0026]    With reference to  FIG. 3 , the depicted embodiment of the system  1  further comprises a sensor array  70  at least partially disposed in the marine asset. The sensor array  70  comprises first  70 ′ and second  70 ″ ends. As shown in  FIG. 3 , the ends  70 ′,  70 ″ are connected to a corresponding survey vessel  71 ′,  71 ″. However, it is contemplated that the sensor array  70  may be connected to only a single survey vessel  71 ′. Further, at least one of the survey vessels  71 ′,  72 ′ may be connected to the marine asset  110  by way of a cable  60  for transmission of electrical current. The survey vessels  71 ′,  72 ″ travel alongside the marine asset  110 , transporting the sensor array  70  below the asset and along a length thereof. 
         [0027]      FIG. 4  depicts the sensor array  70  disposed in the marine environment beneath the hull  111  of the marine asset  110  and spaced a distance therefrom. A survey vessel  71 ′ comprises art. adjustment mechanism  73  to further facilitate disposition of the sensor array  70 . The sensor array  70  comprises at least one sensor  72  disposed thereon. In the embodiment of  FIG. 5 , a plurality of sensors  72  are disposed in spaced relation along the length of the sensor array  70 . The sensors  72  may be structured for sensing fluid current, such as the direction and speed, properties of an electromagnetic field, such as amplitude and direction, or properties of electrical current, such as amplitude and voltage. 
         [0028]    Through the sensors  72 , the sensor array  70  gathers data, such as through steady state data collection or one at a time, about the marine environment and the marine asset  111 . Turning now to  FIG. 5 , this data is used to create a model, which may be in two or three dimensions, of the electromagnetic field  3  running through the hull  111  of the marine asset  110 . By locating irregularities in the electromagnetic field  3 , a condition  4  (as described above) can be located for future repair. 
         [0029]    Since many modifications, variations and changes in detail can be made to the described preferred embodiment of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents. 
         [0030]    Now that the invention has been described,