Patent Publication Number: US-6213021-B1

Title: Electromagnetic sea mine detonation system

Description:
The present invention relates in general to electromagnetic detonation of underwater sea mines. 
     BACKGROUND OF THE INVENTION 
     The clearing of sea mines at underwater locations for removal of shipping threats may presently be accomplished by remote controlled generation of a magnetic field causing detonation of the sea mine some distance from the source of electrical energy from which the magnetic field is derived. Usually a gas turbine powers an electrical generator as the foregoing referred to source of electrical energy, carried on a ship or towed water platform. Such mine clearing arrangements are relatively expensive and require a significant amount of maintenance. It is therefore an important object of the present invention to provide a mine clearing system that is less costly and much simpler to operate and maintain. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention a relatively small underwater vehicle carries a source of electromagnetic energy from which a magnetic field is produced and emitted from the vehicle simulating the magnetic signature of a larger surface ship. Such magnetic field is effective to detonate a sea mine at an underwater location in the vicinity of the vehicle to which it is being towed at a preselected sea water depth and speed by an air traveling helicopter connected to the underwater vehicle by a towing cable. Under such travel conditions of the underwater vehicle, powered rotation of impellers mounted thereon is induced to drive an electrical generator as the source of the electromagnetic energy. 
    
    
     BRIEF DESCRIPTION OF DRAWING 
     A more complete appreciation of the invention and many of its attendant advantages will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing herein: 
     FIG. 1 is a side view illustrating a sea mine detonation system involving an underwater source of electromagnetic energy during helicopter towed travel; and 
     FIG. 2 is a schematic diagram of the detonation system embodied in the apparatus shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring now to the drawing in detail, FIG. 1 illustrates a body of seawater  10  having a surface  12  below which a source of electrical magnetic field generating energy is carried by a vehicle  14  traveling underwater at a preselected depth  16  along a direction denoted by arrow  18 . Such underwater travel of the vehicle  14  is induced by the towing force of a helicopter  20 , during its air travel above water surface  12 . A towing cable  22  accordingly extends from the helicopter  20  to the vehicle  14  through the seawater  10 . Pursuant to the present invention, such underwater travel of the vehicle  14  at a speed of approximately 25 knots is exclusively induced by such towing along travel direction  18  toward a suspected underwater location at which a sea mine is to be detonated in order to remove it as a seawater shipping threat. 
     At the stern end portion of the underwater vehicle  14  as shown in FIG. 1, hydrodynamic impellers  24  are mounted for powered rotation in response to towed travel of the vehicle  14  through the seawater  10 . Also extending rearwardly from the stern end of the vehicle into the seawater is a lengthy sweep tail  26  in spaced relation to a shorter electrode  28 . A stabilizer fin  30  and a depth controlling wing  39  are also mounted on the vehicle  14  as shown to maintain it at its underwater depth  16  during travel. 
     As indicated by dotted line in FIG. 1, the vehicle  14  carries an electric generator  32  driven by the impellers  24  as diagrammed in FIG. 2. A drive motor  34  is also provided for regulatory positioning of the wing  39  in order to establish and maintain a proper underwater depth  16  for the vehicle during underwater travel toward a sea mine location  36  as diagrammed in FIG.  2 . The sea mine is accordingly detonated when disposed within an underwater magnetic field formed by flow of electrical current along an underwater path  38  from the sweep tail  26  to the electrode  28  as also diagrammed in FIG.  2 . The electrical current is derived from the generator  32  and conditioned by rectifier circuitry  40  to simulate the magnetic signature of a surface ship. Such rectifier circuitry  40  is per se well known in the art, heretofore developed for magnetic minesweeping systems. Also control circuitry  42  is provided in association with the rectifier circuitry  40  as diagrammed in FIG. 2 to establish the simulated magnetic signature of the magnetic field during travel of the underwater vehicle  14  at the preselected underwater depth  16 , maintained by regulatory control of the electrical current supplied by the control circuitry  42  to the wing drive motor  34 . Such drive control circuitry  42  is also per se well known in the art. 
     Obviously, other modifications and variation of the present invention may be possible in light of the foregoing teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.