Tethered mine hunting system
United States Patent 1 1 1111 3,880,103  
 Talkington Apr. 29, 1975 [54] TETHERED MINE HUNTING SYSTEM 3 719,l 16 3/1973 Burton et a1. 114/16 R X [75] Inventor: Howard R. Talkington, La Jolla,  
 Calif- PllI7l(ll E.\&#39;aminerSamue1 Femberg Attorney, Agent, or FirmRichard S. Sciascia; Ervin [73] Assignee: The United States of America as F. J h n; William T skfier represented by the Secretary of the Navy, Washington. DC. [57] ABSTRACT [22] Fled: 1972 A tethered mine hunting system capable of aerial de- 21 App| 2 3 127 ployment comprises a lift module attached to an aircraft support vehicle by primary tether and a submarine vehicle attached to said lift module by secondary U.S. u t i R t th Th d submarine hi l are [51] hit. Cl. B63g 8/00 figured so as to permit the Submarine Vehicle to be [58] held of Seal-chm 114/16 240 R3 raged within the lift module during launch and recov- 61/69 R169 A; 37/54 56 ery of the system. A source of hydraulic motive power is located within the lift module and is attached to the [56] References C&#39;ted submarine vehicle via the secondary tether so as to UNITED STATES PATENTS permit the submarine vehicle to have very low acous- 3105453 10 9 3 Hayes 1 9 R X tic and magnetic signatures. Additionally, the lift mod- 3.38l.485 5/1968 Crooks et a1... 61/69 R ule contains other support equipment and electro- 3 550386 12/1970 Ballingcr l l l. 114/16 R X acoustic transducers.  
 3.618.236 11/1971 Pipkin l l l l 37/63 3.626.703 12/1971 Richburg 114/16 10 Claim- 2 Drawing Figures PATENTEDAPRZSISYS 1880,1013  
 SHEET 10F 2 FlG.l  
 TETHERED MINE HUNTING SYSTEM STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufac&#39; tured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.  
 FIELD OF THE INVENTION This invention pertains to the fields of naval architecture and marine engineering. More particularly, the invention pertains to the field of remotely controlled submarine vehicles. In greater particularity, the invention pertains to remotely controlled submarine vehicles operating from a tethered control arrangement. In still greater particularity, the invention pertains to a tethered submarine vehicle having a lift module attached to the support vehicle by means of a primary tether and a submarine vehicle operating from, and attached to, the lift module by means of a secondary tether.  
 DESCRIPTION OF THE PRIOR ART In many marine activities, it is necessary to identify and recover, or perform work on, objects which are located beneath the surface of the sea. For example, the fields of archeology, geology, petroleum production, and transcontinental communications have taken men into the submarine environments which heretofore have been little known outside the field of submarine warfare. In all of these fields of endeavor, an object is located by means of conventional detection and ranging equipment from the surface of the water and divers are sent down to perform the necessary inspection or work upon the object located. Quite obviously, such operations are greatly influenced by the weather conditions and water condition which will permit the employment of divers. Experience has shown that such conditions as would permit the optimum use of divers occur only approximately half of the time even in temperate climate zones.  
  It has been proposed in the prior art to use small submersible vehicles to replace the diver in such opera tions. However, such submarine vehicles are expensive to operate and still require considerable surface support in launch and recovery thereof. Too, in mine hunting operations such vehicles ofttimes actuate the detonating mechanism on the marine mine as the submarine vehicle approaches the mine.  
  Another shortcoming of the prior art systems for locating underwater objects has been the necessity of keeping a relatively large-size surface ship deployed for extended periods of time. Because of the crew requirements for such vessels and their large fixed operating costs combined with their relatively slow speed, the cost of such operations becomes prohibitive. Ifa rotary winged aircraft or lighter than air aircraft could be employed in such operations, the cost and time could be greatly improved. However, heretofore submersible vehicles capable of remote operation have not been able to withstand launch and recovery from a support vehicle above the surface of the water.  
 SUMMARY OF THE INVENTION The system of the invention uses a low noise, low magnetic signature, submarine vehicle operating from a tether. The submarine vehicless tether is attached to a lift module. The lift module, in turn, contains a garage space for the submarine vehicle, a source of motive power for the submarine vehicle and its attachments, and auxiliary ranging and electroacoustic equipment. The lift module is connected to a suitable aircraft support vehicle located above the surface of the water by means of another tether arrangement.  
 STATEMENT OF THE OBJECTS OF THE INVENTION It is, accordingly, an object of this invention to provide an improved tethered vehicle system.  
  Another object of this invention is to provide a tethered vehicle system for submarine exploration and investigation from an aircraft support vehicle.  
  Another object of the present invention is to provide a tethered submarine vehicle mine hunting system.  
  A still further object of the present invention is to provide a tethered submarine mine hunting system employing a separate submarine mine hunting vehicle and a lift module.  
  Another object of this invention is to provide a submersible vehicle operating from a tether which has minimal electromagnetic and acoustic signature.  
  Still another object of the present invention is to provide a tethered mine hunting system employing a lift hydraulically powered submarine vehicle operating from a tethered lift module.  
  Yet another object of the present invention is to provide a tethered vehicle mine hunting system employing a lift module containing a propulsive power source for the tethered vehicle.  
  Still another object of the present invention is to provide a tethered mine hunting system operating from a lift module which contains electroacoustic search transducers.  
  Still another object of the present invention is to provide a tethered mine hunting system employing a hydraulically powered submarine vehicle operating from a tether to a suitable support and lift module which, in turn, is tethered to an aerial support vehicle.  
  These and other objects of the invention will become more readily apparent from the ensuing specification when taken with the drawings.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view showing the system according to the invention being used in a mine hunting situation; and  
  FIG. 2 is a schematic representation of the various components comprising the system of the invention.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an arrangement of the system of the invention to be used in a mine hunting environment will be described. It should be noted that although the system of the invention will be described in connection with its application to the mine hunting problem, other applications where the system of the invention may be used will readily suggest themselves. A support vehicle, such as rotarywinged aircraft 11, having sufficient power and space requirements for operating personnel is shown deployed above the surface of the water. A lift module 12 is illustrated as being connected to rotary wing aircraft 11 by means of a suitable primary tether l3.  
  A submarine vehicle 14 is attached to lift module 12 by means of a secondary tether 15. As illustrated.-submarine vehicle 14 has a television camera 16 mounted in its forward portion to photograph and to transmit images back to the support vehicle by means of tethers 15 and 13. Further, in waters where sufficient natural illumination is not present the object being photographed by television camera 16 may be illuminated by suitable light sources 17 which are also attached to the forward portion of submarine vehicle 14 and directed in front thereof. No particular details are shown for TV camera 16 or light source 17 as they may be conventional prior art arrangements. For example, TV camera 16 may be of the type manufactured by Hydro Products under the designation Model 125.&#34; Light sources 17 may be electrically powered by mains carried in tethers 13 and 15 or battery powered. In some instances where even further reduction in magnetic signature is required the light sources 17 may be photochemically operated.  
  A suitable manipulator arm 18 is attached to submarine vehicle 14 for performing work and investigative assignments upon objects in the near vicinity of submarine vehicle 14. Like TV camera 16, any suitable prior art manipulator may be used in this environment in dependence upon the particular work assignments encountered. However, for purposes of illustrative completeness, it should be noted that the manipulator arm described in U.S. Pat. No. 3,703,968 for Linear Linkage Manipulator Arm by Richard W. Uhrich et al., issued on Nov. 28, 1972, has proven satisfactory.  
  It will be observed that submarine vehicle 14 has motor 19 mounted on either side thereof and a buoyancy chamber, designated at 20, on the interior thereof to regulate propulsive movments and depths about lift module 12. Although some latitude is permitted in choosing motors l9 and buoyancy chamber 20 from designs of the prior art for the provision of propulsive force and buoyancy for submarine vehicle 14, it is highly desirable that such systems exhibit very low acoustic and magnetic signature properties. For this reason, the buoyancy chamber 20 and motor 19 are preferably of the hydraulic control type such as that disclosed in U.S. Pat. No. 3,780,220 by Bruce R. Fugitt et al., for Remote Control Underwater Observation Vehicle&#34; issued on Dec. 18, 1973.  
  If desired, submarine vehicle 14 may carry additional auxiliary equipment as indicated generally at 21. Such auxiliary equipment may include, for example, an explosive charge for providing neutralization of marine mines or a sonar reflector having identifiable conduction characteristics for marking objects examined underwater to aid in their relocation. Also, although only a single auxiliary equipment package 21 is illustrated, a plurality of such packages may be carried by submarine vehicle 14, if desired. Likewise, a variety of methods of release of the package are possible. For example, the package may be extracted by manipulator 18, released by a catch mechanism and allowed to drop, or ejected. For purposes of completeness, the invention may be considered as using the package shown and described in U.S. Pat. No. 3,757,633 issued on Sept. 11, 1973 for Visual Marker System to Paul K. Salzman et al.  
  A suitable tool 22 is shown carried on the distal end of manipulator 18 for performing the desired work or investigative action upon objects in the vicinity of submarine vehicle 14. Such a tool may be, for example, an  
 explosive type cable cutter to sever anchoring cables,  
 for marine mines or other chains or cables attached to the objects under investigation. Of course, if desired, tool 22 may be a gripping, hand-like device to move or operate underwater equipment. A variety of such engaging hands are known in the prior art and choice between them is a matter of design within the purview of one skilled in the art.  
  From the foregoing description it may be seen that submarine vehicle 14 may be hydraulically operated and that tether 15 need carry only small electrical currents necessary to operate TV camera 16 and lights 17. Because of the length of cable 13, it is desirable that the hydraulic power source for manipulator 18, motors l9, buoyancy chamber 20, and operational releases for auxiliary package 21 be provided from lift module 12 rather than from support vehicle 11. Further, to prevent entanglement of tether 15, it is desirable that suitable retractable storage be provided for tether 15 within lift module 12. These functions are provided by means of a suitable winch mechanism 25 and a hydraulic power source 26 carried within lift module 12. The control of the particular functions is provided by means of a conventional solenoid operated hydraulic valve arrangement indicated generally at 27. Such hydrualic power sources and valve arrangements are common in the prior art and unnecessary for the understanding of the invention and therefore are not described in greater detail It will be observed that lift module 12 is enclosed on one end but has provision for submarine vehicle 14 to enter the other end thereof and to be garaged within its hull. This arrangement protects submarine vehicle 14 and its associated equipment from damage as lift module 12 passes through the air-water interface during launch and recovery from support vehicle 11.  
  As shown, an electroacoustic transducer 23 is mounted on lift module 12 and may be connected, via tether 13, to a conventional search sonar located within the support vehicle. Again, sonar systems of the type employing a remote transducer are common in the prior art and a choice among them may be made by one versed in the electroacoustic arts in dependence upon the particular design parameters required.  
  It will also be noted that a second electroacoustic transducer, indicated at 24, is mounted on lift module 12 and may be connected, via tether 13, to other acoustic signal sources for providing the desired acoustic signals within the water. For example, such acoustic signals may provide an influence sweep for marine mines or, optionally, a compressional wave communication system for submarine vehicles operating in the vicinity. Likewise, such a communication system may establish a communication link between a plurality of support vehicles 11 without resort to electromagnetic communications, an obvious advantage in some naval operations.  
  Referring to FIG. 2, the manner in which the various components comprising the system interface with one another will now be described. The major portions of the system such as support vehicle 11, lift module 12, and submarine vehicle 14 are indicated by broken line boxes. The various interconnecting lines represent the connections made via tethers 13 and 15.  
  As shown, a source of electrical power 31 is located within aircraft 11 and may, if desired, comprise a portion of the aircrafts electrical system. The sonar control system 32 is also located within aircraft l1 and is connected by suitable electrical connections to the sonar transducer 23 in lift module 12. Likewise, acoustic signal source 33 is similarly connected to auxiliary electroacoustic transducer 24. Acoustical signal source 33 may be any conventional source of electrical analog signals to produce a desired acoustic energy from transducer 24. For example, acoustical signal source 33 may produce an electrical analog of acoustic signatures to provide a countermeasure sweep for marine mines or, conversely, acoustic signal source 33 may be the electronic portion of a conventional compressional wave acoustic communication system.  
  The next component part of the system of the invention indicated as beinghoused within support vehicle 11 is the function control mechanism 34. This function control mechanism comprises an electrical switching and control arrangement having a plurality of switching mechanisms each corresponding to a desired operational function of submarine vehicle 14. Such operational functions include the direction and magnitude of propelling force supplied by motors 19, the operation of ballast chamber 20, and the operation of manipulator arm 18. A wide variety of such input switching devices is known in the prior art and choice between them is within the purview of one skilled in the art in dependence upon the particular function being controlled. Since such switches are well known and conventional, further description thereof is not deemed warranted.  
  A winch 35 is also located within support vehicle 11 and has tether line 13 wound thereon. Of course, tether line 13 contains a tension bearing member, indicated in FlG. 2 by a heavy broken line, connecting winch 35 with lift module 12. The method of attachment of this tension member to the submarine vehicle is likewise conventional and therefore need not be described in detail for the understanding of the invention.  
  A video readout 36 is also located within support vehicle 11 and is connected to TV camera 16 through internal connections made within lift module 12 so as to provide a visual indication of the object field being photographed by television camera 16.  
  As previously noted, lift module 12, in addition to housing submarine vehicle 14, houses sonar transducer 23 and auxiliary transducer 24. As indicated above, these transducers are connected to their appropriate signal sources within support vehicle 11 by means of electrical connections contained in tether line 13. A winch 25 is also contained within lift module 12. As indicated in FIG. 2, winch 25 may be conveniently powered by a hydraulic motor operating from a common hydraulic power source 26. The operation of winch 25 as well as the various hydraulically controlled functions on submarine vehicle 14 is controlled by means of valve mechanism 27.  
  Valve mechanism 27 is an assembly of a plurality of electrically operated fluid valves which control the individual hydraulically operated mechanisms on lift module 12 and submarine vehicle 14. The use of hydraulic control in these applications provides submarine vehicle 12 with a reduced electrical and magnetic signature thereby permitting it to closely approach influence type mines.  
  As shown by FIG. 2, the previously described systems contained on submarine vehicle 14, TV-camera 16, lights 17, manipulator 18, propulsion motors l9, buoy- &#39;ancy chamber 20, and auxiliary equipment 21 are all connected to their respective sources of power within lift module 12 by a tether 15. Tether 15 is made neutrally buoyant by conventional underwater cabling techniques so as to offer a minimum of resistance and drag to submarine vehicle 14 as it moves about lift module 12.  
  While the foregoing description will enable one versed in the marine engineering and oceanographic instrumentation arts to make and use the invention, the invention will be better understood with reference to the following preferred mode of operation.  
 Preferred Mode Of Operation Of course, the operation of the present system of the invention begins with the submarine vehicle 14 within lift module 12 and supported on support vehicle 11. As previously described, support vehicle 11 may be any suitable vehicle which may be rapidly deployed to an area and operate at relatively low speeds above the surface thereof. Rotary wing aircraft, lighter than air aircraft, and certain surface effect vehicles are completed and have proven satisfactory in the operation of the system of the invention. When the vehicle 11 is in the operational area, winch 35 is operated to lower lift module 12 into the water by means of tether 13. Support vehicle 11 then moves lift module 12 about the area in which search and surveillance is being conducted while operating the sonar system including sonar console 32 and sonar transducer 23. When an object to be investigated has been encountered, support vehicle 11 maneuvers lift module 12 within a convenient operational range and submarine vehicle 14 is caused to disengage and maneuver from lift module 12.  
  During this operation, of course, winch 25 is operated so as to pay out tether 15 and permit submarine vehicle 14 to approach the desired object.  
  Referring to FIG. 1, a marine mine indicated at 41, supported on an anchor chain 42 from an anchor 43 resting on the bottom, is being investigated by submarine vehicle 14. Vehicle 14 may approach mine 41 and by means of manipulator arm 18 cause a suitable cutting tool 22 to engage and sever anchor chain 42 thereby separating buoyant mine 41 from anchor 43. Mine 41 when it reaches the surface may be detonated by a small arms fire or, alternatively, disarmed and picked up by the surface vehicle.  
  Alternatively, the position of mine 41 may be marked by suitable auxiliary equipment 21 comprising a sonar reflector or an acoustic marker generator called a pinger. Also, auxiliary equipment 21 may include an explosive charge which may be placed adjacent a mine of the nonmoored or nonbuoyant type. In such instances, explosive charge 21 may be detonated by a suitable timing mechanism.  
  Of course, other means of mine countermeasures may be employed if mine 41 is of the acoustically detonated type. For example, an acoustic signal may be generated by electroacoustic transducer 24 in response to signals supplied by acoustic signal source 33 to detonate the mine as submarine vehicle 14 permits the mine counter-measures operator to observe the effect of the various acoustic signals on the mine. When the mine neutralization or investigation operation has been completed, submarine vehicle 14 may be guided back to lift module 12 by means of propulsion motors 19 and winch 25 retracting tether line 15. When submarine vehicle 14 is garaged within lift module 12, winch 35 within support vehicle 11 is operated so as to recover lift module 12 with submarine vehicle 14 inside.  
  While the foregoing description of the invention per tains to mine countermeasures. it will be readily apparent that other useful work projects may be performed by the system of the invention. Such fields of utilization include marine salvage, underwater geology and archeology, and petroleum exploration for example.  
  The foregoing description taken together with the appended claims constitutes a disclosure such as to enable a person skilled in the marine engineering and naval architecture arts and having the benefit of the teachings contained therein to make and use the invention. Further. the structure herein described meets the objects of invention. and generally constitutes a meritorious advance in the art unobvious to such a skilled worker not having the benefit of the teachings contained herein.  
  Obviously, many modifications and variations of the present invention are possible in the light of the above teachings, and. it is therefore understood that within the scope of the disclosed inventive concept, the invention may be practiced otherwise than specifically described.  
 What is claimed is:  
 I. An undersea tethered vehicle system comprising:  
 a support vehicle;  
 a primary tether connected to said support vehicle and extending downwardly therefrom for conducting electrical currents and supporting tensional forces therealong;  
 a lift module attached to the primary tether for support thereby;  
 a submarine vehicle configured for retention within the lift module;  
 a source of motive power housed within the lift module; and  
 a secondary tether connected between the submarine vehicle and the lift module and effectively connected to said source of motive power within the lift module for transmission of the motive power therealong and effectively connected to the primary tether for transmission of electrical currents therealong to permit the submarine vehicle&#39;s movement into and out of the lift module and within a predetermined range thereabout.  
  2. A tethered vehicle system according to claim 1 wherein the support vehicle is an aircraft.  
  3. A tethered vehicle system according to claim 1 wherein the lift module is enclosed on one end to minimize hydrodynamic interaction between the retained submarine vehicle and the water during launch and recovery of the system.  
  4. A tethered vehicle system according to claim 1 further including a winch housed within the lift module and effectively connected to the source of motive power to obtain driving power therefrom and having the secondary tether wound thereon for paying out and reeling in the secondary tether in accordance with the movements of the submarine vehicle.  
  5. A tethered vehicle system according to claim 1 wherein the source of motive power includes a source of hydraulic power.  
  6. A tethered vehicle system according to claim 1 including an auxiliary device releasably mounted on the submarine vehicle for selective release therefrom to cooperate with investigated submerged objects.  
  7. A tethered vehicle system according to claim 1 further including a manipulator arm mounted on the submarine vehicle and effectively connected to the source of motive power via the secondary tether for contacting and performing work on objects within the vicinity of the submarine vehicle.  
  8. A tethered vehicle system according to claim 7 further including a tool carried by the manipulator arm.  
  9. A tethered vehicle system according to claim 8 further including a television camera mounted on the submarine vehicle and connected via the aforesaid primary and secondary tethers to the support vehicle to provide personnel therein a view of areas adjacent the submarine vehicle.  
  10. A tethered vehicle system according to claim 9 further including a light source mounted on the submarine vehicle for illumination of objects within the field of view of the television camera.