Patent Publication Number: US-7895948-B2

Title: Buoyancy dissipater and method to deter an errant vessel

Description:
PRIORITY CLAIM 
     This application is a continuation of U.S. patent application Ser. No. 12/362,547, filed on Jan. 30, 2009, now U.S. Pat. No. 7,730,838, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments pertain to deterring vessels by buoyancy dissipation. 
     BACKGROUND 
     There is presently a need to protect harbors from errant ships, interdict smugglers, and prevent ship-based terrorist actions on the high seas. One issue that law-enforcement officials have is the deterrence of these errant ships. Ships that are posing a threat to a harbor, carrying illegal drugs or weapons, or engaging in some other illicit or illegal activity are difficult to deter without destroying the errant ship or the evidence on board and without inflicting any fatalities. 
     Thus, there are general needs for apparatus and methods for deterring an errant ship without destruction of the ship and without inflicting fatalities. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a functional diagram of a buoyancy dissipater in accordance with some embodiments; 
         FIG. 2  illustrates the operation of a buoyancy dissipater in accordance with some embodiments; 
         FIG. 3  is a block diagram of a buoyancy dissipater control system in accordance with some embodiments; and 
         FIG. 4  is a flow chart of a procedure for deterring a vessel in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Examples merely typify possible variations. Individual components and functions are optional unless explicitly required and the sequence of operations may vary. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims. 
       FIG. 1  is a functional diagram of a buoyancy dissipater in accordance with some embodiments. Buoyancy dissipater  100  generates a volume of gas and diffuses the volume of gas below a waterline of a vessel to dissipate the buoyancy of the vessel. By the generation of a sufficiently large volume of gas and the creation of a gas bubble near or under a vessel, the buoyancy of the vessel is dissipated. Accordingly, buoyancy dissipater  100  provides a non-lethal way to alter or divert and possibly disable an errant vessel&#39;s course. 
     Buoyancy dissipater  100  may include, among other things, delivery shell  102 , propellant  104 , diffuser  110 , ballast  112 , fuze  114 , energy storage element  116 , pressure cylinder  118  and igniter  120 . Diffuser may include diffusion ports  108 . Buoyancy dissipater  100  may also include control system  122  to control the operations of the various elements. Igniter  120  may include conical element  106  which may contain explosive material for use in igniting propellant  104 . Igniter  120  along with propellant  104  may comprise a gas generator for generating a volume of gas. 
       FIG. 2  illustrates the operation of a buoyancy dissipater in accordance with some embodiments. Buoyancy dissipater  100  generates a volume of gas resulting in gas bubble  204  below waterline  206  of vessel  202 . Vessel  202  may be an errant vessel that is posing some type of threat or engaging in some sort of illegal or illicit activity. Gas bubble  204  dissipates the buoyancy of vessel  202 . Because gas bubble  204  is significantly more compressed than the volume of water  208  being displaced, the buoyancy of vessel  202  is dissipated or disrupted. In these embodiments, the higher-pressure gas at discharge displaces water until the gas pressure and the water pressure reach equilibrium to create the envelope for gas bubble  204 . 
     Referring to  FIGS. 1 and 2  together, in accordance with embodiments, the gas generator may be configured to generate a volume of gas from propellant  104 , diffuser  110  may be configured to diffuse the volume of gas below waterline  206  of vessel  202 , and igniter  120  may be coupled to the gas generator and configured to ignite propellant  104 . Pressure cylinder  118  may provide a region within buoyancy dissipater to allow propellant  104  to burn and rapidly expand after ignition. 
     Energy storage element  116  may provide energy to igniter  120 , as well as provide energy for other elements of buoyancy dissipater  100 . Energy storage element  116  may, for example, be a battery or a capacitor. 
     Ballast  112  may be configured to maintain buoyancy dissipater  100  at a predetermined level below waterline  206 . Ballast  112  may comprise a material of a predetermined density, or may be a water ballast. Ballast  112  may be used to assure that buoyancy dissipater  100  is below waterline  206  before propellant  104  is ignited. 
     Propellant  104  may be an air-bag propellant or gas generant. In some embodiments, propellant  104  may be an oxidizer such as Copper Nitrate (CuNO 3  or Cu(NO 3 ) 2 ) (e.g., in pellet form) or potassium perchlorate (KCLO 4 ) (e.g., in powder form). In some embodiments, propellant  104  may be cast (i.e., poured into a mold and solidified), although the scope of the embodiments is not limited in this respect. 
     In some embodiments, diffuser  110  may include a plurality of diffusion ports  108  to allow the volume of gas to escape during gas generation and to diffuse the volume of gas. Diffusion ports  108  may comprise holes positioned radially around diffuser  110  to allow the rapidly expanding gas to diffuse radially. The difference in pressure between the higher-pressure gas and lower-pressure water may inhibit water  208  from entering buoyancy dissipater  100 . In some embodiments, diffusion ports  108  may include a cover to inhibit water from entering buoyancy dissipater  100 . The cover may destruct or come off when the gas is generated. 
     In some alternate embodiments, diffusion ports  108  comprise one-way diffusion ports located radially around diffuser  110  to allow the expanding gas to diffuse radially. The inclusion of one-way diffusion ports may inhibit water  208  from entering buoyancy dissipater  100 . 
     Fuze  114  may be configured to initiate detonation of propellant  104 . Fuze  114  may initiate detonation of propellant  104  when an errant vessel, such as vessel  202 , is detected. In some embodiments, fuze  114  may be an impact fuze that may initiate detonation upon impact with waterline  206  and cause propellant  104  to be detonated after a predetermined period of time. Alternatively, fuze  114  may be configured to initiate detonation upon impact with vessel  202 . Fuze  114  may also comprise a magnetic fuze that may initiate detonation upon magnetic detection of vessel  202 , a timed fuze that may initiate detonation after a predetermined period of time, or a proximity fuze that may initiate detonation based on a predetermined proximity of vessel  202 . 
     Delivery shell  102  may be a lightweight delivery shell configured to contain the components of buoyancy dissipater  100 . Delivery shell  102  may comprise lightweight materials such as alloys of aluminum or titanium or may be plastic. In some embodiments, a portion of delivery shell  102  may be configured to rupture or blow during gas generation to allow the large volume of gas to escape and generate gas bubble  204 . In these embodiments, diffuser  110  and diffusion ports  108  are not required. 
     In some embodiments, buoyancy dissipater  100  may be configured to be launched by a gun. In these embodiments, delivery shell  102  and the various components of buoyancy dissipater  100  may be sufficiently hardened to withstand gun launching. In other embodiments, buoyancy dissipater  100  may be missile-launched and may include a rocket engine (not illustrated) and guidance system (not illustrated). In other embodiments (not illustrated), buoyancy dissipater  100  may be launched from an air cannon or may be shoulder launched. In some other embodiments, buoyancy dissipater  100  may be attached to a gun-launched projectile. In other embodiments, buoyancy dissipater  100  may comprise an air-dropped canister. In other embodiments, buoyancy dissipater  100  may be operate as a mine and may include sensors (such as fuze  114 ) configured to activate when a ship, such as vessel  202 , passes over or nearby. In some embodiments, buoyancy dissipater  100  may be remotely activated. In some embodiments, buoyancy dissipater  100  may be provided in a torpedo and may be guided to a target, such as vessel  202 , by guide wires. 
     In some embodiments, buoyancy dissipater  100  may be configurable to provide a variable propellant load in which the propellant charge size is selectable to vary an amount of propellant  104  that is ignited. In these embodiments, more than one igniter  120  may be used. The propellant charge size may be selectable by a user to allow selection to be based on a size or tonnage estimate of vessel  202 . In these embodiments, a charge size selector may be provided to allow the propellant charge size to be selected by the user. Separate portions of propellant  104  may be ignited to vary the amount of propellant  104  that is ignited and burned to control the amount of gas that is generated by the gas generator. In some embodiments, the user may select a vessel size (e.g., very large, large, medium, or small) and the propellant charge size may be varied accordingly. In these embodiments, buoyancy dissipater  100  may provide a non-lethal deterrent to vessel by allowing the propellant charge size to be properly selected so that vessel  202  is not destroyed. 
     In some other embodiments, the propellant charge size may be selectably increased to provide a lethal deterrent in which vessel  202  may be destroyed or sunk. In this way, buoyancy dissipater  100  may be configured to capsize an errant vessel that may be loaded, for example, with destructive materials. By varying the amount of propellant  104 , buoyancy dissipater  100  is scalable for the various situations that may be encountered in the field. 
       FIG. 3  is a block diagram of a buoyancy dissipater control system in accordance with some embodiments. Buoyancy dissipater control system  300  may correspond to control system  122  ( FIG. 1 ) of buoyancy dissipater  100  ( FIG. 1 ) and may be used to control the various operations of buoyancy dissipater  100  ( FIG. 1 ). Buoyancy dissipater control system  300  may include buoyancy dissipater control circuitry  302 , charge size selector  304 , ballast control element  312 , fuze circuitry  314 , igniter circuitry  320  and propellant control element  322 . Buoyancy dissipater control system  300  may also include energy storage element  316  corresponding to energy storage element  116  ( FIG. 1 ). 
     Referring to  FIGS. 1 through 3 , control circuitry  302  may be configured to, among other things, provide an ignition signal to igniter circuitry  320  for igniting propellant  104  with igniter  120 . Fuze circuitry  314  may be responsive to fuze  114  to provide a detonation signal to control circuitry  302 , which may provide the ignition signal to igniter circuitry  320  to cause igniter  120  to ignite propellant  104 . Charge size selector  304  may allow the selection of a propellant charge size by a user, for example, and propellant control element  322  may be responsive to the selection of the propellant charge size. In these embodiments, propellant control element  322  may be responsive to charge size selector  304  to selectably ignite separate portions of propellant  104  to control (e.g., either increase or decrease) the amount of propellant  104  that is ignited and burned. Accordingly, the amount of gas that is generated by the gas generator may be controlled. 
     In some embodiments, charge size selector  304  may allow a user to select a vessel size (e.g., very large, large, medium, or small) and charge size selector  304  may cause propellant control element  322  to vary the propellant charge size accordingly. In these embodiments, buoyancy dissipater  100  may provide a non-lethal deterrent to vessel  202  by allowing the propellant charge size to be properly selected so that vessel  202  is not destroyed. In some other embodiments, the propellant charge size may be increased to provide a lethal deterrent in which vessel  202  may be destroyed or sunk. By varying the amount of propellant  104 , buoyancy dissipater  100  is scalable for various operational situations. 
     Ballast control element  312  may control ballast  112  in response to signals from control circuitry  302 . Ballast control element  312  may be configured to maintain buoyancy dissipater  100  below waterline  206 . In some embodiments, ballast control element  312  may be configured to maintain buoyancy dissipater  100  at a predetermined depth below waterline  206 . 
     Although buoyancy dissipater control system  300  is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. In some embodiments, buoyancy dissipater control circuitry  302  may include one or more processing elements. 
       FIG. 4  is a flow chart of a procedure for deterring a vessel in accordance with some embodiments. Procedure  400  may be performed by a buoyancy dissipater, such as buoyancy dissipater  100  ( FIG. 1 ), although this is not a requirement. 
     In operation  402 , a propellant charge size may be selected, for example, based on a tonnage estimate of an errant vessel. The selection of the propellant charge size may be performed by a user through the use of charge size selector  304  ( FIG. 3 ). 
     In operation  404 , the delivery shell containing the buoyancy dissipater may be launched toward the errant vessel. In other embodiments discussed above, other techniques to locate the buoyancy dissipater near an errant vessel may be used. 
     In operation  406 , detonation may be initiated by a fuze, such as fuse  114  ( FIG. 1 ). In some embodiments, detonation may be initiated when the delivery shell impacts the water, although this is not a requirement. 
     In operation  408 , the propellant, such as propellant  104  ( FIG. 1 ), may be ignited to initiate the rapid generation of gas. In some embodiments, buoyancy dissipater control system  300  ( FIG. 1 ) may be configured to initiate the rapid generation of gas when buoyancy dissipater  100  ( FIG. 1 ) is near (in close proximity to) or under the errant vessel. In embodiments in which the propellant charge size is selectable, selected portions of propellant may be ignited by separate igniters. 
     In operation  410 , the gas is diffused to generate a gas bubble below the waterline of the vessel to dissipate the buoyancy of the errant vessel. The dissipation of the buoyancy of the errant vessel may provide a non-lethal deterring effect allowing law-enforcement official to more easily intercept the errant vessel. 
     The Abstract is provided to comply with 27 C.F.R. Section 1.72(b) requiring an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.