Abstract:
An autonomous system for blowing ballast for eliminating negative buoyancy of a submarine and a method of blowing the same. The autonomous system includes air supply balloons arranged in an area of the submarine protected from mechanical damage; trunk pipelines connected to the balloons for supplying gas to FDT of the submarine; shutoff devices for regulating the supply of gas via the trunk pipelines. According to the method realized using the disclosed system, compressed gas is supplied from the compressed air balloon, over the trunk pipelines, and into the FDT of the submarine. 
     The invention provides bringing the negative buoyancy of the submarine to zero to stop the gravitational dive.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. 61/431,058 of Jan. 10, 2011. The content of this application is hereby incorporated by reference in it entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present method and system relate to shipbuilding industry, in particular, to submarine building and maintenance, and can be used to eliminate negative buoyancy in submarines. 
       BACKGROUND OF THE INVENTION 
       [0003]    The applicant has no knowledge of technical solutions analogous to the disclosed invention. 
         [0004]    Basic knowledge on the subject of submarine building and maintenance can be gathered from the following sources: 
         [0005]    1) Submarine Theory, Ignatyev K. F., M: Voenizdat, 1947; 
         [0006]    2) Basic Submarine Theory, Bolshakov Yu. I., M: Voenizdat, 1977; 
         [0007]    3) Submarine Structure, Prasolov S. M., Amitin M. B., M: Voenizdat, 1973; 
         [0008]      4 ) Submarine Body Design, Shemendyuk G. P., Petrovich Ch. Ch.; Vladivostok: FESTU, 2007; 
         [0000]    http://window.edu.ru/window_catalog/files/r49915/dvgtu101.pdf 
         [0009]    5) Structure and Technological Design of “Kursk” Submarine Cruiser, Baranov I. L., Publishing House of Rubin Central Design Bureau for Marine Engineering, 2003; http://www.rpf.ru/txt/04/04/20-010001f.html 
         [0010]    6) Websites: wikipedia; 5ka.ru; podlodka.ru; sovsekretno.ru; rpf.ru; Deep Storm web page http://www.deepstorm.ru/DeepStorm.files, http://www.deepstorm.ru/DeepStorm.files/45-92/nbrs/667B/list.htm 
         [0011]    One of the most widespread structural designs in submarine building industry in various countries is a twin-hull submarine. The interhull space formed in this design provides significant floatage and a possibility of stationing additional equipment outside the main hull. 
         [0012]    The structure of twin-hull submarines allows to store reserves of high-pressure gas in the upper part of the inter-hull space to facilitate maintenance and repair of high-pressure air system in up-top state and reduce risk to the crew in case of seal failure in the high-pressure air system (if the main hull is located therein). The gas is usually air. 
         [0013]    Main ballast tanks, which are filled when a submarine is diving and drained when surfacing, are also arranged within the inter-hull space. The necessity to be able to control ship damage and in view of the load distribution requirements, causes separation of the inter-hull space into individual tanks (as well as placement thereof along the hull). 
         [0014]    The general construction of a high-pressure air system and the necessity of providing lengthy submarine dives require placing manually and remotely controlled valves and a collector inside the main hull. 
         [0015]    Pipeline connections of high-pressure air system are designed to provide air for any consumer from any group of storage volumes (balloons). In this situation, the necessity to ensure the delivery of compressed air to the consumer requires particular attention to reliability of pipeline communication. 
         [0016]    The prior art emergency (urgent) submarine dive (in various circumstances) can only provide filling of an additional tank, the so called fast dive tank (FDT), the volume thereof exceeding the estimated balance. The ballast introduced therein becomes negative and the ship dives. 
         [0017]    The above described diving method can be limitedly acceptable only under conditions where time and depth are strictly controlled. 
         [0018]    After the consistent diving trend is achieved, the fast diving tank is drained by blowing; otherwise diving (sinking) will continue. 
       BRIEF SUMMARY OF THE INVENTION 
       [0019]    The following definitions are used in the present application: 
         [0020]    Submarine: a technological device of various purposes as shown schematically in  FIG. 1 , capable of diving underwater, surfacing and controlled movement with course and depth (up to maximum) selection. 
         [0021]    External hull (Light-hull): a non-tight body used for providing aerodynamic form (pos.  1 ). 
         [0022]    If an external hull is provided, the submarine can be considered a twin-hull submarine. The external hull is not used for resisting an outside static or dynamic forces. 
         [0023]    Pressure-hull: a rigid body used for resisting outboard pressure and forming a sealed volume for crew life support (pos.  2 ). 
         [0024]    Fin structure (tower): a protective structure for housing various extensible devices (pos.  3 ). 
         [0025]    Interhull space: a volume between the Pressure-hull and the Light-hull used for storing compressed air reserves and ballast tanks (pos.  4 ). 
         [0026]    Ballast: a volume of water freely received when diving and forcefully ejected overboard when surfacing; said water is housed in interhull space tanks (pos.  4 ,  6 ). 
         [0027]    Compressed air (high-pressure air): a system of pressure accumulation for blowing ballast (pos.  5 ). 
         [0028]    Fast dive tank: a rigid volume for placing additional ballast therein during emergency (urgent) dive (pos.  7 ). 
         [0029]    Buoyancy in submerged state: the ability to resist sinking or surfacing; said ability is achieved by bringing the difference between relative weight of water and the submarine to zero. 
         [0030]    Negative buoyancy: a state where in the submarine weight exceeds the weight of water; said state causes gravitational sinking. 
         [0031]    The assumptions made by the inventors lead to the following conclusions: 
         [0032]    1) Removal of ballast taken during submarine dive is executed by blowing the tanks with compressed air, 
         [0033]    2) Compressed air sources (canisters or balloons) can be placed in the interhull space along the entire length of ship body, 
         [0034]    3) Compressed air system efficiency is significantly affected by system structure; in order to ensure air delivery to any consumer, the possibilities of consolidating the entire air supply and dividing the system with a set of bridges are structurally arranged, 
         [0035]    4) Consolidation of air supply is presently considered sufficient for system operation in emergency conditions, 
         [0036]    5) Fast dive tank (FDT) is used for a short time, i.e. it is considered an especially important consumer of compressed air, 
         [0037]    6) Service conditions of various communications within the interhull space (protection by means of the Light-hull, presence in water) are considered steadily safe. 
         [0038]    Considerations in Favor of Inherent Danger Possibility. 
         [0039]    The FDT is not provided with an autonomous compressed air source. 
         [0040]    In view of the above conclusion there is an existing necessity to create a method and system for blowing ballast that would be capable of eliminating negative buoyancy of a submarine. 
         [0041]    Situation Model of Hitting an Obstacle on the Sea Surface and Damages Received Thereby. 
         [0042]    In conditions where various negative factors (sea disturbance, navigation intensity, limited capabilities of observation means or failure thereof) have a direct effect, the crew can only be able to approximate the presence or absence of obstacles. The decision on the ascent is a result of a subjective analysis. 
         [0043]    The possible simultaneous effect of negative conditions makes surfacing a most important routine maneuver. The risk can become critical and a fatal collision danger will thus arise. 
         [0044]    The nature of collisions implicitly indicates the most plausible fore contact (pos.  8 ), wherein damage to the valves of compressed air system (pipelines) in the interhull space is possible. 
         [0045]    A failure of pipeline communications in the compressed air system can lead to unimpeded pressure equalization in the system and outboard (pressure accumulation is impossible); the submarine therefore loses compressed air required for blowing ballast. 
         [0046]    Contact symptoms evident to the crew can be the impact sound, loss of running, tilting and lurching of the submarine, etc. The cause of the emergency situation is evident, while the correct determination of consequences is not. The crew (pos.  2 ) cannot visually assess the condition of the interhull space and locate the damaged areas (pos.  4 ,  5 ). 
         [0047]    The greatest danger for the submarine in shipwreck situation is the Pressure-hull damage hazard, dangerous lurching of the craft and damage to mounting elements of various equipment. 
         [0048]    Time constraints exclude the possibility of lengthy preliminary assessment of possible developments. 
         [0049]    The information efficiency regarding pressure in the system will largely depend on outboard environment resistance, pipeline-distance between control means and the damage area, and the carrying capacity of connecting conduits. 
         [0050]    Furthermore, the occupational crew psychology prevents them from admitting such consequences as the full loss of air supply and impossibility of surfacing (the crew is taught to trust the ship). 
         [0051]    From the crew&#39;s point of view, the top-priority tasks are aimed at immediate physical separation from the obstacle, which is achieved by emergency dive accompanied by filling the FDT (pos.  7 ). 
         [0052]    Irreducible Gravitational Sinking Model 
         [0053]    The acquired negative buoyancy allows to break free from the obstacle, but, in case of specific damage, the submarine will resume forced diving. 
         [0054]    The possibility of ballast blowing is lost due to the fact that the damaged area is located closer to the surface than the openings for dropping ballast where the environmental resistance is higher (pos.  5 ,  6 ,  9 ). Any command issued to the crew and equipment to carry out emergency blowing of all tanks and to remove negative ballast in said conditions is admittedly impractical. 
         [0055]    The crew can only use one emergency means: the consolidated compressed air reserves (pos.  5 . 1 ). So structurally provided consolidation of compressed air supply in case of emergency ensures access for air from any balloon to the damaged area (pos.  5 . 2 ,  9 ). 
         [0056]    The available means for stopping the submarine (elevator in conjunction with increasing running speed) cannot compensate for the negative buoyancy (in the FDT volume), but will lead to increased inertia. 
         [0057]    Low sea depth (comparable to submarine length) defines a change of deciding factor, with the submarine now quickly approaching the sea bottom (ground). 
         [0058]    The submarine will inevitably hits the ground at a speed possible to reach ( 9 ). 
         [0059]    Therefore, the submarine will be subjected to a second mechanical impact on the fore (this time, with much larger contact area) in a short time interval. 
         [0060]    In the case of an adequate supply of depth, the irreducible negative buoyancy will inevitably lead to Pressure-hull destruction upon reaching appropriate depth. 
         [0061]    Difficulties in Using Sectional Partition Possibilities in Conditions of Time Constraints and Increased Vessel Speed. 
         [0062]    Taking into account the above developments, the decision to cut off damaged areas and pipelines (pos.  5 . 2 ) can worsen the situation. 
         [0063]    The most rapid intervension method for cutting off air access to the damaged pipelines can be a remote bridge closure. This method can lead to cutting off consumers (e.g. FDT and other fore tanks of bow tip). 
         [0064]    A solution to connect the compressed air source with the consumer via bridge can be optimal in terms of balance between minimization of increased quantity of actuating elements (shutoff devices) and availability thereof for maintenance (pos.  5 . 1 ,  5 . 3 ). 
         [0065]    It must be noted that the crew&#39;s reaction to the fact that the diving process in uncontrollable can only start from the moment the crew realizes that the FDT blowdown command does not result in change in buoyancy. That is, the futile (and possibly repeated) attempts to use the consolidated air blowdown method will inevitably lead to time loss. 
         [0066]    Critical situation is extremely negative impact on the morale of the crew—become apparent 
         [0067]    1) The futility of efforts to restore the manageability of the vessel, 
         [0068]    2) The inevitable result of gravitational fatal dive. 
         [0069]    If damage is assessed correctly, the most effective course of action is to cut off all bridges or all balloons located in the bow tip. 
         [0070]    Cutting off damaged balloons is a more desirable solution (pos.  5 . 4 ), but it is possible only if the following conditions are met: 
         [0071]    perfectly correct analysis was performed 
         [0072]    reliable information regarding damage scale was obtained. 
         [0073]    In this case, such decisions basically represent a forced reduction in air supply, i.e. rejecting the disclosed advantage of the general system. Additional difficulties are inevitable in the case of manual control valves (pos.  5 . 4 ). 
         [0074]    Cut-offs will help to prevent further air loss, but will not stop gravitational dive; to this end, ballast must be removed immediately. 
         [0075]    Furthermore, reduced air supply and increasing depth resistance will objectively increase the direct tank blowdown time. 
         [0076]    The danger of approaching the ground or sinking into depths exceeding the Pressure-hull strength limit will lead to the subsequent decision to immediately blow all ballast with the remaining air supply. 
         [0077]    The execution of said command can possibly lead to a situation wherein ballast will not be removed from cut-off tanks in the bow tip (in contrast to tanks in the rest of the ship), which will cause risk of dangerous trim on the bow. 
       CONCLUSIONS 
       [0078]    1) safety of equipment and communications in the interhull space cannot be considered perfect, the risk of compressed air loss can arise unexpectedly, 
         [0079]    2) the importance of fast dive tank draws special attention to blowability thereof, 
         [0080]    3) conventional methods of air delivery to the consumers and time constraints significantly impede the making the sole right decision by the crew, 
         [0081]    4) the using of the FDT for the intended purpose requires it to be equipped with an independent blowing system. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0082]    Some embodiments of the proposed invention are illustrated in the accompanying Figures ( FIG. 1-9 ). 
           [0083]    In  FIG. 1  an interior space of the submarine is shown; 
           [0084]    In  FIG. 2  a connecting circuit for connection of compressed gas sources and consumers of the compressed gas (ballast tanks), is shown; 
           [0085]    In  FIG. 3  a group of balloons connected with a common collector, is shown; 
           [0086]    In  FIG. 4  a connecting circuit for connection of balloons and consumers “through bridge” between two collectors, is shown. 
           [0087]    In  FIG. 5  a circuit for delivering of compressed gas to the ballast tank from at least one balloon, is shown; 
           [0088]    In  FIG. 6  most likely location of damage at collision is illustrated. 
           [0089]    In  FIG. 7  a position of submarine when loosing air freely and achieving negative buoyancy, is shown. 
           [0090]    In  FIG. 8  locking units for use in emergency operation, are shown. 
           [0091]    In  FIG. 9  an autonomous system for blowing ballast with independent source of compressed gas, is shown. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0092]    The use of the FDT requires guaranteed removal of the received negative ballast. It can be noted that the conventional means utilize a uniform solution to the problem of blowing down all tanks regardless of purpose thereof; the negative ballast tank uses the same blowing method as the calculated ballast tanks. 
         [0093]    The discussed situation wherein it is impossible to deliver air to the consumer is not considered in modern shipbuilding. In other words, conventional systems do not sufficiently eliminate the risk of ship and crew loss. 
         [0094]    It is believed that system structure and the scope of testing are sufficient to combat known hazards. Further advancement in the general compressed air system is proceeding in the same direction, without considering the described hazard model. 
         [0095]    A necessary requirement for applicability of the method for blowing the tank in specific condition is to provide time necessary to search for an acceptable solution and to subsequently perform the compressed air operation, said time interval not exceeding the time interval of sinking to dangerous depth. 
         [0096]    It is obvious that controlling the time resource is impractical and downright impossible. Only depth control is relatively justifiable (or passive). 
         [0097]    Therefore, it is obvious that there is a need for a combined technical solutions with account to complex factors, including time constraint, possible human error and reaction time of a general ship systems, providing efficient and reliable system and method of blowing ballast in fast dive submarines. 
         [0098]    The object of the invention is to solve or eliminate at least partially critical disadvantages in conventional systems and to increase proper service reliability of the submarine when using negative ballast. 
         [0099]    The object is solved by providing a method for blowing a FDT using a pipeline, which is independent from the general system&#39;s pipeline, and by providing an autonomous system for delivering air without using general system&#39;s collectors. 
         [0100]    The present disclosure is not aimed to create additional improvements over the whole submarine system. The present invention is a technical solution relating to the FDT and method of its operation exclusively. 
         [0101]    Method of Operation of One of Embodiments of a System According to the Invention 
         [0102]    According to the embodiment shown in  FIG. 1-9 , a general system (pos.  5 ,  5 . 1 ) supplies compressed air to a system for blowing ballast according to the invention, and after forming a necessary air reserve, the pipeline connection is securely blocked by a locking means. A main pipeline communication connects the air source and a fast dive tank, and has a remote-controlled (quick-response) valve. 
         [0103]    When the FDT is used, as it is being filled, upon a request from the operator, the remote control station (Central Post sub) forms a signal to open the closed valve (or valves, if a tank is placed on each side). Air reaches the consumer unimpeded, thus removing negative ballast through open kingstons. 
         [0104]    Therefore, compressed air can be directed to the tank at any moment (including non-emergency situations) without using main system pipelines (as shown in pos.  5 . 1 ,  5 . 2 ). 
         [0105]    There is no need to alter the structure of the general compressed air system and of the tank itself. 
         [0106]    The disclosed basic configuration has no prototype, and includes innovative operational units and functional connections. 
         [0107]    In one embodiment of the invention, a system for blowing ballast comprises the following components (widely used in shipbuilding): air storage balloons routinely isolated from the general air supply; said balloons are placed in a location protected from mechanical damage, such as interhull space in the stern behind the Tower, a FDT, a main hull, and a main pipeline, and are used for forming an autonomous air supply and/or for supplying air into the tank. 
         [0108]    In some embodiments of the invention the system can further comprise monitoring devices, shutoff devices (which can be manual, to shut off communication with the general system, or remote-controlled, to supply air into the tank), and remote control means for controlling the system. 
         [0109]    Advantageously, the present method for blowing ballast eliminates negative buoyancy of a submarine and can be implemented independently from the condition of the general system (pos.  5 ,  5 . 1 ), by using an innovative autonomous system for removing ballast temporarily received into the FDT, which is used for blowing the FDT exclusively and comprises an individual source of compressed air and an individual communication pipeline from the air source to the consumer. 
         [0110]    The disclosed system effectively realizes the method for blowing the FDT independently from the condition of the general system and increases reliability of the submarine compressed air system when using negative ballast, which significantly reduces risk of uncontrollable gravitational dive. The reasonable, adequate use of the disclosed system exclusively (without using other communications and functions) ensures bringing the negative buoyancy of the submarine to zero. 
         [0111]    The novelty feature of the present invention is realized by forming in one embodiment of the invention, an additional pressure source used only for the FDT, by providing significantly higher resistance of the disclosed system to physical impact characteristic for collisions, and by providing independence of the disclosed solution from the constructive features of the general compressed air system. 
         [0112]    The above disclosed inventive solution was not possible in the prior art systems; since the removal of balloons from the potentially hazardous area alone will complicate the delivery of air to the consumers located in the bow tip of a vessel. 
         [0113]    The following specific features of the invention describe the purpose of components of the present system which is also innovative and provide the following advantages: 
         [0114]    1. The possibility to use smaller balloons. 
         [0115]    The number and volume of disclosed air sources (balloons) corresponds to the volume of the FDT and to the requirement of ensured ballast removal in shortest time possible, i.e. the invention contemplates the use of several balloons with individual volume thereof possibly lower than that in the general system, which provides additional arrangement possibilities. 
         [0116]    2. The possibility of arranging balloons in the pressure-hull. 
         [0117]    A significantly lower air volume (per one tank) in any case does not pose danger of the magnitude possible if the entire air supply of the general system is arranged within the bounds of the Pressure-hull. 
         [0118]    3. Means for pressure and remote control of the shutoff valves are analogous to those used for control over the general system; said means can be operatively used by one operator. 
         [0119]    In this case, the general system remote control station operator receives an additional circuit key (toggle switch) for remote control of the valve. 
         [0120]    The present system can include an embodiment with joint operation of both the shutoff device of the air pathway and the tank&#39;s kingstons, which is compliant with the principle of use of the FDT and with the time constraint condition. In other words, the operation commenced by the remote control station thus provides simultaneous opening of both the main “air” valve and the tank&#39;s kingstons; whereas when the operation is stopped, the “air” valve and the tank&#39;s kingstons are closed simultaneously. 
         [0000]    Additional advantages of the disclosed method and system include: 
         [0121]    the possibility of blowing the fast dive tank without need to increase the overall air supply, 
         [0122]    An allocation of a portion of the air storage units is permissible. 
         [0123]    the system does not suffer from incorrect evaluation of the condition of the general system, 
         [0124]    The invention fully eliminates the dependency of ballast blowing from operating conditions of the general system. 
         [0125]    complex monitoring systems are not required. 
         [0126]    The disclosed embodiment directly performs the task of blowing, in contrast to implementing general system condition control means in the interhull space, which fails to simplify the general system. 
         [0127]    the solution does not lead to complicating existing systems, does not require new maintenance methods, does not negatively affect characteristics of adjacent systems, 
         [0128]    the method does not interfere with prior art methods. 
         [0129]    The structure of the disclosed autonomous system is not as complex as the general system. 
         [0130]    As a result, the invention provides additional possibility for removing negative ballast in a submarine. An individual blowing method and an autonomous system are fully prepared for the danger of losing air in the general system. The present system is capable of removing negative ballast autonomously. 
         [0131]    When the disclosed system is used in worst conditions modeled above (full loss of compressed air), the submarine will not possess the possibility of blowing the remaining ballast (surfacing to the up-top position is impossible without outside help), but the negative buoyancy will be eliminated, which will cause the gravitational dive to cease and will allow to retain the possibility of controlled movement in a submerged state and the possibility of transmitting an emergency signal. 
         [0132]    The disclosed embodiment is suitable for any submarines wherein the compressed air storage is arranged in the interhull space (regardless of the submarine size and type of power plant). 
         [0133]    Submarines with Pressure-hull thickness of 70 mm possess different structural features. However, a combined effect of negative emergency factors cannot be dismissed.