GB2200872A - Submersible air base - Google Patents

Abstract

A covert floating structure provides an aircraft landing surface at sea and may be submerged for long periods in order to avoid detection. The structure features an aircraft landing surface 8 buoyancy compartments 1 and a buoyancy control system. Optional additional features include an enclosure for accommodating aircraft personnel or supplies including fuel, a stabilised landing surface for use in rough sea conditions and a means of controlling submergeance or emergeance to enhance covert operation. <IMAGE>

Description

SUBMERSIBLE AIR BASE This invention relates to a landing platform for aircraft at sea.

The invention to be described herein is a means of providing support facilities to aircraft in order to improve the extent and/or duration of operations and provide an advantageous landing and/or logistics facility otherwise being absent.

Where land bases are not available aircraft are limited in the extent and duration of their operations by the availability of support facilities.

The aircraft include, but are not limited, to helicopters and similar rotary wing aircraft, aircraft which by special design are capable of short or vertical take off and/or landing and in the case of a large version of the invention conventional fixed wing aircraft.

The outcome of conflict and various adversarial situations involving aircraft will be markedly influenced by the provision of support facilities such as refueling, repairing and re-arming and provision of a base for holding in readiness.

However, the provision of such facilities to aircraft at sea is difficult in many ways and is likely to involve cost and particularly during conflict loss of life. For example an aircraft carrier is an expensive asset which if sunk would involve many deaths.

During periods of either overt or covert military or intelligence gathering operations or operations who's objective is subversion, political interdiction or espionage the provision of support facilities may be opposed by others including military adversaries, a third party and apy party seeking to oppose or nullify the operations in hand.

Thus the provision, of landing and replenishment facilities which are covert and of low cost is advantageous to the general outcome of a conflict and many military operations. For example an aircraft which can be held covertly, fueled and armed near an enemy coast is a siginificant tactical asset.

The term support facilities can include some or all of the facilities for landing, docking, repair and replacement, reprovisioning, ammunition supply, consumable stores supply, fuel supply, personnel replacement and medical care and any service which increases or facilitates the operations of aircraft over the sea. However, the most important for military aircraft are fuel and ammunition supply and the provision of landing facilities.

Support facilities for aircraft operating at sea are generally provided -by aircraft carriers, fleet auxiliaries, fuel supply vessels and in flight refueling aircraft. These support facilities are costly and may if lost bring about the loss of large numbers of lives.

The requirements for an aircraft operating base or support facility may not be confined to a time of war but can arise at any time. In fact a covert aircraft operating base might advantageously be deployed a considerable period of time before a conflict or at any time judged favourable to the outcome of whatever operations were planned.

The invention is primarily of utility to aircraft but the logistics storage facility could, if required, be utilised to the benefit of surface vessels and submarines. Conversely these vessels offer a means of replenishment of consumable stores to the invention.

It is possible to conceive submersible air bases ranging from relatively small to relatively large. A large version could conceivably permit the landing of conventional aircraft. Hence the limitation to aircraft types is primarily construction cost.

In the context of the present invention a formal declaration of war is not necessary. The invention is a means of giving one party a tactical or logistic advantage over another at any time. The invention could conceivably be emplaced years before its required use.

The value of the invention to be described further lies in the provision of some or all of the aircraft support facilities previously described but at lower cost and lower risk of loss of life such that operational effectiveness-may be enhanced; with an improved tactical advantage, and increased probability of concealment and an increased availability.

To further clarify the operational difficulties to be ameliorated it is possible to provide an illustration of one situation where a covert aircraft landing base could be advantageously utilised.

For example a naval force is open to attack from enemy aircraft and consequently withdraws to beyond the range of the hostile aircraft.

Aircraft indiginous to the naval force are required to attack a target which is, as a result of the new juxtaposition of the forces, now at or beyond extreme operational range and the indiginous aircraft are consequently limited in terms of the time spent other than in transit to or from the target.

The invention now to be described will provide in this example a landing platform and refueling base for use by the aircraft indiginous to the naval force relatively nearer to the target. Consequently the aircraft may land and refuel and if required re-arm close to their target. The safety of the main naval force is however maintained.

According to the present invention there is provided a covert surfacing and submersible equipment offering aircraft landing and/or take off facilities from water. A number of specific embodiments of the invention will now be described by way of example with reference to the following drawing in which: Fig. no. 1 shows a cross section of a submersible landing platform at the sea surface with an aircraft standing thereon.

Fig. no. 2 shows a cross section of a submersible landing platform illustrating a simple system for controlling buoyancy and thereby degree of submergeance.

Fig. no. 3 shows a perspective view of a submersible landing p]atform at the sea surface restrained by an anchor and showing an aircraft taking off.

Fig. no. 4 shows a cross section of a submersible landing platform at an intermediate position between the sea surface and sea bottom and including a controllably extendible anchoring system.

Fig. no. 5 shows a perspective view of a submersible landing platform at an intermediate position between the sea surface and the sea bed and having been permitted to drift some distance from the point of anchoring.

Fig. no. 6 shows two submersible air base in different sea conditions where the platform operating in smooth sea conditions only just breaks the sea surface and the platform operating in rougher sea conditions protrudes to a greater extent from the mean water level.

Fig. No. 7 shows a submersible landing platform including a stabilised aircraft landing platform providing á more stable landing surface for aircraft to land and take off from.

Fig. no. 8 is a block diagram serving to illustrate a possible means of achieving an overall functional control system for one or more of the embodiments described.

Fig. no. 9 shows a submersible landing platform including an enclosure for aircraft personnel or supplies capable of providing their protected accommodation whilst submerged and opening when surfaced to allow exit.

Refering to the assembly shown in Figures 1 & 2 there is provided a ballast/bouyancy containment 1, a gas reservoir or source 2, a gas and water flow control valve system 3, a water/gas flow control unit 4, a power supply 5, a timer 6 an interconnecting piping assembly 7 and an aircraft landing surface and main structural assembly 8.

In order to illustrate the possibilities for differing structural and design features, figures 1 and 2 have been drawn differently -though they possess similar functional characteristics. In figure no. 1 the ballast/ buoyancy containment 1 is also a part of the overall structure whereas in fig. no. 2 separate ballast/buoyancy containments are provided. In both cases the functional charasteric of providing ballast or buoyancy remains unchanged.

The function of the ballast/buoyancy containment 1 is to provide buoyancy to the structure plus supported load if present when it is filled wholly or partly with sufficient gas and to contain water in place of gas when it is desired that the structure shall sink.

The function of the gas source or reservoir 2 is to provide gas for the purposes of filling the ballast containment 1 with gas.

The function of the gas and water flow control valve system 3 is to control the flow of gas and water when commanded to do so by the water/gas flow control unit 4.

The function of the water/gas flow control unit 4 is toprovide commands to the gas and water flow control system 3 when commanded to do so by the timer 6.

The function of the power supply 5 is to store or generate power for the continued functioning of the timer 6 and for the operation of the water/gas flow control unit 4 and the gas and water flow control valve system 3.

The function of the timer 6 is to control the operation of the gas and water flow control unit 4 and thereby govern its operation in a pre-determined sequence of events.

The function of the aircraft landing surface and main structural assembly 8 is to provide sufficient area for one or more aircraft to land thereon and fulfill the function of uniting the various subsystems with adequate strength.

The function of the piping assembly 7 is to provide passages for the flow of either gas or water between the gas reservoir 2, the gas and water flow control valve system 3 & the ballast containment 1 and the surrounding sea or air as is necessary to charge or discharge the ballast containment with gas or water.

The function of the ballast/buoyancy containment 1 gas reservoir or source 2, gas and water flow control valve system 3, water/gas flow control unit 4, power supply 5, timer 6 and piping assembly 7 when assembled as a system is to provide a means of controlling the buoyancy of the aircraft landing base. By this means the emergeance and or submergeance of the whole assembly may be ordered on a predetermined basis such that the equipment can surface when desired and submerge when desired.

The manner of operation of the equipment shown in Figs. no. 1 & 2 will now be described taking for illustrative purposes only the equipment resting upon the sea bed though it would alternatively be possible to commence with the equipment assembly on the surface of the water or some intermediate depth.

An equipment at rest upon the sea bed would be in the condition wherein the ballast containment 1 is sufficiently full of water for the structure to have negative buoyancy, the gas reservoir 2 is available, the gas flow control is closed, the water flow control initially having permitted water to enter the ballast containment 1 is either open or closed, the power supply 5 is available, the timer is in the state of containing a pre-determined sequence of system operating commands and can provide a timed basis for the ordering of the operation of the events next to be described.

At the pre-set time of surfacing the timer 6 issues a surfacing command where upon the water/gas flow control Unit 4 causes a water flow control valve, within the gas and water flow control system 3, to close or remain closed and a gas flow control valve within the gas and water flow control system 3 to open and a further valve which permits gas to exit the ballast buoyancy compartment also to close.

The result of these operations is that water within the buoyancy/ballast containment 1 is replaced by air thereby generating in the equipment overall a positive buoyancy causing it to ascend towards the water surface thence to remain with the ballast containment full of gas and the gas and water flow control valves shut until a further time, if any, pre set in the timer, when by operation of valves within the gas and water flow control system 3 and through the control of the water/gas flow control unit 4 the operation of submerging is required.

The equipment assembly may be constructed from normally available ship building materials such as steel and aluminium of an appropriate grade but advantageously plastics would be used such as Kevlar, fibre glass, polyethylene or polypropylene with adequate structural re-inforcement.

The size of the equipment is limited by the requirement to provide sufficient support for the weight of one aircraft at least.

The shape of the equipment is not especially sig nificant only being required to accommodate an adequately shaped surface for a aircraft to land upon.

Fig. no. -1 includes item 6 which has been described as a timer in a most simple example. However in a more advantageous example this might be replaced by means of receiving external commands either when- surfaced or submerged. If it is desired to effect external command the simple timer may be replaced by an external command receiver fulfilling the control function of the timer but capable additionally of receiving external commands.Available means of providing a command system are by ELF at 30Hz. to 3KHz., VLF at 3KHz. to 30KHz. and LF at 30 KHz. to 300 KHz. or a blue green laser operating at a wave length of typically 450 to 510 nano-metres- all of which have some potential for transmission to a submerged equipment whilst numerous radio command systems are available for use when surfaced, or submerged with emerged autenna assemblies.

With reference to figures 3 and 4 the following may be seen.

In fig. no. 3 a submersible landing platform is shown at the sea surface but restrained from drifting by an anchoring system.

Fig. no. 4 includes the items previously specified in Figs. no. 1 & 2 plus a depth control system 10 and an extensible anchoring system 11 and a command control unit 12. Fig. no. 4 also illustrates a keel 9.

The function of the depth control system is to control the depth of the assembly by executing a proporational buoyancy control as commanded by the command control unit 12.

The function of the extensible anchoring system is to extend or reduce the length of anchor scope as commanded by the commanded control unit 12.

The function of the command control unit 12 is to cause the depth control system 10 and the anchoring system 11 to operate in conjunction to achieve controlled depth position. The degree of contribution to depth control by systems 10 and 11 may not necessarily be equal it only being required that they in conjunction or even individually achieve a desired depth.

For example a system with approximately neutral buoyancy could be pulled down a relatively short distance beneath the sea surface by the extensible anchoring system.

The manner of operation of the system illustrated in Fig. no. 4 is as follows.

Starting for convenience of explanation with an assembly as shown in Fig.

no. 3 the command control system 12 commands the depth control system to achieve a specified depth as predetermined between the surface and the bottom. The depth control system by proportional control of the degree of buoyancy causes the assesmbly to sink to an approximately achieved depth.

Simultaneously the command control unit 12 commands the extensible anchoring system to reduce the scope of the anchor to a length compatible with the depth simultaneously commanded by the command control unit for the buoyancy control system.

The function of the depth control system 10, the extensible anchoring system 11 and command control unit 12, when operating in conjunction is to jointly achieve a desired intermediate depth of submergeance there to remain until the ordering of some further operation such as surfacing.

The result of this operation is to achieve a desired position in readiness for emergeance. Depth control may, as is conventional, be achieved by partial evacuation of the liquid from a ballast containment or alternatively by the total evacuation of a proportion only of a number of ballast containments or buoyancy compartments. Differing size containments may be observed in fig. no. 2.

An extensible achoring system may be achieved by the provision of a winch and drive capable of realing in or out a required length of anchor scope.

It is not essential that the buoyancy control system and extensible anchoring system act in exact unison; the two systems may interact such that the sum of the buoyancy forces plus the restraining force provided by the extensible anchoring system jointly produce a controlled depth- of submersion.

Alternatively it is possible to control degree of submergeance by buoyancy control alone and to utilise a non extensible conventional anchor system for prevention of drifting only. Depth and emergeance control are not limited to the setting of an intermediate depth followed by emergeance. Rather an equipment might rest upon the sea bed for some time, then rise to an intermediate depth for a time then surface, then submerge in accordance with a predetermined advantageous schedule.

For illustrative purposes Fig. no. 4 shows an equipment having a keel 9 formed in a conventional manner by a structure protruding beneath the equipment to enhance stability in rough sea conditions and in response to the weight of an aircraft. A keel is not an essential feature but may be provided to improve stability.

Ballast may be provided in the form of heavy metal in addition to a controllably buoyant structure.

Fig. no. 7 illustrates a further embodiment of the invention wherein is provided a dynamicaliy stabilised aircraft landing surface 19 Fig. no. 8 is a block diagram showing the functional units present. In this embodiment are provided a positional reference unit 15, a hydraulic system 16 a set of hydraulic actuators 17, a hydraulic control unit 18, a landing surface 19 and main control system 20. The function of the positional reference unit 15 is to provide a dynamic measurement of the relationship between platform reference axes and fixed stationary reference or earth axes.

The function of the hydraulic system 16 is to provide hydraulic pnwer to the actuators 17 plus, if any, other units requiring it.

The function of the hydraulic actuators 17 is to control the position mechanically of the aircraft landing surface by their extension and withdrawal.

The function of the hydraulic control unit 18 is to carry out calculations, if any, relating actuator length to landing platform position and additionally using signals from the positional reference unit 15 command the extension or withdrawal of the hydraulic actuators thereby to produce an advantageous stabilisation of the aircraft landing surface.

The function of the main control unit 20 is to control the platform surfacing submerging operations in conjunction with the operation of the hydraulic control unit 18 and the hydraulic system 16.

With reference to figure 8 one possible embodiment of an overall platform control system may be seen. The main control unit 20 in this example is in overall control of the subordinate command control unit 12 for the submergeance/emergeancy systems 10 and 11 together with the hydraulic control unit 18 for the landing surface stabilisation systems 15-19.

Figures 5 and 6 illustrate further embodiments of the invention. Fig.

no. 5 shows an equipment held at an intermediate depth by buoyancy and anchor scope control but relatively near the surface Fig. no. 6 shows equipments in conditions of rough and calm seas, wherein it can be seen that in the rougher sea state the equipment protrudes to a greater extent from the sea surface.

The equipment illustrated in fig. no. 6 contains a sea state measuring equipment 13 and proportional buoyancy control 10 as previously described and an emergeance control system 14.

The function of the sea state measuring equipment 13 is to determine the roughness of the sea.

The function of buoyancy control system 10 is to proportionally control buoyancy as commanded by the emergeance control system 14.

The function of the emergeance control system 14 is to command emergeance in relation to sea state in a pre-ordained advantageous relationship.

This means that by using this technique in very calm conditions the landing platform would just break the sea surface, whereas in relatively rougher conditions the equipment would protrude to a greater extent through the surface.

The pre-determination of the emergeance control unit would be advantageously set to minimise detectabilty to surveylance methods such as radar or electro optical surveylance whilst maintaining the aircraft landing surface sufficiently above breaking seas to permit aircraft landing.

A sea state measuring equipment 13 may be manufactured by using for example spatial attitude sensing transducers or an inertial reference unit or a ball resting upon the surface connected to a transducer.

Alternatively emergeance may be commanded proportionately above the sea surface by a control system external to the aircraft landing base.

Fig. no. 7 shows an aircraft landing surface with sea spray shields provided to advantageously protect aircraft and personnel. Spray shields are not essential but are shown here to illustrate that various sea states may be withstood.

It is not essential that the aircraft landing surface be fully and totally stabilised but that an adequate degree of stablisation be achieved for aircraft to land or take off.

A suitable hydraulic system for this purpose might for example consist of a diesel e gine, fuel supply and control system, hydraulic pump consuming typcially 500 Kw, interconnecting hydraulic pipes and flow control valves governing the position of the hydraulic actuators.

Fig. no. 9 illustrates a further embodiment of the invention wherein is provided an enclosure capable of accommodatingone or more aircraft, personnel or logistic supplies during the submergeance of the submersible landing base.

In addition or alternatively to one or more of the previous embodiments there is provided a pressure hull 21, a set of hinged opening bulkhead doors 22, shown closed but in chain dots in the open position, a preassure seal 23, a door opening mechanism 24, accommodation area 25, air supply and environmental control unit 26 and enclosure functional control unit 27.

The function of the pressure hull 21 is to withstand the external pressure of the water during subermegeance and to provide a support and aperture for the bulkhead doors 22.

The function of the bulkhead doors 22 is, when closed to withstand the external pressure of the outside water during submergeance and when open to permit the exit or entry of aircraft, logistic supplies or personnel.

The function of the pressure seal 23 is to contain the atmosphere of the enclosure and prevent the ingress of water during submergeance.

The function of the door opening mechanism 24 is to open or close the bulkhead doors 22 when surfaced and to maintain the doors in a desired position.

The function of the accommodation area 25 is to provide space and facilities as necessary for the storage and accommodation of aircraft or personnel or logistic stores in any desired combination.

The function of the air supply and environmental control unit 26 is to provide adequate air supply if personnel are present and an atmosphere with controlled temperature and as necessary humidity for the storage of aircraft fuel and ammunition and such logisitc supplies as may be desired.

The function of the enclosure functional control unit 27 is to control the environmental control unit 26 and the door opering mechanism 24 when so directed by an overall command unit such as unit -20 though external control through an external signal receiver is alternatively possible.

The function of the pressure hull 21, hinged opening bulkhead doors 22, pressure seal 23, door opening mechanism 24, accommodation area 25, air supply and environmental control unit 26 and enclosure functional control unit 27, is to provide a means whereby whatever combination of personnel, aircraft and logisitic supplies is desire may be accommodated below or above sea surface.

Further this embodiment includes a means of towing the invention submerged by surface vessel or submarine to a desired location.

A pressure hull and bulkhead doors may be constructed using technology readily available in submarine construction.

Claims (8)

1. What I Claim is: 1. A covert surfacing and submersible equipment offering aircraft landing and/or take off facilities from water being identified in Fig. no.1
2. 2. An equipment as in claim no.1 and including additionally or alternatively to one or more of claims 1-9 as a means of maintaining position and contributing to or controlling degree of submergeance and/or emergeance one or more anchors and extendible connecting elements and a control system being indentified in Fig. no. 2.
3. 3. An equipment as in claim no.1 and including additionally or alternatively to one or more of claims 1-9 a means of controlling either the performance or the degree of performance of the operations of surfacing and/or submerging of the equipment being identified in Fig. no. 4.
4. 4. An equipment as in claim no. 1 and including additionally or alternatively to one or more of claims 1-9 a means of controlling emergeance adavantageously to avoid detection in consistency with sea state.
5. 5. An equipment as in claim no.1 and including additionally or alternatively to one or more of claims 1-9 a means of stabilising the motion of the aircraft landing surfaces to a degree advantageous in facilitating the landing and take off of aircraft, being shown in fig. no. 7.
6. 6. An equipment as in claim 1 including additionally or alternatively to one or more of claims 1-9 a means of providing a protective environment for personnel or materials or supplies or equipment or any combination thereof being shown in fig. no. 9.
7. 7. An equipment with a likeness in appearance, to manual or automatic surveylance, to the equipment in claim no. 1 or to any equipment formed by the embodiment of one or more of the features specified under claims 1-9, into the equipment claimed in claim no. 1 or any other means of embodiment with or without some or all of the functional capabilities descrbied in order to perform the function of a decoy.
8. 8. An equipment substantially as desribed herein with reference to figs.l-9.