WO2011018597A1

WO2011018597A1 - Automatic flood barrier system

Info

Publication number: WO2011018597A1
Application number: PCT/GB2009/051776
Authority: WO
Inventors: Thomas Henry Bell
Original assignee: Gtp Developments Limited
Priority date: 2009-08-14
Filing date: 2009-12-24
Publication date: 2011-02-17
Also published as: GB2472643A; GB0914245D0; GB2472643B

Abstract

The present invention relates to a barrier assembly comprising a barrier (16) adapted to move between a first raised position and a second lowered position; actuating means (rack 12 and pinion 14) adapted to actuate the barrier between the first and second positions; and means in the form of a diaphragm arrangement comprising a diaphragm (7), a diaphragm cage (8) and a cup mechanism (9), adapted for transferring a fluid pressure associated with a variable head of a first fluid to the actuating means wherein the fluid pressure associated with the variable head of the first fluid is translated to the actuating means in order to actuate the barrier.

Description

AUTOMATIC FLOOD BARRIER SYSTEM

The present invention relates to a barrier assembly and a barrier system, in particular but not limited to a barrier assembly and barrier system for diverting sea, river or ground water to prevent flooding, for controlling oil spillage at sea or for providing a protection area for bathers or an activity area for water sport.

Flooding often occurs when run off surface water from sustained and heavy rain, or overspill from streams or rivers, overwhelms water drainage, removal systems and flood containment plains. In some areas this is compounded by incoming high tides backing up the river water and occurring in sequence with higher raised river levels. This causes overspill onto the surrounding land.

There are different types of flood barriers including those which prevent localised flooding i.e. preventing ingress of water into premises, and diversion barriers which direct water away from premises, habitation, or restrict tidal flow.

The majority of diversion barriers are permanent solid-state wall barriers constructed from stone or brick etc. In some cases earth mounds can be formed on riverbanks to divert water away from premises and habitation. Dumping solid-state material to raise land levels can also be used to form sea barriers.

The advantage of these systems is that they are permanent and provide a long-term solution for flood prevention . A problem is that they are expensive to install and in most cases will only be used in higher risk areas. Some barriers are automatically operated by motorised and hydraulic systems to raise and lower a barrier e.g. The Thames Barrier. The same design principle is applied to smaller scale barriers. In the case of the larger scale systems justification has to be based on the costs of installation set against the costs of material damage and in the worst-case scenario, injury and loss of life.

On the smaller scale systems they are only operational if a power source is available to activate them - in storm condition power cuts can occur. In the event of failure of th is primary power source, standby power generators and/or fuel power water evacuation pumps located below ground surface, such as in basements (which is often the case), can be disabled by water flooding into the area where they are located, thus removing the last line of defence of the building. Additionally, independent motorised systems require constant maintenance.

Automatic floatation barriers are self-activating and require no power, or maintenance. One version of this is a vertically disposed flotation barrier, which elevates on self sealing guide tracks, between channel posts when water rises within a subterranean housing containing the floatation barrier.

The problem with this is that when the barrier raises against floodwater, the hydrostatic forces of the rising water on the barrier face increases friction on the guide tracks and seals, causing the barrier to resist the buoyancy forces raising it. Therefore sufficient elevation of the barrier requires a good buoyancy construction and to be manufactured from lightweight materials (to maximise its displacement force). However this can then renders it fragile in face of floating flood debris. The installation of the vertical disposed buoyant barrier also requires excavation of the ground to a depth which is much greater than the vertical height of the barrier. Placement would also be prohibitive in structures which contain below ground chambers, such as underground parking garages etc.

Interlocking portable barriers, which can be constructed of laminated sheeting and held in place with sand bags, can provide a temporary measure to divert flood water away from premises and habitation. Other types are inflated by using air or water.

The problem is that storms, which produce heavy flooding, often occur sporadically, which disadvantages portable barriers, as they have to be erected on site. It is often too late to achieve that before the ingress of water to the buildings.

Smaller scale portable barriers have some practical use when installed across a door entrance, if sufficient warning is given, as they can be erected very quickly. However flooding often occurs without warning.

There are other types of self rising barriers which require no motorised mechanism but depend on attached floatation to partially raise them. One such device is US patent 4377352 issued May 22 1983 to Goldstien. This describes a self-actuating water containment barrier for guarding open fields along flooding streams, or rising lakes. The barrier comprises a plurality of stanchions, which are mounted for pivotal movement from a normal dormant horizontal position to an active vertical position. The stanchions are interconnected with water barrier-forming sheeting to form a barrier that can conform to a particular land mass or shoreline. Float members are mounted on the bottom of the outer ends of the stanchions. At low water levels, the float members rest on a shallow body of water, or on the ground in a near horizontal position. As the level of water rises, the float members cause the adjacent stanchions to pivot into a vertical position, thereby raising the sheeting between them to form a water barrier. Albeit the hydraulic pressure from water accumulating on the waterside of the barrier is supposed to complete the closure.

This type of barrier would be impractical to use in most flood conditions, due to its above ground construction, particularly openings to buildings where traffic of people, machines, or cars normally pass over.

Adapting this form of barrier on the contours of a lake, or river would be equally impractical and costly as trees and shrubbery would have to be removed. Over time debris would inevitably form on the barrier sheeting, restricting floatation. High Flow Rivers generate high kinetic energy, which would override the barrier preventing complete closure. Such forces have been known to carry cars and boulders within their flow. In accompanying conditions any high winds blowing adverse to the rising barrier would prevent closure.

It can be seen that it would be beneficial to provide a new type of barrier system which does not suffer from the same restrictions as the above systems and would be versatile in most applications. Objectives of this system would be :- to provide a flood barrier system which utilises the pressure head of water to produce a measurable force to raise a flood barrier without the need of any motorised mechanism; - to provide a flood barrier which automatically activates and pre-empts any personal action needed to put a flood barrier into place;

- to provide a flood barrier which activates a warning signal prior to rising;

-to provide a low cost flood barrier system as opposed to a high cost solid- state system;

-to provide a flood barrier which can double up as a walkway and is unobtrusive and concealed when not in use;

-to provide a flood barrier wh ich can be of s ing le structu re or interconnected by sealed upright stanchions to form a chain of barriers; -to provide a flood barrier which utilise the pressure head of water to inflate a containment barrier for oil spillage at sea, a protection area for bathers or an activity area for water sport.

According to a first aspect, the present invention provides a barrier assembly comprising a barrier adapted to move between a first raised position and a second lowered position; actuating means adapted to actuate the barrier between the first and second positions; and means adapted for transferring a fluid pressure associated with a variable head of a first fluid to the actuating means wherein the fluid pressure associated with the variable head of the first fluid is translated to the actuating means in order to actuate the barrier. The present invention thus provides a barrier assembly which utilises the pressure head of water to produce a measurable force to raise the barrier without the need of any motorised mechanism. In addition, the barrier assembly can be util ised as a flood barrier, wh ich would have the advantage of being adapted to be automatically activated and pre-empt any personal action needed to put a flood barrier into place to prevent any unwanted ingress of water into an area.

Preferably the means for transferring a fluid pressure associated with a variable head of the first fluid comprises a second fluid.

Preferably the second fluid is a transposition fluid.

In exemplary embodiments of the invention, the transposition fluid is air.

In alternative embodiments of the invention, the transposition fluid is water.

Preferably the barrier assembly further comprises a diaphragm

arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid.

In exemplary embodiments of the invention wherein the barrier assembly comprises a diaphragm arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid, the second fluid is contained within one or more tubes which are

connected at a first end to the diaphragm arrangement and a second end of said one or more tubes is located below a surface of the head of the variable head of the first fluid. Preferably the one or more tubes are contained within a bottom sealed chamber tube.

Conveniently the bottom sealed chamber tube has a top inlet aperture and a smaller outlet tube which extends to a bottom of the chamber tube for emptying the contents of the tube.

Preferably the diaphragm arrangement comprises a diaphragm, a diaphragm cage and cup mechanism.

In exemplary embodiments of the invention, the barrier assembly is deployable such that the diaphragm arrangement is above the variable head of the first fluid. In alternative exemplary embodiments of the invention, the diaphragm arrangement is located below a surface of the variable head of the first fluid and the transference of pressure acting on the diaphragm is by means of a rod, which interconnects with the actuating means. In a further alternative embodiment, the barrier assembly comprises a piston and a cylinder bore arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid. The piston and cylinder bore arrangement provides an alternative means to a diaphragm arrangement.

In a further alternative embodiment, the barrier assembly comprises a bellows-like arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid. The bellows-like arrangement provides an alternative means to a diaphragm arrangement or piston and cylinder bore arrangement. Preferably in embodiments of the first aspect of the invention, the barrier assembly further comprises vertical stanchions and the actuating means is housed in the vertical stanchions.

Preferably the barrier assembly is fitted with bottom and opposite end shafts, which are housed into sealed bearings connected into stanchions.

Preferably one of the shafts is fitted with a pinion to interconnect with a rack.

Preferably the stanchions incorporate compressible seals adapted to prevent the ingress of water when the barrier is in the first raised position. In embodiments of the invention, the barrier assembly incorporates bottom compressible seals, which compress against a plinth to further prevent water ingress.

In alternative embodiments of the invention, the barrier assembly incorporates bottom compressible seals, which are set into an attached bottom plinth to prevent water ingress.

Preferably the actuating means comprises a rack and pinion assembly. Preferably the barrier assembly further comprises plates to form a grade when the barrier is in a horizontal position.

Preferably the barrier assembly further comprising an automatic locking device adapted to maintain the barrier in a closed position. The provision of the locking device maintains the barrier in the closed position in the event of failure of the measurable force utilised to maintain the barrier in a closed position.

Preferably the barrier assembly further comprising a plurality of diaphragm arrangements adapted to form a containment barrier, said diaphragm arrangements being adapted to be inflated by a second fluid associated with the variable head of a first fluid, and comprising one or more apertures that provide communication of air pressure through capillary tubes to form a containment barrier.

Preferably the barrier assembly further comprising a top positioned inlet tube which is extendable to a position for collect rising floodwater in order to actuate the barrier. In exemplary embodiments, the barrier assembly further comprising an inlet pipe adapted to prevent any back pressure opening the barrier connected via a non-return valve to the inlet tube.

Preferably the barrier assembly is a flood barrier assembly.

According to a second aspect, the present invention provides a barrier system comprising at least one barrier assembly according to the first aspect of the invention. In exemplary embodiments of the invention, the barrier system is adapted to create a flood protection wall.

By using the barrier system to create a flood protection wall, the barrier system can be utilised to divert rising inland, or sea water from flooding habitable, industrial, farming land or any area that would be inundated. Preferably the barrier system is a Pressure Head Flood Barrier System (PHFBS) adapted to control floodwater from a water source from causing damage in habitable areas.

In an alternative exemplary embodiment of the invention, the barrier system is adapted to be used as a containment barrier for oil spillage.

In an alternative exemplary embodiment of the invention, the barrier system is adapted to form a designated area for recreational use.

In an alternative exemplary embodiment of the invention, the barrier system is adapted to provide a fence or gate which can be raised or lowered from a horizontal to a vertical position.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

There now follows a description of a preferred embodiment(s) of the invention, by way of non-limiting example, with reference being made to the accompanying drawings, in which: Fig 1 shows the advantage of using a concentric tube;

Fig 2 shows cup and cage mechanism;

Fig 3A-3C show diagrams of a barrier assembly in accordance with an embodiment according to a first aspect of the present invention;

Fig 4 shows an alternative embodiment of a barrier assembly of according to the invention with an alternative arrangement of a diaphragm system without a chamber;

Fig 5 shows an alternative embodiment of a barrier assembly according to the invention with the diaphragm adapted to be positioned under the water level;

Fig 6 shows an alternative embodiment of a barrier assembly according to the invention with a piston housed in a cylinder bore; Fig 7 shows an alternative embodiment of a barrier assembly according to the invention incorporating a bellow-like arrangement;

Fig 8 shows the arrangement of a rack and pinion assembly adapted to negate the effect of back pressure;

Fig 9 shows different vent arrangements suitable for allowing the escape of air from the chamber;

Fig 10 shows the flood barrier stanchion (A) and plinth seals (B) (C) (D); Fig 11 shows a typical flood barrier ramping arrangement which can be located at an opening accessed by pedestrian and motorised traffic;

Fig 12 shows an optional attachment comprising a barrier locking mechanism; and

Fig 13 shows an embodiment of a second aspect of the invention in the form of a containment barrier. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the invention as defined by the appended claims.

Further, although the invention will be described in terms of specific embodiments, it will be understood that various elements of the specific embodiments of the invention will be applicable to all embodiments disclosed herein.

Working principles

In order to understand the working principles behind a barrier assembly according to the invention it is important to understand water forces and pressure. Water pressure acting on the base of a tank is proportional to the head of water and not just the volume of water in a tank. For example the pressure at the base of a tank with 1 m² holding 1 cubic metre of water is 9.81 kn/m² the same as a tank with a base of 10m² holding 10 cubic metres of water with the same pressure head (1 metre). By experimentation it was found that by placing a manometer tube into a tank the head of water at the base of the tank would register a pressure head of water on the manometer even if the manometer was held above the tank. This effect occurs because the force of the water at the base of the tube transfers the water pressure via the air between the two water columns.

It is known that the volume of a fixed mass of air is always inversely proportionate to the pressure (according to Boyle's law). For example if the pressure is doubled then the volume of air in a tube is halved.

By experimentation it was found that by inserting top end sealed tubes 480 mm long vertically, of different diameters, into a tank of water, only 5% of pressure head was lost when 300mm of pressure head was applied. This was due to the upward pressure of the water compressing the air in the tube until the pressure equalized with the applied water pressure.

Because water pressure equalises in all directions the same results will register regardless of the diameter of the tubes. However if the length of a tube is doubled the percentage of up thrust is doubled.

It is not just the volume of air in the tube but the position and shape of the tube which will determine the minimum up thrust to maximise the pressure head available. An example would be (see Fig1A) by inserting a top end sealed tube vertically into a water tank to create an applied pressure which reduces its air volume by half, this will inevitably reduce the pressure head available. A vessel with the same volume of air and the same applied pressure but shaped with less vertical height (See Fig1 B) will also have its volume of air reduced by half but less pressure head will be lost. By adapting this design principle, a vessel which creates less vertical head can be fitted with a small-extended vertical tube (See Fig 1 C) to form a concentric tube without losing too much pressure head. This concentric tube is an improvement by the authors earlier PCT application namely publication no. WO 2005/001319.

Also any top adaptations such as a diaphragm when extended will increase the space of air, but can be allowed for within the bottom vessel without losing too much pressure head. In practice any transposition force can be increased by acting that force on a larger area such as a diaphragm to produce an increased pressure to raise a horizontal barrier to a vertical position.

The barrier assembly of the invention operates because there is a correlation between the size of the diaphragm and the pressure head available. The greater the pressure head the smaller the diaphragm the smaller the pressure head the greater the diaphragm. However maximum design options can be adopted according to the forces which need to be applied.

Cup and Cage mechanism

The diaphragm inflated extends and applies an outward force. Most designs have a solid-state disc to attach at the top to project that force to activate or move an object. A percentage of that force is lost by distension around the annulus. This was addressed by the authors in their earlier PCT application, (namely PCT publication No. WO 2005/001319) by surrounding the diaphragm with a cage, which increases its performance by housing all the forces projected by the diaphragm and preventing any back pressure.

However in this application greater pressures are appl ied and an additional cup shaped mechanism 40 (as shown in Fig 2) is positioned on top of the cage 41 . When the diaphragm 42 is applying its upward force the cup is forced downwards onto the flexible cage to maintain its shape and harness most of the applied force.

Example of the barrier assembly and barrier system

Referring to Figs 3A-3C an embodiment of a barrier assembly and barrier system for use relating to automatically closing off an opening to prevent ingress of water is shown.

The barrier assembly 1 comprises a barrier 16 adapted to move between a first raised position and a second lowered position and actuating means, in the form of a rack 12 and pinion 14 adapted to actuate the barrier between the first and second positions; and means adapted for transferring a fluid pressure associated with a variable head of a first fluid to the actuating means wherein the fluid pressure associated with the variable head of the first fluid is translated to the actuating means in order to actuate the barrier.

In the embodiment shown, the means adapted for transferring a fluid pressure associated with a variable head of a first fluid to the actuating means is in the form of a diaphragm arrangement. The diaphragm arrangement comprises a diaphragm 7, a diaphragm cage 8 and a cup mechanism 9 and is contained in a diaphragm housing 5. The diaphragm cage 8 and cup mechanism 9 are of the type and arrangement previously described above.

The diaphragm housing 5 comprises a vent 21 for allowing the escape of air from the housing 5 as the diaphragm arrangement rises within the housing 5 during actuation of the barrier 16 from a lowered position to a raise position.

The means for transferring a fluid pressure associated with a variable head of the first fluid comprises a second fluid which is in the form of a transposition fluid. The transposition fluid may be air or water. The transposition fluid is contained within one or more tubes which are connected at a first end to the diaphragm arrangement and a second end of said one or more tubes is located below a surface of the head of the variable head of the first fluid.

In the embodiment shown, the transposition fluid is contained in a concentric tube 6 contained within a bottom sealed chamber tube 4. The bottom sealed chamber tube 4 has a top inlet aperture and a smaller outlet tube 19 which extends to a bottom of the chamber tube for emptying the contents of the tube.

In the embodiment shown, the barrier assembly is deployable such that the diaphragm arrangement is above the variable head of the first fluid.

The barrier assembly further comprises vertical stanchions 17 and the actuating means is housed in the vertical stanchions 17. The barrier assembly is fitted with bottom and opposite end shafts, which are housed into sealed bearings connected into stanchions 17. One of the shafts is fitted with a pinion 14 to interconnect with a rack 12. The stanchions 17 incorporate compressible seals adapted to prevent the ingress of water when the barrier is in the first raised position.

The barrier assembly further comprises a top positioned inlet tube/pipe 1 a which is extendable to a position for collect rising floodwater in order to actuate the barrier. The inlet pipe 1a has an end thereof located in the inlet aperture of the chamber 4 and houses a filter 2 to prevent debris from entering the chamber 4. The inlet aperture further comprises a non-return valve 3 which is adapted to prevent any back pressure opening the barrier 16 or hampering the movement of the barrier 16 from its lowered position to its raised position.

The workings of the barrier assembly 1 as a Pressure Head Flood Barrier will now be described. As floodwater enters through the inlet pipe 1 a which the houses filter 2 and flows past the non-return valve 3 to fill the chamber 4 which is hermetically sealed to the diaphragm housing 5. As the water rises in chamber 4, air vents out through the inlet pipe 1 a to allow for a gradual build up of a pressure head of water. This head of water compresses the air in the concentric tube 6 causing a pressure to be created within the tube 6; the tube 6 is hermetically sealed to the diaphragm housing 5. The pressure extends the diaphragm 7, which is sealed to the bottom of the housing 5, and forms it into a segment shaped sphere, which also increases its pressure area. To maintain its shape and to prevent any distension the diaphragm 7 is contained in the cage 8 assisted by the cup 9. As the water continues to fill into chamber 4 more pressure is created which further extends the diaphragm 7 upwards to move an actuating shaft 10 through the diaphragm housing 5 and seals 11. The actuating shaft 10 is connected to the rack 12 and moves the rack 12 within its guides 13 to turn the pinion 14, which is attached onto the bottom barrier shaft 15. To reduce friction, the bottom barrier shaft 15 is connected through a bearing (not shown). As the pinion 14 continues to turn, it raises the barrier 16 until it compresses against the stanchion 17, seals 18 and plinth seals (which are not shown in the drawings). See Fig 10 and associated description below for further details of the arrangement of the stanchion and plinth seals.

Additionally the closure of the barrier 16 is assisted by the leverage from the centre of the bottom barrier shaft 15 to the rack 12.

When the floodwater recedes below the inlet pipe 1 a, a jack pump can be attached to the outlet pipe 19 by removing an associated plug 20. As the water is pumped from the chamber 4, the barrier 16 slowly returns to its horizontal or lowered position.

In embodiments of the invention, the inlet pipe 1 a is telescopic and can be preset at a flood water level. Also by installing a plurality of these barriers, a barrier system 30 in the form of a flood protection wall can be formed, as shown in Fig 3C, to divert rising inland or seawater from flooding onto habitable, industrial, farming land or any area that would be inundated. Alterative embodiments

An alternative embodiment of a barrier assembly according to the invention is presented in Fig 4. In this embodiment the barrier assembly does not have a fill chamber. The first fluid acts directly on the second fluid to extend the diaphragm 50 which connects to the shaft 51 to move the rack 52 upwards. The diaphragm housing comprises a vent 53 for allowing the escape of air from the housing. The barrier then acts in a similar manner to the embodiment described above.

Figure 5 shows another alternative embodiment of a barrier assembly according to the invention. In this embodiment, the diaphragm 60 and diaphragm housing 61 are positioned under the water level in use. A sealed tube 62 extends upwards through a seal at the stanchion base 63.

The transposition of pressure from the first fluid on the base of the diaphragm arrangement is by an inner rod 64, which moves upwards to engage the rack which then acts in a similar manner as described above.

The diaphragm housing 61 comprises a vent 65 for allowing the escape of fluid from the housing during the upward movement of the diaphragm.

Fig 6 shows a further alternative embodiment of a barrier assembly according to the invention . The barrier assembly d iffers from the arrangement shown in Figs 3A and B in that rather than the use of a diaphragm arrangement associated with the means for transferring a fluid pressure associated with the variable head of the first fluid, a piston 71 housed in a cylinder bore 72 is employed to facilitate the raising of the barrier 70. The advantage of this is that a longer stroke can be obtained to increase the force by the use of gears to raise a barrier, to that of a diaphragm. As the fluid pressure acts on the base of the piston 71 , housed in the cylinder bore 72, piston seals 73 which are set into grooves in the piston wall prevent any pressure from escaping. The pressure moves the piston 71 upwards to act on the vertical positioned shaft 74, connected to the rack 75. The diaphragm housing comprises a vent 78 for allowing the escape of air from the cylinder bore 72. The rack 75 then moves from a stationary position to an upward position. In doing so it engages with the gear 76, connected to the barrier base shaft 77. This movement pivots the barrier 70 from a horizontal lowered position to a vertical raised position. The piston 71 can also be set below the water level in a similar fashion to the diaphragm mechanism described in Fig 5. Referring to Fig 7, a further alternative embodiment of a barrier assembly according to the invention is shown. The barrier assembly differs from the arrangement shown in Figs 3A and B in that rather than the use of a diaphragm arrangement associated with the means for transferring a fluid pressure associated with the variable head of the first fluid, a bellows-like arrangement is employed to facilitate the raising of the barrier 80.

As the fluid pressure acts on the bellows 81 , housed in the cylinder bore 82. The pressure expands the bellows upwards to act on the vertical positioned shaft 84 located on one end of the bellows and connected to the rack 85. The diaphragm housing comprises a vent 88 for allowing the escape of air from the cylinder bore 82. The rack 85 then moves from a stationary position to an upward position. In doing so it engages with the gear 86, connected to the barrier base shaft 87. This movement pivots the barrier 80 from a horizontal lowered position to a vertical raised position.

It would be understood by a person skilled in the art that the bellows-like arrangement can also be set below the water level in a similar fashion to the diaphragm mechanism described in Fig 5. Referring to Fig 8, a retention mechanism 90 adapted to prevent the failure of the barrier assembly due to back pressure is shown. The retention mechanism 90 comprises a gear 92 which is connected to the rack (not shown) of the barrier assembly and a locking arm 97 having an end engagable with the teeth of the gear 92. The gear 92 is coupled to the rack such that linear movement of the rack results in rotation of the gear 92.

The locking arm 97 is rotatably mounted on a pin 91 and rests on a stopper 93 which restricts the rotation of the locking arm 97 about the pin 91.

The pin 91 is connected to a slide 96 which is housed in channel in the stanchion. The slide 96 is moveable within the channel by means of a key shaft 94 extending through a face 95 of the stanchion. The key shaft 94 comprises a threaded shaft which is adapted to engage with a threaded hole in the face 95 of the stanchion. The slide 96 is connected to the shaft of the key shaft 94 in such a way that its relative position on the shaft is maintained while allowing for rotation of the key shaft relative to the slide 96. For example, the slide 96 could be received on the shaft and with holding pins passing through the shaft on either side of the slide. Other methods of retaining the slide 96 on the shaft of the key shaft 94 while allowing rotation of the key shaft 94 will be obvious to a person skilled in the art.

Rotation of the key shaft 94 moves the slide 96 along the channel which in turn adjusts the relative position of the locking arm 97 in relation to the gear 92. In use, the retention mechanism is positioned such that the locking arm 97 pivots on pin 91 and engages gear 92. When the barrier is actuated and the ratchet moves to raise the barrier from its lowered position towards its raised position, as the rack moves it will cause the gear 92 to turn in an anticlockwise direction. When the gear 92 turns in an anticlockwise direction, the locking arm 97 due to its angular face will lift upward and allow for free movement of the gear 92. If the raising of the barrier is interrupted due to back pressure effects or failure of the means adapted for transferring a fluid pressure associated with a variable head of a first fluid to the rack, downward movement of the barrier and hence the rack would cause the gear 92 to move in a clockwise direction. As the gear is forced in the opposite direction, the locking arm 97 would pivot anticlockwise and will lock against the stopper 93. As further movement of the locking arm 97 is prevented, it would engage a tooth of the gear 92 and prevent further rotation of the gear 92 which in turn would restrict the movement of the rack. As the movement of the rack is prevented, the barrier will be held in the position where the locking arm 97 prevents the movement of the gear 92. Due to the nature of the retention mechanism 90 subsequent movement of the barrier towards its closed position is not prevented.

The retention mechanism 90 will also hold the barrier in a closed position thus preventing gravity or wind from undesirably lowering the barrier once raised. When the barrier has to be lowered, the key shaft 94 can be turned anticlockwise to draw the slide 96 towards the face 95 of the stanchion and hence the locking arm 97 away from the gear 92. Once the locking arm 97 has been moved away and has been disengaged from the gear 92, the gear is allowed to freely rotate the barrier can be lowered.

Referring to Fig 9, various alternative designs of vent arrangements for allowing the escape of fluid from the diaphragm housing/cylinder bore are shown. The vent arrangement 100 rather than being an uncovered opening may comprise a hinged flap as shown in Fig 9a which covers the opening when not in use. Rather than a flap, the vent arrangement 101 may be covered by means of a inverted cup structure which allows the flow of air through the vent but prevents debris or the like from entering the vent.

Alternatively, the vent arrangement 102 may comprise a moveable flap which is adapted to rise to open the vent during the escape of air from the housing/cylinder bore. On controlling tidal flow the flood barrier system (not shown) can be set at intervals across a bay, or tidal river. A plurality of pressure chambers can be built into the river, or seabed. When high tides occur, water entering the chamber, as described above, raises the barrier. When the water recedes the water in the chambers can be pumped out so that the barrier returns to a horizontal position.

Flood Barrier seals

Fig 10A presents a diagram of compressible rubber seals 110 vulcanised to the stanchion 1 1 1 . As the barrier 1 12 closes onto the stanchion the seals symmetrically compress to form a watertight seal.

Fig 10B presents a diagram of the plinth 120 and seals 121. As the barrier 122 closes onto the plinth 120 it compresses the seals 121 to form a watertight joint.

Fig 10C and 10D present a diagram of an alternative means of sealing the bottom of the barrier 130. The barrier 130 sits into a concaved housing 131 incorporating a compressible seal 132. As the barrier 130 rises from a horizontal position to a vertical position the bottom of the barrier engages on the compressible seal 132 vulcanised onto the side of the concave housing to form a watertight joint.

Barrier ramp

In certain situations, flood barriers located at an opening accessed by pedestrian and motorised traffic can be recessed into the ground to form a flat platform, but if this not possible, a ramp is required. Referring to Fig 1 1 , an embodiment of a typical ramp arrangement 140 incorporating a barrier assembly according to the invention is shown. It consists of a basic fabrication, consisting of reinforced graded stanchions 143 that can be fixed into place at either sides of the ramp. The ramp comprises a ramped section 142 which is attached to an end of the barrier 141 of the ramp assembly. Barrier backpressure /locking device

In flood conditions, when the barrier is raised, the hydrostatic forces of the water should be sufficient to seal it against the stanchions. Also if any backpressure does occur due to adverse wind on the barrier, the diaphragm cage should absorb this. However, precautionary adaptations can be added such as a barrier locking device. Fig 12 shows three stages of operation of a barrier-locking device. Stage one, a rack 200 on its ascension to close the barrier the rack 200 engages a butterfly lever 201 pushing it in an anti-clockwise direction and away from its edge until it has passed the rack grove 202. When the butterfly lever returns to a horizontal position, due to a bias spring 203, it engages the underside of the rack grove 202 and the underside of the helical keyed stop pin 204. At this second stage the rack 200 is locked and the barrier cannot be lowered. To release the rack 200 a third stage operation involves manually turning a helical pin 204 upwards to release the locking mechanism. An optional extra (not shown) can be added to the flood barrier system to provide an automatic warning system. Prior to the flood water reaching its level to activate the barrier through the first inlet pipe, described above, a secondary inlet tube, set below the level of the first inlet pipe fills a small chamber to inflate a small diaphragm which extends to activate a micro switch to switch on a battery operated intermittent warning light and /or siren. This battery could be self-charging by a photo voltic cell.

Containment barrier

While the barrier assembly and barrier system according to the invention has been described with reference to its use as a flood barrier, the barrier system according to the invention can be adapted to be used as a containment barrier for oil spillage, or to form a designated area for recreational use.

To illustrate this Fig 13 shows small diameter tubes 300 which, when inflated help to form a triangular shaped section 301 . Each section end consists of solid backed inflatable panels 302. The overall section is covered with light weight plastic sheeting 303, incorporating an open air vent 304.

This type of structure requires less air to inflate opposed to a tubular structure of sim ilar vol ume . A pl ural ity of these sections when interconnected form an inflatable barrier. To complete the barrier below the water line a ballast skirting 305 is extended downwards and connected onto concentric tubes 306 which on the water line connect into the inflatable sections.

When the concentric tubes 306 are submerged in open water the pressure head of water compresses the air in the tubes which is forced upwards to inflate the sections, to form a containment barrier for oil spills, or create a designated area for recreational activity.

As an oil spill containment barrier they can be reeled off one trawler and fixed between the first trawler and another trawler, to encircle the oil, which could be recovered from the sea surface.

In an operation to protect a bay from oil spillage they can be reeled off a trawler and anchored across the bay at either end. Any oil drifting towards the beach will be blocked and prevented from contaminating that area.

To form a designated area for water recreational it can be reeled off a small boat or from an anchor point on land and tied to anchored buoys. Fig 13b illustrates the slim profile of the barrier tube 306 and section when deflated. This will allow it to be wound round a reel for easy installation.

Raising fences and gates

A barrier system (not shown) according to the present invention may also be adapted as fencing or gates that can be raised or lowered from a horizontal to a vertical position or vice versa. To achieve this, water can be manually poured into an inlet tube, which can be extended above the ground for easy access, to activate the mechanism to raise a fence or gate, in a similar set up to that described with reference to Fig 3A and 3B to raise a flood barrier. To lower the fencing the water can be pumped from an outlet tube in a similar manner as that described with reference to

Fig 3A and 3B.

The Pressure Head Flood Barrier System exhibits several advantages over those barrier systems known in the art. In the first instance it automatically activates before any floodwater can cause damage to property.

It can produce forces without the need for expensive motorised hydraulic mechanism, or pressure pumps. Also unlike floatation barriers restricted by their self built buoyancy to produce a lifting force, the System can produce forces far beyond the possibilities of floatation barriers and measurable against any motorised method. An example would be a 1 metre diameter diaphragm with a 7 metre head which would create over 53.9kN of force.

However a significant advantage is that it can be deployed in any area regardless of remoteness. When deployed as a diversion barrier along the banks of rivers, lakes, burns etc it can be built off the banks on ground where it is easy to construct unlike floatation barriers which must be built within the contours, so that the floatation part of the barrier is in contact with the water.

It can be built from recycled material, which adds to the low cost structure. When not in use as a barrier it doubles up as a foot or cycle path.

The versatility of the design will allow for a broad range of barrier sizes and lengths. This is due to the symmetry of the design whether that is a one off barrier across a door or a chain of barriers.

The concentric tube plays a significant part in the design, particularly in small barrier installation. The tube size can be as little as 28 x 35mm but this will still produce a significant force. The tube also plays a major part in open water installation whether that it is to control oil spills, or tidal flow. The modified diaphragm, cage, and cup mechanism maximise the force which can be provided which significantly improves the forces required for barrier closure. The foregoing description of the invention has been presented for the purpose of illustration and descriptions, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use upon completion. Therefore further modifications and improvements may be incorporated without departing from the scope of the invention herein intended.

Claims

1. A barrier assembly comprising a barrier adapted to move between a first raised position and a second lowered position; actuating means adapted to actuate the barrier between the first and second positions; and means adapted for transferring a fluid pressure associated with a variable head of a first fluid to the actuating means wherein the fluid pressure associated with the variable head of the first fluid is translated to the actuating means in order to actuate the barrier.

2. A barrier assembly according to claim 1 wherein the means for

transferring a fluid pressure associated with a variable head of the first fluid comprises a second fluid.

3. A barrier assembly according to claim 2 wherein the second fluid is a transposition fluid.

4. A barrier assembly according to claim 3 wherein the transposition fluid is air.

5. A barrier assembly according to claim 3 wherein the transposition fluid is water.

6. A barrier assembly according to any one of claims 1 to 5 further

comprising a diaphragm arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid.

7. A barrier assembly according to claim 6 when dependent any one of claims 2 to 5 wherein the second fluid is contained within one or more tubes which are connected at a first end to the diaphragm arrangement and a second end of said one or more tubes is located below a surface of the head of the variable head of the first fluid.

8. A barrier assembly according to claim 7 wherein the one or more tubes are contained within a bottom sealed chamber tube.

9. A barrier assembly according to claim 8 wherein the bottom sealed chamber tube has a top inlet aperture and a smaller outlet tube which extends to a bottom of the chamber tube for emptying the contents of the tube.

10. A barrier assembly according to claim any one of claims 6 to 9

wherein the diaphragm arrangement comprises of a diaphragm, a diaphragm cage and a cup mechanism.

11. A barrier assembly according to any one of claims 6 to 10 wherein the barrier assembly is deployable such that the diaphragm

arrangement is above the variable head of the first fluid.

12. A barrier assembly according to any one of claims 6 to 10 wherein the diaphragm arrangement is located below a surface of the variable head of the first fluid and the transference of pressure acting on the diaphragm arrangement is by means of a rod, which interconnects with the actuating means.

13. A barrier assembly according to any one of claims 1 to 5 further

comprising a piston and a cylinder bore arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid.

14. A barrier assembly according to any one of claims 1 to 5 further comprising a bellows-like arrangement associated with the means for transferring a fluid pressure associated with a variable head of a first fluid.

15. A barrier assembly according to any one of claims 1 to 14 further comprising vertical stanchions and the actuating means is housed in the vertical stanchions.

16. A barrier assembly according to any one of claims 1 to 15 wherein the barrier assembly is fitted with bottom and opposite end shafts, which are housed into sealed bearings connected into stanchions.

17. A barrier assembly according to claim 16 wherein one of the shafts is fitted with a pinion to interconnect with a rack.

18. A barrier assembly according to any one of claims 15 to 17 wherein the stanchions incorporate compressible seals adapted to prevent the ingress of water when the barrier is in the first raised position.

19. A barrier assembly according to any one of claims 1 to 18 wherein the barrier assembly incorporates bottom compressible seals, which compress against a plinth to further prevent water ingress.

20. A barrier assembly according to any one of claims 1 to 18 wherein the barrier assembly incorporates bottom compressible seals, which are set into an attached bottom plinth to prevent water ingress.

21. A barrier assembly according to any one of claims 1 to 20 wherein the actuating means comprises a rack and pinion assembly.

22. A barrier assembly according to any one of claims 1 to 21 wherein the barrier assembly further comprises plates to form a grade when the barrier is in a horizontal position.

23. A barrier assembly according to any one of claims 1 to 22 further comprising an automatic locking device adapted to maintain the barrier in a closed position.

24. A barrier assembly according to any one of claims 1 to 23 further comprising a plurality of diaphragm arrangements adapted to form a containment barrier, said diaphragm arrangements being adapted to be inflated by a second fluid associated with the variable head of a first fluid, and comprising one or more apertures that provide communication of air pressure through capillary tubes to form a containment barrier.

25. A barrier assembly according to any one of claims 1 to 24 further comprising a top positioned inlet tube which is extendable to a position for collect rising floodwater in order to actuate the barrier.

26. A barrier assembly according to claim 25 further comprising an inlet pipe adapted to prevent any back pressure opening the barrier connected via a non-return valve to the inlet tube.

27. A barrier assembly according to any one of claims 1 to 26 wherein the barrier assembly is a flood barrier assembly.

28. A barrier system comprising at least one barrier assembly according to any one of claims 1 to 27.

29. A barrier system according to claim 28 adapted to create a flood protection wall.

30. A barrier system according to claim 29 wherein the barrier system is a Pressure Head Flood Barrier System (PHFBS) adapted to control floodwater from a water source from causing damage in habitable areas.

31. A barrier system according to claim 28 wherein the barrier system is adapted to be used as a containment barrier for oil spillage.

32. A barrier system according to claim 28 wherein the barrier system is adapted to form a designated area for recreational use.

33. A barrier system according to claim 28 wherein the barrier system is adapted to provide a fence or gate which can be raised or lowered from a horizontal to a vertical position.

34. A barrier assembly generally as hereinbefore described with

reference to and/or illustrated in any one of figures 3A to 13 of the accompanying drawings.

35. A barrier system generally as hereinbefore described with reference to and/or illustrated in any one of figures 3A to 13 of the

accompanying drawings.