Avalanche protection system

Abstract

Apparatus is described for arresting or at least retarding an avalanche. In the described embodiment the apparatus comprises a plurality of elongate substantially cylindrical bodies (1) which are positioned on a mountainside in a likely avalanche path, for deployment into an avalanche. Each body is provided with a multiplicity of bristles (10) for engaging with one or more of the other cylindrical bodies (1) with which it may come into contact when the bodies are deployed. The bristles may be provided with locking mechanisms such as hook and loop mechanisms (14,16) for locking one cylindrical body to another when the bristles (10) of each come into contact. Each body may further be provided with anchor cables (26) to brake and arrest the body when deployed into an avalanche. The apparatus includes one or more stands (2) for deploying the cylindrical bodies into an avalanche. In use the stand(s) are fixed to the mountainside in strategic positions in the predicted avalanche path.

Description

RELATED APPLICATIONS

[0001] This application claims priority to PCT Application No. PCT/GB2004/005143, dated Dec. 3, 2004, the content of which is incorporated herein by reference. That application claims priority to UK Application No. 0327965.0 filed Dec. 3, 2003.

FIELD OF THE INVENTION

[0002] The invention relates to an avalanche protection system in particular, though not exclusively, for deployment near ski resorts or residential areas where an avalanche can occur.

BACKGROUND OF THE INVENTION

[0003] It is well known that almost two hundred people a year are killed by avalanches around the world. As skiing and other winter sports are becoming more popular this number will unfortunately increase. Ski resorts and residential areas normally have no warning of an impending avalanche. This is a particular problem at night time when most people resident in the areas are sleeping.

SUMMARY OF THE INVENTION

[0004] An object of the present invention is to provide front line protection to the residents of a winter sports resort or a town where avalanches can occur. Another object of the invention is to provide a device which will arrest or at least retard the flow of ice and snow in an avalanche in order to save life and property.

[0005] According to a first aspect of the invention there is provided avalanche impeding apparatus comprising a plurality of elongate bodies and deployment means for deploying said bodies into an avalanche, each body being provided with engaging means for engaging with at least one other said body with which it may come into contact when the bodies are deployed.

[0006] Preferably the elongate bodies are each substantially cylindrical. Preferably, the engagement means comprises a multiplicity of bristles extending outwardly from a central tubular portion of each body. Preferably, the bristles are mounted in a spaced apart relationship along substantially the whole length and circumference of the central tubular portion.

[0007] The engagement means may further include automatic locking means for locking automatically each body to any other said body with which it comes in to contact. The locking means may, for example, comprise at least one hook and loop locking mechanism provided on at least some of the bristles. Preferably, each bristle is provided with a plurality of hooks, and a series of loops configured for engaging with the hooks on other ones of said bristles. The hooks may be arranged in a spaced apart relationship in lines extending generally parallel to the axis of the bristle with each hook preferably extending generally perpendicularly to the axis of the bristle.

[0008] Preferably at least one of the elongate bodies further comprises at least one anchor cable attached at one end to the elongate body and secured, in use, to the ground by fixing means at or near the other end of said cable. Conveniently if more than one anchor cable is used, the cables are attached to the elongate body in a spaced apart relationship along the length of the elongate body.

[0009] Preferably the at least one of the elongate bodies further comprises a plurality of anchor cables, each attached at one end to said elongate body, said anchor cables being interconnected by at least one bracing element and, in use, being secured to the ground by fixing means at or near the other end of the cable.

[0010] Most preferably a plurality of bracing elements are used and interconnect the anchor cables to form a lattice or net like structure, of cables and bracing elements, when the cables are deployed on a slope. Desirably the bracing elements may interconnect the anchor cables at more or less regular intervals along the length of the cables.

[0011] When being deployed ready for use each anchor cable is laid out along the ground, at a time when snow is generally absent, in a direction generally away from the elongate body, generally downhill on a slope where an avalanche may be expected. If a plurality of anchor cables is employed, the cables are laid out in a spaced apart relationship running generally downhill. Where bracing elements are used the lattice or net like structure is laid out on the hillside, downhill of the location of the elongate body. The bracing elements may be cables, rods or bars for example.

[0012] In use, the anchor cables are secured to the ground by fixing means at one or more attachment points near the end of the cables distant from the elongate bodies. The attachment points may be on the anchor cables, the bracing elements or at the connections between cables and bracing elements. When an avalanche occurs the anchor cables act to brake and arrest the elongate bodies as described hereafter.

[0013] The deployment means may comprise at least one stand for holding one or more of said bodies prior to deployment. The stand is preferably configured to be mounted on a mountainside. Preferably, the stand is formed and arranged to hold several of said bodies. The bodies are preferably held generally horizontally and one above another, between two generally vertical end supports of the stand. This has the advantage that each body is deployed from a different height, into the avalanche. The stand may be formed and arranged so that the bodies simply rest on the stand with any attached anchor cables laid out generally downhill from the stand, but are free to move out of the stand under the force of an avalanche hitting the stand. Desirably at least one of the elongate bodies held in a stand has a said at least one anchor cable attached. Preferably all the elongate bodies have a plurality of anchor cables attached. Most preferably all of the elongate bodies have attached a plurality of anchor cables, interconnected with bracing elements, forming a lattice structure of cables and bracing elements.

[0014] Alternatively the deployment means may conveniently further include at least one sensor for sensing an avalanche and activation means in communication with the sensor(s) and configured to deploy said elongate bodies upon receiving a signal from the sensor(s) that an avalanche has been detected. The activation means may be designed to deploy the bodies by forcing them out of the stand into the path of the avalanche or, alternatively, may be designed to simply release the bodies (for example by releasing a retaining means which may be holding the bodies in the stand) so that they are free to move whereby they will be pulled out of the stand by the force of the avalanche when the avalanche hits the stand. The sensors may be motion and/or acoustic sensors, or any other type of sensor capable of detecting an avalanche approaching the stand.

[0015] In practice, the deployment means preferably comprises several stands each preferably holding several of said bodies, the various stands being placed strategically at different positions on a mountainside where an avalanche is likely to take place. The anchor cables or lattice of braced anchor cables from each elongate body (where fitted) are laid out in a spaced apart relationship downhill from each stand and fixed to the ground by appropriate fixing means at their attachment points.

[0016] The invention then works in the following manner. When an approaching avalanche is detected by the deployment sensors in the uppermost stand(s)the elongate bodies on those stands are released into the avalanche. Alternatively where sensors are not used the elongate bodies are dislodged from the stands by the force of the avalanche. As the avalanche tumbles down the mountainside the energy from the avalanche causes the bodies to lock together as they touch one another (by means of the bristles and hook and loop mechanisms on the bristles) so that they become one or more larger units. This absorbs the energy of the avalanche and reduces the airflow in the avalanche. At the same time as the elongate bodies descend the mountainside with the avalanche their attached anchor cables are pulled out from under the original snow cover on the ground causing a braking action. The elongate bodies are brought to stop, or at least slowed substantially, by virtue of the fixing means holding the anchor cables to the ground at their attachment points.

[0017] Where a plurality of anchor cables are used on a given elongate body this braking action can be further enhanced by the provision of panels constructed of, for example cloth or sheet metal, attached between cables or between cables and bracing elements. As the elongate bodies travel downhill during an avalanche the panels provide enhanced braking action by virtue of the energy they expend in lifting the original snow cover from the slope, or by their interaction with the snow and air mass of the avalanche.

[0018] By arranging several sets of cylinders at different intervals down the avalanche slope this will ensure that if the avalanche snow and ice takes a path past or over the first set of cylinders then the next set of cylinders positioned further down the slope will be deployed to further retard the avalanche.

[0019] The bodies may be made from carbon fibre and/or plastics material. Preferably the central tubular portion of each body is made of stainless steel or carbon fibre. The bristles are preferably made from glass fibre or a plastics material. The length of each body may be in the range of ten to fifteen metres, the diameter of the central tubular portion may be approximately one metre and the length of the bristles may be between one and two metres. The cables may be made from steel and are preferably about 50 metres in length. Longer or shorter cables may be employed depending on the requirements of the location in which the avalanche protection system is being deployed. The bracing elements are also preferably made of steel or steel cable. The fixing means, used to attach the cables to the ground at their attachment points may comprise any suitably strong means, for example bolts screwed directly into the ground or into a concrete structure such as a block buried in the ground.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Preferred embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which:

[0021] FIG. 1 is a front view of an avalanche impeding apparatus according to one embodiment of the invention;

[0022] FIG. 2 is a detailed view of a portion of the apparatus of FIG. 1;

[0023] FIG. 3 is an end view of a cylinder provided with bristles;

[0024] FIG. 4 is a detailed side view of a bristle provided with a hook and loop locking mechanism;

[0025] FIG. 5 is a schematic view of an elongate body (cylinder) with a lattice of anchor cables and bracing elements attached according to one embodiment of the invention;

[0026] FIG. 6 is a schematic side view of a mountainside showing avalanche protection apparatus deployed thereon;

[0027] FIG. 7 is a perspective view of four substantially cylindrical bodies of an avalanche impeding apparatus according to another embodiment of the invention;

[0028] FIGS. 8(a) and (b) illustrate schematically a portion of a mountainside provided with avalanche impeding apparatus according to the invention, FIG. 8(a) showing the mountainside before the avalanche and FIG. 8(b) illustrating the mountainside after an avalanche has fallen; and

[0029] FIG. 9 is a detailed end view of a stand forming part of the apparatus of FIG. 1.

[0030] For clarity the anchor cable or cables that may be attached to the elongate bodies (cylinders) are omitted from FIGS. 1-3 and 6-8.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

[0031] FIG. 1 shows avalanche impeding apparatus for arresting or at least retarding an avalanche. The apparatus comprises a number of cylinders 1 (five shown) mounted on a stand 2 in which the cylinders are arranged in parallel one above the other. In use of the apparatus, the stand 2 is positioned on a mountainside in a likely avalanche path. The stand is fixed to the ground such that the cylinders 1 are held horizontally relative to two generally vertically extending end supports 4, 6 of the stand 2. The stand may be fixed to the ground by means of bolts or piles screwed through a base plate 8 (shown in FIG. 9) of the stand, or by any other suitable means. Attached to each cylinder 1 are long bristles 10 which are arranged in spaced apart relationship along the full length of the cylinders 1 and around the full circumference of each cylinder 1. The bristles 10 extend outwardly from an outer cylindrical surface 12 of the cylinders 1, in the preferred embodiment extending perpendicularly to this cylindrical surface, as shown in FIG. 3. In this embodiment the cylinders 1 are made from stainless steel or a carbon fibre material and the bristles are made from glass fibre or a plastics material, the bristles being permanently attached to the cylinders 1 by means of adhesive and/or mechanical mounting means e.g. screws. In this embodiment the length of each cylinder is 10 metres and the diameter of the cylinder (not including the bristles) is 1 metre and the length of each bristle is 1.5 metres. However, other dimensions are also possible.

[0032] Half way along the length of each bristle 10, from the mid-point to the free end of the bristle 10, locking mechanisms are provided in the form of hooks 14 and loops 16. The hooks are mounted in lines extending parallel to the axis of the bristle and the loops are provided in the form of a mesh 17 also extending in a direction generally parallel to the axis on the bristle, as shown in FIG. 4. In this embodiment there are two lines of hooks 14 provided on each bristle, and two lines of loops 16 arranged between the lines of hooks. The hook and loop mechanisms lock one cylinder 1 to another when the bristles of any two cylinders engage after the cylinders have been deployed into an avalanche.

[0033] The cylinders 1 are held in place in the stand 2 by means of a central shaft 18 provided in each cylinder 1 which shaft protrudes from the end surfaces 20, 22 of each cylinder 1 and which slides into and rests in a complimentary recess 24 (see FIG. 9) provided therefor in the end supports 4,6 of the stand 2. In this embodiment the shafts 18 are simply sitting in the recesses provided therefore on the stand 2 (see FIG. 9), these recesses 24 being configured as slots angled such that when an avalanche hits the stand 2 the cylinders are simply pulled out of the stand by the force of the snow and ice in the avalanche. However, in an alternative embodiment the stand may be provided with sensors for detecting the approach of an avalanche and activating an actuation means which deploys the cylinders into the avalanche. In this case, for example, the cylinder shafts 18 may be held in the stand by a locking means (not shown) which is actuated by the sensor to release the cylinders upon detection of an approaching avalanche. Alternatively, the actuation means may be configured to physically eject the cylinders from the stand upon detection of an approaching avalanche by the sensors. In any of these embodiments once the cylinders 1 have been deployed the cylinders will lock together as the avalanche tumbles down the mountainside and this will arrest the snow and ice and reduce the airflow and energy of the avalanche. This has the effect of reducing friction between the falling snow and ice. It is this friction in the snow and ice which causes it to melt, initiating and/or continuing the avalanche. When the friction is stopped or reduced the snow and ice tends to freeze up again thereby stopping or reducing the avalanche.

[0034] The cylinders lock together by means of the hook and loop mechanisms provided on the bristles 10. It will be appreciated that the cylinders are moved down the avalanche path by the energy of the avalanche and also partly by gravity. The extent to which the cylinders proceed down the slope is limited by the braking and anchoring effect of attached anchor cables where fitted, (not shown but see FIG. 5) together with the effect of their locking together.

[0035] In practice, several stands 2 each containing several of the cylinders 1 will be positioned on an avalanche slope at different intervals down the slope, such that if avalanche snow and ice takes a path past or over a first set of cylinders arranged in one or more stands positioned uppermost on the hillside, then one or more further sets of cylinders positioned further down the slope will be released. If there are no avalanche sensors provided, and the cylinders therefore simply rest in recesses provided in their respective stands, the lower cylinders will simply be pulled out of the lower stands when snow or ice, or a higher and earlier released cylinder, hits the lower cylinder(s). Alternatively, if a sensor system is provided, it may for example be configured to release the lower cylinders at predetermined sequential time intervals after release of the first released cylinders, or upon detection of the impact of another cylinder. The stands should be arranged so that all the cylinders are substantially parallel to one another (this tends to encourage the cylinders to lock together when they are deployed into the avalanche). This is illustrated schematically in FIGS. 8(a) and (b) in which each horizontal straight line represents one cylinder 1.

[0036] FIG. 5 shows schematically a typical arrangement for the attachment of anchor cables and bracing elements to an elongate element of the invention. The cylinder 1 (elongate element) has attached at intervals along its length a number of anchor cables 26, typically made of steel. Bracing elements 28 and 30 connect the anchor cables 26 to form a lattice structure. In this example the bracing element 28 is a steel bar which assists in keeping cables 26 spaced apart near their attachment points to the cylinder, helping to prevent snagging of the cables with the cylinder and aiding the evenly spaced deployment of the cables downhill of the cylinder. Additional cables 32 have been provided in this example at each extremity of the bracing element (bar) 28. The other bracing elements 30 are steel cables. The spaces 34 between the cables and the bracing elements can be fitted with panels of cloth or sheet metal to provide additional braking in use if needed. In use, the cable and bracing element lattice is deployed generally downhill from the stand in which the cylinder 1 is located. It is attached to the ground by fixing means at attachment points 36, distant from the cylinder 1. When a cylinder 1 is deployed into an avalanche this arrangement allows maximum opportunity for interaction between the avalanche and the cylinder and with other deployed cylinders before the cylinder 1 is stopped by the anchor cables 26 at the limit of possible downhill travel.

[0037] FIG. 6 shows schematically a multiplicity of deployed cylinders 1 tumbling down a mountainside 38 in an avalanche 40. FIG. 7 shows four slightly modified versions of the cylinders 1 of FIG. 3, showing how the bodies engage via the bristles 10. In the FIG. 7 embodiment each body is in the form of a substantially cylindrical central portion having rounded ends 40, rather than flat ends as in the embodiment of FIGS. 1 to 3.

[0038] The cylinders are placed onto the stand at heights which should avoid the apparatus simply being buried by snow. For example, the lowermost cylinder may be placed at a height of about 6 to 8 metres above the surface of the hillside. If desired each cylinder may be wrapped in a thin bag, for example a thin PVC bag, to prevent snow or ice build up on the cylinders. However if there is a heavy fall of new snow it may be necessary to place an additional cylinder in each stand, on top of the existing cylinders.

[0039] It will be appreciated that as the cylinders 1 lock together after deployment they form one or more larger units which in turn may lock together to form a single body which comes to rest on the hillside. This may also have the advantage of forming a wall to any snow and ice continuing to fall down the hillside on to them. The resulting effect is that the avalanche is significantly retarded and/or prevented from progressing any further down the hillside and therefore people and properties located further down the slope are safe.

[0040] It will be appreciated that various modifications to the above described embodiments are possible without departing from the scope of the invention as claimed.

Claims

1. Avalanche impeding apparatus comprising a plurality of elongate bodies (1) and deployment means (2) for deploying said bodies into an avalanche, each body being provided with engaging means (10) for engaging with at least one other said body with which it may come into contact when the bodies are deployed.

2. Avalanche impeding apparatus according to claim 1, wherein each said elongate body (1) is substantially cylindrical.

3. Avalanche impeding apparatus according to claim 1, wherein each said elongate body (1) comprises a central tubular portion and a multiplicity of bristles (10) extending outwardly from the central tubular portion.

4. Avalanche impeding apparatus according to claim 1, wherein the bristles (10) are mounted in spaced apart relationship along substantially the whole length and circumference of the central tubular portion.

5. Avalanche impeding apparatus according to claim 1, wherein the engagement means further includes automatic locking means for locking automatically each body to any other said body with which it comes into contact.

6. Avalanche impeding apparatus according to claim 1, wherein the locking means comprises at least one hook and loop mechanism (14,16) provided on at least some of the bristles (10).

7. Avalanche impeding apparatus according to claim 1, wherein each bristle (10) is provided with a plurality of hooks (14) and a series of loops (16) configured for engaging with the hooks on other ones of said bristles.

8. Avalanche impeding apparatus according to claim 1, wherein the hooks (14) are arranged in spaced apart relationship in lines extending generally parallel to the axis of the bristle (10) with each hook extending substantially perpendicularly to the axis of the bristle.

9. Avalanche impeding apparatus according to claim 1, wherein at least one of said elongate bodies (1) further comprises at least one anchor cable (26) attached at one end to the said elongate body, said anchor cable, in use, being secured to the ground by fixing means at or near the other end of said anchor cable.

10. Avalanche impeding apparatus according to claim 1, when more than one anchor cable (26) is used, wherein the said anchor cables are attached to said elongate body (1) in a spaced apart relationship along the length of said body.

11. Avalanche impeding apparatus according to claim 1, wherein at least one of said elongate bodies (1) further comprises a plurality of anchor cables (26) each attached at one end to said elongate body, said anchor cables being interconnected by at least one bracing element (28,30) and said anchor cables, in use, being secured to the ground by fixing means at or near the other end of said anchor cable.

12. Avalanche impeding apparatus according to claim 1, wherein said plurality of anchor cables (26) are interconnected by a plurality of bracing elements (28,30) formed and arranged, in use, to form a lattice structure of said anchor cables and bracing elements.

13. Avalanche impeding apparatus according to claim 1 wherein at least one panel of cloth or sheet metal is fitted between anchor cables (26) or between anchor cables and bracing elements (28,30) to act as a braking device in use of the apparatus.

14. Avalanche impeding apparatus according to claim 1, wherein the deployment means comprises at least one stand (2) for holding one or more of said elongate bodies (1) prior to deployment.

15. Avalanche impeding apparatus according to claim 1, wherein the stand (2) is formed and arranged to hold several of said elongate bodies (1).

16. Avalanche impeding apparatus according to claim 1, wherein all of the elongate bodies held in a stand have a plurality of anchor cables (26) attached.

17. Avalanche impeding apparatus according to claim 1, wherein each elongate body (1) held in a stand (2) has a plurality of anchor cables (26) attached which are interconnected with bracing elements (28,30) formed and arranged to form a lattice structure of said anchor cables and bracing elements.

18. Avalanche impeding apparatus according to claim 1, wherein the bodies (1) are held generally horizontally and one above another between two generally vertical end supports (4,6) of the stand.

19. Avalanche impeding apparatus according to claim 1, wherein the end supports (4,6) are formed and arranged so that the bodies (1) rest on the stand but are free to move out of the stand under the force of an avalanche hitting the stand.

20. Avalanche impeding apparatus according to claim 1, wherein the deployment means further includes at least one sensor for sensing an avalanche, and activation means in communication with the sensor and configured to deploy said elongate bodies upon receiving a signal from the sensor that an avalanche has been detected.

21. Avalanche impeding apparatus according to claim 1, wherein the sensor is a motion and/or acoustic sensor capable of detecting an avalanche approaching the stand.

22. Avalanche impeding apparatus according to claim 1, wherein the deployment means comprises several stands (2) holding said elongate bodies (1).

23. Avalanche impeding apparatus according to claim 1, wherein the length of each elongate body (1) is in the range of ten to fifteen metres.

24. Avalanche impeding apparatus according to claim 1, wherein the length of the bristles (10) is between one and two metres.

25. A method of impeding an avalanche, comprising placing the avalanche impeding apparatus of claim 1 on a mountainside in the predicted path of an avalanche and fixing the stand (2) of said apparatus to the mountainside in said predicted path.

26. A method of impeding an avalanche, comprising positioning the avalanche impeding apparatus of claim 1 on a mountainside in the predicted path of avalanche and so that the plurality of stands (2) are strategically positioned at different positions on the mountainside.

27. The method according to claim 26, wherein the stands (2) are positioned and fixed to the mountainside such that the cylinders (1) in all the stands are substantially parallel.