EP0022807A1

EP0022807A1 - Process and device of controlled triggering of avalanches

Info

Publication number: EP0022807A1
Application number: EP19800900141
Authority: EP
Inventors: Peter SCHRÖCKSNADEL; Karl Habicher
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-01-19
Filing date: 1980-07-29
Publication date: 1981-01-28
Also published as: WO1980001511A1

Abstract

On amene une charge explosive a partir d'un point de depart (B) a l'abri des avalanches vers la region de rupture (A) d'une avalanche au moyen d'un vehicule de transport teleguide, par exemple un helicoptere sous forme de modele reduit. La charge explosive et un element sensible a une distance minimum de la surface de la neige sont reunis dans un bloc explositif de facon que la charge explosive puisse etre positionnee a une hauteur determinee au-dessus de la surface de la neige. Ensuite, on fait exploser la charge a partir du point de depart (B), de preference au moyen d'un cable captif.An explosive charge is brought from a starting point (B) sheltered from avalanches to the region of rupture (A) of an avalanche by means of a remote transport vehicle, for example a helicopter in the form of reduced model. The explosive charge and an element sensitive to a minimum distance from the surface of the snow are combined in an explosive block so that the explosive charge can be positioned at a determined height above the surface of the snow. Then, the charge is detonated from the starting point (B), preferably by means of a captive cable.

Description

Method and device for the artificial triggering of avalanches

The invention relates to a method for artificially triggering avalanches by means of an explosive charge which is brought from an avalanche-safe starting point into the avalanche marking area, is positioned there at a distance from the snow surface and is finally ignited in a controlled manner from the starting point, and devices for carrying it out.

In order to prevent the automatic triggering of large avalanches in areas at risk of avalanches, they have been blown up or shot down for a long time. However, these known methods have various disadvantages, so that the desired effect is often not achieved or the desired extent is exceeded. For example, it is known to trigger avalanches by bombarding them with grenades or rockets. This possibility "is hardly given, especially for safety reasons. In addition, each miss is associated with the same costs as a hit and the number of misses is higher, since the projectile has to hit the avalanche starting point, but it can shift due to wind.

It is also known to trigger avalanches using so-called explosive devices. Explosives are moved along a rope stretched in the crack area and finally electrically detonated.

According to this procedure, only those avalanches can be triggered which form at the previously known locations, since the rope must be laid before the avalanche forms. Avalanches forming at other points outside the area of the blasting track cannot be detected with this. Finally, a method of the type mentioned at the outset to detonate avalanches is to lower an explosive charge from above onto the avalanche site and to detonate it when it is reached, the detonating charge being approximately on a boom

Hangs 1.5 m above the ground. A completely exact triggering at the point of cracking is not necessary here, so that a margin of a few meters is achieved, since the pressure wave nevertheless strikes the point of cracking in the event of such deviations.

This method, too, which seems to be independent of location, cannot be used to artificially trigger all the avalanches desired, since there are limits to the transport of the transport sled. It can therefore generally only be used on mountains whose slopes opposite the avalanche slope can be driven by a snow groomer or the like pulling the transport sledge, so that the transport sledge can be lowered over the ridge into the marking area. The slope can only be approached from the side in a few topographically favorable cases.

It is therefore the object of the invention to provide a method of the type mentioned at the outset in which the detonation of the explosive charge can take place safely and reliably at a minimum distance above the surface of the earth which is dependent on the particular circumstances. Preferably, it should also be possible to achieve an almost or even complete independence from location, so that avalanches cannot be triggered only at locations which are already known or are particularly accessible.

According to the invention, this object is achieved in that the explosive charge and the minimum distance from the optic surface-determining element is combined in a blasting unit, which is transported into the marking area and is ignited after the determination of the minimum distance.

In the case of the method of the type mentioned at the beginning, the distance between the explosive charge and the snow surface was determined by fastening it to the boom of the explosive sled. Because the detonator had to remain in place during the detonation to the explosive charge. to keep, its uses, as mentioned, are limited, and other transport options cannot be used.

The installation of the explosive charge in an explosive device, the determination of the ground clearance by the explosive device itself and not by the transport device, opens up a number of different previously impossible options for transport to almost any location, as well as a selection of the most suitable procedure.

This makes it possible to bring the blasting unit into the marking area by means of deflectable transport devices. For this purpose, model (or small) caterpillar vehicles, airships, helicopters or the like are particularly suitable, which are unmanned in any case, and for this reason, since their load-bearing capacity only has to correspond to the explosive unit, light, agile and may be limited to the essential components.

The starting point can be chosen at any point, for example at the top station of a lift or a cable car, on a ski run that can be accessed by a snow groomer, etc. Both the steering and the triggering of the detonation can be done on the one hand by wireless remote control, but on the other hand also be conducted via a tether and / or an ignition cable. In this case, line-based steering and ignition - regardless of whether the watering device is a ground or an aircraft - should be preferred in order to avoid accidents caused by wireless remote control failure, external interference, etc.

Depending on the type of transport device, the element that determines the minimum distance can now be designed, for example, as a support rod that is inserted into the snow in the cracking area, a snow plate, a wire mesh, laterally protruding pieces of wire or the like being provided to determine the minimum distance. The explosive charge is attached to the upper end part of the support rod and - in the case of wired ignition - the end of the ignition cable is attached to it. This version of the blasting unit can now be transported to the cracking area with the transport device and set down there in the snow. If a model caterpillar vehicle is used as the transport device, this is ordered back at least a small distance from the danger zone, the ignition line being designed for wired ignition.

Of course, the vehicle can also return to the starting point and route the ignition cable along the entire route.

The same procedure can also be followed if the explosive unit is carried by a missile. After stopping in the marking area, the explosive device, which hangs on the underside of the missile, is put into the area with him or alone

Snow lowered. The explosive unit sinks into the fresh fresh snow due to the weight of the explosive charge, the snow plate or the like limiting the sinking depth. There is now again the possibility mentioned above to redirect the missile and, if necessary, to lay the ignition line. However, it is also readily possible to lift the missile in place in order to achieve a sufficient height distance from the Spreig charge, for example between 10 and 20 meters, and then to trigger the detonation. For this purpose, the tether can be designed as an ignition line.

However, the explosive device can also be constructed differently for transport with a missile. It is thus possible to attach a sensor to the explosive charge, the contact with which on the ground shows the minimum distance when it drops. The sensor can provide a visual or acoustic display directly or via the tether.

For an optical display it is conceivable, for example, to determine the contact with the ground by observing the deviation of the sensor from the vertical. In any case, the triggering of the avalanches is only possible if there is visual contact at least from the starting point to the crack area. For this purpose, the sensor can be formed, for example, by a rope, a line or the like, a rod etc., which preferably has a snow plate, a wire mesh or the like at the lower end in order to prevent it from sinking into the snow. For better detection, signal bodies (flags or the like) can protrude from the side of the sensor.

An acoustic display can be transmitted to the starting point, for example, via the tether line. This design of the explosive unit does not, of course, allow it to be set down in the crack area and the missile to be redirected. However, there is the possibility already mentioned of letting the missile rise in order to bring the missile to a safe distance from the explosive charge.

The use of conventional plastic-covered electrical lines as a supply line for the drive unit of the transport device, or as a tether, and / or as an ignition line is made possible by the extremely low friction of the plastic coverings on snow. If the transport device is moved back to the starting point after the detonation unit has been set down and the ignition line is laid out in this way, the detonation of the explosive charge can be controlled and carried out electrically in a manner which is harmless to the surroundings, an energy source customary for detonations being able to be used. The transport device itself is preferably also driven by an electric motor, which is fed via the supply line, which also serves as a tether. A portable car battery or that of a snow groomer are available as energy sources, and their power supply in the vicinity of the lift or cable car station. After the detonation, the ignition cable can be pulled back from the starting point. The transport device could of course also be driven by an internal combustion engine. In addition to the drive unit, it is preferably provided with a holding device for the blasting unit, which allows the blasting unit to move in the marking area from the transport position into the release position. In the case of a ground vehicle, this can be a pivotable support arm that can be coupled to the drive unit, while in the case of missiles, for example, a cable winch with a cable drum can be provided, from which the ignition line or a support cable for the blasting unit is unwound. Instead of the cable winch with cable drum, from which the supporting cable unwinds, a sufficiently long supporting cable can be attached to the underside of the missile in order to reduce weight, the transport taking place at a higher flight height. In this case, the suspension cable remains under tension during the flight, when positioning in the marking area and possibly also during the ignition due to the weight of the explosive unit. In the case of the ground vehicle, the ignition line, which is designed when returning to the starting point, is also advantageously wound on a cable drum, which can be connectable to the drive unit.

Furthermore, each of the transport devices mentioned can have a second cable drum for the supply line, preferably also connectable to the drive unit, from which the supply line unwinds during the outward movement and winds up during the return movement. Coupling them to the drive unit is particularly advantageous in the case of a ground vehicle, since the cable drum can be automatically excavated by switching on the vehicle, which may be stuck in the snow.

The cable drum for the supply line, on the other hand, can also be set up at the starting point, so that a reduction in weight of the transport device is achieved, which will be of particular advantage in the case of missiles. The explosive device according to the invention can, however, also be conveyed into the marking area in a further manner and deposited there. In this case, the tether, which in turn preferably forms the ignition line, is attached directly to the upper end of the support rod, which is not to be inserted into the snow, which in turn has a snow plate, a grid or the like to determine the minimum distance.

According to this type of method according to the invention, the blasting unit is fired together with the tether line from a launcher into the marking area. To stabilize the flight, the upper end of the support rod, which is connected to the tether, is provided with stabilizing wings. This type of transport can also be carried out satisfactorily in many cases, since the marking area is often relatively close to the starting point, for example 50-150 m away. In the event of a miss that does not occur in the marking area, there is no danger to the surroundings, since the detonation unit can easily be retrieved on the tether line or a suitable time can be selected to trigger the detonation.

After the explosive charge has been triggered in a controlled manner, the ignition cable can be pulled back in again. The firing direction can also be operated with explosives. For example, the use of a crossbow or the like is also conceivable.

As already mentioned, there is no need to create an explosive device by means of which the explosive charge has a minimum distance from the snow surface at the time of the detonation, which is, for example, 1.5 m can, the use of new transport and remote release options without the presence of operating personnel in the immediate vicinity of the cracking area is necessary, since the positioning of the explosive charge in the air creates a scattering area within which the avalanche is triggered.

The invention will now be described in more detail below with reference to the figures in the accompanying drawings, without being limited thereto.

1 schematically shows the implementation of the method according to the invention on an avalanche slope, FIGS. 2 to 4 embodiments of explosive units according to the invention, FIGS. 5 and 6 a side view and top view of a ground vehicle, FIGS. 7 and 8 each show two side view aircraft when positioning the blasting unit, and Fig. 9 a launcher for a further variant of the method.

On the mountain range shown in FIG. 1, a cable car, a ski lift or the like is shown with S. L means the part of the slope which is at risk of avalanches, in which A represents the marking area and P the exact marking point. To carry out the method, an avalanche-proof starting point B is selected, from which the blasting unit 1 is brought along the line C into the marking part A.

As already mentioned, the method according to the invention essentially consists in transporting and detonating an 'explosive unit 1 (FIGS. 2-4), consisting of an explosive charge 2 with an element 3, 4 determining a minimum distance from the snow surface, into the marking area , which can trigger controlled avalanches. Since the explosive charge 2 with the help of element 3, 4 above the snow surface is positioned in front of the ignition, the blasting unit 1 does not have to be positioned exactly at the marking point P, but somewhere in the marking area A, which is swept by the pressure wave hitting the snow surface from above.

From this, according to the invention, there is also the possibility of transporting the blasting unit 1 into the marking area A in a manner which was previously not feasible, since the direct presence of an operator in the marking area A is not necessary due to the scope given by the blasting unit, but rather observation from a greater distance enough. The explosive unit 1 can therefore be transported, for example, with an unmanned remote-controlled transport device 23, for example according to FIGS. 5 and 6 with a model caterpillar vehicle 10, according to FIG. 7 with a model helicopter 11, or according to FIG. 8 with a model airship 12. It is also possible to fire the blasting unit 1, for example by means of a crossbow 22 (FIG. 9).

An explosive device for transport by a model caterpillar 10 is shown in FIG. 2, for example. The explosive charge 2 is fastened on a support rod 3 with a plug-in tip 6, a snow plate 4, for example in the form of laterally protruding wire pieces, or the like, being arranged at a distance from the explosive charge 2 corresponding to the minimum distance 9 from the snow surface. An ignition line 5, which is connected to the explosive charge 2, leads away from the upper end of the support rod 3. A model tracked vehicle 10 suitable for transport has a support frame 14 in which a drive unit, in particular an electric motor 15, is arranged in the center, with the aid of which, for example, via chain drives 19 and Magnetic clutches 20, the two crawler belts 13, a cable drum 17 at the front end for the ignition line 5 for explosive charge, a holding device 18, also at the front end, for receiving the explosive unit 1 and a second cable drum 16 at the rear end can be driven individually, jointly or in groups. The second cable drum 16 carries the supply line 24 for the electric motor 15, which also serves as a tether 21.

The holding device 18 consists of a U-shaped

Bracket with a central claw into which the support rod 3 of the blasting unit can be inserted. A support, not shown, can serve to support the explosive charge 2 at the rear end.

The model crawler vehicle 10 is steered with the explosive unit 1 from the starting point B into the marking area A, the supply line 24 being unwound from the cable drum 15 as a tether line 21. In the marking area A, which is approached at least laterally or from above, the holding device 18 is pivoted forward, whereby the tip 6 of the support rod is pressed into the snow until the snow plate 4 is supported in the snow. The explosive charge 2 is thus at the necessary minimum distance 9. The vehicle 10 is then retracted, the cable drum 16 winding up the tether line 21 and the cable drum 17 handling the ignition line 5. After returning to starting point B, the avalanche can be ignited in a controlled manner. Unexploded ordnance can be removed from the scribing area again, since the explosive unit 1 can be retrieved via the ignition line 5. The cable drum 16 for the tether 21 can optionally also be provided at the starting point B. The explosive unit 1 of FIG. 2 can also be transported by an aircraft, the cable drum 17 for the ignition line being arranged in or below the airship 12 or helicopter 11.

However, in order to save weight, preferably no cable drums are provided on the aircraft. The cable drum 16 for the tether 21 is set up at the starting point B, while the cable drum 17 can be omitted if a sufficiently long line is attached as a holding device 18 below the aircraft to which the explosive unit hangs. The necessary length of the line is approximately 10-20 m in order to avoid damage to the aircraft due to the detonation, which in this embodiment cannot detonate the explosive unit 1 if it is to be detonated using a line. The tether line 21 and the tether line 18 also serve as the ignition line 5, the tether line 21 also serves as the supply line 24 for the electric motor 15 of the aircraft.

If the blasting unit 1 is not set down and the aircraft has no cable drum and therefore cannot be moved back to the starting point B before the detonation, a blasting unit 1 according to FIG. 3 can be used which is of low weight. In this embodiment, a rope, chain, line or the like 3 'serves as the distance-determining element, which can also have a snow plate 4' at the lower end. Here the distance-determining element serves as a sensor, the contact of which with the floor is evident from the vertical deviation. For better visibility, flags 3 'or other signal bodies 7 are attached to the line 3'. The tether 18 again serves as the ignition line 5. The wired ignition and steering of the transport devices increases the safety of the controlled triggering of the avalanche. However, it does not have to be wired, but both the steering of the transport devices and the ignition could be wireless.

Another variant of the method according to the invention provides for the firing of explosive units 1 by means of a firing device, such as a crossbow 22 (FIG. 9). A blasting unit 1 that can be used for this purpose is shown, for example, in FIG "provided to reduce the

Air resistance can be a coarse mesh grid or the like. Stabilizing wings 8 are formed or attached to the upper end of the support rod 3 ″. The ignition line 5 serves as a tether line 21, on which the blasting unit 1 can be retrieved in the event of a miss.

Further modifications are also conceivable within the scope of the invention, for example the starting point B cannot be stationary, but can also be mobile. This can be an advantage in some cases where the marking area A cannot be seen from any point on the ground. In this case, the starting point can be a manned helicopter.

Claims

Patent claims:

1. A method for the artificial triggering of avalanches by means of an explosive charge, which is brought from an avalanche-safe starting point into the avalanche marking area, positioned there at a distance from the snow surface and finally ignited in a controlled manner from the starting point, characterized in that the explosive charge (2) and an element determining their minimum distance from the snow surface (3, 4; 3 ', 4'; 3 ", 4") are combined in a blasting unit (1) which is conveyed into the marking area (A), positioned and finally ignited.

2. The method according to claim 1, characterized in that the explosive unit (1) is conveyed using a tether (21) and detonated by a line.

3. The method according to claim 1 or 2, characterized in that the blasting unit (1) is brought and positioned by means of a motorized transport device (23) in the marking area (A).

4. The method according to claim 3, characterized in that the transport device (23) before the ignition of the explosive unit (1) is moved back to the starting point (B).

5. The method according to claim 3 or 4, characterized in that the explosive unit (1) on a remotely steerable missile (11, 12) is moved hanging in the marking area (A).

6. The method according to claim 4, characterized in that the explosive unit (1) by means of a remote-controlled and off-road ground vehicle in the marking area (A) is moved and set down.

7. The method according to claim 5, characterized in that the minimum distance (9) in the positioning of the blasting unit (1) by observing the deviation of the minimum distance (9) determining element (3, 4; 3 ', 4') from the vertical is set.

8. The method according to claim 1 and 4, characterized in that the ignition line (5) is designed by the moving back to the starting point (B) transport device (23).

9. The method according to claim 2, characterized in that the explosive unit (1) is shot together with the tether (21) in the marking area.

10. Blasting unit for performing the method according to one of claims 1 to 6 and 9, characterized in that the explosive charge (2) is attached to a support rod (3, 3 ") which can be inserted into the snow and on which the minimum distance (9) a snow plate (4, 4 ") or the like is arranged for the element determining the snow surface.

11. Blasting unit for performing the method according to one of claims 1, 2, 3, 5; or 7, characterized in that a sensor (3 ', 4') is arranged on the explosive charge (2), the contact with the ground of which determines the minimum distance (9).

12. Blasting unit according to claim 10, for carrying out the method according to claim 9, characterized in that on the explosive charge (2) carrying the end part of the support rod (3 "), the tether (21) and stabilizing wing (8) are arranged.

13. Transport device for performing the method according to claim 4, 6 or 8 in the form of a model caterpillar (10).

14. Transport device for performing the method according to one of claims 3, 4, 5, 7 or 8 in the form of a model airship (12).

15. Transport device for performing the method according to one of claims 3, 4, 5, 7 or 8 in the form of a model helicopter (11).

16. Transport device according to one of claims 13 to 16, characterized by an electric motor (15) as the drive unit and by a holding device (18) for the blasting unit (1) which can be moved by the electric motor (15) between the transport position and the release position.

17. Transport device according to one of claims 13 to 15, characterized by a with the electric motor (15) couplable cable drum (17) for the ignition line (5) which is connected to the explosive unit (1) t.

18. Transport device according to one of claims 13 to 17, characterized by a with the electric motor (13) couplable cable drum (16) for the supply line (24) of the electric motor (15).

19. launcher for performing the method according to claim 9 in the form of a crossbow (22).