Patent Grant
9347756
The subject invention concerns a method of initiating an avalanche in which a non-explosive triggering device; an electric acoustic device, is deployed into a predetermined avalanche zone or zones in which the avalanche is to be initiated.
A device is also described for the use of this method to initiate an avalanche, including means of generating resonance that overcomes the attenuation of the snowpack in a predetermined zone or zones in which the avalanche is to be set.
This invention relates to an electronic device able to produce high amplitudes and low frequency longitudinal waves with sufficient intensity to overcome the attenuation properties of a snowpack, thus creating a geometrical resonance in the snowpack's framework, ultimately collapsing the weak layer, and here by initiating an avalanche.
Longitudinal waves created by sonic booms with Sound Pressure Levels (SPL) of magnitudes equal to or greater than 133 to 150 dB or 2 to 13 pounds Per Square Foot (psf) have proven to be capable of causing snow avalanches. One example of an existing technology in use worldwide using overpressures to initiate avalanche release is Gaz-Ex exploders. These exploders produce overpressures up to 162 dB or 52 psf and due to the fact they are explosive there is an accompanied shock wave. There currently are no known acoustic devices in use to deliberately initiate snow avalanches.
An example of a commercially available acoustic device (subwoofer) capable of generating high amplitude low frequency SPLs is the TH 221 from Danley Sound Labs. While this subwoofer is in fact capable of producing peak overpressures up to 144 dB/6.6 psf it is too big and too heavy to be considered for avalanche control.
Avalanches can present serious dangers to persons and or property when triggered in an uncontrolled manner, whether by natural causes such as weather conditions or unintentionally as a result of human activity such a skiing or hiking. Therefore the continuous maintenance of avalanche control programs worldwide has become well established.
Control techniques can be divided into two main categories; passive and active. Two examples of passive techniques include the construction of terraced barriers on the mountain slopes designed to pin the snow layers thus preventing slippage and the construction of snow dams at the base of the slope intended to divert avalanche run outs from structures considered to be at risk. Active techniques such as launching artillery from Howitzers or Avalaunchers, placing explosives by hand, heli-bombing, and cross cut skiing are all common practices carefully coordinated with weather system surveillance, local condition forecasting, infrasonic sensing, and notification systems all designed to induce controlled artificial avalanche releases.
The practice of regularly triggering small, controlled releases is intended to minimize the buildup of snow in known starting zones which, if left uncontrolled would eventually release naturally. Such natural releases of large volumes of snow can accumulate into massive slides ultimately causing extensive damage to services, infrastructures, a variety of property and people. Every year approximately 30 people are killed by avalanches, worldwide.
This invention supports active methods of avalanche control and in particular is intended to replace a number of explosive practices currently in use today. The safest explosive method is known as Gaz-Ex in which a large divergent tube is constructed in known starting zones and is aimed downward toward the snowpack. A mixture of oxygen and propane is ignited inside the tube by a remote management system. The resulting shockwave from the explosion above the snow surface stimulates a controlled release of the snowpack. It is well documented that an explosion or overpressure that meets or exceeds 52 psf. just a few feet above the snow surface is the most effective method of avalanche initiation.
There have been substantial advancements in pyrotechnic delay fuse technology and the designing of shaped charges to increase the effectiveness of the explosive charges and increase the safety for control personnel. Widely in use today in alpine countries in Europe are Wyssen towers and Doppelmayr bomb trams. These systems of pylons and cable networks deploy explosives into inaccessible regions and allow for safe remote and or timed delay fuse detonation of explosives over predetermined starting zones. Regardless of newer, more effective, and safer developments however the industry is still in danger of untimely detonations and subject to rigorous transportation, storage, and handling procedures enforced by the United States Army and Homeland security.
The use of explosives of any kind presents inherent dangers to control personnel regardless of the strict protocols in place to hedge these dangers. In recent years some national parks have banned the use of explosives. Transportation entities for example, BNSF Railroad have been forced to spend millions rebuilding snow sheds, tunnels, and bridges damaged by wildfires to protect their transportation routes due to the banning of explosives in Glacier National Park. In the avalanche community it is unanimous that a satisfactory alternative be identified sooner than later.
Compounding the known dangers of explosives use the United States Geological Survey (USGS) has conducted surveys in the Wasatch Mountains of Utah where explosives are used for avalanche control to determine the concentration of explosive compounds in snow, soil, and lake-bottom sediment. While the Unites States Environmental Protection Agency (USEPA) has set health advisories for four of the explosive-residue compounds found in snow samples it is not a legally enforceable standard.
The USGS and USEPA use two benchmarks to measure the cancer risk threshold: (1) 10−4 cancer risk, which is the concentration of a chemical in drinking water corresponding to an estimated cancer risk of 1 in 10,000; and (2) HA, which is the concentration of a chemical in drinking water that is not expected to cause any adverse non-carcinogenic effects for a lifetime of exposure. Up to seven explosive compounds were found to be present in the samples tested although all compounds were found to be in quantities under the above mentioned safety thresholds. None the less these studies are raising the eyebrows of many that live, work, and play in and near these wilderness areas.
The present invention offers a solution to all of the above mentioned disadvantages and describes a method to initiate avalanches in any and all topographies considered to be avalanche control areas.
One example of a configuration of the invention comprises a pair of infrasonic generators (Fi BTL-N315 or equivalent subwoofers) positioned contiguously with one another in a housing with the aperture or mouth of the housing of each facing in a downward fashion so as to direct the high amplitude pressure waves toward the snow surface. The apertures of the generator's housing is where the longitudinal/compression waves are released into the environment. One example of a pan and tilt and fully rotatable housing and gantry system described below allows for the “aiming” of fore mentioned compression waves. The generators are contained in a suitable housing made from high density woods, High Density Polyethylene (HDPE), and or carbon fiber. Mounted permanently or semi-permanently (with tie-down straps and holes in the housing's frame to accept the hooks from the straps) to the top of the generator's housing is a ruggedized Pelican case or equivalent to house all on board electronic components comprising; power supply, inverter, amplifier(s), and an RF receiver which are all permanently mounted to Raxxess rack rails inside the case to prevent shifting and subsequent damage.
In this embodiment the power supply; a 12 VDC Lithium Ion 100 amp/hour battery or equivalent manufactured by Smart Battery is positioned inside an industry standard, rigid, hard, plastic battery case which is fixed to the rack rails. Fastened to the positive and negative posts of the battery are (2) 18″ 2awg cables (1 cable to each post) that reach to the respective positive and negative terminals of the DC to AC inverter. An AIMS 12 VDC/120 VAC modified pure sine wave inverter (PWRI500012S or equivalent) powered by the battery is mounted to the rack rails as stated previously to provide clean stable AC power for the RF receiver and amplifier(s) which in turn power the infrasound generators. The RF receiver (the ULXP4 system for example) manufactured by Shure receives digital signals (from the remote transmitter) and sends these digital signals to the amplifier for digital to analog signal processing. The receiver too is permanently mounted to the rack rails and is plugged into one of the available AC power outputs of the power inverter. Mounted to the rack rails directly below the power inverter is a QSC Class D amplifier (PL380 PowerLight or equivalent). The amplifier converts digital signals received from the wireless RF receiver and converts them to analog and sends these signals to the generators via a pair of SpeakON cables. The amplifier power cord also plugs into one of the available AC outputs of the power inverter. The main outputs of the amplifier each receive a SpeakON cable that plug directly into each respective generator's SpeakON input. The SpeakON cables carry the analog signals from the amplifier to the generators that in turn produce the acoustic compression waves.
Opposing ends of the housing for example could be provided with slave gears to be met with a pair of powered gears at either end of the housing's balanced pivot point or X-axis. For example a lower gantry is equipped to either side of the housing's pivot points providing a fixed position for a pair of electric motors fitted to either side with respective drive gears to tilt the device around the X-axis. Both Sides of the lower gantry would meet above the housing at the balanced center or Z-axis and be equipped with a slave gear to be met with its respective drive gear for example. A median gantry might have a fixed electric motor fitted with a drive gear to drive the slave gear on the top of a lower gantry, thus rotating the device and housing around the Z-axis. Fixed to the median gantry could be a winch(s) equipped with a length of cable(s) that ascend to an upper gantry or other configuration to prevent uncontrolled spinning while allowing the operator to raise and lower the equipment along the Z-axis. A set of pulleys equipped with small electric motor(s) for example could allow the deployment of the device along any length of cable or cables on the X-axis. All drive motors and associated components shall receive power from the onboard power supply and inverter.
The compression waves propagated by the generators of sufficient intensity can overcome the attenuation properties of the snow. The waves disrupt top or upper layers and penetrate the snowpack lower layers causing a forced harmonics and or a sympathetic resonance within the snowpack framework causing the geometry to vibrate and collapse. With this collapse the snow can no longer support its own weight and being subject to gravity the avalanche is initiated.
The invention is deployed into predetermined starting zones manually and or automatically using wireless RF communication systems operated by a control operator(s) in one example; a single line of 1/2 6×19 stainless steel wire rope is stretched between two trees/rocks, or engineered pylons installed into the bed rock in the flanks of the avalanche starting zone using heavy duty rigging loop slings and a heavy duty chain come along. In this embodiment a CMI RT trolley can be incorporated to allow pulling the generators and associated equipment along the length of wire rope to and from either side of the starting zone using only two lengths of heavy duty nylon rope. A Warn electric winch w/wireless remote for example can be fastened with a plurality of wire ropes and class “D” carabiners to the trolley, and operated from either flank to ascend and descend the generators. Yet another plurality of wire ropes and class “D” carabiners are fastened to the generator's housing and the winch cable. The winch plugs into the fore mentioned inverter for power. In another example a more elaborate system best described as a reeving positioning system as described in U.S. Pat. No. 7,239,106 B2 is ideal for larger autonomous applications; affords control operators the luxury of autonomous fluid positioning of the generators and associated equipment anywhere in 3-dimensional space (within the limits of the system of course). The apertures of the acoustic device(s) can be positioned to any height above the snow surface (within the limits of the system installation) and aimed or positioned in any manner deemed necessary by the operator. The present invention allows unparalleled control of the pressure waves with limitless proximity potential. The invention boasts far reaching signal processing capabilities with NCH Tone Generator software for example; allowing the operator in real time to focus or oscillate through a range of frequencies, vary the frequency modulation and intervals, and position the equipment almost anywhere in three dimensional space using reeving technology. Currently there is not a solution in the industry that can come close to offering the range of options and potentials the present invention offers. Additionally, the present invention is non-explosive and is environmentally neutral.
This invention can be integrated with numerous technologies already in place and or in existence. For example, the present invention can be integrated with existing bomb trams, GPS systems for exacting deployment, on board power supply, inverter, video, and sensing systems, digital signal processing equipment, notification and sensing software programs and computer platforms, robust remote technologies for manual and autonomous operations, as well as elaborate reeving technologies used typically to navigate cameras anywhere in a three dimensional space at stadiums and live events.
Avalanche control happens to be only one market the present invention can be used for. For example this system can be used to eradicate bark beetles from forested areas. With digital signal processing and the implementation of forced harmonics and or sympathetic resonance and the appropriate frequency amplitude and modulation the beetles could no longer find their present residence livable.
In another example the invention can be used in agricultural areas for the elimination of nuisance rodents, birds, and even insects from a given area. Extremely low frequency pulses can be generated below human hearing levels while making the “treated” area a haven for thriving plants and a dead zone for unwanted animals and insects.
To protect animal trainers and animal handlers this invention can be used to alert or “communicate” with the animal(s) in turn protecting humans from a would be assault or even death due to an attack.
While the subject invention can be deployed on land it could also be used in under-sea applications. Using the appropriate frequencies in conjunction with proper placement of the apparatus whales will no longer beach themselves and sharks could be prevented from entering waters where people like to enjoy surfing, swimming, and the like.
Furthermore, the present invention can be used for calibrating seismic sensing equipment that is commonly used in mining, nuclear testing, and avalanche mitigation.
Still another example where the invention might be used is at large stadiums and or live performance venues where low frequency and high modulation of a digital signal(s) is desired to round out the overall sonic experience for the listener.
In another example this invention could even be used for crowd control. Extremely low frequencies combined with very high sound pressure levels can deter would be attacker(s) from approaching beyond a certain point for instance.
The present invention can be used to power heating and cooling systems through a process known as thermo-acoustic generation.
With reference to
Attached at an appropriate pivot point 9 of the lower gantry 5 is an upper gantry 10 equipped with an electric motor 11 provided with a drive gear 12 which turns the lower gantry's slave gear 13 that rotates the lower gantry 5, acoustic device 1, and housing 2 around an axis 9.
Also in this figure, mounted to the upper gantry 10 is a network of winches 14 each equipped with a length of cable 15 and hooking apparatuses 16 which attach the above described embodiment to a system stabilization component 17 that is appropriately supported by a number of stabilizing cables 18 by means of hooking apparatuses 19. The stabilizing cables 18 from either side of the stabilization component 17 converge to a buckle 20 and are attached again by means of hooking apparatuses 21. Opposite the stabilizing cables 18 extending from both of the buckles 20 is a length of cable 22 attached to the buckle 20 with appropriate hooking components 21.
The apparatus described above by way of an example of the invention can obviously undergo numerous modifications and or variations. For example, a single length of cable 22 could be descended by a length of cable 15 that might correspond to a single winch 14 assembly for raising and lowering the above described configuration. The entire gantry system could in fact be abandoned for a more cost conscious and streamline deployment where topography might permit.
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