Patent Publication Number: US-8985251-B2

Title: Mobile refuge chamber

Description:
COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material that is subject to copyright or mask work protection. The copyright or mask work owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright or mask work rights whatsoever. 
     FIELD OF THE DISCLOSURE 
     This disclosure relates to refuge chambers for use in mines or other underground areas where workers require a possible escape, rescue or a protection device that, and more specifically to a mobile refuge chamber that is independently drivable within a mine environment. 
     INTRODUCTION 
     Glossary: As Used Throughout this Document 
     The phrase “refuge chamber” shall mean an enclosed, reinforced, and protected device for use in a mine environment within which light, air, water, waste disposable, food, medical and other types of support supplies are stored, and within which a livable environment for a limited amount of time is provided. 
     The term “mobile refuge chamber” shall mean a refuge chamber that is provided with its own controlled mobility system by which the chamber is itself independently movable within a mine environment without the need for other towing or moving equipment. 
    
    
     
       DESCRIPTION OF PRESENTLY PREFERRED EXAMPLES OF THE INVENTION 
       Brief Description of Figures 
       The invention is better understood by reading the following detailed description with reference to the accompanying drawings in which: 
         FIG. 1  is a side perspective view of the refuge chamber according to the present invention; 
         FIG. 2  is a frontal perspective view thereof; 
         FIG. 3  is a rearward perspective view thereof; 
         FIG. 4  shows the rear end of the refuge chamber; 
         FIG. 4A  is a partial side view showing the rear of the chamber and a side of the power module; 
         FIG. 4B  is an elevational view looking into the power module; 
         FIG. 4C  is a view of details of the power module 
         FIG. 5  is a top plan view with the outer surface having been removed to show the purge air system and internal structures including compartments, doorways and storage areas, 
         FIG. 6  is a cross sectional view taken along line  6 - 6  in  FIG. 5 ; 
         FIG. 7  is a top plan view with the outer surface having been removed to show the oxygen air system; 
         FIG. 8  is a cross sectional view taken along line  8 - 8  on  FIG. 7 ; 
         FIG. 9  is a side of the refuge chamber with the outer structure removed; 
         FIG. 10  is a side elevational view showing the refuge chamber in a normal, level position; 
         FIG. 11  is a side elevational view showing the refuge chamber when oscillated toward the front of the refuge chamber; 
         FIG. 12  is a side elevational view showing the refuge chamber when oscillated toward the rear of the refuge chamber; 
         FIG. 13  is a top diagrammatic view of a mobile refuge chamber moving within a mine environment; 
         FIG. 14  is circuit diagram of the power module hydraulic system; 
         FIG. 15  is a electric circuit schematic for the controller; 
         FIG. 16  is a wiring diagram for the controller; and 
         FIG. 17  is a continuation of the controller wiring diagram. 
     
    
    
     DESCRIPTION 
     A. Overview 
     To gain a better understanding of the invention, a preferred embodiment will now be described in detail. Frequent reference will be made to the drawings. Reference numerals or letters will be used throughout to indicate certain parts or locations in the drawings. The same reference numerals or letters will be used to indicate the same parts and locations throughout the drawings, unless otherwise indicated. 
     B. Environment 
     The preferred embodiment for the mobile refuge chamber includes a track assembly on each side of the chamber structure providing an on board drive assembly and thereby the ability to move the mobile refuge chamber within a mine environment and through roadways, tunnels, and crosscuts, and even through passageways that have low overhead clearances. The scale of the embodiment, therefore, is to be understood with respect to this type of device. It is to be understood as well, however, that the invention is not limited to one size refuge chamber, but on the contrary it is applicable to a variety of other sized refuge chambers and its scale can vary accordingly. 
     The mining of coal, other ores or materials in underground areas is frequently associated with hazardous environmental conditions that exposes miners to roof collapses, explosions, toxic gases, dust, carbon monoxide and carbon dioxide, to name but a few. Consequently, it imperative to provide some form of emergency shelter and protection for miners during their work, and especially for those miners working close to the working face. Preferably such a shelter should be repositionable easily and quickly in order to remain relatively close to the mine face as possible, as the mine face will be advancing and the shelter will need to be repositioned at least every few days or more frequently than that depending upon the speed at which the mine face is advancing. This keeps the shelter immediately available in the event of an accident or the onset of some hazardous event. 
     The present invention as described herein comprises such a temporary shelter for about 96 hours, and is made from materials that will provide the desired shelter and employs a drive system that makes the shelter a mobile refuge chamber that is easily movable within the mine environment and without any external assistance such as shovels, tractors or scoops present in the mine for other purposes. 
     The most common shelters or refuge chambers are conventionally provided with skids or only a set of tires that permits them to be lifted, pulled or pushed around a mine by miners, by a towing machine or by some other separate equipment that can push or pull the shelter into a desired position. Where such shelters are long or big structures they must be frequently man-handled or “rough housed” to get them to turn corners or to physically maneuver them from one place to another within the confines of the mine roadways. Such rough housing cannot only damage the structure of the chamber itself, but can damage equipment or supplies stored or contained therein. It can also ruin sensor equipment provided on or within the shelter for sensing the atmosphere inside or around the chamber, gas monitoring equipment, flow meters, regulators, communication equipment, piping within the chamber, or other parts of the chamber. Further, if such sensor equipment is not ruined it may be moved with sufficient force that the normal calibration will be adversely effected which can thereby render such equipment inoperable for their intended functions. By employing such a drive system the present refuse chamber can be made from stronger, thicker materials, with a denser structural integrity, higher yield structured and recovering plates, additional amounts of oxygen cylinders, additional water and other supplies, as total weight of the chamber and the various items and supplies provided internally within the refuge chamber are not an issue with the mobility features. 
     The present mobile refuge chamber disclosed herein differs in that it is itself mobile and includes a drive mechanism or mobility system that will transport the entire refuge chamber directly into and out of a mine as well as within a mine and along mine tunnels, roadways or crosscut networks of passageways normally associated with and found in an underground mine environments, without the need for any separate drive or movement devices. 
     C. Structure 
       FIGS. 1-4  show a refuge chamber  10  formed with a strong and reinforced exterior comprised of, for example, a roof  12 , left and right sides  14  and  16  when looking rearwardly along the chamber  10  from the front end wall  18 , respectively, a rear end wall  20 , and a bottom wall  22 . Preferably the exterior skin will be formed from metal panels or sheeting, for example, steel, aluminum or mine environment approved composite materials, welded or otherwise interconnected and attached to an underlying support structure to form a pressure and vacuum proof interior. Each of these exterior wall panels or sheets can be attached to an internal or underlying support structure formed from interconnected beams or cross beams, for example those shown for the top at  30 ,  32 ,  34  and  36 , as shown in  FIG. 5 , and for the sides diagonally extending beams or supports  40 ,  42  and  44 , as shown in  FIG. 9 , extend between and can be connected to horizontal fore-to aft-beams  46  and  48 . Similar supports will b provided in the bottom wall  22 . Collectively these corner, diagonal, side bottom and internal supports will be interconnected in a pattern, for example, as shown in  FIGS. 5-9 , and will provide an inner skeleton that will support and reinforce the exterior skin. 
     These support tubes can have a variety of dimensions, and typically then can be, for example, 3×3×⅛ or 3×3×¼ to 2.5×2.5× 3/16. 
     As noted above, the external skin can be formed from, for example, steel plating that can preferably have a thickness that can vary from ⅛ th  at a minimum, to about ¼ inches thick. However, it should be understood that other metals, such as aluminum, or other materials, such as polycarbonates or composite materials such as reinforced plastics, or combinations of these could be used with or co-molded with metal or other materials, could also be used. Also, while a range of thicknesses has been proposed, other plate thicknesses could be used depending upon a particular mine environment that is to be using a particular shelter which might need to be made with a stronger or more impact resistant exterior. It is preferred that the corners be further reinforced by using a welded over lay comprised of a right angled steel edge cap  50  as is shown in  FIG. 9 , at the upper right corner, for example, but any desired reinforcing can be used. 
     Front end wall  18  includes a sealable marine grade door structure  60  that can include, for example, a marine type hatch  62 , manufactured from cast aluminum or other strong material, that is attached by hinges  64  and  66  closing on opening  68  that is also shielded by a raised exterior wall  70 . The door  60  will further include an integral exterior handle  72  and suitable latching and seals, not shown, that will render the door  60  airtight so as to maintain a positive pressure there within the chamber located adjacent the intern of door  60 . This will be more fully discussed below in connection with the air lock used upon entry into chamber  10  in an emergency situation. Door  60  can operated either manually or hydraulically with the opening and closing being possible from both outside and then inside. Front wall  18  also includes a sight port  52  that is provided with a cover plate  54  that can be secured in place when the chamber  10  is not being used. Prior to entering chamber  FIG. 10  miners can open cover  54  thus exposing a glass window  56  through which miners in chamber  10  can see out and by which those outside chamber  10  can see into chamber  10 . 
     Rear wall  20  supports a separate power module  80 , with power module  80  being removably connected thereto by a latch structure  82  that can extend across the top of rear wall  20 , be engaged by the top portion  81  of the power module  80 , and by suitable bolted interconnections  84  provided at the sides. 
     As shown in  FIG. 5 , for example, the refuge chamber  10  preferably has two interior compartments, a front one shown at  90  and a main compartment shown at  100 . In between is an interior bulkhead wall  110  that is provided with another air lock door  112  with door  112  being, for example like door  60 , and being closed or opened from either compartment  90  or  100 . 
     The front compartment  90  comprises an air lock chamber that is accessed from the outside via door  60  and from the main chamber  100  via an interior door  112 . Front chamber  90  is large enough to permit five miners to enter at one time. Once those five miners are housed in chamber  90  door  60  is closed, either from the inside or outside, and a purge system  92  will be activated and used to purge the mine&#39;s atmosphere from within the front air lock chamber  90 , thereby preventing that atmosphere from affecting the main chamber&#39;s atmosphere as the interior door  112  will also be closed and sealed. Once the miners are in chamber  90  and door  60  is closed and secure, a purge switch  94  is actuated that releases compressed air from purge air tanks  96  into chamber  90  via suitable tubes  98 . Miners will release the purge air for approximately 5 to 7 minutes while also taking readings from hand held gas monitors, which can be provided within chamber  90 . After the volume of chamber  90  has been raised about 3 times, or to a pressure of about 0.6 to 1.2 psi, and preferably about 0.8 psi, and when the atmosphere within chamber  90  has reached a safe level, air within chamber  90  is purged from chamber  90  to the exterior of refuge chamber  10  via a relief port  102 . Once the purge and cylinder is completed, the miners within chamber  90  will open the interior bulkhead door  112  and enter the main chamber  100 . Once the interior bulkhead door  112  is then re-closed, the next set of five miners can open door  60  from outside chamber  10  and enter chamber  90 . Once door  60  is again closed the process for purging the mine atmosphere from within chamber  90  can then be repeated with that next set of miners. If there are fifteen miners total this air purging process will be repeated three times until all fifteen miners are housed within the main chamber  100 . 
     Relief port  102  can have two valves that can control the pressure level within the above noted limits, and to prevent either chamber  90  or  100  from being over pressured. The test port  102  allow miners to hook up a gas monitor to a valve internally mounted within purge chamber  90  and using flexible tubing miners can hook up to the relief port and with the valve opened they can then check or monitor gases or the environment exterior to the chamber  10 . 
     The interior dimensions for the front air lock chamber  90  can be, for example, about six feet in length, with a height of about four and a half feet, and a width of about seven feet eight inches. The main interior chamber  100  can have an internal length of about twenty-two feet and hung the same height and width as air lock chamber  90 . The external dimensions for the whole refuge chamber  10  will be about twenty eight feet and hung inches in overall length, about eight feet in width, and about four feet seven inches in height. The unit is also offered in a 30″ inch height up to a 55″ inch which is also provided with same mobility features. 
     Main compartment  100  is shown in  FIGS. 5-9  and includes an oxygen system  120 , a CO 2  extraction or discharge system  130 , a sewage or waste system that discharges to the exterior  140 , an interior wall/ceiling system  150 , and an electrical/communications system  160  in a box located on a side wall inside chamber  90 . 
     The oxygen or O 2  system starts with a plurality of oxygen tanks  122  that can be stored within chamber  90  as shown in  FIG. 6 , and through a suitable controller  124  and manifold  126  the flow of oxygen can be sent through a series of discharge tubes  128  into the main chamber  100 . 
     The CO 2  extraction or discharge system  130  is comprised of a series of carbon-dioxide absorbing screens or curtains (not shown) that can be stored in the seats provided in the main chamber  100  or in storage areas beneath removable flooring panels  114  and once removed for use can be unfolded and hung from hanger rods  132  that are supported from the ceiling of the main chamber  100  so as to run along a major portion of the axial length of that chamber, as shown in  FIGS. 5 and 7 . One example of such CO2 absorbing fabric can be found in U.S. Pat. No. 6,699,309, which is incorporated herein by reference. The curtain or sheet can be, for example, a Lithium Hydroxide curtain that acts as a passive CO 2  absorbent structure that provides rapid CO 2  reduction in enclosed areas, especially for the amount of time miners would be expected to remain within the chamber. When hung up with all sides exposed, such curtains can effectively absorb carbon dioxide out of the air such as that being expelled by the miners housed within the main compartment or chamber  100 . Such absorbing curtains do not require electric power to operate, but rather only need to be hung from rods  132  with all sides exposed so the soda lime chemicals can react with the CO 2  gases and remove them. 
     The sewage or waste system  140  includes a toilet  142 , a supply of water in a tank  144  to operate toilet  142 , and a discharge outlet  146  to discharge waste outside of refuge chamber  10  as shown in  FIG. 8 . 
     The interior wall/ceiling system  150  can be comprised of a series of ceiling panels  152  and wall panels  154  that can be rolled or folded up and then installed once miners are inside chamber  100 . Alternatively, panels  152  and  154  could be permanently installed inside chamber  100  and will preferably, regardless of which form they take, will be white to thereby reflect light within chamber  100 . 
     Provided by a plurality of hung flash lights  162 , the electrical/communications system  160  will include the plurality of interior lights  162 , preferably in the form of MSHA approved intrinsically safe flash lights that can be suspended from the ceiling, as well as suitable controls for various sensors, air pressure controls, oxygen controls and the communications equipment. There is also a communication phone  164  provided in chamber  10 . The main chamber  100  can also be provided with bench style seating extending along the length of the main compartment  100  that can include as well suitable amounts of built-in storage areas therein to provide space, for example, for medical supplies, food, drinking water, bedding, extra light bulbs, flash lights, MSHA approved batteries, and other emergency supplies. 
     As is demonstrated in  FIG. 13 , it is necessary that a mobile refuge chamber  10  be moved along and through roadways and cuts within the mine. The chamber  10  is shown, for example, moving form a position A, then through a position B that entails maneuvering around a corner, and then to a position C. In order to provide the moving ability for refuge chamber  10  a motive system  200  is provided in the form of, for example, a pair of hydraulic powered, crawler side frames with integral drive system or tractor assemblies  202  and  204  manufactured by Intertractor America Corp., in Elkhorn Wis., universal side frame models, for example, model number UQ946A00N00003/4 or UQ901A00N00101/102. It is preferable the mounting for tractor assemblies  202 / 204  include fluid ride mounts to minimize vibration as chamber  10  is moved. 
     Each tractor assembly will include a central track frame  206  that extends along the interior length of the track assemblies  202 / 204 , and will be mounted to a bottom central portion of each side of chamber  10  by way of, for example, a mounting assembly  208 . This mounting assembly  208  can be bolted or otherwise securely secured to welled trunions  207 , shown on  FIGS. 6 and 8 , with trunions  207  being in turn welded or otherwise secured to the internal support structure of chamber  10 , for example to the appropriate diagonal and horizontal beam  40 - 48 . 
     Track frame  206 , as used on each of the track assemblies  202 / 204  will support a spring tensioned, front idler  210 , a tensioning spring  214 , a rear drive sprocket  212 , one or more optional top idlers  216 , a plurality of bottom track rollers  218  all of which support and drive an outer track  220 . Not shown is a suitable brake assembly to hold tracks  220  in a fixed position, with the hydraulic circuit showing brake releases at  282  and  284 . 
     Each of the tractor assemblies  202 / 204  will be powered, for example, by hydraulic drive motors  252  and  254 , respectively, as shown on  FIG. 14  that shows the entire hydraulic circuit  250 . Hydraulic motors  252 / 254  will be powered by a 45 to 75 horse power electric motor  320 , shown on  FIGS. 4B and 15 , that is an explosion proof for cooled 480 volts, 3-phase motor, for example a WEG mode 107518XP3E365TC or equal quality and capability motor. Motor  320  will be connected to and powered by an approved, mine power source as will be further explained below in connection with the power controller and electrical system as shown in  FIGS. 15-17 . It should be understood, however, that any other MSHA approved power system could also be used. 
     Each of the tractor assemblies  202 / 204  is also provided with its own tilt control system  230  and  232 , respectively, that is preferably mounted adjacent one end thereof, for example the front end as shown in FIGS.  1  and  9 - 12  and operated by a lever  257 , for example as shown in  FIGS. 4 and 4A  and located within a recess  258  provided in the side of the power module  80 . Each of these tilt control systems  230 / 232  includes a double acting, hydraulic cylinder  234  and  236 , respectively, which is preferably mounted between the tractor assemblies  202 / 204 , and specifically the frame  206 , or the mounting assembly  208 , and the trunions  207  that are mounted directly to the internal frame of the chamber  10 . Between those two points of attachment the hydraulic cylinders  234 / 236  can have a range of motion of about 10″ inches. Chamber  10  will be supported by the tractor assemblies  202 / 204  so that the bottom of the chamber will be in a level condition relative to the mine floor and have a normal, nominal clearance of about 3 inches between the bottom and the mine floor or the supporting surface. This level condition is shown in  FIG. 10 . It can be noted that a pin  239  is contained within a slot  238  in the track assembly  202 , and when in this level condition pin  239  will be positioned about mid-way along slot  238 . By use of the tilt control systems  230 / 232  on each side of chamber  10 , the whole chamber  10  can be tilted so that either the front of the rear portion of chamber  10  can be made to almost touch the mine floor, which will provide coordinated rise at the opposite end of the chamber  10  that can vary from about 8 inches to about 9.5 inches, and preferably about 9 inches.  FIG. 11  shows the rear end portion being raised, with pin  239  now at the bottom of slot  238 , while  FIG. 12  shows the front end portion being raised with pin  239  at the top of slot  238 . Cylinders  234 / 236  are preferably hydraulic cylinders driven by the same hydraulic system, as described more fully below. However, they could also be powered by another approved MSHA approved power source. 
     Details of the power module  80  are shown in  FIGS. 4B and 4C  and include a top frame  83 , a front frame  85 , and a rear from  87 , with a bottom section  88 . As shown in  FIGS. 4 and 4A  the power module  80  has an outer skin provided by a rear panel  103 , side panels  105  and a top panel  107 . 
     The hydraulic system is shown in  FIG. 14  and the two main hydraulic motors  252  and  254  for the tractor assemblies  202 / 204 , respectively, are shown in the upper left of the figure. Each motor is controlled by direction inputs that can be provided by either a joy stick controller,  256 A and  256 B, that can be seen as well in  FIG. 4  located within a recess  258  at the upper rear of panel  105 , or from a separate pendent controller  400 . By either of these signal input devices, signals can be initiated to control the movement of chamber  10  and the forward or rearward movement of tracks  202 / 204 . In each case, an operator will stand outside of chamber  10  and can use the joy sticks or the pendent controller  400  to direct and thereby control the forward and rearward movement of chamber  10 . 
     The joy stick controllers  256 A/B, or the inputs from pendent controller  400 , will each control one track, for example joy stick  256 A can control the operation of motor  252  for tractor assembly  202 , and joy stick  256 B can control motor  254  for tractor assembly  204 . Each joy stick controller  256  A/B, or alternatively if using the pendent control then inputs from the pendent controller  400 , operates pump control valves  260  and  262 , respectively, through two pairs of shuttle valves,  261 A and  261 B and  263 A and  2643 B, respectively, which in turn connect through first and second charge pumps  278  and  280 , and then to control motors  252 / 254  through pump circuits  264  and  266 , respectively. 
     As can be noted on  FIG. 14  pump circuits  264  and  266  include a series of pressure gauges primary drive system  265 , tilt control system  267 , left track drive forward  269 , right track drive forward  271 , left track drive reverse  273  and right track drive reverse  275 , respectively, and these are also shown grouped together on a control gauge panel  404  at the rear of the power module  80  as in  FIG. 4A . An additional pressure gauge  277  is provided to monitor charge pressure left primary pump and  278  is charge pressure on right primary pump systems. 
     On the right side of  FIG. 15  are the two double acting, lift cylinders  234  and  236  in the front of the tracks and two double acting in the rear that will be powered by a hydraulic motor  237  that is connected to cylinders  234 / 236  by a pump control valve  272 , a counter balance, or holding, valve  274  and a flow divider  276  to assure that cylinders  234 / 236  operate in unison. The control of lift cylinders  234 / 236  will be provided by way of a separate control lever  257  that will actuate one of two solenoids No. 5 or 6 in the electrical controls for solenoids  337 , shown in  FIG. 15 , to control the pump valve  272  and thereby operate cylinders  234 / 236  in one of an up or down direction. Brake releases  282  and  284  will be connected to the lift cylinder control circuit via a pressure reducing valve  286  so that lift cylinders  234 / 236  will only operate when the brakes are released. 
     As mentioned above, electrical system is set forth in  FIGS. 15-17  with  FIG. 15  showing the electric schematic for the controller and  FIGS. 16 and 17  showing the wiring diagrams for the controller components shown in the electrical schematic of  FIG. 15 . 
       FIG. 15  shows a main controller at  314 , which includes a power input section  314 A, a motor controller section  314 B, and a solenoid section  314 C, all of which are provided within power module  80 . A 3-phase power connection of power input section  314 A of the main controller  314  is generally shown at  300  that includes a 480 VAC input. This input power supply  300  can be supplied directly from the main source of power in a mine, for example, via a power cable  302  and a suitable plug  304  that plugs into a connection terminal  306  provided on the rear wall  308  of the power supply module  80  that can be attached to the rear of chamber  10  as shown. Alternatively, this main 480 VAC, 3-phase power supply can be provided from a secondary source such as a rock drill with similar power requirements. 
     Looking first at the motor controller section  314 A, the power connection  300  includes a circuit breaker  310  in the form of a 150 amp fuse and power is thereafter directed to a main pump and motor  320  via a soft start controller  312 , such as, for example, a WEG SSW-06 Series, Soft start device. Such soft-starters are static starters intended to accelerate, decelerate and protection of three phase induction motors. The control of the voltage applied to the motor by the means of the thyristors triggering angle variation, allows the soft-start to start and stop smoothly an electric motor, as is being done here for main pump/motor  320 . 
     The three phase power input for motor controller section  314 A is also connected to a first transformer  316  via fuses  318  and then to a series of control buttons  322 ,  324  and  326 . A fan  328  is controlled by a run/stop solenoid  330 / 331  with fan  328  being located within the power module  80  to provide cooling to the main pump/motor  320 . The run/stop solenoid  330 / 331  has its control connections shown as coming from pin connections  7  and  2  of a receiver/decoder  332 , with the run side being shown within the motor controller section  314 B, and the stop connection being shown in the solenoid controller section  314 C. 
     Transformer  316  steps the voltage down from 480 VAC to 120 VAC and a second transformer  334  steps the voltage down from 120 VAC to a low voltage system using 12 volts. The intervening control buttons, previously noted, provide an emergency stop command via button  322 , a start command via button  326  and a stop command via button  324 . 
     Main controller solenoid control section  314 C is set up to permit various movement control inputs. One source of such control inputs can occur via a connection to a set of joy stick controllers  256  A/B, whose input signals are provided via a receiver/decoder device  332 , such as a Cervis, CST/RD-6467, that is powered by its connection within controller section  314 C to the second transformer  334 , a rectifier  335  and time delay fuses  336 . Joy stick inputs are provided at pin connections  1 - 6  via a series of solenoids  338 . In addition, or as an alternative source of control inputs, control over the chamber&#39;s movement can also be provided via a pendent type of signal input, with a separate control box, indicated at  400  in  FIG. 4A , which can be connected to the power module  80  via a cable  402  that can be, for example, a cable on the order of about 50 feet in length. Where control is provided by the pendent controller  400  then additional umbilical inputs can be provided via pin connections  10  and  11 . 
     D. Operation 
     When a chamber  10  is delivered to a mine, the tracks  202 / 204  can be used to unload it from a transport and to then drive the chamber  10  into a mine through a road system. No other device is needed to maneuver the chamber  10  and one individual can easily control the movement and positioning thereof. As small obstacles are encountered the front and rear elevation of chamber  10  can be tilted to override that obstacle and to thereby avoid being stuck thereon or thereby. By use of its own drive system the chamber  10  can be constructed without concerns about weight, and further chamber  10  can be stocked with supplies, tools, monitoring equipment, water, and other materials that might otherwise not be included due to weight issues. Also, by having the ability to move chamber  10  by tracks  202 / 204  an operator not only has full control over its movement, but it is easily moved as a mine face recedes, and it can be moved in a way that is gentle and protective of on-board supplies, monitoring equipment, air cylinders, CO2 systems, water systems, piping, flow meters, and all other equipment that is sensitive to shocks and motion that could be resulting from deployment of such chambers. 
     When introducing elements of various aspects of the present invention or embodiments thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements, unless stated otherwise. The terms “comprising,” “including” and “having,” and their derivatives, are intended to be open-ended terms that specify the presence of the stated features, elements, components, groups, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, and/or steps and mean that there may be additional features, elements, components, groups, and/or steps other than those listed. Moreover, the use of “top” and “bottom,” “front” and “rear,” “above,” and “below” and variations thereof and other terms of orientation are made for convenience, but does not require any particular orientation of the components. The terms of degree such as “substantially,” “about” and “approximate,” and any derivatives, as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least +/−5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.