Abstract:
A collapsible material system for slowing a vehicle. The system including: a predetermined thickness of collapsible material disposed over a base; a covering disposed over a top surface of the collapsible material over which the vehicle travels; and a transition portion that further includes: a predetermined thickness of collapsible transition material disposed over a base; and a transition covering disposed over a top surface of the collapsible material over which the vehicle travels. Where one of the collapsible transition material and the transition covering have a different characteristic from the collapsible material and the covering, respectively.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a Divisional Application of U.S. application Ser. No. 11/980,285, filed on Oct. 30, 2007, the entire contents of which is incorporated herein by its reference. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to emergency apparatus for use with aircraft runways, and more particularly, to collapsible concrete systems for runways. 
         [0004]    2. Prior Art 
         [0005]    Runway segments are sometimes added to the end of runways that are constructed with a special type of “concrete” that collapses in a more or less controlled manner under the load of an airplane tire, generally referred to as Engineered Material Arresting System (EMAS). Such runway segments have the problem of lack of control because the collapsed EMAS tends to constrain the tire to travel, more or less, in the generated “groove”, making it difficult for the plane to maneuver (turn) sideways due to the resistance that the uncrushed “EMAS wall” provides against the tire as it attempts to turn sideways. 
         [0006]    In addition, the EMAS material cannot be formed such that it is sufficiently homogeneous to prevent bumpy rides. 
         [0007]    In addition, the collapsible EMAS runway breaks up into smaller pieces that can be projected out towards the aircraft, thus creating a safety hazard. 
         [0008]    In addition, the collapsible EMAS runway cannot support the weight of the vehicle that is intended to use it in emergency situation. As a result, the collapsible EMAS runway sections cannot be used for regular landing and take-off of aircraft. 
         [0009]    In addition, once used by an aircraft to slow its speed and bring it to a stop, the collapsible EMAS runway section becomes essentially unusable. As a result, the related runway may have to be closed for a relatively long periods to allow the repair crew to repair the damaged section of the collapsible EMAS runway section. 
       SUMMARY 
       [0010]    Therefore, there exists a need in the art to overcome the deficiencies of the collapsible EMAS systems of the prior art. 
         [0011]    Accordingly, a collapsible material system for slowing a vehicle is provided. The system comprising: a predetermined thickness of collapsible material disposed over a base; a plurality of panels disposed over a top surface of the collapsible material over which the vehicle travels; and a support structure for supporting one or more of the plurality of panels in a first position and for allowing the collapsible material to be compressed under the weight of the vehicle in a second position. 
         [0012]    The collapsible material system can further comprise a hinge disposed between adjacent panels of the plurality of panels. The hinge can be disposed to pivot about an axis parallel to a direction of travel of the vehicle. The hinge can be disposed to pivot about an axis perpendicular to a direction of travel of the vehicle. The hinge can further comprises a seal. 
         [0013]    The collapsible material system can further comprise a seal disposed between adjacent panels of the plurality of panels. 
         [0014]    The collapsible material system can further comprise a transition portion comprising: a predetermined thickness of collapsible transition material disposed over a base; one or more transition panels disposed over a top surface of the collapsible material over which the vehicle travels; and a transition support structure for supporting the one or more panels in a first position and for allowing the collapsible material to be compressed under the weight of the vehicle in a second position; wherein one of the collapsible transition material and the one or more transition panels have a different characteristic from the collapsible material and the plurality of panels, respectively. The different characteristic can be a different orientation of the one or more transition panels. The different characteristic can be a different resistance to compression of the transition material. 
         [0015]    The support structure can comprise: a linkage having two or more links, one of the two or more links being connected to the base and the other of the two or more links being connected one or more of the plurality of panels; and one or more locking elements for selectively locking and unlocking the linkage between a locked state corresponding to the first position and an unlocked state corresponding to the second position. 
         [0016]    The support structure can comprise: a tubular member connected to one of the base and one or more of the plurality of panels; and one or more members slidingly disposed with the tubular member connected to the other of the base and one or more of the plurality of panels; wherein the one or more member are actuatable between a locked state corresponding to the first position and an unlocked state corresponding to the second position. 
         [0017]    Also provided is a collapsible material system for slowing a vehicle. The system comprising: a predetermined thickness of collapsible material disposed over a base; a covering disposed over a top surface of the collapsible material over which the vehicle travels; and a transition portion comprising: a predetermined thickness of collapsible transition material disposed over a base; and a transition covering disposed over a top surface of the collapsible material over which the vehicle travels; and wherein one of the collapsible transition material and the transition covering have a different characteristic from the collapsible material and the covering, respectively. 
         [0018]    The different characteristic can be a different orientation of the transition covering. The different characteristic can be a different resistance to compression of the transition material. 
         [0019]    Still further provided is a method for slowing a vehicle. The method comprising: disposing a predetermined thickness of collapsible material over a base; disposing a plurality of panels over a top surface of the collapsible material over which the vehicle travels; and selectively either supporting one or more of the plurality of panels or allowing the collapsible material to be compressed under the weight of the vehicle. 
         [0020]    The method can further comprise pivoting adjacent panels of the plurality of panels with respect to each other. 
         [0021]    The method can further comprise sealing between adjacent panels of the plurality of panels. 
         [0022]    The method can further comprise: providing a transition portion comprising: a predetermined thickness of collapsible transition material disposed over a base; one or more transition panels disposed over a top surface of the collapsible material over which the vehicle travels; and a transition support structure for supporting the one or more panels in a first position and for allowing the collapsible material to be compressed under the weight of the vehicle in a second position; and providing one of the collapsible transition material and the one or more transition panels have a different characteristic from the collapsible material and the plurality of panels, respectively. 
         [0023]    The providing of the one of the collapsible transition material and the one or more transition panels to have a different characteristic from the collapsible material and the plurality of panels can comprises differing an orientation of the one or more transition panels. 
         [0024]    The providing of the one of the collapsible transition material and the one or more transition panels to have a different characteristic from the collapsible material and the plurality of panels can comprises differing a resistance to compression of the transition material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    These and other features, aspects, and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
           [0026]      FIG. 1  illustrates an embodiment of a deployable collapsible EMAS materials based system having substantially rigid structures deployed. 
           [0027]      FIG. 2  illustrates the deployable collapsible EMAS materials based system of  FIG. 1  in which a wheeled vehicle travels over the same. 
           [0028]      FIG. 3  illustrates the deployable collapsible EMAS materials based system of  FIG. 1  with the substantially rigid structures in a retracted (un-deployed state). 
           [0029]      FIG. 4  illustrates the deployable collapsible EMAS materials based system of  FIG. 3  where a wheeled vehicle has collapsed a portion thereof. 
           [0030]      FIG. 5  illustrates a variation of the deployable collapsible EMAS materials based system of  FIG. 4  having a transition region. 
           [0031]      FIG. 6  illustrates another embodiment of a deployable collapsible EMAS materials based system with the substantially rigid structures in a retracted (un-deployed state). 
           [0032]      FIG. 7  illustrates the deployable collapsible EMAS materials based system of  FIG. 7  having a transition region. 
           [0033]      FIG. 8  illustrates an embodiment of a substantially rigid structure. 
           [0034]      FIG. 9  illustrates another embodiment of a substantially rigid structure. 
           [0035]      FIG. 10  illustrates yet another embodiment of a substantially rigid structure. 
           [0036]      FIG. 11  illustrates a top view of another embodiment of a deployable collapsible EMAS materials based system. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    Although this invention is applicable to numerous and various types of roadways and surfaces, it has been found particularly useful in the environment of runways for aircraft. Therefore, without limiting the applicability of the invention to runways for aircraft, the invention will be described in such environment. Those skilled in the art will appreciate that the collapsible EMAS materials based systems of the present invention can be used on roadways for automobiles and trucks and for other wheeled vehicles. 
         [0038]    Referring now to  FIG. 1 , there is shown a first embodiment of a deployable collapsible EMAS materials based (hereinafter referred to as collapsible material based) system, generally referred to by reference numeral  100 . The collapsible material based system  100  has a predetermined thickness t of collapsible material  102  over a base  104 . The fabrication of collapsible material and the proper thickness for the same for different applications is well known in the art. Generally, the collapsible material can be provided in blocks and stacked along the base  104  to cover an appropriate portion of the base. The collapsible material system  102  further has relatively rigid panels  105 , which can be separate from each other or preferably interconnected, such as by a hinge  106  to allow relative rotation about axes lateral to the direction of travel  107 . 
         [0039]    The hinges  106  that connect the panels  105  may be constructed as a narrow “strip” of relatively flexible material (not shown) to join the panels as well as seal the collapsible material  102  and protect it from elements such as rain, snow, etc., and essentially act as living joints. Alternatively, even when mechanical hinges  106  are used, the panels may still be joined together on the top surface with similar narrow strip of relatively flexible material to protect the underlying collapsible material  102 . The provision of such narrow strip of relatively flexible material would have the added advantage of providing the collapsible materials based system  100  with a smooth surface. 
         [0040]    The panels  105  are supported by substantially rigid structures  108 , such that under the load transmitted by the wheel  110  of a typical vehicle  111  that will use the system  100 , as shown in  FIG. 2 , it would not cause the collapsible material system  102  to be crushed. 
         [0041]    The support structures  108  are, however, deployable, i.e., in its deployed state they are substantially rigid structures and would support the load exerted by the wheel  110  of the passing vehicle  111  over the supported panels  105 . In their un-deployed (retracted) state  113 , the supports provide minimal to no resistance to the load exerted by the wheel  110  of the passing vehicle  111  over the “un-supported” panels  105 , thereby allowing the said load to press the panels  105  against the collapsible material system  102 ,  FIG. 3 . This would then cause the collapsible materials  102  to be crushed as shown in  FIG. 4  to certain depth  115  (the fully crushed region is indicated as  114 ) depending on the load exerted by the wheel  110  of the passing vehicle  111 , thereby absorbing the kinetic energy of the passing vehicle and eventually bringing it to a stop or slowing it down as intended by the system user and/or designer. Hereinafter, the aforementioned support structures  108  are referred to as “deployable support structures”. 
         [0042]    The different methods of providing the aforementioned deployable support structures and their various embodiments are described below. 
         [0043]    The length (L),  FIG. 1 , of the panels  105  is chosen depending on the size of the typical wheel that will use the system (or a range of wheel sizes). The width of the panels  105  (perpendicular to the direction of travel  107 ) can vary from the width of the typical wheel that will use the system (and perhaps even smaller) to the width of the runway, however, in general, the larger the surface area of the panel  105 , the less crushing force is exerted on the collapsible material covered by the panel  105 . 
         [0044]    The hinges  106  may be provided with certain amount of flexibility and/or play to allow certain amount of relative displacement between the panels  105  in the vertical plane of the schematic cross-sections of  FIGS. 1-2 . Such relative displacements would accommodate certain amount of rotation and downward motion of one panel  105  relative to the next panel as a typical wheel  110  rolls over panels  105  as shown in  FIG. 3 . Thus, the hinges  106  would allow the panels  105  to assume a sloped configuration as the vehicle  111  wheel  110  rolls over a panel and to push the leading edge  112  down as shown in  FIG. 3 . 
         [0045]    In general, the side by side panels  105 , i.e., the panels positioned side by side in the direction perpendicular to the direction of the travel  107  of the vehicle  111  are preferably connected by flexible elements (not shown) so that the depression of one panel  105  under the weight of the vehicle  111  transmitted by the wheel  110  to the said panel would also exert a force on the sides of the adjacent panels to avoid the creation of abrupt discontinuities. 
         [0046]    In the  FIGS. 1-4 , all the like features are denoted by identical reference numerals. 
         [0047]    To make the transition from the regular section of a runway  119  commonly constructed with concrete  117 ,  FIG. 5 , to the deployable collapsible materials based system section  100 , a slightly sloped transition section  118  is constructed with similar panels  105  that are hinged together with similar hinges  106 , and supported by appropriately sized support structures  108 . Similar collapsible material  102  that are appropriately sized  116  are similarly used to fill the space between the panels  105  of the transition section  118  and the base  104  as shown in  FIG. 5 . The transition section  118  would allow the vehicle  111  to begin to decelerate slowly and smoothly to its final deceleration rate as the wheel  110  of the vehicle  111  travels from the regular section of the runway  119  over to the transition section  118  and from there to the deployable collapsible materials based system section  100 . 
         [0048]    The resulting runway section having the collapsible concrete system  100  will then act very similar to the runway system described in U.S. Pat. No. 6,969,213 entitled “Roadway for Decelerating a vehicle Including an Aircraft,” the entire contents of which is incorporated herein by reference. In the present collapsible concrete system,  100 , the collapsible concrete  102  and  116  ( FIGS. 1-5 ) is used in place of the support and control elements disclosed in U.S. Pat. No. 6,969,213. The difference is that when substantially rigid support structures  108  ( FIGS. 1 ,  2  and  5 ) are in their retracted state  113  ( FIGS. 3-4 ), the kinetic energy of the vehicle is used to crush the collapsible concrete (collapsible EMAS materials) rather than being stored in springs or absorbed by dampers or brake elements. Thus, as shown in  FIG. 5 , as a wheel  110  of the vehicle  111  enters the collapsible EMAS materials system  100 , the wheel  110  first enters the transition section  118  from the regular runway section  119  as shown in  FIG. 5 . The load transmitted by the wheel  110  will then begin to press the panels  105  of the transition section  118 , forcing the panels to crush the collapsible materials  116  under the transition section  118 . The wheel will then reach the level section of the collapsible EMAS materials system  100 , and keep on depressing the panels  105  down and crush the collapsible materials  102  to certain height  115 ,  FIG. 4 , which is dependent on the level of load transmitted by the wheel  110  of the vehicle  111 . 
         [0049]    In addition to the panels  105  preventing debris from being thrown, another advantage of using such panels  105  over collapsible EMAS materials  102  ( 116 ) is that the vehicle travels much smoother since it would average out the strength of the collapsible EMAS materials system  102  ( 116 ), the homogeneity of which is hard to control. 
         [0050]    Still another advantage of the collapsible EMAS materials system  100  is that there is no resulting loss of control of the vehicle  111  as it travels over the panels  105  rather than in grooves generated by the sinking wheel  110  in the collapsible EMAS materials  102  ( 116 ) in the absence of the panels  105 . 
         [0051]    Still another advantage of the collapsible materials system  100  is that with the substantially rigid support structures  108  deployed ( FIGS. 1 ,  2  and  5 ), the system  100  is substantially rigid and the load transmitted by the wheel  110  of the vehicle  111  will be carried substantially by the substantially rigid support structure  108 . The section  100  would therefore function as a regular section of a runway and add to the total length of the regular runway, a feature which is highly desirable for all runways. However, when an emergency situation is encountered, the substantially rigid support structures  108  are retracted to their un-deployed (retracted) state,  FIGS. 2-3 , and the vehicle  110  traveling in the direction  107  is decelerated safely to a stop. 
         [0052]    Still another advantage of the collapsible EMAS materials system  100  is that following an emergency use of the section of the runway to decelerate a vehicle, for example a runaway aircraft, the substantially rigid support structures  108  may again be deployed and the section of the runway used for ordinary landing while the damaged collapsible EMAS materials ( 102  and  116 ,  FIG. 5 ) sections are ready to be replaced. As a result, the runway does not have to be closed while the collapsible EMAS materials ( 102  and  116 ,  FIG. 5 ) sections are being made. In addition, the collapsible EMAS materials system  100  is still mostly effective since the chances of a second runaway vehicle to follow exactly the path of a previous runaway vehicle is very small. 
         [0053]    In another embodiment, the schematics of which is shown in  FIG. 6 , a collapsible materials based system  120  is constructed such that the panels  121  connected together with hinges  132  are flush with the regular runway section  122 , both for the transition section  123  panels and the main section  124  panels. In their deployed state, the aforementioned substantially rigid support structures  133  support the panels  121 , such that under the load transmitted by the wheel  125  of a typical vehicle  126  that will use the system  120 , as shown in  FIG. 6 , it would not cause the collapsible materials  128  and  130  to be crushed. The collapsible EMAS materials  128  and  130  of both sections  123  and  123  and the substantially rigid support structures  133  are supported by a similar base (foundation) structure  134 . 
         [0054]    However, the transition from the regular runway section  122  to the collapsible materials based system  120  is highly desirable to be smooth for the wheel  125  of the vehicle  126 , i.e., the wheel  125  of the vehicle  126  is desired to slowly increase its vertical (downward) travel (i.e., crushing depth of  127  of the collapsible EMAS materials  128 ) as it moves from the regular runway section  122  to over the panels  121  to its nominal depth  129 ,  FIG. 7 . To this end, the collapsible EMAS materials  128  following the regular runway section  122  in the transition section  123  is made out of stronger collapsible EMAS materials, i.e., collapsible EMAS materials that crush less under the same load, and then become progressively weaker to the nominal strength of the collapsible EMAS materials  130  of the remaining section  124  of the collapsible EMAS materials system  120 . As a result, as the wheel  125  of the vehicle  126  traveling in the direction  131  enters the section of the runway constructed with the collapsible materials based system  120 , the first few panels  121  positioned along the aforementioned transition section  123  are depressed due to the crushing of the stronger collapsible EMAS materials  128  continuously more to bring the wheel  125  smoothly to its nominal depth  129  over the remaining section  124  of the collapsible materials system  120  as shown in  FIG. 7 . 
         [0055]    The support structures ( 108  in  FIGS. 1-2  and  5  and  133  in  FIGS. 6-7 ), while supporting the vehicle load over the substantially rigid panels ( 105  in  FIGS. 1-5  and  121  in  FIGS. 6 and 7 ), are constructed to prevent the collapsible materials ( 102  in  FIGS. 1-5  and  128  and  130  in  FIGS. 6 and 7 ) from being crushed under the weight of the vehicle ( 111  in  FIGS. 2-5  and  126  in  FIGS. 6 and 7 ) as transmitted by the vehicle tires ( 110  in  FIGS. 2-5  and  125  in  FIGS. 6 and 7 ). The support structures  108  and  133 , however, are capable of being released, i.e., being made incapable of supporting the aforementioned vehicle load, thereby allowing crushing of the collapsible materials ( 102 ,  128  and  130 ) under the vehicle load. 
         [0056]    The support structure releasing action may be initiated manually, for example by the flight control personnel or by the aircraft crew, or may be initiated automatically when sensors measuring the speed of the landing aircraft determine that the aircraft is moving too fast and may run past the runway. The automatic means of release mechanism initiation may also be onboard the aircraft and initiate the release directly or by communicating with a runway station. The support structures  108  and  133  and their release mechanisms may be constructed in a varieties of ways, some of which are described in the following embodiments. 
         [0057]    In general, the mechanisms for the support structures  108  and  133  can be configured to either retract out of the direction of collapsible material ( 102 ,  128  and  130 ) crushing, or can be configured to move with the panels ( 105  and  121 ) with minimal resistance. Alternatively, while moving with the panels  105  and  121 , the support structures may also provide certain amount of (braking-like) resistance, thereby absorbing a portion of the kinetic energy of the vehicle. 
         [0058]    In one embodiment, the support structures  108  and  133  are designed as linkage mechanisms with a releasable locking element, which when locked, would transform the mechanism to a (substantially rigid) structure (no degree-of-freedom for motion), supporting the vehicle load on the panels  105  and  121  as previously described. However, once the locking mechanism is released, the linkage mechanism is essentially free to “collapse”, thereby allowing the panels  105  and  121  to crush the underlying collapsible materials ( 102 ,  128  and  130 ). 
         [0059]    In one embodiment, the linkage mechanism types used for the construction of the present support structures  108  and/or  133  have at least two degrees-of-freedom in motion to allow arbitrary motion of the panels  105  and  121  relative to the base foundation ( 104  in  FIGS. 1-5  and  134  in  FIGS. 6-7 ). In general, fewer degrees-of-freedom in motion is preferable since it would require fewer locking elements to transform the mechanism into a substantially rigid structure (in general, one such locking mechanism is required for each degree-of-freedom of the linkage mechanism to transform the mechanism into a substantially rigid structure). 
         [0060]    One such degree-of-freedom linkage mechanism embodiment for the construction of the present support structures  108  and/or  133  is shown in the schematic drawing of  FIG. 8 . This mechanism is constructed with two links  142  and  143 , which are connected together with a hinge  146 . The link  142  is hinged to the panel  141  through the attachment support  144 . The link  143  is in turn attached to the runway foundation  151  through the support  145 . The panels  141  are shown to be attached to each other by hinges  140 . The locking elements  147  and  149  are provided to prevent rotary motion of the links  143  and  142 , respectively, relative to the runway foundation, portions of which are shown as  148 . It is noted that in the schematic of  FIG. 8  and for the sake of simplicity the locking elements  147  and  149  are shown only on one side the links  143  and  142 , but in an actual device the locking elements are intended to provide locking elements positioned on both sides of the links (e.g., by providing U shaped elements instead of blocks  147  and  149  as shown in  FIG. 8 ) to restrict the links  143  and  142  from undergoing any rotational motions. When the locking elements  147  and  149  are preventing the links  143  and  142  from rotating, the two links function as a structure, i.e., function as substantially rigid support structures  108  and  133 , thereby supporting the load  150  exerted by the vehicle wheel ( 110  and  125  in  FIGS. 1-7 ) on the panels  141 , thereby preventing the panel to be pushed down and crush the collapsible materials  102  or  128  and/or  130  (not shown in  FIG. 8 ). When a vehicle traveling over the runway section needs to be slowed down, the locking elements  147  and  149  are withdrawn, thereby preventing the links  143  and  142  (the linkage mechanism) to provide a substantial resistance to the applied load  150 , thereby allowing the panels  141  to crush the collapsible materials  102  or  128  and/or  130 , absorbing part of the kinetic energy of the vehicle and therefore slowing the vehicle down. 
         [0061]    The links  149  and  147  (linkage mechanism) may be provided with spring elements (not shown) to bias them into their collapsed position. The linkage mechanism may also be provided with braking elements (frictional or viscous damping type) to absorb parts of the kinetic energy of the passing vehicle as the weight of vehicle pushes the panels  141  down to crush the collapsible materials  102  or  128  and/or  130 . 
         [0062]    In another embodiment of the present invention, the linkage mechanism type used for the construction of the present support structures  108  and/or  133  has only one degrees-of-freedom in motion; thereby would only allow the panels  105  and  121  to undergo a prescribed motion relative to the runway foundation ( 104  and  134 ). The prescribed motion is preferably the actual motion pattern of the panels  105  and  121  as the vehicle load is applied to the surface of the panels and travel along its length, causing the collapsible materials  102  or  128  and/or  130  to crush. However, since this pattern of motion for the panels  105  and  121  is different for different vehicles and their speed, one compromise would be to provide linkage mechanisms that allow only vertical motion, and attach them to the panels by a, preferably, spherical joint that would allow for rotational motion of the panels  105  and  121  about axes parallel to the plane of the foundation, i.e., usually the horizontal plane. The rotation of the panels  105  and  121  about the vertical axis is prevented since more than one support structure  108  and/or  133  is used for each said panels. 
         [0063]    One such an embodiment is designed as a “scissor” type of linkage mechanism  160  shown in the schematic drawing of  FIG. 9 . The scissor mechanism is constructed with a series of pairs of links  171  that are joined together as shown in  FIG. 9  with hinges  172 . On the foundation  170  side, one of the links  171  is hinged to the support  165 , which is in turn fixed to the foundation  170 . The other link  171  of the scissor mechanism  160  is hinged to the support  166 . The support  166  rests over the surface of the foundation  170  and is free to translate along the line connecting the supports  165  and  166 . Similarly on the panel  161  side, one of the links  171  is hinged to the support  164 , which is fixed to the plate  173 . The other link  171  is then hinged to the support  175 , which is free to translate along the line connecting the supports  164  and  175 . The panel  161  is then supported by the scissor type mechanism via the ball joint  174 . The panels  161  are attached together as previously described by the hinge joints  162 . The ball joint  174  may be a living joint. 
         [0064]    In the schematic drawing of  FIG. 9 , the translation of the support  166  over the surface of the foundation  170  away from the fixed support  165  is prevented by the locking element  168  which is positioned between the support  166  and the stop  167 , which is fixed to the foundation  170 . When the locking element  168  is positioned as shown in  FIG. 9  between the support  166  and the stop  167 , then the scissor mechanism  160  is substantially rigid and the top plate  173  can support the vehicle load  169  that is applied to the panel  161  as the vehicle travels over the said panel. However, when the locking element  168  is pulled away from its aforementioned locking position shown in  FIG. 1 , then the support  166  is free to translate away from the fixed support  165 , thereby allowing the scissor mechanism to collapse, thereby allowing the panel  161  to crush the collapsible materials  102  or  128  and/or  130  as the vehicle travels over the panel  161  and applies the load  169  to the said panel. 
         [0065]    As described for the mechanism of  FIG. 8 , the links  171  (linkage mechanism) may be provided with spring elements (not shown) to bias them into their collapsed position. The linkage mechanism may also be provided with braking elements (frictional or viscous damping type) to absorb a portion of the kinetic energy of the passing vehicle as the weight of the vehicle pushes the panels  161  down to crush the collapsible materials  102  or  128  and/or  130  (not shown). 
         [0066]    In yet another embodiment, the support structures  108  and/or  133  is constructed as a one degree-of-freedom telescopic column type of mechanism  180  shown in the schematic drawing of  FIG. 10 . Here, the mechanism  180  is shown to consist of a moving section  185  (can be cylindrical or other shapes), which could travel down inside the second tubular section  186 . The section  186  is fixed to the foundation  183 , and is preferably buried substantially inside the foundation for increased support and to allow the section  185  to move down a sufficient amount for the proper operation of the present system. The locking element  188  provides the means to lock the section  185  of the telescopic mechanism  180  up in the position shown in  FIG. 10 . In this position, the telescopic mechanism functions as a support structure support structures  108  and/or  133 , and support the load  184  applied by the tire of the vehicle passing over the panel  181  via the ball joint  187 . The panels  181  are attached together as previously described by the hinge joints  182 . The ball joint  187  may be a living joint. 
         [0067]    When the locking element  187  is pulled out of the telescopic (column) mechanism  180 , the section  185  is free to retract into the section  186 , thereby allowing the panel  181  to crush the collapsible materials  102  or  128  and/or  130  (not shown) as the vehicle travels over the panel  181  and applies the load  184  to the said panel. 
         [0068]    As described for the mechanisms of  FIGS. 8 and 9 , spring elements (not shown) may be used to bias the translation of the section  185  inside the section  186  of the telescopic mechanism  180  to bias the mechanism into its collapsed position. The telescopic mechanism may also be provided with braking elements (frictional or viscous damping type) to absorb parts of the kinetic energy of the passing vehicle as the weight of vehicle pushes the panels  181  down to crush the collapsible materials  102  or  128  and/or  130  (not shown). 
         [0069]    Such telescopic column type mechanisms may also be constructed with more than one telescopic section to minimize the length of the buried section  186 . However, since each section has to be provided with a separate locking element  188 , the resulting support structure will have more components and more locking elements to be removed when the runway section is intended to be used to slow the passing vehicle. 
         [0070]    Referring now to  FIG. 1 , there is shown a top view of another embodiment of a collapsible material based system  200 . In the embodiment of  FIG. 11 , in addition to the panels  105  being pivotal about hinges (or flexures)  106  which pivot about an axis perpendicular to the direction of travel  107 , the panels  105  can also be pivotal about hinges (or flexures  202 ) which pivot about an axis parallel to the direction of travel so as to arrest any component of motion of the aircraft in the sideways direction which would otherwise cause the aircraft to leave the side of the runway. In such an embodiment, an appropriate number of support structures  108  are needed to support each panel  105 , such as three or more of such support structures  108  per panel  105 . The side-to-side (perpendicular to the direction of travel  107 ) spacing of the hinges  202  can be more, less or the same as the lengthwise spacing between hinges  106 . However, it is preferred that the side-to-side spacing between hinges  202  is greater than the lengthwise spacing between hinges  106  such that the panels are wider in the side-to-side direction than they are in the lengthwise (direction of travel  107 ) direction. 
         [0071]    While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.