CA2406361A1 - Steel cable suspended energy absorbing and impact attenuating barrier system - Google Patents
Steel cable suspended energy absorbing and impact attenuating barrier system Download PDFInfo
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- CA2406361A1 CA2406361A1 CA 2406361 CA2406361A CA2406361A1 CA 2406361 A1 CA2406361 A1 CA 2406361A1 CA 2406361 CA2406361 CA 2406361 CA 2406361 A CA2406361 A CA 2406361A CA 2406361 A1 CA2406361 A1 CA 2406361A1
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
- E01F15/00—Safety arrangements for slowing, redirecting or stopping errant vehicles, e.g. guard posts or bollards; Arrangements for reducing damage to roadside structures due to vehicular impact
- E01F15/02—Continuous barriers extending along roads or between traffic lanes
- E01F15/06—Continuous barriers extending along roads or between traffic lanes essentially made of cables, nettings or the like
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Abstract
An improved steel cable suspended energy absorbing and impact attenuating barrier system for use as a motorsports or traffic safety barrier wherein the barrier system comprises a plurality of displaceable, impenetrable barrier sections forming a continuous barrier suspended in a generally vertical configuration with respect to the race track or roadway by a plurality of steel suspending and anchor cables. The steel suspending cables maintain the plurality of impenetrable barrier sections in a specified overlapping manner with respect to the direction of traffic and are held by cable support rings fixed to the barrier sections to have a designated tension or slack per barrier section depending on the desired maximum displacement of the burner sections and are fixed at their terminus to an immovable structure. The plurality of barrier sections are anchored to existing concrete barriers or other structures by means of a plurality of generally horizontal steel anchor cables generally perpendicular to the direction of the steel suspending cables. An energy absorbing medium or media may be positioned in the space between the concrete barriers or other structures and the steel cable suspended impenetrable barrier sections.
Because the steel cable suspended energy absorbing and impact attenuating barrier system of this invention is displaceable and not fixed, and comprises overlapping sections to form a continuous barrier rather than a continuous inflexible or non displaceable impenetrable barrier as compared to those of prior art, the present invention offers an improved energy absorbing and impact attenuating response. A further improvement of the present invention is the ability of the barrier system to redirect impacting vehicle or racecars back onto the roadway or racing surface in the direction of traffic resulting from the decreased compressive strength of the trailing segment of the impenetrable barrier sections relative to the leading segment.
Because the steel cable suspended energy absorbing and impact attenuating barrier system of this invention is displaceable and not fixed, and comprises overlapping sections to form a continuous barrier rather than a continuous inflexible or non displaceable impenetrable barrier as compared to those of prior art, the present invention offers an improved energy absorbing and impact attenuating response. A further improvement of the present invention is the ability of the barrier system to redirect impacting vehicle or racecars back onto the roadway or racing surface in the direction of traffic resulting from the decreased compressive strength of the trailing segment of the impenetrable barrier sections relative to the leading segment.
Description
STEEL CABLE SUSPENDED ENERGY ABSORBING AND IMPACT
ATTENUATING BARRIER SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention This invention pertains generally to a displaceable and compressible crash barrier and associated cable barrier and suspending system used to absorb the energy and attenuate the impact of an incident colliding vehicle or racecar without permanent deformation, frequent repair or replacement, or causing a 'pocketing' response to the incident vehicle or racecar.
More specifically, this invention relates to an improved energy absorbing and impact attenuating burner system for use as a motorsports or traffic safety barrier comprising a plurality of overlapping, impenetrable barrier sections forming a continuous barrier at the periphery of or at a distance from the roadway or racing surface suspended in a generally vertical configuration with respect to the race track or roadway by a plurality of steel cables positioned at different heights above and parallel to the roadway or racing surface and displaced from the existing concrete barrier so as to allow for an energy absorbing medium or media to be placed between the existing concrete burner and the suspended, overlapping impenetrable barrier sections.
DESCRIPTION OF PRIOR ART
Automobile racing tracks require a burner that defines the outer limits of the race track to prevent racecars from leaving the racing surface, and to contain any debris from the normal course of the racing event or racing collisions which occur during the racing event within the confines of the race track. Roadways also require verge and median barriers to prevent vehicles from leaving the roadway. Automobile racing tracks also require a barrier that defines a spectator area physically separate and remote from the racetrack to provide a safe environment for spectators. A necessary and increasingly important characteristic of this type of burner that has emerged as vehicle and racecar speeds have increased is that it must have some degree of energy absorbing and impact attenuating properties to minimize physical damage to vehicles and racecars and injury to drivers and occupants upon collision with the barrier.
Historically, a number of devices have been utilized primarily for the purpose of defining the outer limits of the racing surface or track and defining a remote spectator area -devices such as hay bales, dirt beans, wooden and metal railings, concrete abutments, wire fencing or combinations of the above. In particular, steel fencing, such as Armco, and concrete abutments, such as concrete barners with a rectangular surface parallel to and in a vertical orientation to the racetrack and with associated wire containment fencing, serve as barriers commonly utilized in European, Asian and North American automobile racing events respectively. Concrete barrier systems have become commonplace in North American racing because they are modular, not dislodged or damaged after an impact with an incident racecar, do not require repair within or between racing events, and have no associated parts that may be dislodged during the collision that cause a danger to other racing vehicles, drivers or spectators.
However, while the latter barner systems serve well to define the outer limits of the racetrack and contain ordinary or extraordinary racing debris, they do so by providing a fixed, hard surface ('hard wall') that does not have any significant energy absorbing and impact attenuating properties to reduce peak impact forces and assist in preventing serious injury to a racing driver or significant damage to the racecar. The impact absorbing responsibility of such a collision lies almost solely with the racecar.
A commonplace and economical solution used in road racing applications is to supplement the existing racetrack barrier system, e.g., concrete barners, metal barners and terms, with tire barners consisting of used automobile tires lying horizontally and bundled several tires high in adjoining vertical columns, sometimes with a rigid tube placed in the tire opening of the vertical column, to provide energy-absorbing characteristics (refer to Federation Internationale de L'Automobile Standard 8861-2000, FIA Energy Absorbing Inserts for Formula One, Tire Barriers Standard). These tire
ATTENUATING BARRIER SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention This invention pertains generally to a displaceable and compressible crash barrier and associated cable barrier and suspending system used to absorb the energy and attenuate the impact of an incident colliding vehicle or racecar without permanent deformation, frequent repair or replacement, or causing a 'pocketing' response to the incident vehicle or racecar.
More specifically, this invention relates to an improved energy absorbing and impact attenuating burner system for use as a motorsports or traffic safety barrier comprising a plurality of overlapping, impenetrable barrier sections forming a continuous barrier at the periphery of or at a distance from the roadway or racing surface suspended in a generally vertical configuration with respect to the race track or roadway by a plurality of steel cables positioned at different heights above and parallel to the roadway or racing surface and displaced from the existing concrete barrier so as to allow for an energy absorbing medium or media to be placed between the existing concrete burner and the suspended, overlapping impenetrable barrier sections.
DESCRIPTION OF PRIOR ART
Automobile racing tracks require a burner that defines the outer limits of the race track to prevent racecars from leaving the racing surface, and to contain any debris from the normal course of the racing event or racing collisions which occur during the racing event within the confines of the race track. Roadways also require verge and median barriers to prevent vehicles from leaving the roadway. Automobile racing tracks also require a barrier that defines a spectator area physically separate and remote from the racetrack to provide a safe environment for spectators. A necessary and increasingly important characteristic of this type of burner that has emerged as vehicle and racecar speeds have increased is that it must have some degree of energy absorbing and impact attenuating properties to minimize physical damage to vehicles and racecars and injury to drivers and occupants upon collision with the barrier.
Historically, a number of devices have been utilized primarily for the purpose of defining the outer limits of the racing surface or track and defining a remote spectator area -devices such as hay bales, dirt beans, wooden and metal railings, concrete abutments, wire fencing or combinations of the above. In particular, steel fencing, such as Armco, and concrete abutments, such as concrete barners with a rectangular surface parallel to and in a vertical orientation to the racetrack and with associated wire containment fencing, serve as barriers commonly utilized in European, Asian and North American automobile racing events respectively. Concrete barrier systems have become commonplace in North American racing because they are modular, not dislodged or damaged after an impact with an incident racecar, do not require repair within or between racing events, and have no associated parts that may be dislodged during the collision that cause a danger to other racing vehicles, drivers or spectators.
However, while the latter barner systems serve well to define the outer limits of the racetrack and contain ordinary or extraordinary racing debris, they do so by providing a fixed, hard surface ('hard wall') that does not have any significant energy absorbing and impact attenuating properties to reduce peak impact forces and assist in preventing serious injury to a racing driver or significant damage to the racecar. The impact absorbing responsibility of such a collision lies almost solely with the racecar.
A commonplace and economical solution used in road racing applications is to supplement the existing racetrack barrier system, e.g., concrete barners, metal barners and terms, with tire barners consisting of used automobile tires lying horizontally and bundled several tires high in adjoining vertical columns, sometimes with a rigid tube placed in the tire opening of the vertical column, to provide energy-absorbing characteristics (refer to Federation Internationale de L'Automobile Standard 8861-2000, FIA Energy Absorbing Inserts for Formula One, Tire Barriers Standard). These tire
2 barners are typically used in applications where the racetrack barrier system is at a distance from the racing surface itself such as may be the case in road racing circuits; that is, where a section of pavement, gravel trap or grass field intercedes between the racing surface and racetrack barrier system. However, tire barners are not useful in applications where the racing surface and barrier system are immediately adjacent to one another, e.g.
oval racetracks, because significant impacts with an incident racecar during the event can dislodge the tire barner module itself or break the tire bundles causing the dislodged tires or associated hardware from the barner to be a safety hazard to the racing event.
Additionally, the speeds associated with racecars in oval race tracks would cause a snagging hazard.
Those skilled in the art have previously described energy absorbing or attenuating elements in a plurality of barner modules manufactured of a variety of materials such as wood, metal, polymers, elastomers, or rubber to be utilized for absorbing the impact of incident colliding vehicles. Yunick (1997, US Patent 5,645,368) described a racetrack consisting of barrier modules including a base mounted on the barrier support surface delineating two crash barrier rings circumscribing the racing surface with the inner ring in a juxtaposed relationship with the racing surface. Yunick's invention relates also to racetracks and their construction, more particularly to new vehicle racetracks constructed with novel and improved crash barners. However, the novel barrier method described by Yunick cannot be integrated easily, if at all, with existing barrier systems found at existing racetracks.
Muller (1998, US Patent 5,851,005) described the use of hexagonal metal elements to absorb incident impacts, however, the impact absorbing capabilities of such a device are exhausted after a single severe impact and afford no further impact absorbing properties for collisions that may occur immediately after this first impact or prior to repair. Arthur (1999, US Patent 6,276,667) described the use of cylindrical elements of a rubber or polymer material that may retain their impact-absorbing characteristics after an initial severe impact. Muller and Arthur have both chosen to align the impact absorbing hexagonal or cylindrical elements such that the long axes are parallel and longitudinal to the vertical surface of the existing barrier rather than orthogonal. Such alignment provides for only limited collapse or compression of the elements as defined by the material, and width of the hexagonal or cylindrical elements. Moreover, longitudinal alignment of similar hexagonal or cylindrical elements does not provide for as efficient energy absorbing or impact attenuating characteristics as by placing the hexagonal or cylindrical elements in a horizontal alignment, such as is the case when placing a honeycomb-type energy absorbing medium with its thickness (T) direction parallel to the racing surface and generally perpendicular to the existing concrete barrier.
More recently, those skilled in the art have considered barriers whereby materials of relatively low density, for example, low, medium or high density foam, have been placed in front of the existing concrete barrier system to provide energy absorbing and impact attenuating characteristics generally known as 'soft wall' barriers. Due to the relatively low density of these materials, however, a significant depth of material is required to attenuate racing vehicles, thus decreasing the overall usable surface of the racetrack.
Moreover, these materials are generally not resilient and a single impact may exhaust or significantly reduce the energy absorbing and impact attenuating characteristics of such barriers. In addition, unless a combination of materials of various densities is utilized in the 'soft wall' barrier design, the energy absorbing and impact attenuating properties of such a system are also of a single phase owing to the single density energy-absorbing medium.
Thermoset elastomers (TSE) consisting of cross-linked polymer chains have also been considered for 'soft wall' applications. Safari Associates, Inc. utilize a material called MolecuthaneTM for soft wall applications in automobile racing. While TSE
barriers may be designed with suitable energy absorbing and impact attenuating characteristics in their thickness direction, and may provide mufti-phase absorption and attenuation due to layers of differing densities, they may cause a 'pocketing' response as described below and are also generally not recyclable as thermoplastic elastomers (TPE) are.
Other 'soft wall' barrier solutions such as sacrificial inertial barriers that utilize frangible burners containing energy absorbing dispersible mass including sand and water (Fitch, 1999, US Patent 5,957,616) have been described. A single, severe impact with the frangible barrier will not only exhaust or significantly reduce its energy absorbing and impact attenuating capabilities, but also may contaminate the racing surface with the dispersed energy-absorbing material.
However, 'soft wall' barrier solutions may result in a 'snagging' or 'pocketing' characteristic that snags incident cars upon impact when they penetrate the relatively soft materials thereby causing a very fast deceleration of the incident car that in fact may cause significant damage to the driver in the collision of the car with the 'soft wall' due to the pronounced deceleration forces associated with the 'pocketing' response.
A solution in prior art to the problems of 'soft walls' and 'pocketing' responses is to use an impenetrable outer surface to the barrier system such as high-density polyethylene, guardrails or rectangular metal tubing.
The Indy Racing League (IRL) and Indianapolis Motor Speedway (IMS) installed a barrier system on the inside of Turn 4 in 1998 called the Polyethylene Energy Dissipating System (PEDS) utilizing 5-foot long overlapping, high density, polyethylene impact plates with two 16-inch diameter polyethylene cylinders bolted behind the impact plates acting as the energy absorbing medium. However, the high-density polyethylene impact plates are not sufficiently resilient when positioned on the outside of a curve to avoid penetration and subsequent 'snagging' or 'pocketing' by an impacting racecar.
Fitch (1999, US Patent 5,921,702) described a displaceable highway safety barrier system extending along the side of a roadway that includes a number of skid assemblies resting without attachment on a supporting surface adjacent to the roadway. However, such displaceable guardrail barriers require many mounting and interface members and significant space requirements. Fitch (2000, US Patent 6,010,275) also described a compression guardrail including a rail extending longitudinally along a roadway with a plurality of fixed support posts spaced behind the rail and resilient compressible energy absorbing means mounted between the rail and the posts. However, in both systems described by Fitch, the barrier itself is a continuous, strong, impenetrable surface and, while bendable, as such is not easily displaceable or compressible, therefore not providing as efficient an energy absorbing or impact attenuating response as possible.
The Indy Racing League (IRL) and Indianapolis Motor Speedway (IMS) have developed a barrier system in conjunction with the Midwest Roadside Safety Facility at the University of Nebraska -Lincoln called the SAFER (Steel and Foam Energy Reduction) barner that was installed on the outside of turns at IMS in the spring of 2002. The barner consists of four rectangular structural steel tubes welded together forming sections, each section joined to the next by heavy steel internal splines. Bundles of 2-inch thick polystyrene sheets are placed between the structural steel tube barrier and the existing concrete barrier. However, once again the barrier itself is a continuous, strong, impenetrable surface and as such is not easily bendable, displaceable or compressible, therefore not providing as efficient an energy absorbing or impact attenuating response as possible. The SAFER barrier has been described by those skilled in the art (Bill Milliken, Milliken Research Associates and John Fitch, Race Safety) as an extremely rigid wall, one whose section inertia is so high on the structural steel tubes that they can't possibly bend or deflect to absorb enough energy, thus not utilizing the energy absorbing medium (polystyrene blocks) effectively.
An effective and efficient racing safety barrier should resist damage or breaking, avoid snagging of incident vehicles or racecars, bend or displace to absorb a significant amount of impact energy, and redirect the incident vehicle or racecar without bouncing it back across the traffic stream. Thus, an object of an improved energy absorbing and impact attenuating barrier is to utilize the advantages of a 'soft wall' system, i.e., effective energy absorption due to the compression of an energy absorbing medium or media, with the advantages of a 'hard wall' barrier, i.e., without the inherent detrimental 'pocketing' response, yet provide for improved energy absorption by providing a more bendable, displaceable and compressible barner system as compared to fixed, continuous, 'hard wall' systems such the IRL SAFER system.
One such way of accomplishing the aforementioned characteristics of a more efficient racing safety barrier is to utilize a multiple cable barrier to 'suspend' an impenetrable barrier in overlapping sections such that the impacted section or sections are capable of displacing a significant distance against the tension or elastic stretching of the suspending cables so as to compress an energy absorbing media or medium, thus effectively absorbing impact energy and attenuating the impact in a controlled fashion.
Those skilled in the art have described multiple cable barriers as traffic safety barriers decades ago; such cable barriers were largely replaced by better-performing and lower maintenance concrete and metal beam barriers. However, modern cable barrier designs perform significantly better than those used in the 1950s and 1960s and have advantages over concrete or metal beam barners such as being inexpensive and quickly constructed, and are relatively forgiving barriers that can more gradually attenuate the impact of an incident vehicle even in large angle collisions. Multiple cable (for the purposes of this description the term cable is synonymous with wire rope) safety barriers have been adopted by some U.S. states as guardrails and median barriers where the median or shoulder allows for sufficient deflection of the cables (Oregon Department of Transportation, Weak Post Three-Cable Guardrail and Median Barrier Report;
Oklahoma Department of Transportation, Brifen Four-cable Safety Fence). Multiple cable or wire rope safety barriers are also utilized extensively in other countries around the world such as Australia and the United Kingdom.
Thus, this invention relates to an improved suspended rather than fixed 'hard wall' barrier system of overlapping, impenetrable, dependent barrier sections that form a continuous crash barrier system capable of significant displacement, tensioning or elastic stretching of the steel suspending cables, and compression of an associated energy absorbing medium or media said energy absorbing medium or media used in this embodiment to enhance the energy absorption characteristics because of the limited distance for deflection of the suspending cable and banter sections to absorb the impact energy of vehicles or racecars colliding with barner systems used on roadways or race tracks including, but not limited to, oval, tri-oval, speedway, super speedway, temporary street circuits, road racing courses, drag racing or any combination of the former.
The steel cable suspended energy absorbing and impact attenuating burner system of this invention is installed in a prescribed fashion as described herein independently or with existing concrete barrier systems thereby interacting with incident colliding vehicles or racecars from a multitude of incident angles and in a multitude of orientations to displace in a controlled fashion, due to the tensioning or elastic stretching of the associated steel suspending cables and, in the preferred embodiment, compression of an associated energy absorbing medium or media, to absorb energy and attenuate the impact of the vehicle or racecar thereby decreasing the peak force of impact and deceleration as described in multiples of the force of gravity (g-force) and increasing the time as measured in milliseconds over which the peak gforce is exerted thereby reducing injury to the vehicle or racecar driver and damage to the incident colliding vehicle or racecar.
Peak g-forces of deceleration resulting from impact and time over which the impact energy are absorbed are particularly significant in collisions between a racecar and an energy absorbing and impact attenuating burner system. Peak gforces associated with the impact must be reduced as much as possible and the length of time that impact energy is dissipated as measured in milliseconds must be increased as much as possible.
The steel cable suspended energy absorbing and impact attenuating burner system of this invention may also be used in applications not associated with existing concrete burners to replace existing fixed steel or metal guardrail systems such as Armco fencing on roadways or in road racing circuits. In this embodiment of the invention, an energy absorbing medium or media may not be associated with the application and the energy absorbing response of the steel cable suspended energy absorbing and impact attenuating barrier system largely is due primarily to the displacement of the barrier section or sections against the tension or elastic stretching of the suspending steel cables.
Upon impact by an incident racecar with the improved steel cable suspended energy absorbing and impact attenuating barner system of this invention, the racecar will firstly impact a suspended impenetrable barrier section or sections without any harmful 'pocketing' characteristic, causing the suspended impenetrable barner section or sections to absorb energy of the collision by displacing in the direction of the impact against the tension of the steel suspending cables as the slack is taken up and potential elastic stretching of the cables, and compressing the energy absorbing medium or media placed in the space between the existing concrete barrier and plurality of impenetrable apron sections. The specified overlapping configuration of the plurality of impenetrable apron sections described herein will naturally redirect the car back to the racing surface due to the decreased compressive strength of the trailing segment of the plurality of impenetrable barrier sections with respect to the leading segment of the plurality of impenetrable apron sections. After impact, the tensioning and potential elastic stretching of the steel suspending cables, and compression and elasticity of the energy absorbing medium or media will serve to rebound and partially realign the plurality of impenetrable barrier sections to their original positions (resting state). The impenetrable barrier sections are made of a material that is relatively impenetrable and inflexible with respect to the impact energies of the vehicle or racecar. Such materials include but are not limited to plate steel, rectangular or round tubing or beams, and sheet metal guardrails (e.g.
Armco), however it is important that the barrier sections form a smooth continuous barrier surface with no significant abutments or openings. Complete realignment of the improved energy absorbing and impact attenuating barrier system described herein is quickly accomplished by repair crews.
Accordingly, several objects and advantages of the steel cable suspended energy absorbing and impact attenuating barrier system of the invention described herein are:
(a) the energy-absorbing characteristics of the steel cable suspended energy absorbing and impact attenuating barrier system are not broken or exhausted after a single impact such as is the case in energy absorbing barner systems utilizing a light density crushable material such as foam (Nelson, 1999,US Patent 5,860,762) or metal (Muller, 1998, US
Patent 5,851,005) that do not provide energy absorbing or impact attenuating characteristics for a secondary incident following the primary impact prior to repair being effected.
(b) the steel cable suspended energy absorbing and impact attenuating barrier system is integrated easily and inexpensively with the existing concrete barrier system as compared to other 'soft wall' and 'hard wall' designs so as to be practical and economical.
(c) the steel cable suspended energy absorbing and impact attenuating barrier system is relatively compact yet more efficient as compared to existing 'hard wall' or 'soft wall' safety barners or other safety barriers because an energy absorbing medium or media is used in addition to the tensioning and potential elastic stretching of the cables to attenuate the incident vehicle upon displacement of the barrier sections.
(d) the steel cable suspended energy absorbing and impact attenuating barrier system elements are fixed with a minimum of hardware to the existing concrete barner system in a manner that prevents elements from being dislodged or damaged such that they or debris from them may be dangerous to other drivers, vehicles or spectators.
(e) there are no dispersible elements of the steel cable suspended energy absorbing and impact attenuating barrier system that will interfere with the racing circuit or cause consequence to the race after impact and consequent rupture of the energy absorbing barrier such as is the case with frangible barners.
(f) the energy absorbing characteristics of the steel cable suspended energy absorbing and impact attenuating barrier system are mufti-phase due to the inherent compressive strength of the barner sections due to their mass, cable tension and elasticity, and energy absorbing medium or media rather than providing a single phase attenuation due to the use of a single energy absorbing medium of consistent density, shape, configuration or physical dimension.
(g) the steel cable suspended energy absorbing and impact attenuating barner system is relatively more efficient in its energy absorbing response than current 'hard wall' barrier systems due to the ability of the suspended barrier sections to be significantly displaced in the direction of the impacting force of the collision energy and significantly compress the associated energy absorbing medium or media.
(h) the energy-absorbing and attenuating characteristics are designed such that in relative terms, the steel cable suspended energy absorbing and impact attenuating barrier system is:
~ relatively 'hard' for crash energy below approximately 5 to 10 times the multiple of the force of gravity (5-lOg). That is, the suspended barrier sections do not displace significantly and the racing vehicle primarily absorbs the bulk of the impact, thus not sacrificing absorption characteristics of the wall for inconsequential collisions, nor having 'soft' portions of the wall that an incident racecar could interact with (e.g., puncture, get impeded by, get caught up with) in highly oblique collisions.
This is achieved by means of the overlapping, impenetrable barrier sections positioned in intimate contact and in a prescribed fashion external to the energy absorbing medium or media and facing incident colliding vehicles or racecars.
~ relatively 'firm', yet progressively more energy absorbing and impact attenuating as compared to current 'hard wall' barrier systems for crash energy between approximately 10 to 40 times the multiple of the force of gravity (10-40g).
That is, the overlapping, impenetrable barrier sections displace on impact causing the slack of the suspending steel cables to be taken up, tensioning and potentially elastically stretching the steel cables, and partially compressing the associated energy absorbing medium or media, and the vehicle or racecar and said steel cable suspended energy absorbing and impact attenuating barrier system share the impact energy of the crash. Due to the preferred displacement of the trailing segment of the impenetrable barrier section or sections, the steel cable suspended energy absorbing and impact attenuating barrier system will also assist in redirecting the incident vehicle or racecar back onto the racing surface after the collision.
~ relatively 'soft' for crash energy above approximately 40 times the multiple of the force of gravity (40g). That is, the overlapping, impenetrable barrier sections displace significantly on impact causing the slack of the suspending steel cables to be taken up, tensioning and potential elastic stretching of the suspending cables, and compressing the associated energy absorbing medium or media whereby the steel cable suspended energy absorbing and impact attenuating barrier system absorbs a shared but increasingly larger portion of the impact energy of the crash than current 'hard wall' barner systems. Due to the preferred displacement of the trailing segment of the impenetrable barrier section or sections, and the rebounding of the impenetrable barrier section or sections against the tension and elastic stretching of the suspending steel cables and compression of the energy absorbing medium or media, the steel cable suspended energy absorbing and impact attenuating barrier system will also assist in redirecting the incident vehicle or racecar back onto the racing surface after the collision.
(i) that, where it is understood that the impact absorbing and attenuating barrier system is not required to be installed adjacent to the existing concrete burner system around the racetrack in its entirety, that contoured or tapered end-piece components be designed and manufactured with a similar function to define the beginning and end of the energy absorbing and impact attenuating barrier system that do not pose a hazard.
(j) the steel cable suspended energy absorbing and impact attenuating barrier system manufacturing and installation process is simple thereby offering both an economical and practical advantage.
Further objects and advantages of the steel cable suspended energy absorbing and impact attenuating barrier system described herein are to provide an energy absorbing and impact attenuating barrier system for roadways and race tracks that are inert to environmental forces, require a minimum of maintenance and repair, and maintain a surface for other previously defined functions of the concrete barrier system, e.g.
advertising.
Still further objects and advantages will become apparent from review and consideration of the ensuing description and drawings.
SUMMARY OF THE INVENTION
Briefly, in the present invention a steel cable suspended energy absorbing and impact attenuating barrier system is described that provides absorption of impact energy from a colliding vehicle or racecar. The improved energy absorbing and impact attenuating barrier system for use as a motor sports or traffic safety barner described herein comprises a plurality of overlapping, impenetrable barner sections forming a continuous barrier at the periphery of or at a distance from the roadway or racing surface suspended in a generally vertical configuration with respect to the race track or roadway by a plurality of steel cables, and displaced from the existing concrete barrier by an energy absorbing medium or media. The steel suspending cables are held in place by cable support rings in which said suspending steel cables are free to slide back and forth in said cable support rings, said suspending steel cables having a designated slack or tension per barrier section depending on the desired maximum displacement of the impenetrable barrier section and impact energy, said cable support rings being fixed to the impenetrable barrier sections, said suspending steel cables being fixed at their terminus to an immovable structure, said plurality of impenetrable barrier sections of which are positioned in a specified overlapping manner with respect to the direction of traffic. The plurality of impenetrable barner sections are anchored to existing concrete barriers or other structures by means of a plurality of generally horizontal steel cables which also attach to the cable support rings perpendicular to the direction of the steel suspending cables. An energy absorbing medium or media is positioned in the space between the concrete barriers and steel cable suspended impenetrable barner sections.
Because the steel cable suspended energy absorbing and impact attenuating barner system of this invention is displaceable and not fixed, and comprises sections to form a continuous barner rather than a continuous inflexible or norrdisplaceable impenetrable barner as compared to those of prior art, the present invention offers an improved energy absorbing and impact attenuating response. The energy absorbing and impact attenuating response is provided by the tension and elastic stretching of the suspended steel cables against the displacement of the sections upon impact, and the compression of the energy absorbing medium or media by the displaced barrier section or sections. A
further improvement of the present invention is the ability of the barrier system to redirect impacting vehicle or racecars back onto the roadway or racing surface in the direction of traffic resulting from the decreased compressive strength of the trailing segment of the impenetrable barrier sections relative to the leading segment.
The above discussed and many other features, objects and advantages of the present invention will be better understood by reference to the following detailed description and accompanying drawings.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the ensuing diagrams, an exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 is shown generally in FIG.
1 wherein said barner system is an energy absorbing barner for racecars on oval race tracks comprising a plurality of overlapping impenetrable barrier sections 11, 12, 13, 14, 15 forming a continuous barrier with respect to the roadway or racing surface and direction of travel of the racecar. In the preferred embodiment, the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 is shown integrated with an existing concrete barner commonly used at oval racetracks. However, the exemplary steel cable suspended energy absorbing and impact attenuating burner system may be modified for use on roadways or other types of racing tracks and integrated with other structures. Whereas multiple cable safety barriers of prior art do not utilize impenetrable barrier sections placed in front of the cables to firstly interact with an impacting vehicle or racecar, in the application of the exemplary embodiment described herein, the impenetrable barrier sections are required to prevent an incident vehicle or racecar from penetrating between cables and having the cables cause damage to the vehicle or racecar and driver or occupants.
Each barner section 11, 12, 13, 14, 15 is suspended in a generally vertical alignment with respect to the roadway or racing surface by a plurality of suspended steel cables 6 generally parallel to and at different heights with respect to the roadway or racing surface whose diameter and core structure are dependent on the required tension, elasticity and breaking strength for a specific application, each suspended steel cable 6 of which is held in position by a plurality of cable support rings 3 at different heights with respect to the roadway or racing surface in which the suspending cables are free to move. The inner surface of the cable support rings 3 may be reinforced and lubricated to facilitate such movement. The plurality of cable support rings 3 are fixed to the barrier sections 11, 12, 13, 14, 15 by stove head bolts 4 or similar fixing hardware that will not intrude on the smooth surface of the barner system to form abutments. The impenetrable barrier sections 11, 12, 13, 14, 15 are placed external to an energy absorbing medium or media 8 in the preferred embodiment to face incident racecars. However, the steel cable suspended energy absorbing and impact attenuating barrier system 10 of this invention may also be used in applications not associated with existing concrete barners 9 to replace existing fixed steel or metal guardrail systems such as Armco fencing on roadways or in road racing circuits. In the latter embodiment of the present invention, an energy absorbing medium or media 8 may not necessarily be associated with the application and the energy absorbing response of the steel cable suspended energy absorbing and impact attenuating barrier system 10 largely is due primarily to the displacement of the barrier section or sections against the tension or elastic stretching of the suspending steel cables. The impenetrable barrier sections 11, 12, 13, 14, 15 may overlap to form a linear or curved continuous burner.
The impenetrable barrier sections 11, 12, 13, 14, 15 are made of an appropriate material, core, thickness, and structure suitable for the strength required, for example plate steel, rectangular, round or other shaped metal tubing or beams, metal fencing or guardrails.
Regardless of the material, the impenetrable barner sections 11, 12, 13, 14, 15 must form a continuous barrier surface without any significant abutments or openings.
The impenetrable barrier sections 11, 12, 13, 14, 15 are anchored to the existing concrete barrier 9 by steel cables 5 generally horizontal to and at different heights with respect to the roadway or racing surface whose diameter and core structure are dependent on the required tension, elasticity and breaking strength for a specific application and are fixed on the one end to the cable support rings 3 and on the other end to anchors 21 imbedded within the existing concrete barners 9 or by other means.
The impenetrable barner sections have a leading segment 31 which is that area extending from top to bottom of the barrier section at the end of the barrier section farthest along the section with respect to the direction of travel of the vehicle or racecar, and a trailing segment 32 which is that area extending from top to bottom of the barrier section at the end of the barner section nearest on the section with respect to the direction of travel of the vehicle or racecar. The impenetrable barrier sections have a leading edge 33 which is that cross-sectional surface at the end of the barrier section farthest along the section with respect to the direction of travel of the vehicle or racecar, and a trailing edge 34 which is that cross-sectional surface at the end of the barrier section closest along the section with respect to the direction of travel of the vehicle or racecar. The impenetrable barrier sections 11, 12, 13, 14, 15 have a plurality of overlap stops 7 fixed generally at the leading segment 31 at different heights on the internal surface of the barner section to butt against the overlapping trailing edge of the subsequent barrier section to prevent forward displacement (i.e., displacement in the direction of the traffic direction) of the impenetrable barrier sections 11, 12, 13, I4, 15 upon impact and maintain the integrity of the continuous barner surface formed by the overlapping impenetrable barrier sections 11,12,13,14,15.
Generally, the steel cable suspended energy absorbing and impact attenuating barrier system 10 will be considered to have three states as shown generally in FIG. 2 for the purposes of this description: resting, impact or compression, and rebound.
The resting state of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 is shown generally in FIG. 2A. The barner sections 11, 12, 13, 14, 15 are suspended in a generally vertical alignment with the roadway or racing track by anchor cables S having a diameter, core structure, tension, elasticity and breaking strength appropriate for the application with an energy absorbing medium or media 8 of appropriate density, compressive strength or strengths, and height, width and thickness interceding between the existing concrete barrier 9 and the barner sections 11, 12, 13, 14, 15. Note that by adjusting the length of the upper, mid and lower anchor cables 5 that the barner sections may have a positive or negative camber with respect to the racing surface should such a camber provide an improved energy absorption or impact attenuation. The anchor cables 5 hold the barrier sections 1 l, 12, 13, 14, 15 in intimate association with the energy absorbing medium or media 8. Thus the barrier sections 11, 12, 13, 14, 15 are maintained in a generally vertical alignment with respect to the roadway or racing surface on the one side by the energy absorbing medium or media 8 and by the length and tension of the anchor cables S.
The barrier sections 1 l, 12, 13, 14, 15 overlap one another at their leading segments 31 and trailing segments 32 by an appropriate length depending on the strength and maximum displacement of the barrier sections such that the leading segment 31 of one section is positioned in front of (i.e., towards the roadway or racing surface facing incident vehicles or racecars) the trailing segment 32 of the next panel with respect to the direction of travel of the roadway or racing surface. The overlap length must be appropriate related to the strength of the barrier sections 11, 12, 13, 14, 15 such that an impact at one section may flex the impacted barner section but will not cause the impacted barner section to deform permanently rather than transfer the impact energy to displace the trailing segment 32 of the next subsequent section. The overlap length must be appropriate related to the maximum displacement of the barner sections such that at maximum displacement of one panel with respect to it's previous or subsequent barrier section, that a continuous barrier surface is maintained with respect to the travel of the vehicle or racecar without creating an abutment or loss of integrity of the barrier surface.
The trailing edge of each the barrier sections 11, 12, 13, 14 butt against the plurality of overlap stops 7 fixed to the internal surface (i.e., facing away from the roadway or racing surface, or towards the energy absorbing medium or media 8) of the leading segment of barrier sections 12, 13, 14, 15.
The suspending steel cables 6 form a multiple cable safety barner and also serve to maintain the barrier sections 11, 12, 13, 14, 15 in their prescribed overlapping fashion to form a continuous impenetrable barner and have a diameter, core structure, tension, elasticity and breaking strength appropriate for the application and to also function as a multiple cable safety barrier. The suspending steel cables 6 have an amount of tension or slack per barrier section appropriate for the maximum displacement of the barner sections such that upon impact the barner sections 11, 12, 13, 14, 15 are capable of displacing an appropriate amount in the direction of the impact against the taking up of the slack, tension and elastic stretching of the suspending steel cables 6.
In the impact or compression state of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 shown generally in FIG. 2B, the barrier section 13 is impacted by an incident racecar 25 in an oblique collision. The front, right portion of the racecar 25 impacts barrier section 13 such that the trailing segment of barner section 13 more readily displaces and compresses the energy absorbing medium or media 8 because the leading segment 32 of barrier section 13 overlaps that of barrier section 12 in front (i.e., towards the roadway or racing surface) of barner section 12, thus requiring barrier section 12 to also be displaced against the tension of the steel suspending cables 6 and compression of the energy absorbing medium or media 8.
Forward displacement of the impacted barrier section 13 (i.e., displacement of barner section 13 in the direction of traffic towards barrier section 12 in oblique collisions) is prevented by the plurality of overlap stops 7 fixed on the internal surface of the leading segment 31 of barrier section 13 that butt against the trailing edge 34 of barner section 12. The barrier section 13 displaces in the direction of the impact, trailing segment 32 more so than leading segment 31, causing the incident racecar 25 to be redirected back to the racing surface in the direction of travel after impact and causing the slack of the steel suspending cables 6 to be taken up, tension to increase and possible elastic stretching depending on the severity of the impact in the steel suspending cables 6 thereby causing displacement of neighbouring sections 12 and 14 against the energy absorbing medium or media 8. The anchoring cables 5 of barrier sections 12, 13, 14 have slackened while the anchor cables 5 of other barrier sections will be at tension holding the barrier sections from pulling away from the concrete barriers to which they are attached due to the increased tension or potential elastic stretching of the steel suspending cables 6. The displaced barrier sections 12, 13, 14 will compress the associated energy absorbing and impact attenuating medium or media 8 to varying degrees, generally more so in the region of the trailing segment 32 of the impacted section 13. The barrier sections 12, 13, 14 remain in an overlapped condition with one another even while displaced to maintain a continuous impenetrable barrier surface with respect to the travel of racecar 25 without creating an abutment or loss of integrity of the barrier surface.
In the rebound state of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 shown generally in FIG. 2C, the barner section 13 rebounds after impact from the incident racecar 25 which has now been redirected and traveled .
further along the racing surface. Subsequent to barrier sections 12, 13, 14 reaching their maximum displacement due to the impact energy, steel suspending cable 6 is at tension and possibly stretched elastically depending on the severity of the impact due to the displacement of barner sections 12, 13, 14, and the energy absorbing medium or media 8 is compressed to varying degrees more so in the region of the trailing segment 32 of burner section 13. The steel suspending cable 6 tensioning and possible elastic stretching, and elasticity of the compressed energy absorbing medium or media 8 will cause a partial rebound of barrier sections 12, 13, 14 to their resting state positions after the impact depending on the severity of the impact. The barrier sections 12, 13, 14 maintain overlap with one another even while rebounding to maintain a continuous impenetrable barrier surface that is maintained with respect to the travel of racecar 25 without creating an abutment or loss of integrity of the barrier surface. The barrier sections 12, 13, 14 are then completely restored to their resting state positions quickly and easily by repair crews. The mufti-phase energy absorbing and impact attenuating module 10 is designed to be sufficiently resilient to accommodate multiple impacts and resist incapacitating damage that will cause it to lose integrity or function during a racing event.
Further details of the exemplary steel cable suspended energy absorbing and impact attenuating barner system 10 are shown generally in FIG. 3, FIG. 4, FIG. 5 and FIG. 6.
Conceivably, those persons knowledgeable in this field of endeavor will, upon studying this disclosure, consider various modifications and/or improvements to the inventive concept presented, but still within this concept. Though primarily designed for the preferred embodiments and aspects as mentioned herein, this in no way limits the use of the invention. In fact, steel cable suspended energy absorbing and impact attenuating barrier systems may be useful in a wide variety of applications in which energy absorption and impact attenuation of a vehicle or racecar are desired.
Therefore, the invention herein is not to be limited to the preferred embodiments and aspects set forth as exemplary of the invention, but only by the scope of the claims and the equivalents thereto.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system wherein said barrier system is an impact-absorbing barrier for race tracks or roadways.
FIG. 2 is a top view of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system wherein said burner system is impacted by an incident racecar.
Figure 2 consists of three sub-figures representing the dynamics of the crash and response of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system.
FIG. 2A demonstrates an incident racecar and said exemplary steel cable suspended energy absorbing and impact attenuating barrier system in its resting state.
FIG. 2B demonstrates the impact of an incident racecar with said exemplary steel cable suspended energy absorbing and impact attenuating barrier system and exhibits the response of said exemplary steel cable suspended energy absorbing and impact attenuating barrier system in the impact or compression phase.
FIG. 2C demonstrates the re-direction of the impacting racecar back onto the racetrack by preferential deflection of the trailing segment of the impacted barrier section and the response of said exemplary steel cable suspended energy absorbing and impact attenuating barrier system after the impact during the rebound state.
FIG. 3 is a detailed top view of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in its resting state isolating the overlapping joint of t:he barrier sections, steel suspending cables, anchor cables and cable support rings of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in its resting state.
FIG. 4 is a side view of an exemplary steel cable suspended. energy absorbing and impact attenuating barrier system in its resting state.
FIG. 5 is a top view of an alternate embodiment of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in which the energy absorbing medium or media is placed between the anchor cables of the leading segment of one impenetrable barrier section and the anchor cables of the trailing segment of the subsequent impenetrable barrier section.
FIG. 6 is a side view of an alternate embodiment of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in which the upper anchor cable is anchored to withstand the potentially higher tension created when an open wheel racecar (e.g. IRL or CART
racecar) impacts the impenetrable barrier section lower to the racing surface in comparison to a closed wheel car (e.g., NASCAR car).
[DRAWINGS]
Figure 1 Figure 2A
Figure 2B Figure 2C
Figure 3 Figure 4 Figure 5 Figure 6
oval racetracks, because significant impacts with an incident racecar during the event can dislodge the tire barner module itself or break the tire bundles causing the dislodged tires or associated hardware from the barner to be a safety hazard to the racing event.
Additionally, the speeds associated with racecars in oval race tracks would cause a snagging hazard.
Those skilled in the art have previously described energy absorbing or attenuating elements in a plurality of barner modules manufactured of a variety of materials such as wood, metal, polymers, elastomers, or rubber to be utilized for absorbing the impact of incident colliding vehicles. Yunick (1997, US Patent 5,645,368) described a racetrack consisting of barrier modules including a base mounted on the barrier support surface delineating two crash barrier rings circumscribing the racing surface with the inner ring in a juxtaposed relationship with the racing surface. Yunick's invention relates also to racetracks and their construction, more particularly to new vehicle racetracks constructed with novel and improved crash barners. However, the novel barrier method described by Yunick cannot be integrated easily, if at all, with existing barrier systems found at existing racetracks.
Muller (1998, US Patent 5,851,005) described the use of hexagonal metal elements to absorb incident impacts, however, the impact absorbing capabilities of such a device are exhausted after a single severe impact and afford no further impact absorbing properties for collisions that may occur immediately after this first impact or prior to repair. Arthur (1999, US Patent 6,276,667) described the use of cylindrical elements of a rubber or polymer material that may retain their impact-absorbing characteristics after an initial severe impact. Muller and Arthur have both chosen to align the impact absorbing hexagonal or cylindrical elements such that the long axes are parallel and longitudinal to the vertical surface of the existing barrier rather than orthogonal. Such alignment provides for only limited collapse or compression of the elements as defined by the material, and width of the hexagonal or cylindrical elements. Moreover, longitudinal alignment of similar hexagonal or cylindrical elements does not provide for as efficient energy absorbing or impact attenuating characteristics as by placing the hexagonal or cylindrical elements in a horizontal alignment, such as is the case when placing a honeycomb-type energy absorbing medium with its thickness (T) direction parallel to the racing surface and generally perpendicular to the existing concrete barrier.
More recently, those skilled in the art have considered barriers whereby materials of relatively low density, for example, low, medium or high density foam, have been placed in front of the existing concrete barrier system to provide energy absorbing and impact attenuating characteristics generally known as 'soft wall' barriers. Due to the relatively low density of these materials, however, a significant depth of material is required to attenuate racing vehicles, thus decreasing the overall usable surface of the racetrack.
Moreover, these materials are generally not resilient and a single impact may exhaust or significantly reduce the energy absorbing and impact attenuating characteristics of such barriers. In addition, unless a combination of materials of various densities is utilized in the 'soft wall' barrier design, the energy absorbing and impact attenuating properties of such a system are also of a single phase owing to the single density energy-absorbing medium.
Thermoset elastomers (TSE) consisting of cross-linked polymer chains have also been considered for 'soft wall' applications. Safari Associates, Inc. utilize a material called MolecuthaneTM for soft wall applications in automobile racing. While TSE
barriers may be designed with suitable energy absorbing and impact attenuating characteristics in their thickness direction, and may provide mufti-phase absorption and attenuation due to layers of differing densities, they may cause a 'pocketing' response as described below and are also generally not recyclable as thermoplastic elastomers (TPE) are.
Other 'soft wall' barrier solutions such as sacrificial inertial barriers that utilize frangible burners containing energy absorbing dispersible mass including sand and water (Fitch, 1999, US Patent 5,957,616) have been described. A single, severe impact with the frangible barrier will not only exhaust or significantly reduce its energy absorbing and impact attenuating capabilities, but also may contaminate the racing surface with the dispersed energy-absorbing material.
However, 'soft wall' barrier solutions may result in a 'snagging' or 'pocketing' characteristic that snags incident cars upon impact when they penetrate the relatively soft materials thereby causing a very fast deceleration of the incident car that in fact may cause significant damage to the driver in the collision of the car with the 'soft wall' due to the pronounced deceleration forces associated with the 'pocketing' response.
A solution in prior art to the problems of 'soft walls' and 'pocketing' responses is to use an impenetrable outer surface to the barrier system such as high-density polyethylene, guardrails or rectangular metal tubing.
The Indy Racing League (IRL) and Indianapolis Motor Speedway (IMS) installed a barrier system on the inside of Turn 4 in 1998 called the Polyethylene Energy Dissipating System (PEDS) utilizing 5-foot long overlapping, high density, polyethylene impact plates with two 16-inch diameter polyethylene cylinders bolted behind the impact plates acting as the energy absorbing medium. However, the high-density polyethylene impact plates are not sufficiently resilient when positioned on the outside of a curve to avoid penetration and subsequent 'snagging' or 'pocketing' by an impacting racecar.
Fitch (1999, US Patent 5,921,702) described a displaceable highway safety barrier system extending along the side of a roadway that includes a number of skid assemblies resting without attachment on a supporting surface adjacent to the roadway. However, such displaceable guardrail barriers require many mounting and interface members and significant space requirements. Fitch (2000, US Patent 6,010,275) also described a compression guardrail including a rail extending longitudinally along a roadway with a plurality of fixed support posts spaced behind the rail and resilient compressible energy absorbing means mounted between the rail and the posts. However, in both systems described by Fitch, the barrier itself is a continuous, strong, impenetrable surface and, while bendable, as such is not easily displaceable or compressible, therefore not providing as efficient an energy absorbing or impact attenuating response as possible.
The Indy Racing League (IRL) and Indianapolis Motor Speedway (IMS) have developed a barrier system in conjunction with the Midwest Roadside Safety Facility at the University of Nebraska -Lincoln called the SAFER (Steel and Foam Energy Reduction) barner that was installed on the outside of turns at IMS in the spring of 2002. The barner consists of four rectangular structural steel tubes welded together forming sections, each section joined to the next by heavy steel internal splines. Bundles of 2-inch thick polystyrene sheets are placed between the structural steel tube barrier and the existing concrete barrier. However, once again the barrier itself is a continuous, strong, impenetrable surface and as such is not easily bendable, displaceable or compressible, therefore not providing as efficient an energy absorbing or impact attenuating response as possible. The SAFER barrier has been described by those skilled in the art (Bill Milliken, Milliken Research Associates and John Fitch, Race Safety) as an extremely rigid wall, one whose section inertia is so high on the structural steel tubes that they can't possibly bend or deflect to absorb enough energy, thus not utilizing the energy absorbing medium (polystyrene blocks) effectively.
An effective and efficient racing safety barrier should resist damage or breaking, avoid snagging of incident vehicles or racecars, bend or displace to absorb a significant amount of impact energy, and redirect the incident vehicle or racecar without bouncing it back across the traffic stream. Thus, an object of an improved energy absorbing and impact attenuating barrier is to utilize the advantages of a 'soft wall' system, i.e., effective energy absorption due to the compression of an energy absorbing medium or media, with the advantages of a 'hard wall' barrier, i.e., without the inherent detrimental 'pocketing' response, yet provide for improved energy absorption by providing a more bendable, displaceable and compressible barner system as compared to fixed, continuous, 'hard wall' systems such the IRL SAFER system.
One such way of accomplishing the aforementioned characteristics of a more efficient racing safety barrier is to utilize a multiple cable barrier to 'suspend' an impenetrable barrier in overlapping sections such that the impacted section or sections are capable of displacing a significant distance against the tension or elastic stretching of the suspending cables so as to compress an energy absorbing media or medium, thus effectively absorbing impact energy and attenuating the impact in a controlled fashion.
Those skilled in the art have described multiple cable barriers as traffic safety barriers decades ago; such cable barriers were largely replaced by better-performing and lower maintenance concrete and metal beam barriers. However, modern cable barrier designs perform significantly better than those used in the 1950s and 1960s and have advantages over concrete or metal beam barners such as being inexpensive and quickly constructed, and are relatively forgiving barriers that can more gradually attenuate the impact of an incident vehicle even in large angle collisions. Multiple cable (for the purposes of this description the term cable is synonymous with wire rope) safety barriers have been adopted by some U.S. states as guardrails and median barriers where the median or shoulder allows for sufficient deflection of the cables (Oregon Department of Transportation, Weak Post Three-Cable Guardrail and Median Barrier Report;
Oklahoma Department of Transportation, Brifen Four-cable Safety Fence). Multiple cable or wire rope safety barriers are also utilized extensively in other countries around the world such as Australia and the United Kingdom.
Thus, this invention relates to an improved suspended rather than fixed 'hard wall' barrier system of overlapping, impenetrable, dependent barrier sections that form a continuous crash barrier system capable of significant displacement, tensioning or elastic stretching of the steel suspending cables, and compression of an associated energy absorbing medium or media said energy absorbing medium or media used in this embodiment to enhance the energy absorption characteristics because of the limited distance for deflection of the suspending cable and banter sections to absorb the impact energy of vehicles or racecars colliding with barner systems used on roadways or race tracks including, but not limited to, oval, tri-oval, speedway, super speedway, temporary street circuits, road racing courses, drag racing or any combination of the former.
The steel cable suspended energy absorbing and impact attenuating burner system of this invention is installed in a prescribed fashion as described herein independently or with existing concrete barrier systems thereby interacting with incident colliding vehicles or racecars from a multitude of incident angles and in a multitude of orientations to displace in a controlled fashion, due to the tensioning or elastic stretching of the associated steel suspending cables and, in the preferred embodiment, compression of an associated energy absorbing medium or media, to absorb energy and attenuate the impact of the vehicle or racecar thereby decreasing the peak force of impact and deceleration as described in multiples of the force of gravity (g-force) and increasing the time as measured in milliseconds over which the peak gforce is exerted thereby reducing injury to the vehicle or racecar driver and damage to the incident colliding vehicle or racecar.
Peak g-forces of deceleration resulting from impact and time over which the impact energy are absorbed are particularly significant in collisions between a racecar and an energy absorbing and impact attenuating burner system. Peak gforces associated with the impact must be reduced as much as possible and the length of time that impact energy is dissipated as measured in milliseconds must be increased as much as possible.
The steel cable suspended energy absorbing and impact attenuating burner system of this invention may also be used in applications not associated with existing concrete burners to replace existing fixed steel or metal guardrail systems such as Armco fencing on roadways or in road racing circuits. In this embodiment of the invention, an energy absorbing medium or media may not be associated with the application and the energy absorbing response of the steel cable suspended energy absorbing and impact attenuating barrier system largely is due primarily to the displacement of the barrier section or sections against the tension or elastic stretching of the suspending steel cables.
Upon impact by an incident racecar with the improved steel cable suspended energy absorbing and impact attenuating barner system of this invention, the racecar will firstly impact a suspended impenetrable barrier section or sections without any harmful 'pocketing' characteristic, causing the suspended impenetrable barner section or sections to absorb energy of the collision by displacing in the direction of the impact against the tension of the steel suspending cables as the slack is taken up and potential elastic stretching of the cables, and compressing the energy absorbing medium or media placed in the space between the existing concrete barrier and plurality of impenetrable apron sections. The specified overlapping configuration of the plurality of impenetrable apron sections described herein will naturally redirect the car back to the racing surface due to the decreased compressive strength of the trailing segment of the plurality of impenetrable barrier sections with respect to the leading segment of the plurality of impenetrable apron sections. After impact, the tensioning and potential elastic stretching of the steel suspending cables, and compression and elasticity of the energy absorbing medium or media will serve to rebound and partially realign the plurality of impenetrable barrier sections to their original positions (resting state). The impenetrable barrier sections are made of a material that is relatively impenetrable and inflexible with respect to the impact energies of the vehicle or racecar. Such materials include but are not limited to plate steel, rectangular or round tubing or beams, and sheet metal guardrails (e.g.
Armco), however it is important that the barrier sections form a smooth continuous barrier surface with no significant abutments or openings. Complete realignment of the improved energy absorbing and impact attenuating barrier system described herein is quickly accomplished by repair crews.
Accordingly, several objects and advantages of the steel cable suspended energy absorbing and impact attenuating barrier system of the invention described herein are:
(a) the energy-absorbing characteristics of the steel cable suspended energy absorbing and impact attenuating barrier system are not broken or exhausted after a single impact such as is the case in energy absorbing barner systems utilizing a light density crushable material such as foam (Nelson, 1999,US Patent 5,860,762) or metal (Muller, 1998, US
Patent 5,851,005) that do not provide energy absorbing or impact attenuating characteristics for a secondary incident following the primary impact prior to repair being effected.
(b) the steel cable suspended energy absorbing and impact attenuating barrier system is integrated easily and inexpensively with the existing concrete barrier system as compared to other 'soft wall' and 'hard wall' designs so as to be practical and economical.
(c) the steel cable suspended energy absorbing and impact attenuating barrier system is relatively compact yet more efficient as compared to existing 'hard wall' or 'soft wall' safety barners or other safety barriers because an energy absorbing medium or media is used in addition to the tensioning and potential elastic stretching of the cables to attenuate the incident vehicle upon displacement of the barrier sections.
(d) the steel cable suspended energy absorbing and impact attenuating barrier system elements are fixed with a minimum of hardware to the existing concrete barner system in a manner that prevents elements from being dislodged or damaged such that they or debris from them may be dangerous to other drivers, vehicles or spectators.
(e) there are no dispersible elements of the steel cable suspended energy absorbing and impact attenuating barrier system that will interfere with the racing circuit or cause consequence to the race after impact and consequent rupture of the energy absorbing barrier such as is the case with frangible barners.
(f) the energy absorbing characteristics of the steel cable suspended energy absorbing and impact attenuating barrier system are mufti-phase due to the inherent compressive strength of the barner sections due to their mass, cable tension and elasticity, and energy absorbing medium or media rather than providing a single phase attenuation due to the use of a single energy absorbing medium of consistent density, shape, configuration or physical dimension.
(g) the steel cable suspended energy absorbing and impact attenuating barner system is relatively more efficient in its energy absorbing response than current 'hard wall' barrier systems due to the ability of the suspended barrier sections to be significantly displaced in the direction of the impacting force of the collision energy and significantly compress the associated energy absorbing medium or media.
(h) the energy-absorbing and attenuating characteristics are designed such that in relative terms, the steel cable suspended energy absorbing and impact attenuating barrier system is:
~ relatively 'hard' for crash energy below approximately 5 to 10 times the multiple of the force of gravity (5-lOg). That is, the suspended barrier sections do not displace significantly and the racing vehicle primarily absorbs the bulk of the impact, thus not sacrificing absorption characteristics of the wall for inconsequential collisions, nor having 'soft' portions of the wall that an incident racecar could interact with (e.g., puncture, get impeded by, get caught up with) in highly oblique collisions.
This is achieved by means of the overlapping, impenetrable barrier sections positioned in intimate contact and in a prescribed fashion external to the energy absorbing medium or media and facing incident colliding vehicles or racecars.
~ relatively 'firm', yet progressively more energy absorbing and impact attenuating as compared to current 'hard wall' barrier systems for crash energy between approximately 10 to 40 times the multiple of the force of gravity (10-40g).
That is, the overlapping, impenetrable barrier sections displace on impact causing the slack of the suspending steel cables to be taken up, tensioning and potentially elastically stretching the steel cables, and partially compressing the associated energy absorbing medium or media, and the vehicle or racecar and said steel cable suspended energy absorbing and impact attenuating barrier system share the impact energy of the crash. Due to the preferred displacement of the trailing segment of the impenetrable barrier section or sections, the steel cable suspended energy absorbing and impact attenuating barrier system will also assist in redirecting the incident vehicle or racecar back onto the racing surface after the collision.
~ relatively 'soft' for crash energy above approximately 40 times the multiple of the force of gravity (40g). That is, the overlapping, impenetrable barrier sections displace significantly on impact causing the slack of the suspending steel cables to be taken up, tensioning and potential elastic stretching of the suspending cables, and compressing the associated energy absorbing medium or media whereby the steel cable suspended energy absorbing and impact attenuating barrier system absorbs a shared but increasingly larger portion of the impact energy of the crash than current 'hard wall' barner systems. Due to the preferred displacement of the trailing segment of the impenetrable barrier section or sections, and the rebounding of the impenetrable barrier section or sections against the tension and elastic stretching of the suspending steel cables and compression of the energy absorbing medium or media, the steel cable suspended energy absorbing and impact attenuating barrier system will also assist in redirecting the incident vehicle or racecar back onto the racing surface after the collision.
(i) that, where it is understood that the impact absorbing and attenuating barrier system is not required to be installed adjacent to the existing concrete burner system around the racetrack in its entirety, that contoured or tapered end-piece components be designed and manufactured with a similar function to define the beginning and end of the energy absorbing and impact attenuating barrier system that do not pose a hazard.
(j) the steel cable suspended energy absorbing and impact attenuating barrier system manufacturing and installation process is simple thereby offering both an economical and practical advantage.
Further objects and advantages of the steel cable suspended energy absorbing and impact attenuating barrier system described herein are to provide an energy absorbing and impact attenuating barrier system for roadways and race tracks that are inert to environmental forces, require a minimum of maintenance and repair, and maintain a surface for other previously defined functions of the concrete barrier system, e.g.
advertising.
Still further objects and advantages will become apparent from review and consideration of the ensuing description and drawings.
SUMMARY OF THE INVENTION
Briefly, in the present invention a steel cable suspended energy absorbing and impact attenuating barrier system is described that provides absorption of impact energy from a colliding vehicle or racecar. The improved energy absorbing and impact attenuating barrier system for use as a motor sports or traffic safety barner described herein comprises a plurality of overlapping, impenetrable barner sections forming a continuous barrier at the periphery of or at a distance from the roadway or racing surface suspended in a generally vertical configuration with respect to the race track or roadway by a plurality of steel cables, and displaced from the existing concrete barrier by an energy absorbing medium or media. The steel suspending cables are held in place by cable support rings in which said suspending steel cables are free to slide back and forth in said cable support rings, said suspending steel cables having a designated slack or tension per barrier section depending on the desired maximum displacement of the impenetrable barrier section and impact energy, said cable support rings being fixed to the impenetrable barrier sections, said suspending steel cables being fixed at their terminus to an immovable structure, said plurality of impenetrable barrier sections of which are positioned in a specified overlapping manner with respect to the direction of traffic. The plurality of impenetrable barner sections are anchored to existing concrete barriers or other structures by means of a plurality of generally horizontal steel cables which also attach to the cable support rings perpendicular to the direction of the steel suspending cables. An energy absorbing medium or media is positioned in the space between the concrete barriers and steel cable suspended impenetrable barner sections.
Because the steel cable suspended energy absorbing and impact attenuating barner system of this invention is displaceable and not fixed, and comprises sections to form a continuous barner rather than a continuous inflexible or norrdisplaceable impenetrable barner as compared to those of prior art, the present invention offers an improved energy absorbing and impact attenuating response. The energy absorbing and impact attenuating response is provided by the tension and elastic stretching of the suspended steel cables against the displacement of the sections upon impact, and the compression of the energy absorbing medium or media by the displaced barrier section or sections. A
further improvement of the present invention is the ability of the barrier system to redirect impacting vehicle or racecars back onto the roadway or racing surface in the direction of traffic resulting from the decreased compressive strength of the trailing segment of the impenetrable barrier sections relative to the leading segment.
The above discussed and many other features, objects and advantages of the present invention will be better understood by reference to the following detailed description and accompanying drawings.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the ensuing diagrams, an exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 is shown generally in FIG.
1 wherein said barner system is an energy absorbing barner for racecars on oval race tracks comprising a plurality of overlapping impenetrable barrier sections 11, 12, 13, 14, 15 forming a continuous barrier with respect to the roadway or racing surface and direction of travel of the racecar. In the preferred embodiment, the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 is shown integrated with an existing concrete barner commonly used at oval racetracks. However, the exemplary steel cable suspended energy absorbing and impact attenuating burner system may be modified for use on roadways or other types of racing tracks and integrated with other structures. Whereas multiple cable safety barriers of prior art do not utilize impenetrable barrier sections placed in front of the cables to firstly interact with an impacting vehicle or racecar, in the application of the exemplary embodiment described herein, the impenetrable barrier sections are required to prevent an incident vehicle or racecar from penetrating between cables and having the cables cause damage to the vehicle or racecar and driver or occupants.
Each barner section 11, 12, 13, 14, 15 is suspended in a generally vertical alignment with respect to the roadway or racing surface by a plurality of suspended steel cables 6 generally parallel to and at different heights with respect to the roadway or racing surface whose diameter and core structure are dependent on the required tension, elasticity and breaking strength for a specific application, each suspended steel cable 6 of which is held in position by a plurality of cable support rings 3 at different heights with respect to the roadway or racing surface in which the suspending cables are free to move. The inner surface of the cable support rings 3 may be reinforced and lubricated to facilitate such movement. The plurality of cable support rings 3 are fixed to the barrier sections 11, 12, 13, 14, 15 by stove head bolts 4 or similar fixing hardware that will not intrude on the smooth surface of the barner system to form abutments. The impenetrable barrier sections 11, 12, 13, 14, 15 are placed external to an energy absorbing medium or media 8 in the preferred embodiment to face incident racecars. However, the steel cable suspended energy absorbing and impact attenuating barrier system 10 of this invention may also be used in applications not associated with existing concrete barners 9 to replace existing fixed steel or metal guardrail systems such as Armco fencing on roadways or in road racing circuits. In the latter embodiment of the present invention, an energy absorbing medium or media 8 may not necessarily be associated with the application and the energy absorbing response of the steel cable suspended energy absorbing and impact attenuating barrier system 10 largely is due primarily to the displacement of the barrier section or sections against the tension or elastic stretching of the suspending steel cables. The impenetrable barrier sections 11, 12, 13, 14, 15 may overlap to form a linear or curved continuous burner.
The impenetrable barrier sections 11, 12, 13, 14, 15 are made of an appropriate material, core, thickness, and structure suitable for the strength required, for example plate steel, rectangular, round or other shaped metal tubing or beams, metal fencing or guardrails.
Regardless of the material, the impenetrable barner sections 11, 12, 13, 14, 15 must form a continuous barrier surface without any significant abutments or openings.
The impenetrable barrier sections 11, 12, 13, 14, 15 are anchored to the existing concrete barrier 9 by steel cables 5 generally horizontal to and at different heights with respect to the roadway or racing surface whose diameter and core structure are dependent on the required tension, elasticity and breaking strength for a specific application and are fixed on the one end to the cable support rings 3 and on the other end to anchors 21 imbedded within the existing concrete barners 9 or by other means.
The impenetrable barner sections have a leading segment 31 which is that area extending from top to bottom of the barrier section at the end of the barrier section farthest along the section with respect to the direction of travel of the vehicle or racecar, and a trailing segment 32 which is that area extending from top to bottom of the barrier section at the end of the barner section nearest on the section with respect to the direction of travel of the vehicle or racecar. The impenetrable barrier sections have a leading edge 33 which is that cross-sectional surface at the end of the barrier section farthest along the section with respect to the direction of travel of the vehicle or racecar, and a trailing edge 34 which is that cross-sectional surface at the end of the barrier section closest along the section with respect to the direction of travel of the vehicle or racecar. The impenetrable barrier sections 11, 12, 13, 14, 15 have a plurality of overlap stops 7 fixed generally at the leading segment 31 at different heights on the internal surface of the barner section to butt against the overlapping trailing edge of the subsequent barrier section to prevent forward displacement (i.e., displacement in the direction of the traffic direction) of the impenetrable barrier sections 11, 12, 13, I4, 15 upon impact and maintain the integrity of the continuous barner surface formed by the overlapping impenetrable barrier sections 11,12,13,14,15.
Generally, the steel cable suspended energy absorbing and impact attenuating barrier system 10 will be considered to have three states as shown generally in FIG. 2 for the purposes of this description: resting, impact or compression, and rebound.
The resting state of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 is shown generally in FIG. 2A. The barner sections 11, 12, 13, 14, 15 are suspended in a generally vertical alignment with the roadway or racing track by anchor cables S having a diameter, core structure, tension, elasticity and breaking strength appropriate for the application with an energy absorbing medium or media 8 of appropriate density, compressive strength or strengths, and height, width and thickness interceding between the existing concrete barrier 9 and the barner sections 11, 12, 13, 14, 15. Note that by adjusting the length of the upper, mid and lower anchor cables 5 that the barner sections may have a positive or negative camber with respect to the racing surface should such a camber provide an improved energy absorption or impact attenuation. The anchor cables 5 hold the barrier sections 1 l, 12, 13, 14, 15 in intimate association with the energy absorbing medium or media 8. Thus the barrier sections 11, 12, 13, 14, 15 are maintained in a generally vertical alignment with respect to the roadway or racing surface on the one side by the energy absorbing medium or media 8 and by the length and tension of the anchor cables S.
The barrier sections 1 l, 12, 13, 14, 15 overlap one another at their leading segments 31 and trailing segments 32 by an appropriate length depending on the strength and maximum displacement of the barrier sections such that the leading segment 31 of one section is positioned in front of (i.e., towards the roadway or racing surface facing incident vehicles or racecars) the trailing segment 32 of the next panel with respect to the direction of travel of the roadway or racing surface. The overlap length must be appropriate related to the strength of the barrier sections 11, 12, 13, 14, 15 such that an impact at one section may flex the impacted barner section but will not cause the impacted barner section to deform permanently rather than transfer the impact energy to displace the trailing segment 32 of the next subsequent section. The overlap length must be appropriate related to the maximum displacement of the barner sections such that at maximum displacement of one panel with respect to it's previous or subsequent barrier section, that a continuous barrier surface is maintained with respect to the travel of the vehicle or racecar without creating an abutment or loss of integrity of the barrier surface.
The trailing edge of each the barrier sections 11, 12, 13, 14 butt against the plurality of overlap stops 7 fixed to the internal surface (i.e., facing away from the roadway or racing surface, or towards the energy absorbing medium or media 8) of the leading segment of barrier sections 12, 13, 14, 15.
The suspending steel cables 6 form a multiple cable safety barner and also serve to maintain the barrier sections 11, 12, 13, 14, 15 in their prescribed overlapping fashion to form a continuous impenetrable barner and have a diameter, core structure, tension, elasticity and breaking strength appropriate for the application and to also function as a multiple cable safety barrier. The suspending steel cables 6 have an amount of tension or slack per barrier section appropriate for the maximum displacement of the barner sections such that upon impact the barner sections 11, 12, 13, 14, 15 are capable of displacing an appropriate amount in the direction of the impact against the taking up of the slack, tension and elastic stretching of the suspending steel cables 6.
In the impact or compression state of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 shown generally in FIG. 2B, the barrier section 13 is impacted by an incident racecar 25 in an oblique collision. The front, right portion of the racecar 25 impacts barrier section 13 such that the trailing segment of barner section 13 more readily displaces and compresses the energy absorbing medium or media 8 because the leading segment 32 of barrier section 13 overlaps that of barrier section 12 in front (i.e., towards the roadway or racing surface) of barner section 12, thus requiring barrier section 12 to also be displaced against the tension of the steel suspending cables 6 and compression of the energy absorbing medium or media 8.
Forward displacement of the impacted barrier section 13 (i.e., displacement of barner section 13 in the direction of traffic towards barrier section 12 in oblique collisions) is prevented by the plurality of overlap stops 7 fixed on the internal surface of the leading segment 31 of barrier section 13 that butt against the trailing edge 34 of barner section 12. The barrier section 13 displaces in the direction of the impact, trailing segment 32 more so than leading segment 31, causing the incident racecar 25 to be redirected back to the racing surface in the direction of travel after impact and causing the slack of the steel suspending cables 6 to be taken up, tension to increase and possible elastic stretching depending on the severity of the impact in the steel suspending cables 6 thereby causing displacement of neighbouring sections 12 and 14 against the energy absorbing medium or media 8. The anchoring cables 5 of barrier sections 12, 13, 14 have slackened while the anchor cables 5 of other barrier sections will be at tension holding the barrier sections from pulling away from the concrete barriers to which they are attached due to the increased tension or potential elastic stretching of the steel suspending cables 6. The displaced barrier sections 12, 13, 14 will compress the associated energy absorbing and impact attenuating medium or media 8 to varying degrees, generally more so in the region of the trailing segment 32 of the impacted section 13. The barrier sections 12, 13, 14 remain in an overlapped condition with one another even while displaced to maintain a continuous impenetrable barrier surface with respect to the travel of racecar 25 without creating an abutment or loss of integrity of the barrier surface.
In the rebound state of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system 10 shown generally in FIG. 2C, the barner section 13 rebounds after impact from the incident racecar 25 which has now been redirected and traveled .
further along the racing surface. Subsequent to barrier sections 12, 13, 14 reaching their maximum displacement due to the impact energy, steel suspending cable 6 is at tension and possibly stretched elastically depending on the severity of the impact due to the displacement of barner sections 12, 13, 14, and the energy absorbing medium or media 8 is compressed to varying degrees more so in the region of the trailing segment 32 of burner section 13. The steel suspending cable 6 tensioning and possible elastic stretching, and elasticity of the compressed energy absorbing medium or media 8 will cause a partial rebound of barrier sections 12, 13, 14 to their resting state positions after the impact depending on the severity of the impact. The barrier sections 12, 13, 14 maintain overlap with one another even while rebounding to maintain a continuous impenetrable barrier surface that is maintained with respect to the travel of racecar 25 without creating an abutment or loss of integrity of the barrier surface. The barrier sections 12, 13, 14 are then completely restored to their resting state positions quickly and easily by repair crews. The mufti-phase energy absorbing and impact attenuating module 10 is designed to be sufficiently resilient to accommodate multiple impacts and resist incapacitating damage that will cause it to lose integrity or function during a racing event.
Further details of the exemplary steel cable suspended energy absorbing and impact attenuating barner system 10 are shown generally in FIG. 3, FIG. 4, FIG. 5 and FIG. 6.
Conceivably, those persons knowledgeable in this field of endeavor will, upon studying this disclosure, consider various modifications and/or improvements to the inventive concept presented, but still within this concept. Though primarily designed for the preferred embodiments and aspects as mentioned herein, this in no way limits the use of the invention. In fact, steel cable suspended energy absorbing and impact attenuating barrier systems may be useful in a wide variety of applications in which energy absorption and impact attenuation of a vehicle or racecar are desired.
Therefore, the invention herein is not to be limited to the preferred embodiments and aspects set forth as exemplary of the invention, but only by the scope of the claims and the equivalents thereto.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system wherein said barrier system is an impact-absorbing barrier for race tracks or roadways.
FIG. 2 is a top view of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system wherein said burner system is impacted by an incident racecar.
Figure 2 consists of three sub-figures representing the dynamics of the crash and response of the exemplary steel cable suspended energy absorbing and impact attenuating barrier system.
FIG. 2A demonstrates an incident racecar and said exemplary steel cable suspended energy absorbing and impact attenuating barrier system in its resting state.
FIG. 2B demonstrates the impact of an incident racecar with said exemplary steel cable suspended energy absorbing and impact attenuating barrier system and exhibits the response of said exemplary steel cable suspended energy absorbing and impact attenuating barrier system in the impact or compression phase.
FIG. 2C demonstrates the re-direction of the impacting racecar back onto the racetrack by preferential deflection of the trailing segment of the impacted barrier section and the response of said exemplary steel cable suspended energy absorbing and impact attenuating barrier system after the impact during the rebound state.
FIG. 3 is a detailed top view of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in its resting state isolating the overlapping joint of t:he barrier sections, steel suspending cables, anchor cables and cable support rings of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in its resting state.
FIG. 4 is a side view of an exemplary steel cable suspended. energy absorbing and impact attenuating barrier system in its resting state.
FIG. 5 is a top view of an alternate embodiment of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in which the energy absorbing medium or media is placed between the anchor cables of the leading segment of one impenetrable barrier section and the anchor cables of the trailing segment of the subsequent impenetrable barrier section.
FIG. 6 is a side view of an alternate embodiment of an exemplary steel cable suspended energy absorbing and impact attenuating barrier system in which the upper anchor cable is anchored to withstand the potentially higher tension created when an open wheel racecar (e.g. IRL or CART
racecar) impacts the impenetrable barrier section lower to the racing surface in comparison to a closed wheel car (e.g., NASCAR car).
[DRAWINGS]
Figure 1 Figure 2A
Figure 2B Figure 2C
Figure 3 Figure 4 Figure 5 Figure 6
Claims
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2406361 CA2406361A1 (en) | 2002-10-15 | 2002-10-15 | Steel cable suspended energy absorbing and impact attenuating barrier system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2406361 CA2406361A1 (en) | 2002-10-15 | 2002-10-15 | Steel cable suspended energy absorbing and impact attenuating barrier system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2406361A1 true CA2406361A1 (en) | 2004-04-15 |
Family
ID=32399691
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2406361 Abandoned CA2406361A1 (en) | 2002-10-15 | 2002-10-15 | Steel cable suspended energy absorbing and impact attenuating barrier system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2406361A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013077945A1 (en) * | 2011-11-23 | 2013-05-30 | Engineered Arresting Systems Corporation | Vehicle catch systems and methods |
| US11162274B2 (en) * | 2019-01-15 | 2021-11-02 | Terry Brock | Catch fence system |
-
2002
- 2002-10-15 CA CA 2406361 patent/CA2406361A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013077945A1 (en) * | 2011-11-23 | 2013-05-30 | Engineered Arresting Systems Corporation | Vehicle catch systems and methods |
| US9677234B2 (en) | 2011-11-23 | 2017-06-13 | Engineered Arresting Systems Corporation | Vehicle catch systems and methods |
| US11162274B2 (en) * | 2019-01-15 | 2021-11-02 | Terry Brock | Catch fence system |
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