GB2399584A

GB2399584A - Vehicular crash barrier

Info

Publication number: GB2399584A
Application number: GB0306214A
Authority: GB
Inventors: David John Spanswick-Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-19
Filing date: 2003-03-19
Publication date: 2004-09-22
Anticipated expiration: 2023-03-19
Also published as: GB2399584B; GB0306214D0

Abstract

The crash barrier comprises a series of flexible rubber sheets 10 which are each anchored along one edge of a retaining wall. The sheets are profiled so that the free end portions all extend in the same direction generally parallel to the wall 2. The trailing edge of each free end portion overlaps the leading end of the free end portion lying immediately downstream. Blocks 8 of foam are located one between each two adjacent sheets and retained against the wall by the sheets. Any vehicle impacting the barrier has its impact absorbed by the blocks and is pushed from one block to the next by the sliding of the free end portions of the sheets over one another. Also claimed is a crash barrier designed to float on water and to be towed behind a water craft.

Description

Vehicular Crash Barriers The present invention relates to vehicular crash

barriers and, in particular, to impact absorbing vehicular crash barriers.

Road crash barriers conventionally consist of profiled metal strips or wires supported by a row of posts on one or both sides of a carriageway. The main object of these barriers is to prevent out of control vehicles from totally leaving the carriageway.

However, vehicles travelling at speed with components of motion both in the direction of, and at rights to the carriageway, are likely, when hitting the barrier, to be immediately deflected away from the barrier with significant momentum so as to be a danger to following traffic.

This situation becomes all the more precarious when the carriageway is a race track and the vehicles are racing cars. On race tracks, instead of metal strips or wires, an array of rubber lyres are used, particularly when the race track is lined by a concrete wall. Such arrays of rubber lyres are fashioned by fastening rubber lyres to the wall at a suitable height and because they are of rubber, they inflict less severe damage to the impacting vehicles and drivers. However, their resilience ensures that any impacting vehicle is more likely to bounce away from the wall.

It is an object of the invention to provide an improved vehicular crash barrier.

According to the present invention, there is provided a vehicular crash barrier comprising a plurality of flexible sheet, each anchored along one edge to and, at spaced intervals along, a surface susceptible to impact, the sheets being formed with a profile so that when anchored to said surface, their free end portions all extend in the same direction generally parallel to said surface with each sheet partially overlapping an adjacent sheet, and a plurality of blocks of impact absorbing material, each block being located between adjacent sheets and retained in position against said surface by said sheets.

According to the present invention there is provided a crash barrier arranged to float on water and be towed by a waterborne craft, the barrier comprising a plurality of elongate buoyant supports lying side by side and linked to one another by linkage means, a plurality of sheets each anchored along one edge to the linkage means at intervals corresponding to the spacing of the supports from one another so that each sheet extends upwardly between an adjacent pair of supports, the sheets being formed with a profile such their free end portions all extend in the same general direction in a generally horizontal plane with each sheet partially overlapping an adjacent sheet, and means for coupling the crash barrier to a waterborne craft.

Vehicular crash barriers embodying the present invention, will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of a crash barrier mounted on one face of a wall; Figure 2 is a fragmentary plan view, to an enlarged scale, of the barrier of Figure 1; - 3 Figure 3 is a fragmentary horizontal cross-section through a sheet of the barrier; Figure 4 is a perspective view of a crash barrier mounted on an aircraft runway; and Figure 5 is a side elevation of a sea-borne crash barrier.

As shown in Figures 1 and 2, a concrete wall 2 lines one side of a carriageway 4, and a crash barrier 6, embodying the invention, is mounted on that face 2A of the wall that lies adjacent the carriageway 4. The barrier 6 consists essentially of a series of vertically extending overlapping sheets of rubber that hold a row of blocks of impact absorbing foam against the wall 2.

Thus, as can be more clearly seen in Figure 2, the blocks 8, which stand on the ground are aligned in a row, spaced from one another, against the face 2A of the wall 2.

The blocks 8 are generally of rectangular configuration and are of foamed impact absorbing material. The blocks 8 may be of foamed rubber or plastics or some other resilient material so that they can be used to accommodate more than one impact. Instead, they may be of relatively nonresilient material for example of foamed metal which, once subject to impact, needs to be replaced.

Mounted on the wall 2 between adjacent blocks are thick flexible sheets 10 of rubber, plastics or other material.

Each sheet has one vertical edge secured to the wall 2 and is profiled to have a first portion which extends away from the wall and a second portion, at right angles to the first portion, which lies parallel to the wall so that it extends along two adjacent sides of a respective block 8 and overlaps the second portion of the sheet 8 which corresponds to the block immediately downstream.

The edge of the sheet 8 which abuts the wall may be T-shaped in horizontal cross- section, as shown in Figure 3, and is secured to the wall 2 by a series of bolts. The sheet itself may thus form a living hinge. To facilitate this, the sheet may be provided with a linear area of reduced thickness. Instead, the sheet may be secured to the wall by means of a piano hinge (not shown) or any other equivalent mechanism. Each sheet is advantageously some 2.5 cm thick but, advantageously, lies in the range of from 1.5 cm to 7.0 cm thick. The free ends of the sheets 8 all face in the downstream direction The sheets 10 are preferably the same height as the blocks and advantageously lie in the range of from SO cm to 2.00 M high.

In operation, when a vehicle impacts the barrier 6, with a component of motion in the downstream direction of the carriageway 4, the sheets 10 that are first contacted by the vehicle will compress respective the foam blocks 8 to absorb the impact. As each sheet 10 acts to compress its respective foam block 8, its second end portion will be displaced in the downstream direction to progressively increase the angle between its first and second portions and so slide over the downstream sheet 10 and to start to compress the block 8 associated with the immediately downstream sheet. The vehicle in moving in the - 5 downstream direction will then contact the imrnediate1y downstream sheet to which will then take over the act of compressing its associated block 8. The vehicle will thus proceed down the row of blocks 8 until it comes to a halt.

It will be appreciated that the sheets in progressively handing over the impact absorption from one block to the next along the row of blocks in the downstream direction ensures that there is relatively little reactive force urging the vehicle away from the wall 2 and so the vehicle will not "bounce" off the wall into the path of the following traffic.

While most of the blocks 8 are rectangular, the leading bock 8A should be generally triangular and enveloped by a corresponding profiled sheet IDA in the event that it is the first one impacted by the vehicle so as to ensure a smooth transfer for the vehicle from the leading sheet lOA to the downstream sheet l O. Each block 8 is enveloped in an enveloping covering 12. The covering 12 may be pervious to air. Instead, the covering may be l 5 impervious and provided with valved orif ces which are so arranged as to release air from within at a relatively high rate of flow when the block is impacted and a relatively low rate of flow when the foam is recovering its shape after impact. The covering l 2 may be omitted.

While the impact absorbing barrier has been described in connection with roadside situations, it will be appreciated that it can be used in many other situations. - 6

In the case of aircraft controlled crash landings, for example, the impact of an aircraft on a runway tends to cause severe damage to the underside of the aircraft, often resulting in the spillage of fuel which is readily ignited by sparks produced as the aircraft scrapes across the runway or by hot components of the aircraft itself.

The embodiment for this eventually is shown in Figure 4 in which the barrier is laid on a specific area of a runway or a site away from the runway specifically designated to deal with controlled crash landings.

As shown in Figure 4, a series of wide, generally rectangular, blocks 22 of foam lie in a closely spaced sequence along the runway. The blocks may be anchored to the runway by means (not shown) or just resting on the runway. The blocks 22 may extend the whole width or substantially the whole width of the runway. Anchored to the runway between adjacent blocks are a series of L-shaped rubber sheets 24, each of which has one arm anchored to the runway (in a manner which may be similar to that described in Figure 1) and extending vertically upwardly from the runway and the other arm extending in the downstream direction of the runway to cover an adjacent block 22 and, particularly, cover the immediately following block 22 and sheet 22, in the downstream direction. Thus, the sheets 24 progressively partially overlap one another in the downstream direction.

The blocks 22 are of foam material and are encased in an impermeable shroud 26.

The shrouds 26 is filled with nitrogen, carbon dioxide and some other flame inhibiting gas. - 7

The shroud 26 are provided with areas of weakness adjacent the exposed sides so that when the shroud and blocks are compressed, the shrouds will rupture to release the gas. In a modification, in addition to gas, the shrouds contain a non-flammable liquid gel.

The leading block 22 may be tapered or of triangular cross-section and its associated rubber sheet 24 similarly profiled.

In operation, when an aircraft crash lands on the barrier, it will compress the first block 22 it strikes to rupture the shroud. The gas released by the shroud will be sucked into the engines and other parts of the aircraft to suppress and incipient flame. The horizontal portion of the sheet will allow the aircraft to slide onto the next block 22 in the downstream direction which in turn will rupture its shroud to release more flame retarding gas and so on until the aircraft comes to a rest. Because each block 22 absorbs some of the energy of impact, there will be little, if any, tendency of the aircraft to bounce up and down on the barrier, so ensuring a smooth and safe landing. With little or no bounce, the frictional contact between the aircraft and the sheets is maintained thus ensuring that the aircraft is arrested sooner rather than later.

In a further embodiment, Figure 5 shows a water-borne crash barrier for being towed behind an aircraft carrier, for example.

As shown, the crash barrier consists of a series of cylindrical supports 30 lying side - 8 by side and linked together by a pair of chains 32 and 34 on each side which are coupled to a stub shaft 34 extending coaxially with and laterally from opposite sides of the cylinders.

Each cylindrical support 30, which is buoyant, may be of solid rubber or be hollow and

inflatable.

A capture or arresting net 36 and a pair of steel cables 40 couple the stub shafts 34 of the leading support 30 to an appropriate anchor point on the craft which is towing the crash barrier.

A series of overlapping sheets 38 of rubber are supported on the row of supports 30.

Each sheet has a first portion extending between adjacent supports 30 vertically upwardly and a second portion extending generally horizontally over the supports 30 with the second portions of adjacent sheets all being directed in the upstream direction and partially overlapping each other. The first portion of each sheet is anchored to the chain 34.

The two cylindrical supports 30A at the downstream end of the row of supports are of smaller diameter than the other supports so that the second portion of the sheet extending between those two supports slopes generally upwardly to the second portions of the other sheets.

In operation, an aircraft landing on the crash barrier at the downstream end thereof will engage the second portions of the rubber sheets 38 and will be ultimately arrested by - 9 - the net 36. The arrested aircraft may be eventually landed on the towing watercraft by drawing the net 36 onto the craft.

It will be appreciated that the outer surface of the sheets may be treated to have an increased coefficient of friction or lined with a surface layer providing increased surface friction. Also, the outer surface may be coated with a luminous paint to aid night lands.

The area surrounding the barrier may be covered will dense ASTROTURFt Row) .

It will be appreciated that the barrier may be used in other situations, for example on the dockside of a harbour to be impacted by shipping. -

Claims

Claims 1. A vehicular crash barrier comprising a plurality of flexible

sheet, each anchored along one edge tO, and at spaced intervals along, a surface susceptible to impact, the sheets S being formed with a profile so that when anchored to said surface, their free end portions all extend in the same direction generally parallel to said surface with each sheet partially overlapping an adjacent sheet, and a plurality of blocks of impact absorbing material, each block being located between adjacent sheets and retained in position against said surface by said sheets.
2. A barrier according to Claim 1, wherein said sheets are anchored to said surface by hinge means.
3. A barrier according to Claim 2, wherein said hinge is a living hinge.
4. A barrier according to Claim 2, wherein said hinge is a piano hinge.
5. A barrier according to any preceding claim, wherein each said block comprises a resilient foam material.
6. A barrier according to Claim 5, wherein said foam material and said sheets are of rubber. - 11
7. A barrier according to any one of Claims 1 to 4, wherein each said block comprises a metal foam.
8. A barrier according to any preceding claim, wherein each said block is encased in S an impermeable shroud.
9. A barrier according to Claim 8, wherein said shroud is filled with a flmne-retarding gas and/or liquid gel.
10. A barrier according to Claim 9, wherein said shroud is provided with areas of weakness which will rupture when the shroud is subjected to impact.
11. A barrier according to any preceding claim, wherein the sheet has a thickness in the range of from 1.5 to 7.0 cm.
12. A barrier according to any preceding claim, wherein the leading block of the barrier is tapered and the sheet associated with the leading block is similarly profiled to progressively build up the depth of the barrier from the surface to the full depth of the barrier.
13. A barrier according to any preceding claim, wherein the outer surface of each sheet is treated to increase its coefficient of friction. - 12
14. A barrier according to any preceding claim, wherein said surface comprises a retaining wall adjacent a carriageway.
15. A barrier according to any one of Claims 1 to 13, wherein said surface comprises an aircraft runway or crash landing site.
16. A crash barrier arranged to float on water and be towed by a waterborne craft, the barrier comprising a plurality of elongate buoyant supports lying side by side and linked to one another by linkage means, a plurality of sheets each anchored along one edge to the linkage means at intervals corresponding to the spacing of the supports from one another so that each sheet extends upwardly between an adjacent pair of supports, the sheets being formed with a profile such their free end portions all extend in the same general direction in a generally horizontal plane with each sheet partially overlapping an adjacent sheet, and means for coupling the crash barrier to a waterborne craft.
17. A crash barrier according to Claim 16, wherein a coupling means includes a reinforced retaining net.
18. A crash barrier according to Claim 16 or to Claim 17, wherein said linkage means comprises chains.
19. A vehicular crash barrier substantially as hereinbefore described, with reference to, the accompanying drawings.