Field of the invention

This invention relates generally to vehicle separation barriers. In a particularly useful embodiment, the invention provides a relocatable heavy duty vehicle separation barrier for use in delineating roadways for oversize vehicles such as mine trucks and machinery.

Background of the invention

An important issue for operational safety at mining sites is the delineation of routes for haulage trucks and other vehicles, including the separation of vehicles of different sizes and categories. For example, in open cut mining operations, there are extensive roadways including ramps along which haulage trucks, often of a very large size, travel between the surface and current operational faces. Moreover, there are often instances where, for safe operation, routes for very large haulage vehicles need to be delineated and separated from roadways for vehicles of more ordinary dimensions.

Current common practice is to employ earthworks to achieve these goals. Earthmoving machinery is used to build up extensive roadside earth barriers or levies to delineate the edges of roadways and to mark out routes for vehicles of different types. Although this approach has the advantage of utilising locally available resources, it has a number of disadvantages. Mine sites are inevitably dynamic and there is a regular need to relocate roadways or remove existing routes and create new ones. Thus substantial earthworks required on each such occasion utilise excavators and other earthmoving machinery which is diverted from other more productive uses, or which must be retained on site or nearby for the purpose. The time required to carry out these operations may be significant and may disrupt the regular haulage operations of the mine.

Another problem is that extended earth barriers can be both damaged and damaging in the event of heavy rain: they can act as dams, causing water to pool and perhaps flood roadways, they disrupt overland water flow, and high volume flows may significantly undermine or damage the earth barriers.

Relocatable vehicle barriers, whether solid concrete or water fillable hollow structures, are widely employed as separation barriers and vehicle route delineators at roadworks. These barriers are not suitable for use with the oversize vehicles employed on mine sites, and the present applicant has concluded that a simple scaling up would not adequately address the problem.

It is an object of the invention to provide a relocatable vehicle separation barrier that is suitable for use at mine sites or other locations where oversize vehicles are employed.

Summary of the invention

In a first aspect, the invention provides a relocatable vehicle separation barrier comprising a concrete wall structure on a metal skid base. In a second aspect, the invention provides a relocatable vehicle separation barrier, preferably with a concrete wall portion, of a configuration that is particularly useful with oversize vehicles.

In its first aspect, the invention provides a relocatable vehicle separation barrier comprising: an elongated metal skid base, having means for engaging the base for drawing it along a ground surface behind a tow vehicle or in a train with like vehicle separation barriers behind a tow vehicle; a concrete wall structure upstanding from the skid base and extending in the longitudinal direction of the skid base; and coupling elements attached to the elongated metal skid base extending through the concrete for securing the concrete wall structure to the metal skid base. The skid base may include a pair of longitudinally extending shallow side walls, and the coupling elements may then comprise at least two metal rods or bars extending between and attached to the side walls, for example by welding. The rods or bars may conveniently be tubular. In an embodiment, the hollow interior of the such tubular rods or bars registers with matching apertures in the side walls, and the rods or bars are correctly spaced for receiving a pair of forks of a forklift vehicle: this arrangement provides one option for transporting or relocating the barrier.

Preferably, the elongated metal skid base comprises a tray like structure formed by a sheet of metal upturned at its side margins to form said shallow side walls. Fore and aft, the sheet is advantageously slit from the side walls and turned up to form an inclined end wall, which is advantageously welded to the side walls. The resultant overhang portions of each side wall may be cut at the same angle or a shallower angle than the inclination of the aforementioned end wall. An aperture in the overhang portion(s) may provide the aforementioned means for engaging the skid base for drawing it behind a tow vehicle. This aperture is preferably suitably lined to reduce damage from the draw chain or other device placed through the aperture.

The upstanding concrete wall structure preferably has a main upright wall portion with substantially vertical or near vertical side faces, respective longitudinally extending edge portions below and outwardly of the upright wall portion, of which edge portions at least one includes a substantially horizontal surface extending the length of the barrier, and an intermediate portion on at least one, and preferably both, sides of the upright wall portion, joining the wall portion to the edge portion and having an inclined face.

In a second aspect, the invention provides a relocatable vehicle separation barrier having a main upright wall portion with substantially vertical or near vertical side faces, respective longitudinally extending edge portions below and outwardly of the upright wall portion, of which edge portion at least one includes a substantially horizontal surface extending the length of the barrier, and an intermediate portion on at least one, and preferably both, sides of the upright wall portion, joining the wall portion to the edge portion and having an inclined face.

The upright wall portion is preferably a concrete upright wall portion. In one arrangement, the barrier of the second aspect of the invention, or the concrete wall structure of the first aspect, is symmetrical about a vertical plane bisecting the upright wall portion. In another arrangement the edge portion on one side is substantially further out from the wall portion than the edge portion on the other side, thus providing a more asymmetrical configuration. Preferably, the upright wall portion of the concrete wall structure of the first aspect of the invention, or the separation barrier of the second aspect, has, on at least one of said side faces and preferably on both said side faces, a longitudinally extending groove containing a high visibility strip, e.g. a reflective or fluorescent strip. The colours of this strip on the respective sides may be different in order to characterise the side of the barrier being viewed. The provision of the high visibility strip in a groove lessens damage to the strip in the field and extends its useful operational life in terms of required visibility.

In a third aspect, the invention provides a vehicle separation barrier of a kind having a main upright wall portion with respective side faces, wherein on at least one of said side faces and preferably on both said side faces, is a longitudinally extending groove containing a high visibility strip, e.g. a reflective or fluorescent strip. The colours of this strip on the respective sides may be different in order to characterise the side of the barrier being viewed.

Preferably, the top edge of the vertical wall portion is at least 1.5 metres, and advantageously more than 2 metres above the bottom of the skid base. As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.

Brief description of the drawings

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of three vehicle separation barriers according to an embodiment of the invention, shown coupled together end to end to define a boundary between two sections of roadway;

Figure 2 is an end view of the barriers of Figure 1 ; Figure 3 is a side view of one of the barriers of Figure 1 ;

Figure 4 is a perspective view from above of a skid base of the configuration employed in the vehicle separation barrier depicted in Figure 1 ;

Figure 5 is an underneath end view of the skid base of Figure 4;

Figure 6 is a fragmentary close up of a corner region of a barrier with a link chain shown in position; and Figure 7 diagrammatically illustrates a situation in which respective vehicles on either side come too close at the barrier.

Detailed description of embodiments of the invention

Each of the three relocatable vehicle separation barriers 10 shown linked together in Figures 1 to 3 includes an elongated metal skid base 20 and a concrete wall structure 40 upstanding from the skid base and extending in its longitudinal direction.

The skid base 20 is depicted as a separate component in Figures 4 and 5. It comprises a flat metal sheet or plate 22 with side margins upturned at right angles to form shallow side walls 24. At fore and aft, sheet or plate 22 has been slit along the bend 23 for the side walls and the resultant end piece turned up by about 30° (in the range 20 to 70°) to form an inclined end wall 26 and then a vertical edge, section 25. These end walls 26 may be welded at the lateral edges to side walls 24. The side walls 24 are truncated at 27 to match the inclination of end wall 26. Each of the resultant overhangs 28 of the side walls is rounded and provided with a round hole 30 which is fitted with an anti-wear ring (Figure 6). It will be seen that the skid base 20 thus formed from a single sheet of steel may be viewed as both a tray and, for purposes to be further explained shortly, a skid or toboggan, or perhaps a sled.

The side walls 24 are linked by a pair of centrally located bars in the form of rectangular section cross tubes 34. These tubes 34 are attached by welding to the side walls 24 at a spacing that matches the standard lateral spacing of the forks of a forklift machine, and serve to reinforce the side walls against side impacts. Holes 35 are punched from side walls 24 in register with the interiors of tubes 34, so as to define through passages 36 into which forks of a forklift machine may be inserted for transporting or relocating the barrier.

During manufacture of the barrier, base 10 is fitted with other formwork and the concrete wall structure 40 is cast in situ. The concrete fills the tray provided by the base and flows about the cross tubes 34, whereby, in the end product, the cross tubes extend through the concrete and secure or key the wall structure 40 to the base 20. Typically, reinforcement mesh will have been provided within the concrete and this may advantageously be welded to, or otherwise linked to, cross tubes 34. The placed forms result in wall structure 40 having several identifiable portions as follows. A main upright wall portion 42 extends longitudinally and centrally of the base and has near vertical side faces 43, 44 and a top edge face 45 between 1.5 and 3.5 meters above the bottom of base 20, and therefore above ground. Below this main upright wall portion 42, the wall structure 40 flares out on both sides through a steeply inclined first intermediate portion 46, then a shallow inclined intermediate portion 48, and then finally an edge portion 50 with a horizontal or near horizontal flat upper face 52 and a smoothly rolled outer face 54, reaching vertical at the top edge of respective tray side wall 24.

Extending along each side face 43, 44 of main upright wall portion 42, towards the top of the wall portion, is a groove 60 that extends the length of the barrier and contains a high visibility strip 62, for example a reflective and or fluorescent yellow or orange strip. Typically, the colour of this strip will be different on either side, e.g. yellow on one side and orange on the other, so as to characterise the side of the barrier being viewed. The provision of the high visibility strip in a groove lessens damage to the strip in the field and extends its useful operational life in terms of required visibility.

In situ, the multiple barriers 10 are typically placed end to end as depicted in Figures 1 to 3 for three of the barriers. The assembly is stabilised by coupling the barriers together using short chain and shackle arrangements 38 linking adjacent holes 30 of adjacent barriers. Typically, each barrier will be supplied with chains permanently fixed in place at one end, each chain having a safety latch 39 for attachment to the next barrier. Wear rings 32 in holes 30 reduce wear by the chains and latches.

It will be seen that the truncated edges 27 and upturned inclined end walls 26 define openings 70 between each barrier for water to pass through the assembly, thereby reducing the obstruction of overland water flow during heavy rain and minimising pooling at the sides of the assembly. Moreover, the preferred arrangement is to position the barriers slightly apart to increase the size of these water flow openings 70 and to add a gap between the ends of the barriers.

Figure 7 illustrates the advantage of the multi portion configuration of wall structure 40 in a case where a row of the barriers is being employed to separate two roadways. If an oversize haulage truck 100 comes up close to the barrier, its outside wheels 102 will initially ride onto the edge portion 50 and then up the inclined portions 48, 46, thus helping to stabilise the barrier if the side of the vehicle does strike it. The weight of the vehicle is then pushing the barrier down on the ground before the vehicle hits the main upright wall portion 42: this makes it very unlikely that a side-swiping vehicle will roll the barrier over or climb over it. In fact, the wheels riding onto the edge and inclined portions will tend to tip the vehicle up and slightly away from the wall portion of the barrier: Figure 7 depicts how this action on both sides of the barrier will reduce the likelihood that vehicles will actually strike each other when respective vehicles 100, 101 on either side come too close at the barrier.

The cross tubes 34 play an important role in preventing "delamination" of the concrete wall structure 40 from the skid base 20, especially in the event that a vehicle hits the barrier at an angle and might, without the structural locking action of the tubes 34, tip the concrete wall structure over. Tip over is also countered by the longitudinal linking together of the barriers in rows.

A major advantage of the barriers of the invention over prior art earthwork barriers arises when it is necessary to rearrange or redefine roadways and thereby to relocate the barriers. Because of the metal bases 20 providing a skid or sled, the barriers may be drawn as a train, for example of 6-8 barriers, still chained together with the front barrier of the train coupled to a tow vehicle, e.g. with a suitable chain connected with a safety hook or shackle to the appropriate hole or holes 30. Diversion of a mine vehicle for this purpose would be an operation of much shorter duration than the use of earthworking machinery to demolish existing earth walls and create new ones.

A convenient size of vehicle separation barrier 10 is between 5 and 10 metres long, between 2 and 2.7 metres wide and between 1.5 and 3 metres high. Such a barrier may weigh, say 10-30 tonne. This provides the bulk and weight necessary to act as a vehicle separation barrier for oversize vehicles, with the additional benefits obtained by the various features illustrated and described above.

The illustrated heavy duty barrier can be employed as a safety stop for oversize haulage tip trucks to back-up against before they tip their load down a cliff face behind the barrier.

The illustrated barrier is symmetrical about a central vertical plane. In a modified embodiment/ the main upright wall portion may not be centered but may be offset, so that the barrier extends further on one side than the other. The edge portion 50 with its horizontal upper face may be provided on only one side of the barrier, and may be broader or narrower in extent.

In other embodiments, the skid base may comprise a pair of spaced side rails joined by steel sheet and/or by spaced cross-members such as bars or rods. Such a skid base may be described as a sled supporting the barrier wall structure for over ground sliding movement.