GB2326428A - Protective wall of sandbags - Google Patents

Abstract

A protective wall comprises a plurality of larger substantially cuboid sandbags (2) arranged side by side along a line, and a plurality of smaller conventional sandbags (8) disposed between adjacent larger sandbags (2), the sandbags being held together by strap means (10) so as to form a substantially rigid wall. The invention also provides a cuboid sandbag for use in manufacturing the wall, a method of manufacturing the wall, and a sandbag filling machine.

Description

APPARATUS AND METHOD The present invention relates to a protective wall, notably to a wall for protection against bomb blasts, and to a method of manufacturing such a wall. The invention also provides a device and method for manufacturing building elements for use in forming the wall.

An army in a war zone needs bomb blast protection walls which can be assembled where needed and, preferably, which can be removed and transported elsewhere when the army moves on.

A known protective wall comprises a pile of conventional sandbags which are assembled where required and removed when not required. Such walls are liable to collapse under pressure from a nearby bomb blast.

A known protective wall which offers better protection against bomb blasts comprises a steel mesh in a concertina-like configuration, which is filled with rubble to provide a sturdy barrier. This wall suffers from the problem that it is not practical to disassemble it. The rubble becomes tangled with the metal, and the wall effectively becomes a permanent structure.

According to one aspect of the present invention there is provided a protective wall comprising a plurality of larger substantially cuboid sandbags arranged side by side along a line, and a plurality of smaller conventional sandbags disposed between adjacent larger sandbags, the sandbags being held together by strap means so as to form a substantially rigid wall.

By providing conventional sandbags between larger cuboid sandbags, and tightly strapping all the bags together, the wall can be made highly resistant to bomb blasts and to bullets.

The protective wall may be used to protect against bomb blasts or bullets, but it is not limited to this use. The wall may, for example, be used as a temporary or permanent barrier against water, or in constructing shelters or other buildings, road blocks or rifle bunkers. The wall can also be used as a temporary or permanent sea defence, for repairing breaches in river banks or in flood protection.

If the wall becomes damaged, damaged areas can readily be replaced when needed.

The wall may readily be disassembled when no longer required.

The wall may be built as thick or as high as required.

The term "cuboid" is used to refer to a shape which is substantially a parallelepiped with sides which are rectangular or square. It is to be understood that small deviations from a perfect cuboidal form are expected and are within the scope of the invention.

The cuboid sandbags preferably have some structural rigidity, substantially retaining their shape whether full or empty. The conventional sandbags are essentially sacks or tubes with one closed end, which can deform under stress to fill small gaps and act as a binding agent to bind the wall together.

The term "sandbag" is used herein for convenience.

Suitable bags may be filled with sand, earth, gravel, stones, rubble, grit or other filling materials. Any such filled bag will be referred to herein as a sandbag. The size of a sandbag will be described herein with reference to the weight of a sandbag when filled with sand. It will be understood that sandbags filled with more dense or less dense materials will weigh correspondingly more or less.

The larger cuboid sandbags preferably weigh in the range 0.5 to 3 tonnes, notably 1 to 2 tonnes. The smaller conventional sandbags preferably weigh from 20 to 200 kg, notably 40 to 100 kg. The smaller conventional sandbags are preferably of similar height to the larger cuboid sandbags, but of less width and depth. Preferably the width and depth of the smaller conventional sandbags is in the range 150 to 600 mm, notably 250 to 350 mm. The ratio of width of the larger cuboid sandbags to the smaller conventional sandbags is preferably in the range 1.5:1 to 5:1.

The wall may be built to any preferred height, by arranging a further line of sandbags on top of a line on the ground. It is particularly preferred that the wall is three bags high.

The conventional sandbags may be disposed between cuboid sandbags which are in a horizontal or a vertical line.

For ease of construction, it is preferred that the conventional sandbags are disposed between cuboid sandbags which are in a horizontal line, so that in a wall of more than one bag height conventional bags lie one above another and cuboid bags lie one above another. For convenience hereinafter the invention will be described with reference to this embodiment; however the invention is not limited to this embodiment.

The sandbags may be made from any suitable sacking material, for example hessian, polypropylene, nylon and the like. It is preferred that the larger cuboid sandbags comprise a double layer of material for increased strength.

In a preferred embodiment, the cuboid sandbags are in two sizes, of different height but the same breadth and depth.

Similarly it is preferred that the conventional sandbags are in two sizes, of different height but the same breadth and depth. Preferably the taller cuboid sandbags are the same height as the taller conventional sandbags, and the shorter cuboid sandbags are the same height as the shorter conventional sandbags. It is particularly preferred that the taller bags are twice the height of the smaller bags.

This arrangement allows a wall to be constructed with conventional sandbags disposed between cuboid sandbags which are in columns, the conventional sandbags spanning pairs of vertically adjacent cuboid sandbags, thereby improving the structural integrity of the wall. Gaps at the top and bottom of the wall are filled with the halfsize bags.

The wall may be built with a window, comprising a square or rectangular box section member, in place of one or more cuboid sandbags.

The strap means may comprise one or more straps of a plastics material, leather, metal links, or any other suitable material. Belts, ropes or chains may be used as strap means. In a preferred embodiment, each cuboid sandbag is provided with at least one loop for receiving the strap means.

Accordingly, another aspect of the invention provides a cuboid sandbag for use in making a protective wall, the sandbag being provided with at least one guide loop for receiving strap means to be disposed along or around the middle of the sandbag.

The strap means may be tightened around the wall by ratchet means or other means well known to those skilled in the art.

The wall may be constructed in situ where required. This is preferably done by transporting empty sandbags and sandbag filling equipment to the desired location, and filling the sandbags on the spot. Filled sandbags may then be manoeuvred into position by suitable lifting and moving equipment.

Conventional sandbag filling equipment include means for transporting sand from a hopper to a bag filling location, and weighing means which trigger removal of a bag when the desired weight is reached, and replacement of the full bag with an empty bag. A problem with conventional sandbag filling equipment is that jaws which hold the bag under the bag filling location prevent the bag from being held close to the point where sand drops from the transport means. Consequently, the force of sand entering a bag from a height causes an increased weight reading, so that the bag is removed before it is full to the desired weight.

We have devised improved sandbag filling equipment suitable for filling sandbags for use in the present invention.

According to another aspect of the present invention, there is provided sandbag filling equipment including a hopper for receiving and storing sand, means for transporting sand from the hopper to a sand dropping location beneath which a sandbag to be filled can be located, and means underneath the sand dropping location for reducing the speed of sand which drops from the sand dropping location.

By reducing the speed of sand which drops into a sandbag, a truer weight reading can be obtained for the sandbag, and the sandbag can be filled more nearly to its desired weight.

In a preferred embodiment, the means for reducing the speed of the dropping sand comprises at least one baffle located under the sand dropping location, the baffle having an upper surface which is disposed at an acute angle to the horizontal. Preferably the baffle or baffles comprise plates, and the invention will be described hereinafter with reference to such plates. Preferably two plates are employed, one below the other, the bottom edge of the upper plate directing sand onto the upper part of the lower plate. The plate or plates are preferably housed within a spout which is sufficiently narrow to be inserted into a conventional sandbag.

Because the plates slow the sand down, it is preferred that means are provided for vibrating or agitating sand which is in contact with the speed reducing means, to prevent blockages occurring.

In a preferred embodiment, the sand filling equipment is provided with means for distributing sand from the hopper to a plurality of sand dropping locations, so that sandbags may be filled at different locations. Preferably there are two dropping locations, one of which dispenses sand at a greater rate than the other, so that smaller conventional sandbags are filled at one location and larger cuboid sandbags are filled at the other location.

The invention will now be further described, by way of example, with reference to the following drawing in which: Figure 1 is a cuboid sandbag for use in one aspect of the present invention; Figure 2 is a conventional sandbag for use in one aspect of the present invention; Figure 3 is a protective wall in accordance with one aspect of the present invention; Figure 4 is a protective shelter in accordance with another aspect of the present invention; Figure 5 is a plan view of the arrangement of cuboid sandbags in the shelter shown in Figure 4; Figure 6 is a front perspective view of a sandbag filling machine in accordance with a further aspect of the present invention; Figure 7 is a side elevational view of the sandbag filling machine shown in Figure 6; and Figure 8 is schematic sectional view through part of the spout of the filling machine of Figures 6 and 7.

The sandbag 2 shown in Figure 1 is a 2 tonne bag which is generally cuboid. The bag 2 is 910 mm wide and 910 mm deep and 1350 mm high. The bag 2 is provided with lifting loops 4 for supporting the sandbag 2 while the bag is being filled and when the filled sandbag 2 is being moved.

The lifting loops 4 are about 600 mm long.

Guide loops 6 are provided on the outer surface of the sandbag 6, for receiving and guiding one or more straps or the like along the middle of the sandbag. The four sides and the base of the sandbag are manufactured from doubleskinned woven polypropylene (240 gsm), and sewn together with 6000 Denier polypropylene thread, using a double stitch comprising Herakle Overlock and Antaeus Safety Chain. The lifting loops 4 and the guide loops 6 are manufactured from 50 mm wide polypropylene having a minimum tensile strength of 2200 kg.

The sandbag 2 is provided with a discharge spout 3 which communicates with the inside of the sandbag 2 through a hole in the bottom of the bag. The discharge spout 3 is blocked off by being tied with ropes 5 when the sandbag 2 is filled or being filled. To empty the sandbag, the ropes 5 are untied and the discharge spout 3 is opened while the sandbag is held up by the lifting loops 4.

The conventional sandbag 8, shown in Figure 2, is a sack which is of comparable height to the cuboid sandbag 2, but which has a width of about 300 mm.

Referring to Figure 3, a protective wall in accordance with the invention comprises larger cuboid sandbags 2 and smaller conventional sandbags 8, bound tightly together by means of a plurality of ratchet straps 10. The wall comprises vertical columns of cuboid sandbags 2, separated by vertical columns of conventional sandbags 8.

Tightening of the ratchet strap 10 deforms the conventional sandbags 8 sufficiently to obturate gaps through which bullets might otherwise pass. The conventional sandbags 8 act as a binding agent to hold the cuboid sandbags 2 securely in relation to each other.

The wall is three cuboid bags high, the bottom two layers comprising 2 tonne cuboid sandbags 2b, and the top layer comprising 1 tonne, half-height cuboid sandbags 2a.

Conversely, the conventional sandbags 8 have a bottom layer of half-height sandbags 8a and two top layers of full height sandbags 8b. This enables one full-height conventional sandbag 8b to span two pairs of cuboid sandbags 2, thereby binding all the sandbags in the wall together without the need for vertical straps. The fullheight conventional sandbags 8b weigh about 80 kg, and the half-height conventional sandbags 8a weigh about 40 kg.

Referring now to Figures 4 and 5, there is shown a protective shelter constructed on the same principles as the wall shown in Figure 3. The conventional sandbags 8 are not shown in Figure 5, for clarity. The shelter is two bags high, and windows have been provided by replacing one two-tonne sandbag 2b with a rectangular box-section member 12 and a half-height one-tonne sandbag 2a. The shelter is provided with a roof formed from elongate sandbags 14, which are similar to the conventional sandbags 8, but longer. One or more internal support columns 11 of cuboid sandbags may be provided to help support the elongate sandbags 14. Alternatively strips of metal, for example tin, or other support means could be provided. A benefit of having internal columns 11 is that they provide further protection against bullets or bomb blasts for the occupants of the shelter, in line with the windows 12.

Turning now to Figures 6 to 8, a machine 20 for filling sandbags includes a hopper 28 for receiving sand or the like, and a conveyor belt 22 for transporting the contents of the hopper a transverse conveyor belt 26. The transverse conveyor belt 26 is reversible, so that the hopper contents can be conveyed to either side of the machine 20, for filling small or large sandbags. On the right hand side as viewed in Figure 6, there is provided a spout 23 which is connected to jaws 24 for holding a conventional sandbag. The spout 23 is provided with hooks 25 for use with a bag clamp 29. The spout 23 is provided with an internal tube 31 connected to a vibrating motor (not shown) which is selectively activated in response to a signal from a load cell when the sandbag 8 has been filled almost to its desired weight. Vibration of the tube 31 causes sand which is blocked in the tube 31 to become unblocked.

The tube 31 has a pair of angled internal plates 28, one above the other, whereby some of the sand 29 which drops off the end of the conveyor belt 26 at the sand dropping location 27 falls onto the upper plate 28a and then on to the upper part of the lower plate 28b. The remainder of the sand falls outside the tube and into the bag 8. Sand which passes through the tube 31 has its downward momentum greatly reduced.

The sandbag 8 is weighed by means of a load cell which causes the bag to be removed when the desired weight is attained. When the load cell detects that the bag 8 has been filled almost to its desired weight, the transverse conveyor belt 26 is slowed or halted, and the vibrating motor is started up. The bag 8 is topped up to its final weight with sand from the vibrating tube 31 and not significantly with sand which falls outside the tube.

Because the tube 31 is close to the bag 8, falling sand has little momentum, and therefore does not cause the load cell to record significantly more than the true weight.

On a 40 kg bag, the required tolerance is typically about + 200 g, and the apparatus described will fill a bag to about + 100 g.

The machine 20 can either fill large one or two-tonne bags 2 off one side, or small conventional sandbags 8 off the other side. Up to 250 small bags per hour can readily be filled.

The machine 20 is self-contained with its own generator.

It can be put onto drop bodies and transported anywhere in the world for field operation.

When the sandbags 2, 8 are filled, they can be used immediately or transported by road, rail, or air. A large quantity of 1 tonne or 2 tonne bags can be air lifted by helicopter and dropped where needed.

Claims (26)

1. A protective wall comprising a plurality of larger substantially cuboid sandbags arranged side by side along a line, and a plurality of smaller conventional sandbags disposed between adjacent larger sandbags, the sandbags being held together by strap means so as to form a substantially rigid wall.

2. A protective wall as claimed in claim 1, wherein at least some of the cuboid sandbags are provided with at least one loop for receiving the strap means.

3. A protective wall as claimed in claim 1 or claim 2, wherein the larger cuboid sandbags weigh from 0.5 to 3 tonnes.

4. A protective wall as claimed in claim 3, wherein the larger cuboid sandbags weigh from one to two tonnes.

5. A protective wall as claimed in any one of the preceding claims, wherein the conventional sandbags weigh from 20 to 200 kg.

6. A protective wall as claimed in claim 5, wherein the conventional sandbags weigh from 40 to 100 kg.

7. A protective wall as claimed in any one of the preceding claims, wherein the larger cuboid sandbags comprise two different sizes, of different height but the same breadth and depth, and wherein the conventional sandbags are of different sizes, of different height but the same breadth and depth, the wall comprising columns of the cuboid sandbags separated by columns of conventional sandbags, wherein at least some of the conventional sandbags span pairs of vertically adjacent cuboid sandbags.

8. A protective wall as claimed in claim 8, wherein the taller sandbags are twice the height of the shorter sandbags.

9. A protective wall as claimed in any one of the preceding claims, wherein the ratio of width of the cuboid sandbags to conventional sandbags is in the range 1.5:1 to 5:1.

10. A protective wall as claimed in claim 9, wherein the width ratio is in the range 2.5:1 to 3.5:1.

11. A cuboid sandbag for use in making a protective wall according to claim 1, the sandbag being provided with at least one guide loop for receiving strap means to be disposed along or around the middle of the sandbag.

12. A cuboid sandbag as claimed in claim 11, which weighs from 0.5 to 3 tonnes.

13. A cuboid sandbag as claimed in claim 12, which weighs one to two tonnes.

14. A method of manufacturing a protective wall according to claim 1, comprising arranging a plurality of larger cuboid sandbags side by side in a line with a one or more smaller conventional sandbags between adjacent cuboid sandbags, fastening strap means around the sandbags and tightening the strap means to bind the sandbags together to form a substantially rigid wall.

15. A method of manufacturing a protective wall as claimed in claim 14, wherein the cuboid sandbags and the conventional sandbags are arranged in a plurality of columns arranged side by side with columns of conventional sandbags between columns of cuboid sandbags, the conventional sandbags spanning pairs of vertically adjacent cuboid sandbags, and wherein each row of cuboid sandbags is bound tightly by strap means.

16. Sandbag filling equipment including a hopper for receiving and storing sand, means for transporting sand from the hopper to a sand dropping location beneath which a sandbag to be filled can be located, and means underneath the sand dropping location for reducing the speed of at least some of the sand which drops from the sand dropping location.

17. Sandbag filling equipment as claimed in claim 16, wherein the speed reducing means comprises at least one baffle which has an upper surface which is disposed at an acute angle to the horizontal, the baffle being disposed below the sand dropping location so that sand which falls from the sand dropping location lands on an upper region of the baffle.

18. Sandbag filling equipment as claimed in claim 16 or claim 17, wherein the speed reducing means comprises two plates located under the sand dropping location, the plates being disposed, one below the other, at an acute angle to the horizontal, the bottom edge of the upper plate directing sand on to the upper part of the lower plate.

19. Sandbag filling equipment as claimed in any one of claims 16 to 18, wherein the speed reducing means is housed in a spout.

20. Sandbag filling equipment as claimed in any one of claims 16 to 19, further including means for suspending a sandbag to be filled under the speed reducing means, means for locating a sandbag to be filled on the suspending means, means for detecting when a suspended sandbag has reached a desired weight, and means responsive to the detection means for removing the filled sandbag when the sandbag has reached the desired weight.

21. Sandbag filling equipment as claimed in any one of claims 16 to 20, further including means for vibrating or agitating the speed reducing means.

22. Sandbag filling equipment as claimed in claim 21, further including means for slowing or stopping the sand transport means in response to a signal from the weighing means when a sandbag is almost filled to its desired weight, and for causing the vibrating or agitating means to be activated, so that the sand which is added to finally bring the sandbag to its desired weight comes from the speed reducing means.

23. A protective wall substantially as herein described with reference to and as shown in Figure 3 or Figure 4 of the drawing.

24. A cuboid sandbag substantially as herein described with reference to Figure 1 of the drawing.

25. Sandbag filling equipment substantially as herein described with reference to and as shown in any one of Figures 6 to 8 of the drawing.

26. A method of manufacturing a protective wall according to claim 1, substantially as herein described.