GB2249119A

GB2249119A - Manhole cover

Info

Publication number: GB2249119A
Application number: GB9122707A
Authority: GB
Inventors: Anthony William Merricks
Original assignee: BICC PLC
Current assignee: Balfour Beatty PLC
Priority date: 1990-10-26
Filing date: 1991-10-25
Publication date: 1992-04-29
Anticipated expiration: 2011-10-25
Also published as: GB9122707D0; GB9023317D0; GB2249119B

Abstract

A manhole cover 1 comprises an upper portion 3 of rigid material having extending downwardly from its underface a peripheral wall 2 and at least one means 7 by which the cover may be raised or lowered. Preferably, the portion 3 is of such a height that, in use, it will protrude above ground level and be readily visible. <IMAGE>

Description

AN IMPROVED EXCAVATION COVER Many civil engineering projects necessitate the excavation of a deep hole which, until it is permanently bounded with concrete or steel projecting above ground level or is temporarily filled with earth, can constitute a hazard, especially at times when work on a project has temporarily ceased and the site is untended and/or at night when the site is badly lit. Examples of such hazardous excavations include bored piles and diaphragm walls, which can be approximately circular in shape and of any diameter up to 2.5 metres or approximately rectangular in shape and up to 1.5 metres x 6.5 metres in cross-sectional size, and deep holes of substantial cross-sectional size in roads and other rights of way to which the general public has access.

In some circumstances, such deep holes may be at least partially filled with water or other liquid of such a depth as to constitute a further hazard should a person inadvertently fall in the hole.

Until an excavation has been so permanently bounded or has been temporarily so filled, with a view to reducing the risk that a person may fall into the excavation or materials may be deliberately or inadvertently deposited in the excavation, it is the general practice to cover the excavation temporarily and, in some cases, additionally to surround the excavation with a safety barrier. Forms of covering that are currently employed include a sheet or sheets of plywood, a flexible sheet of canvas or plastics material stretched and secured over the excavation, a plurality of wooden railway sleepers and a preformed cover comprising a grid or mesh of steel reinforcing wires extending across a substantially rigid frame; a temporary upstanding casing is sometimes used.All of these forms of covering have the serious disadvantage that they can be readily removed by hooligans or other unauthorised personnel and, in the first two cases have the additional disadvantage that they may not prevent a person from falling into, or material being deposited in, the excavation. A temporary upstanding casing around the periphery of the excavation has the disadvantage that erection and dismantling of the casing is time consuming and, hence, costly.

It is an object of the present invention to provide an improved preformed cover for temporarily covering an excavation, which improved excavation cover has none of the disadvantages of excavation coverings hitherto proposed and used.

According to the invention, the improved excavation cover comprises a lid of substantially rigid material having extending downwardly from its underface a peripherally continuous or discontinuous wall which, when the lid is applied over an excavation, will protrude downwardly into the excavation to prevent or limit the extent of transverse movement of the lid with respect to the excavation and, permanently or detachably secured to the lid, at least one eye or other means to which a crane or other mechanical lifting device can be connected for raising the cover from or lowering the cover over an excavation, the cover being of such a rigidity that it will prevent a person or vehicle from falling into an excavation over which the cover has been applied and being of such a weight that the cover cannot be readily removed from an excavation without the use of a crane or other mechanical lifting device.

Preferably, the lid is of such a height that, when the improved cover is positioned over an excavation, the lid will protrude above ground level and be readily visible and, preferably, also, to reduce risk of injury to a person who inadvertently falls on to the lid and risk of serious damage to a vehicle which may inadvertently collide with the lid, the lid has upstanding side walls which over at least a major part of their height are inclined inwardly. At least a part of the improved cover which will protrude above ground level may be at least partially coloured red and/or may have secured thereto at least one sheet of phosphorescent material to highlight the existence of a potential hazard.

The lid of the improved cover may be of circular, rectangular or other non-circular shape and, with a view to providing for the improved cover to be suitable for covering any excavation having a transverse dimension or transverse dimensions lying within a limited range of transverse dimensions, the downwardly extending peripherally continuous or discontinuous wall preferably is disposed a substantial distance inwardly of the peripheral edge of the lid.

The improved cover may be made of any suitable substantially rigid material, e.g. wood or metal, but, preferably, the improved cover is a vacuum moulding of heavy duty rigid plastics material which enables the lid as a whole to be so shaped that it has substantially no sharp edges which could be potentially dangerous.

The improved cover may have integral with or secured to the lid at least one means on or to which a hazard lamp can be readily mounted or secured.

In addition to the advantages that the improved preformed cover is of such a rigidity that it will prevent a person or vehicle from falling into an excavation over which the cover has been applied and is of such a weight that the cover cannot readily be removed from an excavation without the use of a crane or other mechanical lifting device, the improved excavation cover has the additional important advantage that it can be readily re-used time and time again and, by virtue of its constuction, has a long service life.

The invention is further illustrated by a description, by way of example, of two preferred excavation covers with reference to the accompanying drawings, in which: Figure 1 is a sectional side view of a preferred excavation cover of rectangular shape applied over an excavation; Figure 2 is a view from above of the excavation cover shown in Figure 1; Figure 3 is a sectional side view of a preferred excavation cover of substantially circular shape applied over an excavation, and Figure 4 is a view from above of the excavation cover shown in Figure 3.

Referring to Figures 1 and 2, an excavation E in the ground G is covered by a preferred excavation cover 1 which is of rectangular shape and which comprises a lid 3 overlying the excavation and ground around the periphery of the excavation and, extending downwardly from the undersurface of the lid and into the excavation, a peripherally continuous wall 2. The lid 3 has upstanding side walls 4 and 5 which are inclined inwardly and meet at a ridge 6 so that, in shape, the lid resembles a ridged roof. At opposite ends of the ridge 6, eyes 7 are permanently secured to the lid 3 to which a crane or other mechanical lifting device can be connected for raising the cover 1 from or lowering the cover over the excavation E.The cover 1 is a vacuum moulding of heavy duty plastics material and of such a rigidity that the cover will prevent a person or vehicle from falling into the excavation E and is of such a weight that the cover cannot be readily removed from the excavation without the use of a crane or other mechanical lifting device. The upstanding side walls 4 and 5 of the lid 3 are of such a height that, when positioned over the excavation E, the lid protrudes above ground level and is readily visible. Each side wall 4 and 5 of the lid 3 may have secured to it a sheet of phosphorescent material (not shown) to highlight the existence of a potential hazard and/or the cover 1 may have integral with or secured to the lid 3 at least one means (not shown) on or to which a hazard lamp can be - readily mounted or secured.

Figures 3 and 4 show a hole H in the ground G which is a bored pile and which is covered by a prefered excavation cover 11. The cover 11 is of circular shape and comprises a lid 13 overlying the hole and ground around the periphery of the hole and, extending downwardly from the undersurface of the lid and into the hole, a peripherally continuous wall 12. The lid 13 has an upstanding peripherally continuous side wall 14 which is inclined inwardly to an apex 16 so that the lid is of substantially conical shape. Permanently secured to the apex 16 of the lid 13 is an eye 17 to which a crane or other mechanical lifting device can be connected.The cover 11 is a vacuum moulding of heavy duty plastics material and of such a rigidity that the cover will prevent a person or vehicle from falling into the hole H and is of such a weight that the cover cannot readily be removed from the hole without the use of a crane or other mechanical lifting device. The upstanding wall 14 is of such a height that, when the cover 11 is positioned over the hole H, the lid 13 protrudes above ground level and is readily visible. The cover 11 may be coloured red to highlight the existence of a potential hazard and/or may have integral with or secured to the lid 13 at least one means (not shown) on or to which a hazard lamp can be readily mounted or secured.

As will be seen on referring to Figures 1 and 2 and Figures 3 and 4, in the case of each preferred excavation cover, the downwardly extending peripherally continuous walls 2 and 12 are disposed a substantial distance inwardly of the peripheral edges of the associated lids 3 and 13 so that the cover is suitable for covering any excavation having a transverse dimension or dimensions lying within a limited range of transverse dimensions. Each of the preferred excavation covers can be readily re-used time and time again and, by virtue of its construction, has a long service life.

Claims

CLAIMS:

1. A preformed cover for temporarily covering an excavation comprising a lid of substantially rigid material having extending downwardly from its underface a peripherally continuous or discontinuous wall which, when the lid is applied over an excavation, will protrude downwardly into the excavation to prevent or limit the extent of transverse movement of the lid with respect to the excavation and, permanently or detachably secured to the lid, at least one eye or other means to which a crane or other mechanical lifting device can be connected for raising the cover from or lowering the cover over an excavation, the cover being of such a rigidity that it will prevent a person or vehicle from falling into an excavation over which the cover has been applied and being of such a weight that the cover cannot be readily removed from an excavation without the use of a crane or other mechanical lifting device.

2. An excavation cover as claimed in Claim 1, wherein the lid is of such a height that, when the cover is positioned over an excavation, the lid will protrude above ground level and be readily visible.

3. An excavation cover as claimed in Claim 1 or 2, wherein the lid has upstanding side walls which over at least a major part of their height are inclined inwardly.

4. An excavation cover as claimed in any one of the preceding Claims, wherein at least a part of the cover which will protrude above ground level when the cover is positioned over an excavation is at least partially coloured red.

5. An excavation cover as claimed in any one of the preceding Claims, wherein at least a part of the cover which will protrude above ground level when the cover is positioned over an excavation has secured thereto at least one sheet of phospherescent material to highlight the existence of a potential hazard.

6. An excavation cover as claimed in any one of the preceding Claims, wherein the downwardly extending peripherally continuous or discontinuous wall is disposed a substantial distance inwardly of the peripheral edge of the lid.

7. An excavation cover as claimed in any one of the preceding Claims, wherein the lid of the cover is of circular shape.

8. An excavation cover as claimed in any one of the preceding Claims, wherein the cover is a vacuum moulding of heavy duty rigid plastics material.

9. An excavation cover as claimed in any one of the preceding Claims, wherein the cover has integral with or secured to the lid at least one means on or to which a hazard lamp can be readily mounted or secured.

10. A preformed cover for temporarily covering an excavation substantially as hereinbefore described with reference to and as shown in Figures 1 and 2 or 3 and 4 of the accompanying drawings.