GB2414747A

GB2414747A - Pedestrian guardrail with enhanced visibility therethrough

Info

Publication number: GB2414747A
Application number: GB0511439A
Authority: GB
Inventors: Mark Carney; Matthew Carney
Original assignee: Hugh Logan Plant & Engineering
Current assignee: Hugh Logan Plant & Engineering
Priority date: 2004-06-04
Filing date: 2005-06-06
Publication date: 2005-12-07
Anticipated expiration: 2025-06-06
Also published as: GB0412500D0; GB2414747B; GB0511439D0

Abstract

A guardrail unit for installation end to end with similar units, and affording enhanced visibility, comprises a rail 4, a lower rail 3, a post 5 at each end, and vertical bars 8 between rails 3 and 4 and arranged at an angle thereto so as to provide a line of sight for passing motorists, and has apertures 9 in the posts 5 to provide a line of sight therethrough corresponding to that through the bars 8. The unit is compatible with standard guardrails, and may have a sight gap between rails 2 and 4 as shown. Units are joined by bolts though holes 12, and an adaptor is claimed for connecting units though apertures 9 where the units are at differing heights, e.g. on sloping ground.

Description

Pedestrian Guardrail This invention relates to pedestrian guardrail

suitable for mounting along pavements to separate pedestrians and motor vehicle traffic. The invention relates in particular to, a pedestrian guardrail with high visibility characteristics. The invention further relates to methods of installation and replacement of such guardrail.

Conventional guardrails are formed from pre-fabricated units joined together in end-to end relationship. The most common type of unit (in the UK at least) conforms to an industry standard as to size, configuration, and the location of bolt holes for connecting the units together. These standard units have hollow section construction for end posts and top and bottom rails, with thinner solid vertical bars spaced apart along the centreline of the unit. Due to the fact the units meet an industry standard they are interchangeable and so easily repaired and replaced. Existing installations can be extended with a consistent appearance.

A known problem with conventional guardrails is that the bars impede the view through the railing at oblique angles, for example the view that an approaching motorist would have when approaching a pedestrian crossing. This raised certain safety issues and a solution to this problem was proposed in GB 1585498 (Stewart) in which it was proposed to set of the vertical bars in certain staggered patterns to provide a clearer view through the railing at oblique angles. These "high visibility railings" include separate posts to which sections of railing are bolted once the posts had been fixed into the ground. In order to permit lines of sight through the posts, the posts are made from flat bar sections arranged parallel to the line of the railing with a space between, and are therefore heavy (for a given strength) and not compatible with conventional railings.

This means roads engineers have to specify a new type of railing from the outset, and possibly endure a mismatch between the appearance and also the installation techniques of different sections of railing. Consequently, although they are believed to be very successful at reducing pedestrian casualties where they have been used, the penetration of the high-visibility guard rail into the market has been limited.

An alternative design for high visibility guardrails was proposed in GB 2291902 (Stewart). These railings may be made with hollow section top and /or bottom rail. The vertical post has been eliminated entirely above the bottom rail, so that visibility through the railing is enhanced. This again makes them incompatible with conventional railings and also detracts from their integral strength when a side load is applied. A special coupling has been proposed in GB 2315510 (Stewart) to strengthen this type of railing, but the problems of incompatibility and consequent limited market penetration remain.

It has been demonstrated on numerous occasions that to increase pedestrian safety, at for example pedestrian crossings, the use of the high-visibility guardrail is desirable.

However, their usage is at present hampered by their lack of compatibility with conventional guardrails.

The present invention aims to enable the provision of high-visibility guard rail compatible visually and/or mechanically with the most common type of conventional guard rail.

In accordance with a first aspect of the present invention, there is provided a guardrail unit for installation end-to-end with similar units to form a guardrail, the unit comprising: an upper rail and a lower rail, both of which extend along the length of the unit; a post located at each end of the unit and connecting said upper and lower rails at their ends which posts define the ends of the unit; and a number of vertical bars extending between the upper and lower rails and being arranged in a plane or planes aligned at an acute angle to the line of the upper and lower rails so as to provide a line or lines of sight through the guardrail at said acute angle, wherein each of said posts is provided with an aperture or apertures extending generally parallel with said bars so as to provide a line of sight through the post corresponding approximately to the line of sight provided by the alignment of the bars.

The novel unit can be made from the same materials as the conventional railings (galvanised steel in box section and solid bars) and can therefore be made to conform to the same industry standards of size and location of points for the interconnection of the units. The units of the present invention can be made compatible both visually and mechanically with conventional railing units, providing interchangeability which enables the units of the present invention to be easily mixed with standard railings.

Further the units of the present invention can be retro-fitted into installed railings as an upgrade to visibility where the need has been identified.

The unit may also include a third, top rail which is connected to each of the posts and spaced above the upper rail so as to define a sight gap. The unit in such a case may include further apertures in the posts, level with the sight gap.

Each post may be formed from hollow section with corresponding apertures provided in opposing sides of the post. Rectangular box section steel tubes are used for the posts and rails in the common type of conventional railing. The tubes may in particular be 30mm x 50mm in section, with thicker material preferred for the end posts in practice.

The apertures may be cut, for example, by a laser cutter, and extend over a majority of the width of the post. In cross section the post in the region of the aperture will have a configuration like two opposing Csections separated by the apertures. This helps to maintain the strength and integrity of the post. The apertures may be symmetrical with one another for simplicity, although they could be off-set in accordance with said oblique line of sight to maximise visibility and maximise the material and strength remaining in the post.

The aperture in the post may be formed as a single aperture extending parallel to and substantially along the length of the bars. Alternatively a series of apertures may be provided separated by discrete section of the post material.

In a preferred embodiment, at least two apertures are provided and connection points for joining the unit to another unit are provided in post material between the two apertures.

The connection points may be holes for bolts to pass through the post and an adjacent post of another unit. The connection points may be at heights compatible with those common non-high-visibility guardrail. In the UK, the two holes are conventionally provided, one at a height 152.5mm below the top of this top rail, and another 610mm below that. In other countries different spacings may be conventional.

Where the post is formed in hollow section, compression members may be provided at points adapted for connecting the post to the post of another unit, so as to resist crushing of the post by a connecting means (such as a nut and bolt). The compression members may be integrated with the prefabricated unit, or provided separately for assembly to the posts on-site.

The guardrail unit may be provided in combination with an adaptor suitable for use in connecting together guardrails units. The adaptor may be provided for all connections, l 5 or only where adjacent units are to be installed at different heights (that is. on sloped or stepped ground).

The adaptor in one embodiment includes a bearing member and a tubular section extending from the bearing member such that in use the tubular section extends into the aperture in the post of a guardrail unit to be connected to a second guardrail units so that the bearing member bridges the aperture, and said tubular section resists compression by connecting means when the two units are interconnected.

In one arrangement of the adaptor a hole is provided in the bearing surface and the tubular section is disposed about said hole and in use a bolt extends between the first and second units through said tubular section and hole so as to effect the connection.

The invention in other aspects provides the adaptor separately for use with guardrail units of the first aspect of the invention as set forth above, and a method of using the adaptor for interconnecting such units to form a railing. The adaptor may be claimed independently of the highvisibility guardrail unit.

The invention further provides methods of installation of a guardrail unit according to the first aspect of the invention as set forth above, wherein the unit is placed end to end with at least one other guardrail unit with the posts of the units standing upright against one another and being connected together and set into the ground together.

The other guardrail unit may also be a high-visibility guardrail unit according to the first aspect of the invention, or it may be a conventional unit without apertures in its posts. The method may include removing a previously installed unit and replacing it with the unit according to the first aspect of the invention. The previously installed unit may be of a type without apertures in its posts. Alternatively the method may provide a new installation.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which: Fig I is a side view of a high visibility pedestrian guardrail unit made in accordance with the present invention; Figs 2a & 2b show in perspective and end elevation of a post component forming part of the unit shown in Fig 1; Fig 3 is a perspective view of a section of pedestrian guard rail comprising two of the units as shown in Fig 1; Figs 4a & 4b are cut-away plan views of alternative staggered bar patterns for use in the guardrail; Fig 5 shows an alternative unit made in accordance with the present invention; Fig 6 shows in end elevation a post component forming part ol the unit shown in Fig 5; Fig 7a & 7b show in elevation and cross section an adaptor for use in connecting the guardrail units of Figs 1-6; Figs 8a & 8b show in cross section and elevation an alternative adaptor; Fig 9 is a cross section through two posts joined using the adaptor of Figs 8a and 8b; and Fig 10 is cross section through two posts joined using two of the adapters.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to Figs I and 3 of the drawings there is shown a novel pedestrian guardrail unit I which comprises a top rail 2, bottom rail 3, mid rail 4 and two posts 5 all formed from rectangular hollow section steel, and galvanised for protection against corrosion.

Numbers of such units fixed in the ground end to end beside a carriageway form a railing to guide pedestrians to a safe crossing. The hollow section from which rail 2, 3, 4, and posts 5 are made is in this example 30mm x 50mm in size. The post will normally be of greater wall thickness (e.g. 2.5mm), and so increased strength, compared with the rails (e.g. 2mm).

The top rail 2 has one of the posts 5 welded at either end via mitre joints. The bottom rail 3 and the mid rail 4 are butt welded to each of the posts 5. The unit] thereby has a railing section 6 defined between the bottom rail 3, mid rail 4 and the posts 5 and a sight gap 7 defined by the mid rail 4 top rail 2 and the posts 5. Vertical bars 8 are provided in the railing section 6 which extend between the rails 3, 4.

In the side view shown in Fig. 1, the unit appears identical to the common types of guardrail in use in the UK, and this visual compatibility is indeed an advantage of the novel unit. Differences between the novel unit and those conventional units will be apparent from the following. more detailed description, however.

Figs 2a and 2b show one of the posts 5 in more detail. The post 5 is provided with a slanted surface at its upper end for welded attachment to the top rail 2. The faces of the post 5 transverse to the line of the unit have corresponding apertures 9 cut therein. A landed section 10 between upper and lower apertures is provided for welding to the midrail 4.

The aperture 9 is cut in the centre of the respective side of the post for example by a laser cutting system. A small return of, say 4 - 7mm will be present adjacent the aperture 9 at each face so that in cross section the post 5 appears as two C-sections separated by the apertures 9 (this can be seen in Fig 9). The width of the aperture in a 50mm width of post may be 35 - 42mm, for example.

The vertical bars 8 are disposed in a predetermined pattern such as those, shown in Figs 4a and 4b, to enhance visibility through the railing section 6 for example for an approaching motorist. Specifically, the bars are arranged to lie in a vertical plane or planes aligned at an acute angle (between 2 and 14 degrees for example) relative to the plane of the unit as a whole. This provides a line or lines of sight between the planes, at the same angle and of course over range of angles either side thereof. The pattern is selected to suit the particular circumstances in terms of road curvature and expected speed of approach (and hence stopping distance).

The provision of the apertures in the sides of the posts 5 provides a further line of sight through the posts 5 (two posts in side by side arrangement) when two or more of the units 1,1' are assembled into a railing as shown in Fig 3. The line of sight is most apparent at the same oblique approach angles at which the vertical bars are set to enhance the visibility through the railing and therefore enhances the visibility through the railing as a whole. In fact it can be difficult to determine the location of the posts 5 in the railing as it blends into the run of the vertical bars so naturally see fig 3 in particular. The novel unit therefore combines much of the aesthetic appeal of the no post railing described in GB 2291902, while maintaining the strength of the conventional railing, and being both visually and mechanically interchangeable with the conventional railing.

In the embodiment shown in Figs 1-4 connection points 12 are provided which correspond in location to the connection points provided on standard railings. The connection points 12 comprise a further small land of material between apertures 9, with a hole 12a therein for the insertion through of a bolt. In order to strengthen the unit in the area of the connection point a hollow tubular insert (not shown) is disposed between the sides of the respective post 5. In accordance with the industry standard, the upper bolt hole is centred at a height 152.5mm below the top surface of the top rail 2. The lower bolt hole is centred 610mm below the upper hole.

Alternative connection means may be used as discussed below and the invention is not limited to the provision of this particular means for connection. Alternative connection means may be used at all posts, or only when a stepped arrangement (on a slope) means that the normal connection points won't line up.

Fig 5 and 6 show a second guardrail unit of similar construction to that described above and like numerals have been used to describe like components. In this example the sight gap is not present so the top rail 2 and the mid rail 4 are in effect the same rail and the vertical bars 8 extend over the full height of the railing. In addition the land section in the aperture 9 of the posts 5 is no longer present.

Alternative arrangements for connecting the units 1 together include the use of an adaptor which utilises the aperture 9 to effect secure connection. Various designs of adaptor may be suitable, the important feature is that they extend through the aperture 9 and engage the sides ol the posts adjacent the aperture 9. In cases where an adaptor is used the connecting points 12 may or may not be present, as illustrated in Fig. 6.

Figs 7a & 7b show an adaptor for use in connecting units together in a railing. The adaptor has a flat section 100 with a hole 101 extending there-through, and a tubular section 102 extending from to the back surface of the flat section] 00. These parts may be welded or cast in one piece. In use the adaptor is fitted into the aperture 9 so that the back surface of the flat section engages the sides of the post adjacent the aperture 9 and the tubular section 102 is located within the hollow section. A bolt is located in the hole 101 with the shaft of the bolt extending through the tubular section 102 and through the post of an adjacent unit. The bolt is tightened using conventional tooling and the units 1 pulled together.

Figs 8a & 8b show an alternative adaptor, this adaptor is very similar to that described above and like numerals have been used to identify like components. This adaptor includes sections at the ends of the flat section] 00 of reduced thickness in comparison to the major part of the flat section. These sections of reduced thickness locate in the aperture 9 and hold the adaptor against sideways movement. Fig 9 shows this adaptor in use illustrating the connection of a post, and thereby unit, of the present invention to a post of a conventional guardrail unit, or to a connecting point 12 between apertures 9 in the novel unit. In other situations both posts could be connected through connecting points 12, or both through aperture 9 using two adapters as shown in Fig. 10.

In both of the above examples the adaptor has a tubular section 102 of circular configuration. The tubular section may have any shape cross section, for example square or hexagonal where the sides of the tubular section may engage the sides of the aperture so as to correctly orientate the adaptor in the post 5.

The use of the adaptor enables the interconnection of units to be made at any point along the length of the aperture 9, for example at the correct position for alignment with the connection points of a conventional or standard railing unit, or tucked away so that there is minimum impairment to the view through the apertures 9 of the post 5. In addition in certain situations, particularly on a sloping site, the units are stepped (vertically displaced from the adjacent unit) and the use of the adaptor facilitates this, even if fixed connection points 12 are provided and used to make most of the connections. Without the adaptor, additional holes would need to be drilled in one post on site. This requires power tools on site and breaks the galvanising protection on the metal. The adapter therefore offers an improvement in installation procedures, independently of the high-visibility benefits.

It will be readily apparent to the person skilled in the art that whilst the adaptor illustrated would utilise a bolt passed through the adaptor to effect the connection of the units, alternative types of adaptor may be employed, for example a stud having two components where one is screwed into the other, or hammered together so that a part deforms to secure the two parts together, or a spigot stud where a part rotation secures the two together. External clamps, adhesives and other alternative means of connection can also be envisaged, each of which may work with an aperture 9 or at a land between apertures.

The invention is not limited to posts formed of the standard box section. A post of the same general construction as the GB1585498 post could be used, but integrated into each end of the unit instead of being separately installed between units on site. Such a post might comprise two flat bars 30mm x 6mm, spaced to correspond to the narrower faces of the 30mm x 50mm box, and bridged by small transverse plates so as to leave the required apertures. By positioning such plates at the standard bolt heights, mechanical compatibility and some degree of visual compatibility with the conventional rails is achieved. The bridging pieces with bolt holes maybe located on the inside edge of the flat bars, rather than on their mid-line, so as to be accessible for bolting the units together, and to permit use of the standard length of bolt. Numerous other variations are possible within the scope of the invention as claimed.

Claims

1. A guardrail unit for installation end-to-end with similar units to form a guardrail, the unit comprising: an upper rail and a lower rail, both of which extend along the length of the unit; a post located at each end of the unit and connecting said upper and lower rails at their ends which posts define the ends of the unit; and a number of vertical bars extending between the upper and lower rails and being arranged in a plane or planes aligned at an acute angle to the line of the upper and lower rails so as to provide a line or lines of sight through the guardrail at said acute angle, wherein each of said posts is provided with an aperture or apertures extending generally parallel with said bars so as to provide a line of sight through the post corresponding approximately to the line of sight provided by the alignment of the bars.

2. A guardrail unit as claimed in claim 1, wherein the unit also includes a third, top rail which is connected to each of the posts and spaced above the upper rail so as to define a sight gap.

3. A guardrail unit as claimed in claim 2, wherein the unit includes further apertures in the posts level with the sight gap.

4. A guardrail unit as claimed in claim 1, wherein each post is formed from hollow section with corresponding apertures provided in opposing sides of the post.

5. A guardrail unit as claimed in any preceding claim, wherein the apertures are cut by a laser cutter, and extend over a majority of the width of the post.

6. A guardrail unit as claimed in any preceding claim, wherein the apertures are cut to be symmetrical with one another.

7. A guardrail unit as claimed in any of claims I to 6, wherein the apertures are cut to be off-set in accordance with said oblique line of sight.

8. A guardrail unit as claimed in any preceding claim, wherein the aperture in the post is formed as a single aperture extending parallel to and substantially along the length of the bars.

9. A guardrail unit as claimed in any of claims 1 to 7, wherein a series of apertures is provided in the post separated by discrete section oi the post material.

10. A guardrail unit as claimed in claim 9, wherein at least two apertures are provided in the post and connection points for joining the unit to another unit are provided in post material between the two apertures.

11. A guardrail unit as claimed in claim 10, wherein the connection points comprise holes for bolts to pass through the post and an adjacent post of another unit.

12. A guardrail unit as claimed in any preceding claim, wherein compression members are provided at the connection points so as to resist crushing of the post by a connecting means.

13. A guardrail unit as claimed in claim 12, wherein the compression members are integrated with the pre-fabricated unit.

14 A guardrail unit as claimed in claim 14, wherein, the compression embers are provided separately for assembly to the posts on-site.

15. A guardrail unit as claimed in any preceding claim, wherein the guardrail unit is provided with an adaptor suitable for use in connecting together guardrails units.

16. A guardrail unit as claimed in claim 15, wherein the adaptor includes a bearing member and a tubular section extending from the bearing member such that in use the tubular section extends into the aperture in the post of a guardrail unit to be connected to a second guardrail unit, so that the bearing member bridges the aperture, and said tubular section resists compression by connecting means when the two units are interconnected.

17. A guardrail unit as claimed in claim 16, wherein a hole is provided in the bearing surface and the tubular section is disposed about said hole and in use a bolt extends between the first and second units through said tubular section and hole so as to effect the connection.

18. A guardrail unit as claimed in any of claims 15 to 17, wherein the adaptor is provided separately for use with guardrail units as claimed in any claims I to 14.

19 A method of installing a guardrail unit as claimed in any preceding claim, wherein the unit is placed end to end with at least one other guardrail unit with the posts of the units standing upright against one another and being connected together and set into the ground together.

20. A guardrail unit substantially as hereinbefore described with reference to Figs 1, 2a, 2b, 3, 4aand 4b of the accompanying drawings.

21. A guardrail unit substantially as hereinbefore described with reference to Figs 5, 6, 4a and 4b of the accompanying drawings.

22. An adaptor as substantially hereinbefore described with reference to Figs 7a and 7b of the accompanying drawings and suitable for use with a guardrail unit substantially as hereinbefore described.

23. An adaptor as substantially hereinbefore described with reference to Figs 8a, 8b, 9 and 10 of the accompanying drawings and suitable for use with a guardrail unit substantially as hereinbefore described.