GB2272011A

GB2272011A - Apparatus and method for securing in position a tramway rail.

Info

Publication number: GB2272011A
Application number: GB9222660A
Authority: GB
Inventors: Charles Penny
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-28
Filing date: 1992-10-28
Publication date: 1994-05-04
Anticipated expiration: 2012-10-28
Also published as: GB2272011B; GB9222660D0

Abstract

A tramway rail 2 which is to be laid flush with the ground is secured in place by a shell 7 comprising a base part 8 and upwardly extending side parts 9, 10. The inner profile of the shell 7 is larger than, but corresponding in space to, the outer profile of the rail 2. The space between the shell 7 and the rail 2 is infilled with a material 14 to hold the rail 2. The material 14 is preferably an electrically insulating elastomeric polymer. A vibration-absorbing pad 12 may be inserted between the base of the rail 2 and the shell 7. <IMAGE>

Description

APPARATUS AND METHOD FOR SECURING IN POSITION A TRANWAY OR RAILWAY RAIL This invention relates to an apparatus and to a method for securing in position a tramway or railway rail intended to be laid substantially flush with the adjacent surface.

Particularly in respect of tramways, paved track comprises grooved rail with its running surface flush with the road or pedestrian surface.

One method of installation is to lay a reinforced concrete slab in the ground and to lay and position the rails to the correct line, level and gauge on top of the slab. The rails are maintained to gauge by tie bars at intervals. Concrete is infilled between the rails and a suitable paved finish is placed level with the tops of the rails.

In order to attain desired electrically-insulating properties as well as absorption of vibration and reduction of noise, pre-formed elastomeric pieces can be placed around the rails and insulation is achieved by the use of a liquid elastomeric material which is poured around the rail to surround it. When set, this secures the rail and has high electrical resistance.

In this case, it is known for the elastomeric material to be poured into a channel of substantially rectangular cross-section of concrete or other material.

With such known systems, additional space provision must be allowed during installation to enable correct alignment of the rail in the channel and the rail may be unevenly located in the elastomeric mixture. There is substantially higher useage of the flexible/resilient material than the minimum required for the correct performance of the track in service and the support and performance of the rail in service may not be regular.

According to one aspect of the present invention, there is provided an apparatus for securing in position a tramway or railway rail intended to be laid substantially flush with a ground surface, the apparatus including a shell for embracing non-running surfaces of the rail, the shell having an inner profile larger than, but generally corresponding to, an outer profile of the rail to be embraced thereby to define a space therebetween, the volume so defined by the space between the profiles being intended to be infilled with a material to hold the rail.

According to another aspect of the present invention, there is provided a method for securing in position a tramway or railway rail, including the steps of embracing non-running surfaces of the rail with a shell having an inner profile larger than, but generally corresponding to, an outer profile of the rail being embraced, thereby defining a space therebetween, aligning the rail with shell for the rail to be located as desired, and filling the volume defined by said space with a material to hold the rail.

The material may be electrically-insulating.

Preferably, the space between the profiles is such as to provide the minimum lateral and vertical space required for the insulation and loading performance of the track.

The shell may comprise a first part, a second part and a third part, the first part forming a base of the shell and the second and third parts forming opposite sides of the shell so as to be located on opposite sides of a web of the rail. The first part may be shaped so as to have an inner profile forming a shallow trough to receive a resilient insulating base laid therein and on which resilient insulating base the base of a flange of the rail is intended to be laid. The second and third parts have inner profiles that closely follow the outer profile of the web and head of the rail and including, if the rail is a grooved rail, a check rail flange part of the head.

Preferably, the profiles of the adjacent walls of the first and second parts and the first and third parts, respectively, of the shell are shaped to inhibit lateral separation of the second and third parts.

Means can be provided to join together the first and second parts and the first and third parts, respectively. For example, to maintain correct spacing between the shell and the rail, at least two of the parts of the shell may be clipped or bolted and spacers may be provided between the rail and the shell, e.g. between the head of the rail and the first part, between the check flange and the third part and between the second and third parts and the respective upper sides of the base flange of the rail.

Preferably, the shell is made of a polymer concrete including a synthetic or natural resin material with appropriate filler and/or additives with electrically-insulating properties. The shell can be of a thickness and cross-section to minimise the material content while providing the required structural content.

Preferably, the electrically-insulating material is a liquid elastomeric polymer or other material which can be poured in the space between rail and shell and which then sets. Another possible material, for example, could be bitumen.

In construction, the rail can be attached to a gantry above the location where it is to be laid, the parts of the shell can then be placed around the non-running surfaces of the rail, the shell then also being attached to the gantry. The assembly is then adjusted to its final alignment, using an adjustment means associated with the gantry as necessary.

Alternatively, the shell and insulation may be fixed to the rail post alignment of it.

In situ concrete can then be poured on either side of the shell up to the level required and the polymer is poured in one or more pours between rail and shell.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which Figure 1 is a sectional end view of an apparatus for securing in position a tramway rail intended to be laid substantially flush with an adjacent surface, and Figure 2 is a corresponding view as applied to a railway rail.

Figure 1 shows a grooved tramway rail 1 of typical profile, having a running surface 2 at the head of the rail, a groove 3, a check flange 4, a web 5 and a base flange 6, all being of constant profile.

The apparatus for securing the rail 1 in position on the ground is a shell formation which embraces the non-running surfaces of the rail but is spaced therefrom all around by some 8-12 mm. The shell 7 is of firm material or hard polymer concrete and can be in a single part. As shown, however, it is in three parts, namely a base part 8 of channel section on its inside, a second part 9 which is arranged to be joined to the first part 8 and extends upwardly beside the web 5 and generally follows the outer profile of the head of the rail 1, and a third part 10 which is arranged to be joined to the other side of the first part 8 and extends upwardly therefrom on the opposite side of the web 5 and generally follows the outer profile of the check flange 4.Each of the parts 8, 9 and 10 can be made in varying lengths as required and in straight sections for straight rail or can be in short straight or curved sections to match the curvature of the rail to be laid, this curvature being possible in both horizontal and vertical planes.

An interlocking arrangement 11 is provided at each side of the shell part 8 to inhibit outward lateral movement of the shell parts 9 and 10. Instead, or as well, the shell parts 9 and 10 can be bolted or otherwise secured to the shell part 8.

The shell parts 9 and 10 extend upwardly to be substantially level with the top of the rail 1 and thereby to be substantially flush with a roadway or pavement, for example, in which the rail is to be laid.

In the embodiment shown, the base 6 of the rail 1 is sitting on a cushion of resilient, vibration-absorbing and electrically-insulating material in the form of a strip or pads 12 of rubber or plastics material, the strip or pads 12 being seated in the bottom of the shell part 8.

Alternatively, this material can be of an in situ poured type.

On assembly, either on site or remote therefrom, the shell part 8 with its pad 12 is offered up to the base 6 of the rail and then the shell parts 9 and 10 are fitted on the shell part 8, thereby enclosing the non-running surfaces of the rail. At this stage, inward collapse of the shell parts 9 and 10 towards the rail 1 can be prevented by means such as spacer studs 13, which can be effectively temporary, protruding from the inner profiles of the shell parts 9 and 10. The apparatus thus assembled is then located on site by means of an overhead gantry and adjusted for gauge, level, curvature, etc. with the companion tramway rail and its environment.Such adjustment can be achieved by means of laterally-extending locating lugs (not shown) on either side of the shell part 8, these locating lugs housing lost bolts or the like which can be adjustably secured into the foundation on which the assembly is laid.

Vertical positioning of the shell enclosed rail can alternatively be achieved by threaded studs passing through extensions to the base of the shell.

Once the precise location of the rail 1 has been set, liquid polymer 14 is poured in to fill the remaining void between the rail 1 and the shell 7, the polymer setting to a firm consistency which sets the rail in place and electrically insulates it and permits the deflection of the rail under load. The width of the space between the rail 1 and the inner profile of the shell 7 above the flange is limited by the ease with which the polymer can be poured whilst ensuring that sufficient vertical movement is possible in accordance with the required performance of the resilient material under the rail during loaded and unloaded conditions. This achieves an economy in the use of the polymer as compared with known methods whilst achieving the required reduction in noise and vibration transmission.

Meanwhile, the ground surrounding the shell 7 is made up with in situ concrete with a top layer of paving setts, blocks or asphalt or other material as desired.

In addition, due to the additional electrically-insulating properties of the shell itself over those simply of the resilient polymer, potential is provided for omission of an earth tracking mat forming a Faraday cage normally laid beneath the tramway.

It will be appreciated that the present apparatus using a polymer concrete shell allows concrete and/or other surfacing material to be laid right up to the shell perimeter which, because of the hardness of the shell, thereby inhibits spalling of the concrete surfacing edge, thereby enhancing the aesthetic appearance of the work. Furthermore, the apparatus facilitates setting of the required levels by use of the overhead gantry whilst serving to inhibit uneven rail loading on its resilient base. The level of the surrounding concrete or other material can be laid to the tight tolerances of the rail alignment thus avoiding a disparity between rail and surrounding surfaces.

Drain holes and ducts (not shown) can be provided in the base of the groove 3, leading out through the side of the shell part 10.

Instead of the strip or pads 12 of resilient material, the polymer material 14 can be poured to flow also underneath the base 6 of the rail onto the shell part 8 whilst the rail is suspended from the gantry.

When the rail needs replacing, two neat narrow cuts are made in line with the outer edges of the shell, the concrete surrounding the shell 7 is broken out as far as the shell perimeter and the whole assembly can be pulled out.

Holes (not shown) can be made in the side shell part 10, for example, to receive tie bars which are used to keep the gauge of the tramway track. Each hole can be previously closed by a grommet which can be pushed out on insertion of one end of the tie bar.

Figure 2 illustrates the invention as applied to a railway rail and like reference numerals illustrate like parts.

In this case, it is likely that the railway rail will require fastening to a concrete bed or the like by railway fastening means such as clips. In this case, slots (not shown) are provided in the base of the shell through which the clips can pass, the spaces defined by the slots when not occupied by the clips being occupied by a flexible gasket which envelops that part of the clip passing through the slot and serves to prevent egress of the liquid polymer 14 before it has set.

Electrical insulation is maintained since the end of the clip remote from the flange 6 of the rail is located on electrically insulating material.

An embodiment is also envisaged where the shell part 8, or at least the base of the shell, could be omitted, the railway rail being supported on the resilient pads 12 of electrically insulating material being located between the base of the flange 6 of the rail and the supporting surface below, the economy of polymer material between the rail and the shell sides 9, 10 thus being maintained.

Claims

CLAIMS:

1. An apparatus for securing in position a tramway or railway rail intended to be laid substantially flush with a ground surface, the apparatus including a shell for embracing non-running surfaces of the rail, the shell having an inner profile larger than, but generally corresponding to, an outer profile of the rail to be embraced thereby to define a space therebetween, the volume so defined by the space between the profiles being intended to be infilled with a material to hold the rail.

2. A method for securing in position a tramway or railway rail, including the steps of embracing non-running surfaces of the rail with a shell having an inner profile larger than, but generally corresponding to, an outer profile of the rail being embraced, thereby defining a space therebetween, aligning the rail with shell for the rail to be located as desired, and filling the volume defined by said space with a material to hold the rail.

3. An apparatus or method according to claim 1 or 2, wherein said material is electrically- insulating.

4. An apparatus or method according to claim 1, 2 or 3, wherein the space between the profiles is such as to provide the minimum lateral and vertical space required for the insulation and loading performance of the track.

5. An apparatus or method according to any one of the preceding claims, wherein said shell comprises a first part, a second part and a third part, the first part forming a base of the shell and the second and third parts forming opposite sides of the shell so as to be located on opposite sides of a web of the rail.

6. An apparatus or method according to claim 5, wherein said first part is shaped so as to have an inner profile forming a shallow trough to receive a resilient insulating base laid therein and on which resilient insulating base the base of the flange of the rail is intended to be laid.

7. An apparatus or method according to claim 5 or 6, wherein said second and third parts have inner profiles that closely follow the outer profile of the web and head of the rail and including, if the rail is a grooved rail, a check rail flange part of the head.

8. An apparatus or method according to claim 5, 6 or 7, wherein the profiles of the adjacent walls of the first and second parts and the first and third parts, respectively, of the shell are shaped to inhibit lateral separation of the second and third parts.

9. An apparatus or method according to any one of claims 5 to 8, wherein means are provided to join together the first and second parts and the first and third parts, respectively.

10. An apparatus or method according to claim 9, wherein spacers are provided between the rail and the shell.

11. An apparatus or method according to any one of the preceding claims, wherein the shell is made of a polymer concrete including a synthetic or natural resin material with appropriate filler and/or additives with electricallyinsulating properties.

12. An apparatus for securing in position a tramway or railway rail, substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawings.

13. A method for securing in position a tramway or railway rail, substantially as hereinbefore described with reference to Figure 1 or 2 of the accompanying drawings.