AU2017251724B2

AU2017251724B2 - Track support system

Info

Publication number: AU2017251724B2
Application number: AU2017251724A
Authority: AU
Inventors: Richard McTavish
Original assignee: Asset International Structures Ltd
Current assignee: Asset International Structures Ltd
Priority date: 2017-10-24
Filing date: 2017-10-24
Publication date: 2022-09-01
Anticipated expiration: 2037-10-24
Also published as: AU2017251724A1

Abstract

: A track support system (2) comprising: a foundation layer (4); a first ballast layer (6) to support a track (8), the first ballast layer on top of the foundation layer; and a first 5 ballast retainer (10) comprising: a base (12); a barrier element (14); and at least one spacer (16), wherein the base is located substantially horizontally between the foundation layer and the first ballast layer, the first ballast layer anchoring the base in position, wherein the barrier element extends upwardly from the base to define an angle, the spacer maintains the angle, and the barrier element defines a boundary of 10 the first ballast layer and retains the first ballast layer in place. [Fig. 1a] 1/8 E LO Al Ct E cr) Al 6

Description

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Track support System Field of Invention This invention relates to a ballast retainer and a track support system.

Background Railway tracks are typically supported by a layer of ballast (e.g. coarse gravel or crushed rock laid to form a bed).Such a layer of ballast slopes at a "natural angle of repose". This angle is typically around 40 degrees, which allows the stone to settle and stay in place. Summary The inventors have found that, although an angled bank of stone is stable under normal conditions and can in certain circumstances be stable for many years, in flood conditions the stone in the ballast can move, and in extreme situations be washed away partially or even completely. This can, in turn, cause movement to the track. Additionally, periodic tamping of the ballast is undertaken to ensure that it is packed firmly. This tamping also causes movement of the ballast which can cause movement in the track bed. Therefore, in accordance with a first aspect of the present invention, there is provided a track support system comprising a foundation layer, a first ballast layer to support a track, the first ballast layer being on top of the foundation layer, and a first ballast retainer comprising a base, a barrier element, and at least one spacer, wherein the base is located substantially horizontally between the foundation layer and the first ballast layer, the first ballast layer anchoring the base in position, wherein the barrier element extends upwardly from the base to define an angle, the spacer maintains the angle, and the barrier element defines a boundary of the first ballast layer and retains the first ballast layer in place.

It will be appreciated that this track support system provides a lightweight means for track support. The track support system does not require foundations to be dug, which means that it is easier to install and avoids possible damage to cables. Additionally, the ballast layer provides a level area to walk alongside the track. The base receives ballast thereon, which is therefore held in place by the ballast itself. As the barrier element is connected to/integral with the base, this too is held in place by the ballast on the base, and acts to prevent movement of the ballast above the base, so that the ballast retainer and the ballast work together to hold each other securely in place.

In an embodiment, the base is substantially planar. This improves the anchoring provided by the base, and makes the ballast retainer easier to ship.

In an embodiment, the barrier element is substantially planar. This improves ballast retention and makes the ballast retainer easier to ship.

In an embodiment, the angle is less than 90 degrees. This reduces the bending moment in the barrier element.

In embodiments, the angle is between 60 to 95, 65 to 95, 70 to 90, 75 and 85 degrees (e.g. 80 degrees). This gives a balance between the reduction in bending moment and the height of front element.

In an embodiment, the base is directly connected to the barrier element. This improves track support and structural performance of the system.

In an embodiment, a bottom edge of the barrier element is connected to an outer edge of the base. This provides the maximum amount of ballast on top of the base, thereby improving the anchoring, and allows maximum amount of ballast to be retained by the barrier element. References to the outer edge of the base are to that edge of the base that will be located furthest from the track when in use.

In an embodiment, the base is integrally formed with the barrier element. This improves structural performance of the ballast retainer.

In an embodiment, a series of spacer members are connected to the base and the barrier element. This provides a simple and lightweight means for maintaining the angle between the base and the barrier element.

In an embodiment, each spacer member is connected to a top edge of the barrier element and an inner edge of the base. This provides greater moment for maintaining the angle between the base and the barrier element, thereby reducing the forces in the spacer. References to the inner edge of the base are to that edge of the base that will be located nearest to the track when in use.

In an embodiment, the spacer members are connected to the base and barrier element at substantially 45 cm intervals along the length of the track support system.

In an embodiment, each spacer member comprises a hook at each end, the hooks connecting the spacer member to the base and the barrier element. This provides a simple means for connection of the spacer to the ballast retainer.

In an embodiment, the base has a lattice structure. In an embodiment, the barrier element has a lattice structure. Each of these features means that the ballast retainer is more lightweight. It also ensures that flood water can flow through the system without being impeded, while the lattice is sufficiently small that the stone ballast is fully maintained within the system even when water flows therethrough, for example during heavy rain or flood conditions.

In an embodiment, the track support system comprises u-shaped cramps or staples which anchor the base to the foundation layer. This provides better anchoring to the base.

In an embodiment, the first ballast retainer has a length of substantially 6m. This is a convenient length for shipping but reduces the number of connections required. Other lengths could also be provided, either standard or specials.

In an embodiment, the foundation layer is substantially planar and horizontal. This provides better anchoring for the ballast retainer.

In an embodiment, the foundation layer comprises a gravel sand layer of a depth of at least 25 cm. This provides a stable foundation for the track support system. The formation level between the ballast and the sub-grade will have sufficient load capacity to bear the weight of the system.

In an embodiment, the track support system comprises a second ballast retainer connected to the first ballast retainer, thereby forming a ballast retainer of increased length. This allows a track support system of increased length to be achieved from modular components. It will be appreciated that any number of ballast retainers can be connected in this way to form a track support system of any required length.

In an embodiment, the track support system comprises at least one connecting pipe or interlink which receives a part of a lattice member of the base of the first ballast retainer and a part of a lattice member of a base of the second ballast retainer system, thereby connecting the second ballast retainer to the first ballast retainer. This provides a simple connection between adjacent ballast retainers. The interlink may surround a protruding section of a lattice member on each of the first and second ballast retainers and hold the two against shear movement between the retainers. The interlink may also be crimped to join to the lattice members to prevent or hinder separation of the two sections.

In an embodiment, the first ballast retainer further comprises a second barrier element, and the second barrier element is angled with respect to the barrier element such that the ballast retainer is a corner ballast retainer and the track support system is a corner track support system. This allows ballast to be retained along boundaries in two directions.

In an embodiment, the track support system comprises a substantially planar ground reinforcement element connectable to the base so that the ground reinforcement element is substantially parallel to the base. This provides additional support for ballast for situations in which the subsurface is not stable or for stacking of multiple track support systems.

In an embodiment, the track support system comprises a track on the first ballast layer, at least a part of the base lying between the track and the barrier element.

In an embodiment, a top edge of the barrier element is located within a set distance from the centreline of the track. In embodiments that distance may be around 3m.

In an embodiment, the track support system comprises a second ballast layer to support a track, the second ballast layer on top of the first ballast layer, and a third ballast retainer, wherein a base of the third ballast layer is located substantially horizontally between the first ballast layer and the second ballast layer, wherein a barrier element of the third ballast retainer extends upwardly from the third ballast retainer's base to define an angle, a spacer of the third ballast retainer maintains the angle, and the barrier element of the third ballast retainer defines a boundary of the second ballast layer and retains the second layer of ballast in place. This allows a deeper total layer of ballast to be retained.

In an embodiment, the track support system comprises a track on the second ballast layer, at least a part of each of the bases of the first and third ballast retainers lying between the track and their respective barrier element.

In accordance with a second aspect of the present invention, there is provided a kit of parts for a ballast retainer comprising: a base configured to receive a ballast layer and thereby anchoring the ballast retainer; a barrier element configured to define a boundary of the ballast layer and retain the ballast in place; a plurality of spacer members, each spacer member of the plurality of spacer members configured to maintain an angle of less than 90 degrees between the base and the barrier element, and each spacer member comprising a hook at each end, the hooks configured to connect each respective spacer member to the base and the barrier element respectively. This kit of parts provides a ballast retainer which gives a lightweight means for track support. The ballast retainer does not require foundations to be dug, which means that it is easier to install and avoids possible damage to cables. Additionally, the ballast layer provides a level area to walk alongside the track.

The individual elements of the kit may be in accordance with the corresponding elements described in relation to the first aspect of the invention.

In accordance with a third aspect of the present invention, there is provided a method of installing a track support system, comprising the steps of placing a base of a first ballast retainer of the track support system on a foundation layer, using at least one spacer of the first ballast retainer to fix an angle between the base and a barrier element of the ballast retainer, and placing the first layer of ballast on top of the base and against the barrier element, the base anchoring the track support system and the barrier element defining the boundary of the first ballast layer and retaining the first ballast layer in place.

In an embodiment, the base is placed at least 1m from a slope face which comprises the first load of ballast.

In an embodiment, the method comprises the further step of constructing a track on the first ballast layer.

In an embodiment, the method comprises the further steps of placing a base of a second ballast retainer on the first ballast layer, using at least one spacer of the second ballast retainer to fix an angle between the base and a barrier element of the second ballast retainer, and placing a second ballast layer on top of the base of the second ballast retainer, against the barrier element of the second ballast retainer and on top of the first ballast layer, the base of the second ballast retainer anchoring the second ballast retainer and the barrier element of the second ballast retainer retaining the second ballast layer.

In an embodiment, the method comprises the further step of constructing a track on the second ballast layer. Advantages of embodiments of the invention include, creating a level area to walk alongside track, retaining the ballast preventing loss of ballast overtime, allowing the existing cable troughs to be reinstated. The system can be pre-assembled prior to night shift in 6m lengths, to speed up installation. The system is easy to install as it is light weight 61 to 39kgs for standard 6.Om lengths. Backfilling the system is quick and allows small mobile conveyors to be used. The system can be used for either new shoulders of or renewals of the track ballast shoulder creating a retention system that may improve safety or at least maintain acceptable levels of safety and avoid introduction of hazards. The system can create a stable permanent way for operatives to work on tracks, and in the event of an evacuation of a train, a level permanent way may certainly be of benefit. The system is placed outside the load transfer zone from underside of sleeper and therefore does not reduce track support. The front face of the barrier element will retain fill outside the minimum shoulder width and not compromise the track design. Using different depths of ballast generates different heights in which the system could be used. Embankment slopes below the level of the system can be set any angle and can have significant slopes depending on the site in which the system is installed.

If hand railings or fencing are required for specific sites, these could be introduced into the system. A hollow drum could be placed at a distance, eg 3.0m, from the centres and connected to the system at the base. The drum could be formed in two parts, one placed on either side of an upstanding part, before being joined together to form the closed drum. The area around the outside of the drum could be backfilled, and the inside filled with concrete or graded stone. Fixing posts could be installed prior to filling inside the drum or a steel plate could be fixed to the top. A lid could be provided following filling with concrete and the fixing post attached thereto, which could be anchored using suitable bolts, which could, for example be hilti bolts. This fixing detail could allow a number of options, eg chain link fencing / timber fencing or acoustic panels to be fixed to the system.

Brief Description of Drawings The above and other aspects of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1a is a cross-sectional view of a track support system; Figure 1b is a schematic cross-section of a track support system; Figures 1c, d, e show cross sections of three different sizes of ballast retainers; Figure 1f shows a further schematic cross-section of a track support system; Figure 2 is a perspective view of a pair of ballast retainers; Figure 3 is a perspective view of a ballast retainer; Figure 4 is a cross-section of a portion of a second track support system; Figure 5 is cross-section of a third track support system; Figure 6 is a perspective view of a portion of a corner track support system; and Figure 7 shows a fixing mount for a hand railing.

Specific Description Referring to Figure 1a, there is shown a cross-sectional view of a track support system 2. The track support system 2 comprises a foundation layer 4. The foundation layer 4 has a substantially planar and horizontal upper surface. The foundation layer 4 comprises a gravel sand layer. The gravel sand layer has a depth of at least 25 cm.

The track support system 2 further comprises a ballast layer 6. The ballast layer 6 is located on top of the foundation layer 4.

The track support system 2 further comprises a ballast retainer 10 (described in more detail below with respect to Figure 2). The ballast retainer 10 comprises a base 12, a barrier element 14 and at least one spacer 16. The base 12 is located substantially horizontally between the foundation layer 4 and the ballast layer 6.

The barrier element 14 extends upwardly from the base 12 to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

In use, the base 12 of the ballast retainer 10 is placed on the foundation layer 4. The base 12 is placed at least 1m from a slope face 15, which comprises the ballast layer 6. The at least one spacer 16 is used to fix the angle between the base 10 and the barrier element 14. The ballast layer 6 is placed partially on top of the base against the barrier element 14. The track 8 is constructed on the ballast layer 6.

The at least one spacer 16 maintains the angle between the base 12 and the barrier element 14. The ballast layer 6 anchors the base 12 in position. The barrier element 14 defines a boundary of the ballast layer 6 and retains the ballast layer 6 in place. The ballast layer 6 supports a track 8.

As shown in Figure 1b, there is provided a ballast shoulder retention system 2' which includes a retainer 10'. The retainer 10' comprises a base 12', a barrier element 14' and a spacer 16'. These are arranged as described above in relation to Figure la. A cramp or staple 17' is provided which anchors the base 12' to subgrade material, which underlies the base 12'. As in Figure 1a, the retention system 2' is positioned laterally of a track 8'. The track 8', including sleepers, which in the present embodiment are formed from concrete but could be formed from timber or composite or other materials, is placed on a ballast layer 5'. That ballast layer 5' is, itself, prepared on sub-grade material 4' having an upper surface that is slightly inclined to the horizontal so that it falls, in the present example at a 1 in 30 rate, towards the retention system 2'. This is known as a cessway, which allows waste from trains running on the tracks to flow down away from the track. Different heights of cessway/ballast layer 5' can be provided. The ballast layer 5' is finished horizontally on its upper surface to receive concrete sleepers of the track 8'. Laterally of the track 8' the ballast layer 5'. Laterally of the track 8' a lateral ballast region 9' is provided, which holds the track in place. This lateral ballast region 9' does not include a shoulder region 40', standing above the level of the track 8'. Previously, the shoulder would be provided, and the top of the lateral ballast region 9' would be inclined away from the track 8' to drop down to the formation layer at an angle of incline of around 40 degrees. However, in the present examples, that shoulder is not required. Instead the lateral ballast region 9' extends horizontally to the top of the barrier element 14'. This allows workers and evacuees from a train to walk along the side of the track safely. The system 2' retains the ballast and the presence of additional ballast makes the track 8' more stable. The base 12' is spaced from the ballast layer 5' under the track 8' by an amount sufficient to allow a notional line of a 40 degree angle from the concrete sleeper to touch the formation layer and the base 12' is positioned laterally outside the point where the notional line meets the formation layer.

Figures 1c, d and e show different sizes of retainer. The ratio between the depth D of the base 12a,b,c away from the join between it and the barrier element 14a,b,c and the height E of barrier 14a,b,c element away from the base 12a,b,c can be varied. As well as the ratio of the depth D of the base 12a,b,c to the height E of the barrier 14a,b,c, the depth of the base can also be altered in the different sizes of retainer 10a,b,c. The length of the spacer 16a,b,c is configured accordingly. In some sizes, two different spacers are provided, as shown in Figure le where one spacer 16d extends from the base, distal to the join with the barrier element to approximately half way up the barrier element, and another spacer 16c extends to the region of the top of the barrier element from the base 1Oc.

Figure 1f shows another ballast retention system 2" which is similar to that shown in Figure 1b. Therefore, only differences will be described. The retainer 10" of Figure 1f is larger than that of Figure 1b. Therefore, the base 12" is positioned below the lowest level of the ballast layer 5" under the tracks 8". The base 12" is again placed outside laterally of the notional 40 degree inclined line from the sleeper to the formation layer. This is to provide space for the retainer 10" to be positioned before the lateral ballast region 9" is put in place over the base 12". Again, no shoulder region is needed, and the lateral ballast region 9", rather than being inclined at 40degrees as it extends away from the tracks, can be filled to approximately horizontal, with the top of the lateral ballast region 9" reaching the top of the barrier element 14" and being substantially level with the track 8".

The retainer 10" includes two spacers 16" and 16d", in a similar way to described with reference to figure le above.

Various depths of ballast can be provided, together with various heights of retainer, depending on the speed rating of the track and the weights/loads baring requirements of the system, which determine the amount and depth of ballast required and the size of retainer required to hold that ballast in place. Therefore, to maintain a substantially horizontal lateral ballast top surface, an appropriate size of retainer to hold the required ballast must be placed at a depth below that height corresponding to the height of the barrier element of the retainer. The space above the formation layer between the barrier element and base is then backfilled with ballast to secure the base by the weight of the ballast, and thereby secure the ballast by the barrier element, which is connected to or integral with the base.

Referring to figure 2, there is shown a perspective view of a pair of ballast retainers 10, 10a (the latter shown partially). The ballast retainers 10, 10a are identical to each other. The ballast retainers 10, 10a are elongate, with their longest dimension parallel to the track (see Figure 1). The length (as measured in the direction parallel to the track) of the ballast retainers 10, 10a is substantially 6m. However, it will be appreciated that ballast retainers of other lengths may be employed.

The base 12 is substantially planar. The base 12 has a lattice structure, and is formed from first and second series of lattice members. The lattice members of the first series are orientated so that they are substantially parallel to the length of the ballast retainer 10. The lattice members of the second series are substantially perpendicular to those of the second series. Each lattice member of the first series is connected to all of the lattice members of the second series. The base 12 is formed from a rigid material (e.g. steel). The base 12 has a substantially rectangular shape.

The barrier element 14 is substantially planar. The barrier element 14 has a lattice structure, and is formed from third and fourth series of lattice members connected to each other. The lattice members of the third series are orientated so that they are substantially parallel to the length of the ballast retainer 10. The lattice members of the fourth series are orientated so that they are substantially perpendicular to those of the second series. Each lattice member of the third series is connected to all of the lattice members of the fourth series. The barrier element 14 is formed from a rigid material (e.g. steel, glass reinforced plastic, composite or other materials). The barrier element has a substantially rectangular shape.

The base 10 comprises an outer edge 18. The outer edge 18 is the edge of the base 10 which, in use, is substantially parallel to and furthest from the track 8. The base 10 comprises an inner edge 26. The inner edge 26 is the edge of the base 10 which opposes the outer edge 18 of the base 10. In use, the inner edge 26 is the edge of the base 10 which is substantially parallel to and furthest from the track 8.

The barrier element 14 comprises a bottom edge 20. The bottom edge 20 is the edge of the barrier element 14 which, in use, is closest to the foundation layer 4. The barrier element 14 comprises a top edge 24. The top edge 24 of the barrier element 14 is the edge of the barrier element 14 which opposes the bottom edge 20. In use, the top edge 24 is the edge of the barrier element 14 which is furthest from the foundation layer 4.

The distance between the outer edge 18 and the inner edge 26 is the width of the base 10. The width of the base 10 is measured in a direction parallel to the plane of the base 10 and perpendicular to the length of the base 10. The width of the base 10 is substantially 600 mm.

The distance between the bottom edge 20 and the top edge 24 is the height of the barrier element 14. The height of the barrier element 14 is measured in a direction parallel to the plane of the barrier element 14 and perpendicular to the length of the barrier element 14. The height of the barrier element 14 is substantially 685 mm.

The width of the base 10 may be substantially 564 mm with the height of the barrier element substantially 535 mm. The width of the base may be substantially 615 mm with the height of the barrier element substantially 985 mm.

The length of the base 10 is substantially 6m. The length of the barrier element is substantially 6 m. In other embodiments, other lengths are provided.

In this embodiment, a series of spacer members 22 collectively constituting a spacer are provided. Each spacer member 22 is an elongate rod. The spacer members 22 are constructed from rigid material, such as steel, glass reinforced plastic, composite or other materials. Each spacer member 22 comprises a first hook at a first end of the spacer member 22. Each spacer member 22 comprises a second hook at a second end of the spacer member 22.

The ballast retainer 10 comprises a connecting pipe 28. The connecting pipe 28 is substantially cylindrical. Each end of the connecting pipe 28 has an internal diameter such that it can receive a lattice member of the first series of lattice members. The spacers are, in the present example, each separated from the adjacent spacer by around 450mm. The cramps or staples are positioned in pairs in the base in line with spacers, so that a cramp is placed in the region of each of two adjacent spacers, then a gap of one spacer is left before another pair of cramps are aligned with the next pair of spacers.

The ballast retainer 10 comprises u-shaped cramps for anchoring the base 12 to the foundation layer 4.

The outer edge 18 of the base 10 connects to a bottom edge 20 of the barrier element 14. The outer edge 18 of the base 10 is disconnectable from the bottom edge 20 of the barrier element 14. This allows the ballast retainer 10 to be provided as kit. However, it will be appreciated that the base 10 and the barrier element 14 could be integrally formed. Additionally, the base 10 and the barrier element 14 could be integrally formed such that the outer edge 19 of the base is the same edge as the bottom edge 20 of the barrier element 14.

Each spacer member 22 connects to the barrier element 14. More specifically, the first hook of the spacer member 22 connects to the top edge 24 of the barrier element 14. Each spacer member 22 connects to the base 10. More specifically, the second hook of the spacer member 22 connects to the inner edge 26 of the base 10. It will be appreciated that alternative connection means may be employed rather than the first and second hooks.

In use, the spacer members 22 connect to the base 10 and the barrier element 14 at substantially 45cm intervals along the length of the ballast retainer 10. The spacer members 22 connect to the base 10 at points between pairs of lattice members of the first series which have a smaller separation between them than the other lattice members of the first series.

In the present embodiment, the top edge 24 of the barrier element is located at a set distance, here least 3m, in a horizontal direction from the centreline of the track 8 (see Figure 1). The top edge 24 of the barrier element is located at least 0.5m in a vertical direction below the top of the track 8 (see Figure 1).

The connector 28 receives a lattice member of the first series of lattice members of the ballast retainer 10 and a lattice member of the first series of lattice members of the second ballast retainer 10a. This connects the ballast retainer 10 to the second ballast retainer 10a, effectively forming a ballast retainer of increased length.

Referring to Figure 3, there is shown a perspective view of a ballast retainer 100, which contains all of the features of the ballast retainer 10 described above with respect to Figure 1 and Figure 2. Additionally, the ballast retainer 100 comprises a ground reinforcement element 30. The ground reinforcement element 30 is substantially planar. The ground reinforcement element 30 has a lattice structure, is a geogrid and is formed from a fifth and sixth series of lattice members. The lattice members of the fifth series are parallel to those of the first series. The lattice members of the sixth series are perpendicular to those of the fifth series. Each lattice member of the fifth series is connected to all of the lattice members of the sixth series.

The spacing between the lattice members of the fifth series is considerably less than the spacing between the lattice members of the first series. The spacing between the lattice members of the fifth series is considerably less than the spacing between the lattice members of the third series. The spacing between the lattice members of the sixth series is significantly less than the spacing between the lattice members of the second series. The spacing between the lattice members of the sixth series is significantly less than the spacing between the lattice members of the fourth series.

The ground reinforcement element 30 has a length substantially equal to the length of the ballast retainer 100. The ground reinforcement element 30 has width greater than the width of the base 10.

In use, the ground reinforcement element 30 connects to the base 12 of the ballast retainer 10. The ground reinforcement element 30 is connected to the base 12 using cable ties. However, it will be appreciated that the ground reinforcement element 30 may be connected to the base 12 using alternative connection means.

In use, the ground reinforcement element 30 is located substantially horizontally between the foundation layer 4 and the ballast layer 6.

The ballast retainer 100 operates in the same manner as the ballast retainer 10 described above with respect to Figure1andFigure 2. Additionally, the ground reinforcement element 30 further anchors the base 12 of the ballast retainer.

Referring to Figure 4, there is shown a cross-section of a portion of a second track support system 2a. The second track support system comprises a first ballast retainer 10 and a second ballast retainer 10a. The second track support system 2a comprises a foundation layer (not shown in Figure 4). The second track support system 2a comprises a first ballast layer (not shown) on top of the foundation layer. The second track support system 2a comprises a second ballast layer (not shown in Figure 4) on top of the first ballast layer. Each of the first ballast retainer 10 and the second ballast retainer 10a includes all of the same features as the ballast retainer 10 described above with respect to Figure 2. Additionally, the foundation layer 4 and the first ballast layer are the same as those of the track support system 2 described above with respect to Figure 1.

The upper surface of the first ballast layer is substantially horizontal. The base 12a of the second ballast retainer 10a is located substantially horizontally between the first ballast layer and the second ballast layer.

The outer edge 18a of the base 12a occupies a position directly adjacent to the barrier element 14 of the first ballast retainer 10. The front element engages with the upright bars of the lower grille by means of the bend.

The barrier element 14a of the second ballast retainer 10a extends upwardly from the base to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

The at least one spacer 16a maintains the angle between the base 12a and the barrier element 14a. The ballast layer anchors the base 12a in position. The barrier element 14a defines a boundary of the ballast layer and retains the second ballast layer in place. The second ballast layer supports a track (not shown in Figure 4).

It will be appreciated the ballast retainers according to those described with respect to Figure 3 may also be used in a track support system similar to that of Figure 4.

Referring to Figure 5, there is shown a cross-section of a third track support system 2b. The third track support system 2b comprises a first ballast retainer 100, a second ballast retainer 100a, a third ballast retainer 100b, a fourth ballast retainer 100c and a fifth ballast retainer 100d.

The third track support system 2b comprises a foundation layer 4. The third track support system 2b comprises a first ballast layer 6 on top of the foundation layer 4. The third track support system 2b comprises a second ballast layer 6a on top of the first ballast layer 6. The third track support system 2b comprises a third ballast layer 6b on top of the second ballast layer 6a. The third track support system 2b comprises a fourth ballast layer 6c on top of the third ballast layer 6b. The third track support system 2b comprises a fifth ballast layer 6d on top of the fourth ballast layer 6c.

Each of the first ballast retainer 100, the second ballast retainer 100a, the third ballast retainer 100b, the fourth ballast retainer 100c and the fifth ballast retainer 100d includes all of the same features as the ballast retainer 100 described above with respect to Figure 3.

Further, the foundation layer 4, the first ballast layer 6, the first ballast retainer 100, the second ballast layer 6a and the second ballast retainer 100a are employed in the same way as those described above with respect to Figure 4. However, additionally, the ground reinforcement element of the first ballast retainer 100 is located substantially horizontally between the foundation layer 4 and the first ballast layer 6, and the ground reinforcement element of the second ballast retainer 100a is located substantially horizontally between the foundation layer 4 and the first ballast layer 6.

The upper surface of the second ballast layer 6a is substantially horizontal. The base of the third ballast retainer 100b is located substantially horizontally between the second ballast layer 6a and the third ballast layer 6b. The ground reinforcement element of the third ballast retainer 100b is located substantially horizontally between the second ballast layer 6a and the third ballast layer 6b. The outer edge of the base of the third ballast retainer 100b occupies a position directly adjacent to the barrier element of the second ballast retainer 100a. Again, the front element engages with the upright bars of the lower grille by means of the bend.

The barrier element of the third ballast retainer 100b extends upwardly from the base to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

The at least one spacer of the third ballast retainer 100b maintains the angle between the base and the barrier element of the third ballast retainer. The third ballast layer 6b anchors the base of the third ballast retainer 100b in position. The barrier element defines a boundary of the third ballast layer 6b and retains the third ballast layer in place.

A top kit 32b is provided on the third ballast retainer 100b. The top kit is located horizontally and is produced from a lattice structure.

The upper surface of the third ballast layer 6b is substantially horizontal. The base of the fourth ballast retainer 100c is located substantially horizontally between the third ballast layer 6b and the fourth ballast layer 6c. The ground reinforcement element of the fourth ballast retainer 100c is located substantially horizontally between the third ballast layer 6b and the fourth ballast layer 6c. The base of the fourth ballast retainer 100c is located on top of the top kit 32b of the third ballast retainer 100b.

The barrier element of the fourth ballast retainer 100c extends upwardly from the base to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

The at least one spacer of the fourth ballast retainer 100c maintains the angle between the base and the barrier element of the fourth ballast retainer. The fourth ballast layer

6c anchors the base of the fourth ballast retainer 100c in position. The barrier element 14a defines a boundary of the fourth ballast layer 6c and retains the fourth ballast layer in place.

The upper surface of the fourth ballast layer 6c is substantially horizontal. The base of the fifth ballast retainer 100d is located substantially horizontally between the fourth ballast layer 6c and the fifth ballast layer 6d. The ground reinforcement element of the fifth ballast retainer 100d is located substantially horizontally between the fourth ballast layer 6c and the fifth ballast layer 6d. The outer edge of the base of the fifth ballast retainer 100d occupies a position directly adjacent to the barrier element of the fourth ballast retainer 100c, in the same way as described above.

The barrier element of the fifth ballast retainer 100d extends upwardly from the base to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

The at least one spacer of the fifth ballast retainer 100d maintains the angle between the base and the barrier element of the fifth ballast retainer 100d. The fifth ballast layer 6d anchors the base of the fifth ballast retainer 100d in position. The barrier element defines a boundary of the fifth ballast layer 6d and retains the fifth ballast layer in place.

A top kit 32d is provided on the fifth ballast retainer 100b. The top kit is as described above.

It will be appreciated that alternative arrangements are possible with different numbers of ballast retainers. Additionally, ballast retainers according to those described with respect to Figure 2 may be used in a track support system similar to that of Figure 5.

Referring to Figure 6, there is shown a perspective view of a portion of a corner track support system 2c. The corner track support system 2c comprises a first ballast retainer 10 and a second ballast retainer 10a. Each of the first ballast retainer 10 and the second ballast retainer 1Oa is connected to a corner ballast retainer 200. The first ballast retainer 10 and the second ballast retainer 1Oa are perpendicular to each other.

The corner ballast retainer 200 comprises a first base 212 and a second base 212a. The corner ballast retainer 200 comprises a first barrier element 214 and a second barrier element 214a. Additionally, the corner ballast retainer 200 comprises at least one spacer 206.

The first barrier element 214 extends upwardly from the first base 212 to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

The second barrier element 214a extends upwardly from the second base 212a to define an angle. The angle is less than 90 degrees. More specifically, the angle is substantially 80 degrees.

The first base 212 and the second base 212a have angled edges 217, 217a, such that when the angled edges 217, 217a are brought together, the first base 212 and the second base 212a are angled with respect to each other. More specifically, the first base 212 and the second base 212a have angled edges 217, 217a, such that when the angled edges 217, 217a are brought together, the first base 212 and the second base 212a are substantially perpendicular to each other.

The angled edge 217 of the first base 212 is angled at substantially 45 degrees relative to the first base's inner edge 226 and its outer edge 218. The inner edge 226 has shorter length than the outer edge 218. The angled edge 217a of the second base 212a is angled at substantially 45 degrees relative to its inner edge 226a and its outer edge 218a. The inner edge 226a has shorter length than the outer edge 218a. In use, the inner edge 226, 226a of each base is the edge which is furthest from its respective barrier element 214, 214a.

The first barrier element 214 and the second barrier element 214a are angled with respect to each other. In practice, this is achieved by the first barrier element 214 and the second barrier element 214a having angled edges 219, 219a, such that when the angled edges 219, 219a are brought together, the bottom edges 220, 220a of the corner ballast retainer 200 are angled with respect to each other. Additionally, the first barrier element 214 and the second barrier element 214a have angled edges 219, 219a, such that when the angled edges 219, 219a are brought together, the top edges

224, 224a of the corner ballast retainer 200 are angled with respect to each other. More specifically, the first barrier element 214 and the second barrier element 214a have angled edges 219, 219a, such that when the angle edges 219, 219a are brought together, the bottom edges 220, 220a are substantially perpendicular to each other and the top edges 224, 224a are substantially perpendicular to each other.

The top edge 224 is shorter than the bottom edge 220. The top edge 224a is shorter than the bottom edge 220. The top and bottom edges are as defined above with respect to Figure 2.

The first base 212 is connected to the second base 212a. The first barrier element 214 is connected to the second barrier element 214a. The corner piece is fabricated from standard elements, which are clipped together on site to join them. It will be appreciated that the first base 212 may be integrally formed with the second base 212a. Additionally, it will be appreciated that the barrier element 214 may be integrally formed with the second barrier element 214a.

The first ballast retainer 10 is connected to the corner ballast retainer 200. More specifically, the first ballast retainer 10 connects to the first base 212, using connecting rods of the type described above with respect to Figure 2. The second ballast retainer 10a is connected to the corner ballast retainer 200. More specifically, the second ballast retainer connects to the second base 212a, using connecting rods of the type described above with respect to Figure 2.

It will be appreciated that the features of the ballast retainer 10 and the ballast retainer 100a may also be applied to the corner ballast retainer 200.

In use, the first base 212 and the second base 212a are placed on a foundation layer (not sure in Figure 6). The at least one spacer 16 is used to fix the angle between the first base 212 and the first barrier element 214, and the second base 212a and the second barrier element 214a. A ballast layer is placed on top of the first base 212 and the second base 212a, and against the first barrier element 214 and the second barrier element 214a.

The ballast layer anchors the first base 212 and the second base 212a in position. The first barrier element 214 and the second barrier element 214a define a boundary of the ballast layer and retain the ballast layer in place. The ballast layer may support a track, or may support further ballast layers along with further ballast retainers.

Figure 7 shows how a hand railing or fence can be added to the system. A hollow drum 300a, 300b is placed at a distance, eg 3.0m, from the centres and connected to the system at a base 312. The drum is formed in two halves 300a, 300b, one placed on either side of the barrier element 314, before being joined together to form the closed drum. The drum 300a, 300b is placed on top of the base 312 and fixed thereto, and holes are made in one half of the drum 300b for spacers 316 to extend through. The area around the outside of the drum is backfilled, and the inside filled with concrete or graded stone. Fixing posts could be installed prior to filling inside the drum or a steel plate could be fixed to the top. A lid 320 is provided following filling with concrete and the fixing post attached thereto, which could be anchored using suitable bolts, which could, for example be hilti bolts. This fixing detail could allow a number of options, eg chain link fencing / timber fencing or acoustic panels to be fixed to the system. A series of drums can be placed on the ballast retainer at intervals along the system.

The skilled person will be able to envisage other assemblies without departing from the scope of the appended claims.

A reference herein to a patent document or any other matter identified as prior art, is not to be taken as an admission that the document or other matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

Where any or all of the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A track support system comprising: a foundation layer; a first ballast layer to support a track, the first ballast layer on top of the foundation layer; and a first ballast retainer comprising: a base; a barrier element; and at least one spacer, wherein the base is located substantially horizontally between the foundation layer and the first ballast layer, the first ballast layer anchoring the base in position, wherein the barrier element extends upwardly from the base to define an angle, the spacer maintains the angle, and the barrier element defines a boundary of the first ballast layer and retains the first ballast layer in place.

2. The track support system of claim 1, wherein the base is substantially planar.

3. The track support system of claim 1 or 2, wherein the barrier element is substantially planar.

4. The track support system of any one of the preceding claims, wherein the angle is less than 90 degrees.

5. The track support system of any one of the preceding claims, wherein the angle is substantially 80 degrees.

6. The track support system of any one of the preceding claims, wherein the base is directly connected to the barrier element.

7. The track support system of claim 6, wherein a bottom edge of the barrier element is connected to an outer edge of the base.

8. The track support system of any one of the preceding claims, wherein the base is integrally formed with the barrier element.

9. The track support system of any one of the preceding claims, wherein the at least one spacer comprises a series of spacer members connected to the base and the barrier element.

10. The track support system of claim 9, wherein each spacer member is connected to a top edge of the barrier element and an inner edge of the base.

11. The track support system of claim 10, wherein the spacer members are connected to the base and barrier element at substantially 45 cm intervals along the length of the track support system.

12. The track support system of any of claims 9 to 11, wherein each spacer member comprises a hook at each end, the hooks connecting the spacer member to the base and the barrier element.

13. The track support system of any one of the preceding claims, wherein the base has a lattice structure.

14. The track support system of claim 13 comprising u-shaped cramps which anchor the base to the foundation layer.

15. The track support system of any one of the preceding claims, wherein the barrier element has a lattice structure.

16. The track support system of any one of the preceding claims, wherein the first ballast retainer has a length of substantially 6m.

17. The track support system of any one of the preceding claims, wherein the foundation layer is substantially planar and horizontal.

18. The track support system of any one of the preceding claims, wherein the foundation layer comprises a gravel sand layer of a depth of at least 25 cm.

19. The track support system of any one of the preceding claims, comprising a second ballast retainer connected to the first ballast retainer, thereby forming a ballast retainer of increased length.

20. The track support system of claim 19, when dependent on claim 13, comprising at least one connecting pipe which receives a lattice member of the base of the first ballast retainer; and a lattice member of a base of the second ballast retainer system, thereby connecting the second ballast retainer to the first ballast retainer.

21. The track support system of any one of the preceding claims, wherein the first ballast retainer further comprises a second barrier element, the second barrier element angled with respect to the barrier element such that the ballast retainer is a corner ballast retainer and the track support system is a corner track support system.

22. The track support system of any one of the preceding claims, comprising a ground reinforcement element connectable to the base.

23. The track support system of any one of the preceding claims, further comprising a track on the first ballast layer, at least a part of the base lying between the track and the barrier element.

24. The track support system of claim 23, wherein a top edge of the barrier element is located at least 3m from a centreline of the track.

25. The track support system of any of claims 1 to 24 comprising a second ballast layer to support a track, the second ballast layer on top of the first ballast layer; and a third ballast retainer, wherein a base of the third ballast layer is located substantially horizontally between the first ballast layer and the second ballast layer, wherein a barrier element of the third ballast retainer extends upwardly from the third ballast retainer's base to define an angle, a spacer of the third ballast retainer maintains the angle, and the barrier element of the third ballast retainer defines a boundary of the second ballast layer and retains the second layer of ballast in place.

26. The track support system of claim 25, further comprising a track on the second ballast layer, at least a part of each of the bases of the first and third ballast retainers lying between the track and their respective barrier element.

27. A kit of parts for a ballast retainer comprising: a base configured to receive a ballast layer and thereby anchoring the ballast retainer; a barrier element configured to define a boundary of the ballast layer and retain the ballast in place; and a plurality of spacer members, each spacer member of the plurality of spacer members configured to maintain an angle of less than 90 degrees between the base and the barrier element, and each spacer member comprising a hook at each end, the hooks configured to connect each respective spacer member to the base and the barrier element respectively.

28. A method of installing a track support system, comprising the steps of: placing a base of a first ballast retainer of the track support system on a foundation layer; using at least one spacer of the first ballast retainer to fix an angle between the base and a barrier element of the ballast retainer; and placing the first layer of ballast on top of the base and against the barrier element, the base anchoring the track support system and the barrier element defining the boundary of the first ballast layer and retaining the first ballast layer in place.

29. The method of claim 28 wherein the base is placed at least 1m from a slope face which comprises the first load of ballast.

30. The method of claim 28 or 29, comprising the further step of: constructing a track on the first ballast layer.

31. The method of claim 28 or 29, comprising the further steps of: placing a base of a second ballast retainer on the first ballast layer; using at least one spacer of the second ballast retainer to fix an angle between the base and a barrier element of the second ballast retainer; and placing a second ballast layer on top of the base of the second ballast retainer, against the barrier element of the second track support system and on top of the first ballast layer, the base of the second ballast retainer anchoring the second ballast retainer and the barrier element of the second ballast retainer retaining the second ballast layer.

32. The method of claim 31, comprising the further step of: constructing a track on the second ballast layer.