Railway sleeper system

Abstract

A railway sleeper 100 comprising a rail support portion 102 which defines an x- axis extending between a first end 104 and a second end 106 of the rail support portion. The rail support portion define

Description

The present disclosure relates to a railway sleeper system. Background It is known for railway tracks to be supported on a substrate via railway sleepers. The substrate may be a track ballast, for example crushed stone aggregate. Sleepers are provided to keep the railway tracks apart a set distance and hold them in place. Rails are stiff in a vertical plane, but are relatively flexible laterally (i.e. in a horizontal plane). Changes in temperature will cause the railway tracks to expand and contract, which may induce lateral forces if the rail is not perfectly straight. In extreme high temperatures the lateral force may be sufficient to bend and buckle the railway track in the horizontal plane. Hence in addition to maintaining the railway track in a preferred vertical orientation, sleepers are configured to resist lateral forces including those induced by the expansion and contraction of the railway tracks, and hence prevent the railway tracks from moving laterally or buckling. Concrete sleepers 10 are commonly used, provided as elongate cuboid blocks, for example as shown in a plan view in Figure 1. Even when embedded in the substrate 16, the concrete sleepers 10 may not adequately prevent lateral movement of the railway tracks 12 (e.g. in directions D1, D2 illustrated in Figure 1), hence anchor clamps 14 may be provided on the sleepers, made from a metal frame which clamps around the sleeper 10 and extends into the substrate 16. While effective at resisting lateral forces, each anchor clamp 14 is a relatively complex and weighty fabrication, and it is labour intensive to manufacture, transport, fit and / or retrofit them to sleepers 10, adding extra materials, cost and time to the creation of a length of track. Steel sleepers are also known. These are lighter and smaller than concrete sleepers, meaning they are easier and cheaper to transport. They also require less depth of substrate than a concrete sleeper. Despite their lower weight, steel sleepers have high resistance to lateral movement. However, in some applications the ability to resist higher lateral forces is required. Hence a railway sleeper system which resists high lateral forces without needing complex anchor clamp accessories, and yet is efficient to manufacture, deliver and install, and which requires the minimum of substrate (track ballast), is highly desirable. Summary According to the present disclosure there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. Accordingly there may be provided a railway sleeper system (100). The railway sleeper system (100) may comprise a rail support portion (102) which defines an x-axis extending between a first end portion (104) ofthe rail support portion (102) and a second end portion (106) of the rail support portion (102). The rail support portion (102) may extend along a y-axis, a first edge (108) ofthe rail support portion (102) and a second edge (110) ofthe rail support portion (102) spaced apart from one another along the y-axis; the x-axis being at right angles to the y-axis. The rail support portion (102) may define a rail support side (120) which faces a first side (122) ofthe x-axis, and a substrate engagement side (124) for engagement with a substrate (200) and which faces a second side (126) ofthe x-axis. The rail support side (120) and substrate engagement side (124) may be spaced apart from one another in a z-axis; the z-axis being perpendicular to the x-axis and y-axis. The first end portion (104) may extend at a first angle (A1) to the x-axis to a first free end (130) on the second side (126) ofthe x-axis such that a force in a first direction (D1) from the second end portion (106) to the first end portion (104) is reacted against by the engagement of the first end portion (104) with the substrate (200) and hence motion ofthe rail support portion (102) in the first direction (D1) is inhibited. A first anchor feature (400) may extend from the first end portion (104) at a second angle (A2) to the first end portion (104) to a second free end (402) on the second side ofthe x-axis. The second angle (A2) may have a value such that a force in a second direction (D2) from the first end portion (104) to the second end portion (106) will be reacted against by the engagement ofthe first anchor feature (400) with the substrate (200) and hence motion ofthe rail support portion (102) in the second direction (D2) is inhibited. The second angle (A2) may have a value such that a force in a second direction (D2) from the first end portion (104) to the second end portion (106) will induce a force (F2) on the first end portion in the direction ofthe z-axis towards the substrate (200). The second end portion (106) may extend at a third angle (A3) to the x-axis to a third free end (134) on the second side (126) ofthe x-axis such that a force in the second direction (D2) will be reacted against by the engagement ofthe second end portion (106) with the substrate (200) and hence motion ofthe rail support portion (102) in the second direction (D2) is inhibited. The railway sleeper system (100) may comprise a second anchor feature (410) which extends from the second end portion (106) ata fourth angle (A4)tothe second end portion (106) to a fourth free end (412) on the second side ofthe x-axis. The fourth angle (A4) may have a value such that a force in the first direction (D1) will be reacted against by the engagement of the second anchor feature (410) with the substrate (200) and hence motion of the rail support portion (102) in the first direction (D1) is inhibited. The fourth angle (A4) may have a value such that a force in the first direction (D1) will induce a force (F1) on the second end portion (106) in the direction of the z-axis towards the substrate (200). The first anchor feature (400) may extend at a fifth angle (A5) to the x-axis such that the first end portion (104) and the first anchor feature (400) diverge away from one another along their length to their free ends (130, 402). The first end portion (104) and second end portion (106) may diverge away from one another along their length to their free ends (130, 134). The second anchor feature (410) may extend at a sixth angle (A6) to the x-axis such that the second end portion (106) and the second anchor feature (410) diverge away from one another along their length to their free ends (134, 412). The second anchor feature (410) may extend at a sixth angle (A6) to the x-axis such that the first anchor feature (400) and second anchor feature (410) converge towards one another along their length to their free ends (402, 412) or are substantially parallel to one another. The fifth angle (A5) between the first anchor feature (400) and the x-axis, and the sixth angle (A6) between the second anchor feature (410) and the x-axis may be at least 30 degrees but no more than 60 degrees. The first angle (A1) between the first end portion (104) and the x-axis, and the third angle (A3) between the second end portion (106) and the x-axis may be at least 120 degrees but no more than 150 degrees. The or each anchor feature (400, 410) may be provided as an elongate member (430). The or each anchor feature (400, 410) may comprise two or more elongate members (430) spaced apart from one another in a direction of the y-axis, and / or spaced apart along the x-axis. The or each elongate member (430) may have a head end (440) at the opposite end to its free end (402, 412) and comprise a threaded portion (442) extending from the head end (440) for engagement with an aperture (150, 152) provided in the respective end portion (104, 106). The or each elongate member (430) may comprise a tapered tip (432) at the free end (402, 412). The or each anchor feature (400, 410) may be provided as a plate (450) which extends in the direction of the y-axis across the respective end portion (104, 106). Thefree end (130, 134) of the or each end portion (104, 106) may extend a first distance (L1) in the z-axis direction from the substrate engagement side (124). The free end (402, 412) of the or each anchor feature (400, 410) may extend at least 50%, but no more than 150% of the first distance (L1) in the z-axis direction from the substrate engagement side (124). The rail support portion (102) may comprise a channel-shaped (160) section extending along the x-axis from the first end portion (104) to the second end portion (106). The rail support portion (102) may be configured to be stackable with another identical rail support portion (102). There may be provided a railway track assembly (500) comprising a substrate (200); a railway sleeper system (100) according to the present disclosure located on the substrate (200); and a first rail (300) coupled to the railway sleeper system (100) and fixed relative to the substrate (200) by the railway sleeper system (100). There may be provided a method of installation of a railway sleeper system (100) in a substrate (200), the method comprising providing a railway sleeper system (100) according to the present disclosure, arranging the rail support portion (102) on the substrate (200) such that the substrate engagement side (124) of the rail support portion (102) faces the substrate (200); and adjusting the material of the substrate (200) such that the first end portion (104) and first anchor feature (400, 410) are at least partially submerged in the substrate (200). The method may comprise the step of adjusting the material of the substrate (200) such that the second end portion (106) and second anchor feature (410) are at least partially submerged in the substrate (200). There may be provided a method of manufacture of a railway sleeper system (100), the method comprising providing a railway sleeper system (100) comprising a rail support portion (102) extending along an x-axis between a first end portion (104) and a second end portion (106); the rail support portion (102) defining a rail support side (120) which faces a first side (122) of the x-axis, and a substrate engagement side (124) for engagement with a substrate (200) and which faces a second side (126) of the x-axis; the first end portion (104) extending at a first angle (A1) to the x-axis to a first free end (130) on the second side (126) of the x-axis such that a force in a first direction (D1) from the second end portion (106) to the first end portion (104) is reacted against by the engagement of the first end portion (104) with the substrate (200) and hence motion of the rail support portion (102) in the first direction (D1) is inhibited; and the method further comprising: providing a first anchor aperture (150) in the first end portion (104); locating a first anchor feature (400) in the first anchor aperture (150) such that the first anchor feature (400) is constrained to extend from the first end portion (104) at a second angle (A2) to the first end portion (104) to a second free end (402) on the second side of the x-axis, the second angle (A2) having a value such that a force in a second direction (D2) from the first end portion (104) to the second end portion (106) will: be reacted against by the engagement of the first anchor feature (400) with the substrate (200) and hence motion ofthe rail support portion (102) in the second direction (D2) is inhibited; and induce a force (F2) on the first end portion (104) in the direction of the z-axis towards the substrate (200). The second end portion (106) may extend at a third angle (A3) to the x-axis to a third free end (134) on the second side (126) ofthe x-axis such that a force in the second direction (D2) will be reacted against by the engagement ofthe second end portion (106) with the substrate (200) and hence motion ofthe rail support portion (102) in the second direction (D2) is inhibited; and the method may further comprise: providing a second anchor aperture (152) in the second end portion (106); locating a second anchor feature (410) in the second anchor aperture (152) and in the substrate (200) such that the second anchor feature (410) is constrained to extend at a fourth angle (A4) to the second end portion (106) to a fourth free end (412) on the second side ofthe x-axis, the fourth angle (A4) having a value such that a force in the first direction (D1) will: be reacted against by the engagement ofthe second anchor feature (410) with the substrate (200) and hence motion ofthe rail support portion (102) in the first direction (D1) is inhibited; and induce a force (F1) on the second end portion (106) in the direction ofthe z-axis towards the substrate (200). Hence there is provided a railway sleeper system which resists high lateral forces without needing complex anchor clamp accessories, and yet is efficient to manufacture, deliver and install, and which requires the minimum of substrate (track ballast). Brief Description ofthe Drawings Examples of the present disclosure will now be described with reference to the accompanying drawings, in which: Figure 1 is an illustration of a plan view of a railway track assembly of the related art; Figure 2 is an illustration of a plan view of a railway track assembly of the present disclosure; Figure 3 shows a section of a railway sleeper system ofthe present disclosure in situ in a substrate; Figure 4 shows a side sectional view of a railway sleeper system ofthe present disclosure in situ in a substrate; Figure 5 shows a plan view of a rail support portion of a railway sleeper system of the present disclosure; Figure 6 shows a side sectional view of a rail support portion of a railway sleeper system ofthe present disclosure; Figure 7 shows a plan view of a railway sleeper system of the present disclosure; Figure 8 shows a side sectional view of a railway sleeper system of the present disclosure; Figure 9 shows a perspective view of a rail support portion of a railway sleeper system of the present disclosure; Figure 10 shows a perspective view of a railway sleeper system of the present disclosure; Figure 11 shows a first example of an anchor feature of the present disclosure; Figure 12 shows a second example of an anchor feature of the present disclosure; Figure 13 shows a side sectional view of a further example of a railway sleeper system of the present disclosure; Figure 14 shows an underside view of the railway sleeper system shown in figure 13; Figure 15 shows a perspective sectional view of a rail support portion of the railway sleeper system of the present disclosure; and Figure 16 illustrates a performance characteristic of the railway sleeper system of the present disclosure. Detailed Description The present disclosure relates to a railway sleeper system 100. The railway sleeper system 100 may form part of railway track assembly 500, for example as illustrated in figure 2. The railway track assembly 500 may comprise a substrate 200, a railway sleeper system 100 according to the present disclosure located on the substrate 200, and a first rail 300 coupled to the railway sleeper system 100 and fixed relative to the substrate 200 by the railway sleeper system 100. One or more additional rails 300 may also be coupled to the railway sleeper system 100 and fixed relative to the substrate 200 by the railway sleeper system 100. As best illustrated in figures 4to 10,13, 14, the railway sleeper system 100 may comprise a rail support portion 102 (or “rail seat”) which defines an x-axis extending between a first end portion 104 (or “first spade end”) of the rail support portion 102 and a second end portion 106 (or “second spade end”) of the rail support portion 102. The rail support portion 102 may extend along a y-axis, a first edge 108 (i.e. side edge) of the rail support portion 102 and a second edge 110 (i.e. side edge) of the rail support portion 102 spaced apart from one another along the y-axis, the x-axis being at right angles to the y-axis. The rail support portion 102 may define a rail support side 120 which faces a first side 122 of the x-axis, and a substrate engagement side 124 for engagement with a substrate 200 and which faces a second side 126 of the x-axis. Hence, in normal use (and as shown in figures 4, 6, 8, 13) the rail support side 120 faces upwards and hence and the first side 122 of the x-axis is above the rail support side 120. Also, in normal use, the substrate engagement side 124 faces downwards, and hence the second side 126 of the x-axis is beneath the substrate engagement side 124. The substrate 200 may be provided as a track ballast. As shown in figure 3, the track ballast may comprise pieces of stone aggregate 202. Track ballast may comprise one or more of crushed stone, washed gravel, bank run (unwashed) gravel, torpedo gravel (a mixture of coarse sand and small gravel), slag, chats, coal cinders, sand, or burnt clay. The rail support side 120 and substrate engagement side 124 are spaced apart from one another in a z-axis, where the z-axis is perpendicular to the x-axis and y-axis. The rail support portion 102 (i.e. the main body of the railway sleeper system 100) may be made from a metal or metallic alloy. For example, the rail support portion 102 may be made from steel. In particular, the rail support portion 102 may be made from any material with an appropriate strength, stiffness and fatigue resistance (e.g. steel or more specifically structural steel grades such as those specified in BS EN 10025 or similar). The rail support portion 102 may be formed from rolled metal or metal alloy (for example steel). Figure 15 shows a perspective cross section through an example of rail support portion 102. As illustrated, the structure of the rail support portion 102 may comprise an integrally formed layer of metal or a metallic alloy which is formed as a “U” shaped channel. That is to say, the rail support portion 102 may comprise a channel-shaped 160 section extending along the x-axis from the first end portion 104 to the second end portion 106. A first side wall 180 may extend from the rail support portion 102 to the first edge 108, and a second side wall 182 may extend from the rail support portion 102 to the second edge 110. The first side wall 180 and second side wall 182 may diverge away from one another along their length to their respective edges 108, 110. Hence the first side wall 180, second side wall 182 and rail support portion 102 define a “trough volume". The “U” shaped channel provides rigidity but also enables the rail support portion 102 to be stackable with another identical rail support portion 102. It will be appreciated that the example geometries / shapes shown in the figures for the rail support portion 102, first end portion 104 and second end portion 106 are provided for illustrative purposes only, and the features of the railway sleeper system 100 of the present disclosure are not limited thereto. The first end portion 104 may extend at a first angle A1 to the x-axis to a first free end 130 on the second side 126 of the x-axis. As illustrated in figures 4, 8, the first angle A1 may have a value such that a force in a first direction D1 from the second end portion 106 to the first end portion 104 is reacted against by the engagement of the first end portion 104 with the substrate 200 and hence motion of the rail support portion 102 in the first direction D1 is inhibited. Since the first end portion 104 is angled so that it will extend into the substrate 200, a force in the first direction D1 will induce a force on the first end portion 104 in the direction of the z-axis towards / into the substrate 200, which further resists movement in the first direction D1. Since motion of the rail support portion 102 in the first direction D1 is inhibited, motion of the railway sleeper system 100 in the first direction D1 is also inhibited. The railway sleeper system 100 may further comprise a first anchor feature 400 which extends from the first end portion 104 at a second angle A2 to the first end portion 104 to a second free end 402 on the second side of the x-axis. As illustrated in figures 4, 8, the second angle A2 may have a value such that a force in a second direction D2 from the first end portion 104 to the second end portion 106 (i.e. the force in a second direction D2 in a direction opposite to the first direction D1) will be reacted against by the engagement of the first anchor feature 400 with the substrate 200 and hence motion of the rail support portion 102 in the second direction D2 is inhibited. Since motion of the rail support portion 102 in the second direction D2 is inhibited, motion of the railway sleeper system 100 in the second direction D2 is also inhibited. The second angle A2 may have a value such that a force in a second direction D2 from the first end portion 104 to the second end portion 106 will induce a force F2 on the first end portion in the direction of the z-axis towards / into the substrate 200. That is to say, second angle A2 may have a value such that a force in a second direction D2 from the first end portion 104 to the second end portion 106 will induce a force F2 on the first end portion via the first anchor feature 400 in the direction of the z-axis towards / into the substrate 200. The second end portion 106 may extend at a third angle A3 to the x-axis to a third free end 134 on the second side 126 of the x-axis. The third angle may have a value such that a force in the second direction D2 will be reacted against by the engagement of the second end portion 106 with the substrate 200 and hence motion of the rail support portion 102 in the second direction D2 is inhibited. Since the second end portion 106 is angled so that it will extend into the substrate 200, a force in the second direction D2 will induce a force on the second end portion 106 in the direction of the z-axis towards / into the substrate 200, which further resists movement in the second direction D2. Since motion of the rail support portion 102 in the second direction D2 is inhibited, motion of the railway sleeper system 100 in the second direction D2 is also inhibited. The railway sleeper system 100 may comprise a second anchor feature 410 which extends from the second end portion 106 at a fourth angle A4 to the second end portion 106 to a fourth free end 412 on the second side of the x-axis. The fourth angle A4 may have a value such that a force in the first direction D1 will be reacted against by the engagement of the second anchor feature 410 with the substrate 200 and hence motion of the rail support portion 102 in the first direction D1 is inhibited. Since motion of the rail support portion 102 in the first direction D1 is inhibited, motion of the railway sleeper system 100 in the first direction D1 is also inhibited. The fourth angle A4 may have a value such that a force in the first direction D1 will induce a force F1 on the second end portion 106 in the direction of the z-axis towards / into the substrate 200. That is to say, the fourth angle A4 may have a value such that a force in the first direction D1 will induce a force F1 on the second end portion 106 via the second anchor feature 410 in the direction of the z-axis towards / into the substrate 200. Resistance to movement is also provided by frictional forces generated between the substrate 200 and the side edges 108, 110 to oppose forces from the first direction D1 and / or the second direction D2. There may be provided a first inflexion point 140 between the first free end 130 of the first end portion 104 and the third free end 134 of the second end portion 106 which defines where the first end portion 104 begins. There may be provided a second inflexion point 142 between the third free end 134 of the second end portion 106 and the first free end 130 of the first end portion 104 which defines where the second end portion 106 begins. The first anchor feature 400 may be provided between the first free end 130 and the first inflexion point 140. The second anchor feature 410 may be provided between the third free end 134 and the second inflexion point 142. In examples in which two or more anchor features 400 are provided on the first end portion 104, they may all be provided between the first free end 130 and the first inflexion point 140. In examples in which two or more anchor features 410 are provided on the second end portion 106, they may all be provided between the third free end 134 and the second inflexion point 142. As illustrated in figures 4, 6, 8, 9, 10, 13, the first anchor feature 400 may extend at fifth angle A5 to the x-axis such that the first end portion 104 and the first anchor feature 400 diverge away from one another along their length to their free ends 130, 402. The second anchor feature 410 may extend at a sixth angle A6 to the x-axis. The second end portion 106 and the second anchor feature 410 may diverge away from one another along their length to their free ends 134, 412. The first end portion 104 and second end portion 106 may diverge away from one another along their length to their free ends 130, 134. The first anchor feature 400 and second anchor feature 410 may converge towards one another along their length to their free ends 402, 412 or may be parallel to one another. The first anchor feature 400 and second anchor feature 410 may be substantially parallel to one another. In some examples the first anchor feature 400 and second anchor feature 410 may be extend vertically into the substrate 200. In some examples the first anchor feature 400 and second anchor feature 410 may extend at an angle to the substrate 200 to converge towards one other. In some examples the first anchor feature 400 and second anchor feature 410 may extend at an angle to the substrate 200 to diverge from one another. The first angle A1 and the third angle A3 may have the same value or a different value. The second angle A2 and fourth angle A4 may have the same value or a different value. The fifth angle A5 and sixth angle A6 may have the same value or a different value. The fifth angle A5 between the first anchor feature 400 and the x-axis, and the sixth angle A6 between the second anchor feature 410 and the x-axis may be at least 10 degrees but no more than 80 degrees. The fifth angle A5 between the first anchor feature 400 and the x-axis, and the sixth angle A6 between the second anchor feature 410 and the x-axis may be at least 20 degrees but no more than 70 degrees. The fifth angle A5 between the first anchor feature 400 and the x-axis, and the sixth angle A6 between the second anchor feature 410 and the x-axis may be at least 30 degrees but no more than 60 degrees. The first angle A1 between the first end portion 104 and the x-axis, and the third angle A3 between the second end portion 106 and the x-axis may be at least 100 degrees but no more than 170 degrees. The first angle A1 between the first end portion 104 and the x-axis, and the third angle A3 between the second end portion 106 and the x-axis may be at least 110 degrees but no more than 160 degrees. The first angle A1 between the first end portion 104 and the x-axis, and the third angle A3 between the second end portion 106 and the x-axis may be at least 120 degrees but no more than 150 degrees. The or each anchor feature 400, 410 may be provided as an elongate member 430. For example the or each anchor feature 400, 410 may be provided as a pin, bolt or screw type member, for example as shown in figures 11, 12. As illustrated in figures 7, 8, 13, 14, a single anchor feature 400 may be provided at the first end portion 104 and a single anchor feature 400 may be provided at the second end portion 106. As illustrated in figures 3, 9, 10, the or each anchor feature 400, 410 may comprise two or more elongate members 430 spaced apart from one another in a direction of the y-axis. As illustrated in figures 3, 9, 10, the or each anchor feature 400, 410 may comprise two or more elongate members 430 spaced apart from one another aligned in a direction of the y-axis. Hence two or more anchor features 400 may be provided at the first end portion 104 and two or more anchor features 400 may be provided at the second end portion 106. In other examples (not shown) the or each anchor feature 400, 410 may comprise two or more elongate members 430 spaced apart from one another in a direction of the y-axis, and / or spaced apart along the x-axis. The or each elongate member 430 may have a head end 440 at the opposite end to its free end 402, 412 and comprise a threaded portion 442 extending from the head end 440 for engagement with an aperture 150, 152 provided in the respective end portion 104, 106. The threaded portion may extend part of the way from the head end 440 to the free end 402, leaving an unthreaded section 434 extending between the screw thread and the free end. The threaded portion may extend substantially all of the way from the head end 440 to the free end 402. Examples of elongate members 430 are illustrated in figures 11, 12. As shown in figure 11 the (or each) elongate member 430 may comprise a flat or blunt tip 432 at the free end 402, 412. The flat or blunt tip 432 may be advantageous as it may provide a positive engagement with the substrate material 200. As shown in figure 12 the or each elongate member 430 may comprise a tapered tip 432 at the free end 402, 412, ending in a point. The tapered tip 432 may be advantageous as it may be easier to push into a substrate material 200. In other examples (not shown) the or each elongate member 430 may comprise a rounded tip 432 at the free end 402, 412, for example having a spherical profile. As illustrated in figures 13, 14 the or each anchor feature 400, 410 may be provided as a plate 450 which extends in the direction of the y-axis across the respective end portion 104, 106. As illustrated in figure 8, the free end 130, 134 of the or each end portion 104, 106 may extend a first distance L1 in the z-axis direction from the substrate engagement side 124. The free end 402, 412 of the or each anchor feature 400, 410 may extend at least 50%, but no more than 150% of the first distance L1 in the z-axis direction from the substrate engagement side 124. In some examples some, but not all, of the sleepers 100 in a railway track assembly 500 are provided as the sleeper system 100 of the present disclosure. In some examples all of the sleepers 100 in a railway track assembly 500 are provided as the sleeper system 100 of the present disclosure. A method of installation of a railway sleeper system 100 in / on a substrate 200 may comprise first providing a railway sleeper system 100 according to the present disclosure, and the arranging the rail support portion 102 on the substrate 200 such that the substrate engagement side 124 of the rail support portion 102 faces the substrate 200. The method may further comprise adjusting the substrate 200 such that the first end portion 104 and first anchor feature 400, 410 are at least partially submerged in the substrate 200. For example, the method may comprise arranging elements / pieces 202 of the substrate 200 such that the first end portion 104 and first anchor feature 400 are at least partially submerged in the substrate 200. The elements / pieces 202 of the substrate 200 may be compressed around the first end portion 104 and first anchor feature 400, for example by tamping the substrate 200. The method may further comprise the step of adjusting the substrate 200 such that the second end portion 106 and second anchor feature 410 are at least partially submerged in the substrate 200. For example, the method may further comprise arranging elements / pieces 202 of the substrate 200 such that the second end portion 106 and second anchor feature 410 are at least partially submerged in the substrate 200. The elements / pieces 202 of the substrate 200 may be compressed around the second end portion 106 and second anchor feature 410, for example by tamping the substrate 200. The railway sleeper system 100 may be produced (i.e. assembled) remotely from where it is to be used, or on the site where it is to be used. Hence, after providing the rail support portion 102, a first anchor aperture 150 may then be provided in the first end portion 104. One or more additional apertures 150 may also provided in the first end portion 104, each for receiving an anchor feature 410 (e.g. pin, bolt, screw or the like). A first anchor feature 400 may then be provided in the first anchor aperture 150 such that the first anchor feature 400 is constrained to extend from the first end portion 104 at a second angle A2 to the first end portion 104 to a second free end 402 on the second side of the x-axis. As described above, the second angle A2 is chosen to have a value such that a force in a second direction D2 from the first end portion 104 to the second end portion 106 (i.e. in a direction opposite to the first direction D1 will be reacted against by the engagement of the first anchor feature 400 with the substrate 200 and hence motion of the rail support portion 102 in the second direction D2 is inhibited. The second angle A2 is also chosen to induce such that a force in the first direction D1 will induce a force F2 on the first end portion 104 in the direction of the z-axis towards / into the substrate 200. The method further comprises providing a second anchor aperture 152 in the second end portion 106, locating a second anchor feature 410 in the second anchor aperture 152 and in the substrate 200 such that the second anchor feature 410 is constrained to extend at a fourth angle A4 to the second end portion 106 to a fourth free end 412 on the second side of the x-axis. As described above the fourth angle A4 is chosen to have a value such that a force in the first direction D1 will be reacted against by the engagement of the second anchor feature 410 with the substrate 200 and hence motion of the rail support portion 102 in the first direction D1 is inhibited. The fourth angle A4 is chosen to have a value such so as to induce a force F1 on the second end portion 106 in the direction of the z-axis towards / into the substrate 200. In examples where a single first anchor aperture 150 is provided in the first end portion 104 (for example as illustrated in figures 4, 7) the anchor apertures 150 may be located anywhere between the first edge 108 and the second edge 110, although preferably are located at the midpoint between the first edge 108 and the second edge 110. The first anchor aperture 150 may be provided between the first free end 130 and the first inflexion point 140. The second anchor aperture 152 may be provided between the third free end 134 and the second inflexion point 142. In examples where a two or more anchor apertures 150 are provided in the first end portion 104 (for example as illustrated in figures 3, 9,10) the anchor apertures 150 may be located spaced anywhere between the first edge 108 and the second edge 110, although preferably are spaced apart from one another in the direction of the y-axis between the first edge 108 and the second edge 110. In examples where two or more anchor apertures 150 are provided on the first end portion 104, they may all be provided between the first free end 130 and the first inflexion point 140. In examples in which two or more anchor apertures 152 are provided on the second end portion 106, they may all be provided between the third free end 134 and the second inflexion point 142. The anchor apertures 150, 152 may be produced by any appropriate method, for example by drilling or punching the material of the rail support portion 102. The apertures 150, 152 will have the same depth as the thickness of the material. Byway of non limiting example, the material of the rail support portion 102 may have a thickness of 3mm to 15mm. After drilling, the apertures 150, may be tapped (e.g. provided with a screw thread). Alternatively the apertures 150 may be left plain, and a fixing member, for example a nut, weld or bonding means may be used to hold the anchor features 400, 410 in place. Alternately, the anchor features 400, 410 (e.g. elongate members 430) may be configured to be “self tapping” and hence produce a thread on the apertures as they are inserted. The elongate members 430 may be wound / screwed into the apertures 150, 152. In a further example, the anchor apertures 150, 152 may be produced using anchor features 400, 410 which are configured to be “self drilling self tapping" and hence will create the apertures 150, 152 in the material and tap them at the same time. Hence there is provided a railway sleeper system which resists high lateral forces without needing complex anchor clamp accessories, and yet is efficient to manufacture, deliver and install, and which requires the minimum of substrate (track ballast) compared to examples of the related art. The provision of anchor features 400, 410 results in a sleeper system which is able to resist lateral movement (e.g. in a direction along the x-axis, indicated as directions D1, D2) by providing better engagement with the substrate than possible with examples of the related art. This is achieved by virtue of the first end portion 104, second end portion 106, first anchor feature 400 and second anchor feature 410 (and any further anchor features 400, 410) all extending from the rail support portion 102 towards the same side (i.e. the second side 126) of the rail support portion 102 (e.g. beneath the substrate engagement side 124, when the rail support portion is in situ), and their angle relative to one another. The rail support portion 102 (i.e. the main body of the railway sleeper system 100) is operable to resist higher lateral forces and the likelihood of the sleeper moving in a direction away (i.e. upwards) from the substrate is reduced because of the addition of the anchor features 400, 410. These effects, especially when combined, mean that a railway track assembly 500 comprising a railway sleeper system 100 of the present disclosure is more likely to retain its preferred configuration. That is to say, the tracks coupled by a railway sleeper system 100 of the present disclosure are more likely to be retained in their desired position than sleepers of the related art. For example, with reference to figure 16, the performance of a concrete sleeper is compared with a conventional steel sleeper and a railway sleeper system (“sleeper system”) of the present disclosure. It can be seen from this that a much greater force (lateral load, shown in kN) is required to be applied to a railway sleeper system of the present disclosure than to a concrete sleeper or a steel sleeper to produce the same lateral displacement (e.g. in directions D1, D2 along the x-axis). Additionally, an anchor feature 400, 410, whether provided as pins 430 (as in the examples of figures 3, 4, 7, 8, 10 to 12) or as plates 450 as in the examples of figure 13, 14) can be added to metal sleeper designs without modifying their structure, and retrofitted to already manufactured metal sleepers (for example those which are due to be installed or are already on site and / or in position). Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A railway sleeper system (100) comprising:a rail support portion (102) which defines an x-axis extending between a first end portion 5 (104) of the rail support portion (102) and a second end portion (106) of the rail supportportion (102);wherein the rail support portion (102) extends along a y-axis, a first edge (108) of the rail support portion (102) and a second edge (110) of the rail support portion (102) spaced apart from one another along the y-axis; the x-axis being at right angles to the y-axis; and10 the rail support portion (102) defining a rail support side (120) which faces a first side(122) of the x-axis, and a substrate engagement side (124) for engagement with a substrate (200) and which faces a second side (126) ofthe x-axis; andthe rail support side (120) and substrate engagement side (124) are spaced apart from one another in a z-axis; the z-axis being perpendicular to the x-axis and y-axis;15 the first end portion (104) extending at a first angle (A1) to the x-axis to a first freeend (130) on the second side (126) ofthe x-axis such that a force in a first direction (D1) from the second end portion (106) to the first end portion (104) is reacted against by the engagement ofthe first end portion (104) with the substrate (200) and hence motion of the rail support portion (102) in the first direction (D1) is inhibited; and20 a first anchor feature (400) which extends from the first end portion (104) at a secondangle (A2) to the first end portion (104) to a second free end (402) on the second side of the x-axis, and the first anchor feature (400) extends at a fifth angle (A5) to the x-axis such that the first end portion (104) and the first anchor feature (400) diverge away from one another along their length to their free ends (130, 402), the fifth angle (A5) being at25 least 10 degrees but no more than 80 degrees;the second angle (A2) having a value such that a force in a second direction (D2) from the first end portion (104) to the second end portion (106) will:be reacted against by the engagement ofthe first anchor feature (400) with the substrate (200) and hence motion ofthe rail support portion (102) in the second direction (D2) is 30 inhibited; andinduce a force (F2) on the first end portion in the direction of the z-axis towards the substrate (200).

2. A railway sleeper system (100) as claimed in claim 1 wherein:the second end portion (106) extends at a third angle (A3) to the x-axis to a third free end (134) on the second side (126) of the x-axis such that a force in the second direction (D2) will be reacted against by the engagement of the second end portion (106) with the substrate (200) and hence motion of the rail support portion (102) in the second5 direction (D2) is inhibited; andthe railway sleeper system (100) comprises a second anchor feature (410)which extends from the second end portion (106) at a fourth angle (A4) to the second end portion (106) to a fourth free end (412) on the second side of the x-axis, the fourth angle (A4) having a value such that a force in the first direction (D1) will:10 be reacted against by the engagement of the second anchor feature (410) withthe substrate (200) and hence motion of the rail support portion (102) in the first direction (D1) is inhibited; andinduce a force (F1) on the second end portion (106) in the direction ofthez-axis towards the substrate (200).

153. A railway sleeper system (100) as claimed in claim 2 wherein the first end portion (104) and second end portion (106) diverge away from one another along their length to their free ends (130, 134).

204. A railway sleeper system (100) as claimed in any one of claims 2 to 3 wherein the second anchor feature (410) extends at a sixth angle (A6) to the x-axis such that:the second end portion (106) and the second anchor feature (410) diverge away from one another along their length to their free ends (134, 412); and25 the first anchor feature (400) and second anchor feature (410) converge towards oneanother along their length to their free ends (402, 412) or are substantially parallel to one another.

5. A railway sleeper system (100) as claimed in claim 4 wherein the fifth angle (A5) between30 the first anchor feature (400) and the x-axis, and the sixth angle (A6) between the secondanchor feature (410) and the x-axis are at least 30 degrees but no more than 60 degrees.

6. A railway sleeper system (100) as claimed in any one of claims 2 to 5 wherein the first angle (Al) between the first end portion (104) and the x-axis, and the third angle (A3)between the second end portion (106) and the x-axis are at least 120 degrees but no more than 150 degrees.

7. A railway sleeper system (100) as claimed in any one of claims 1 to 6 wherein the or each5 anchor feature (400, 410) is provided as an elongate member (430).

8. A railway sleeper system (100) as claimed in any one of claims 1 to 6 wherein the or each anchor feature (400, 410) comprises two or more elongate members (430) spaced apart from one another in a direction of the y-axis, and / or spaced apart along the x-axis.

9. A railway sleeper system (100) as claimed in claim 8 wherein the or each elongate member (430) has a head end (440) at the opposite end to its free end (402, 412) and comprises a threaded portion (442) extending from the head end (440) for engagement with an aperture (150, 152) provided in the respective end portion (104, 106).1510. A railway sleeper system (100) as claimed in claims 8 or 9 wherein the or each elongate member (430) comprises a tapered tip (432) at the free end (402, 412).

11. A railway sleeper system (100) as claimed in any one of claims 1 to 6 wherein the or each 20 anchor feature (400, 410) is provided as a plate (450) which extends in the direction ofthe y-axis across the respective end portion (104, 106).

12. A railway sleeper system (100) as claimed in any one of claims 1 to 11 wherein:the free end (130, 134) of the or each end portion (104, 106) extends a first distance (L1) 25 in the z-axis direction from the substrate engagement side (124), andthe free end (402, 412) of the or each anchor feature (400, 410) extends at least 50%, but no more than 150% of the first distance (L1) in the z-axis direction from the substrate engagement side (124).30 13. A railway sleeper system (100) as claimed in any one of claims 1 to 12 wherein the railsupport portion (102) comprises a channel-shaped (160) section extending along the x-axis from the first end portion (104) to the second end portion (106).

14. A railway sleeper system (100) as claimed in claim 13 wherein the rail support portion (102) is configured to be stackable with another identical rail support portion (102).

15. A railway track assembly (500) comprising:5 a substrate (200);a railway sleeper system (100) as claimed in any one of claims 1 to 14 located on the substrate (200);a first rail (300) coupled to the railway sleeper system (100) and fixed relative to the substrate (200) by the railway sleeper system (100).

16. A method of installation of a railway sleeper system (100) in a substrate (200), the methodcomprising:providing a railway sleeper system (100) as claimed in any one of claims 1 to 14;arranging the rail support portion (102) on the substrate (200) such that the substrate 15 engagement side (124) of the rail support portion (102) faces the substrate (200);adjusting the material of the substrate (200) such that the first end portion (104) and first anchor feature (400, 410) are at least partially submerged in the substrate (200).

17. A method as claimed in claim 16 when dependent on claim 2 wherein the method20 comprises the step of adjusting the material of the substrate (200) such that the secondend portion (106) and second anchor feature (410) are at least partially submerged in the substrate (200).2518. A method of manufacture of a railway sleeper system (100), the method comprising:providing a railway sleeper system (100) comprising a rail support portion (102) extending along an x-axis between a first end portion (104) and a second end portion (106);the rail support portion (102) defining a rail support side (120) which faces a first side (122) of the x-axis, and a substrate engagement side (124) for engagement with a substrate (200) and which faces a second side (126) ofthe x-axis;the first end portion (104) extending at a first angle (A1) to the x-axis to a first free end (130) on the second side (126) ofthe x-axis such that a force in a first direction (D1) from the second end portion (106) to the first end portion (104) is reacted against by theengagement of the first end portion (104) with the substrate (200) and hence motion of the rail support portion (102) in the first direction (D1) is inhibited; andthe method further comprising:providing a first anchor aperture (150) in the first end portion (104);5 locating a first anchor feature (400) in the first anchor aperture (150) such that the firstanchor feature (400) is constrained to extend from the first end portion (104) at a second angle (A2) to the first end portion (104) to a second free end (402) on the second side of the x-axis, and such that the first anchor feature (400) is also constrained to extend at a fifth angle (A5) to the x-axis such that the first end portion (104) and the first anchor 10 feature (400) diverge away from one another along their length to their free ends (130,402), the fifth angle (A5) being at least 10 degrees but no more than 80 degrees;the second angle (A2) having a value such that a force in a second direction (D2) from the first end portion (104) to the second end portion (106) will:be reacted against by the engagement of the first anchor feature (400) with the substrate 15 (200) and hence motion of the rail support portion (102) in the second direction (D2) isinhibited; andinduce a force (F2) on the first end portion (104) in the direction of the z-axis towards the substrate (200).20 19. A method as claimed in claim 18 wherein:the second end portion (106) extends at a third angle (A3) to the x-axis to a third free end (134) on the second side (126) of the x-axis such that a force in the second direction (D2) will be reacted against by the engagement of the second end portion (106) with the substrate (200) and hence motion of the rail support portion (102) in the second 25 direction (D2) is inhibited; andthe method further comprises:providing a second anchor aperture (152) in the second end portion (106);locating a second anchor feature (410) in the second anchor aperture (152) and in the substrate (200) such that the second anchor feature (410) is constrained to extend at a 30 fourth angle (A4) to the second end portion (106) to a fourth free end (412) on the secondside of the x-axis, the fourth angle (A4) having a value such that a force in the first direction (D1) will:be reacted against by the engagement of the second anchor feature (410) with the substrate (200) and hence motion of the rail support portion (102) in the first direction (D1) is inhibited; andinduce a force (F1) on the second end portion (106) in the direction of the z-axistowards the substrate (200).LDCM

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