RAILWAY TRACK PANELS
The present invention relates to railway track panels.
Debris and rubbish can accumulate on railway track, particularly where the rails are mounted on sleepers which stand proud of the underlying track foundation. This is particularly so in stations, because of the proximity of passengers to the track. The accumulation of rubbish, silt and water around the rail fastening systems and baseplates can cause corrosion of those elements. It is therefore necessary to periodically remove the debris, rubbish and human waste which has accumulated on the railway track. Water can also penetrate through the concrete formation, for example at joints between the sleepers and the formation, causing the concrete to break away and destabilise the track. With a view to dealing with some of these problems, some tracks are formed in situ with a drain between the running rails which feed into a main drain. However, these drains themselves can become blocked by rubbish and waste, preventing the flow of water away from the rail fasteners and baseplates. Moreover, the presence of sleepers can prevent sweeping or hosing away of such matter.
According to a first aspect of the present invention there is provided a precast concrete railway track panel having an upper surface to which railway rails may be secured when the track panel is in use, wherein the upper surface is inclined with respect to the lower surface of the track panel in a direction transverse to the intended direction of the longitudinal axes of the railway rails and is formed with a drainage channel which extends across the track panel along or adjacent to a side of the inclined upper surface of the track panel which is lowermost.

As the drainage channel is formed integrally with the track panel, leakage of water between the track panel and the formation is reduced.
To adjust the fall of the drainage channel, which has been pre-cast in the track panel, once the track panel is in situ the drainage channel may be provided with channel-shaped inserts, supported within the channel at a desired longitudinal inclination in accordance with the desired fall of the drainage channel.
In order to connect the drainage channel to the main drainage pipe alongside the track, the drainage channels of some track panels may be formed with a further channel which communicates with the drainage channel and extends transversely with respect thereto so as to intersect the lowermost side of the inclined upper surface of the track panel, preferably intersecting at a T-shaped junction.
The drainage channels are preferably covered by gratings for inhibiting the entry of debris into the drainage channels which might otherwise create a blockage.
The end faces of the panel connecting the lowermost side to the side opposite thereto may be shaped so as to have male and female mating features whereby the panel may be connected to corresponding female and male mating features of an adjoining such panel. Such an arrangement helps to prevent the ingress of water. Preferably, the top of the track panel above the male/female features is shaped so that, when the track panel engages an adjoining track panel, a gap of predetermined width is formed between them into which a sealing material may be introduced.
The upper surface is provided with at least two spaced-apart plinths for supporting a railway rail baseplate when the panel is in use. As the baseplates are mounted on plinths, there is no obstruction down the centre of the

track, leaving easy access for the removal of debris and waste by either mechanical or manual means.
The upper surface of the panel may be provided with an upstand along the lowermost side thereof for inhibiting the flow of water from the track panel onto an underlying foundation. The panel is also desirably provided with such an upstand along a side thereof which is uppermost. Thus, upstands prevent damage to the formation from overflowing water.
An assembly comprising a track panel embodying the first aspect of the present invention may further comprise at least one elastomeric pad on which the panel is mounted. Preferably, the assembly further comprises a trough of approximately U-shaped cross-section in which the said panel is supported on the or each pad.
Reference will now be made, by way of example to the accompanying drawings, in which:
Figure 1 shows a plan view of a railway track employing track panels which embody the present invention;
Figure 2 shows a plan view of a track panel embodying the present invention;
Figure 3 shows a cross-sectional view taken on the line A-A of Figure 2;
Figures 4A and 4B show respective cross-sectional views of part of a track panel embodying the present invention, and Figure 4C shows a plan view of Figure 4A;
Figure 5A shows a side view of the ends of two track panels embodying the present invention and Figure 5B shows a more detailed side view of part of two interlocked track panels; and
Figure 6 shows a cross-sectional view of a track panel embodying the present invention in an alternative arrangement.

As shown in Figure I, a railway track is formed by a plurality of track panels 1 embodying the present invention which are laid end to end. Interspersed with the track panels 1, at spacings of approximately 100 metres along the track for example, are modified track panels 1'. The track panel 1, 1' is a factory manufactured pre-cast concrete unit with a smooth finish to the upper concrete surface, so assisting in the prevention of a build-up of debris and waste on the upper surface.
As shown in more detail in Figures 2 and 3, a track panel 1 embodying the present invention comprises a slab of pre-cast concrete, for example approximately 2600 mm x 3795 mm. The upper surface 10 of the track panel 1 is formed so as to have an inclination, for example 1 in 40, so that the upper surface 10 of the track panel 1 is lower at one side of the track panel 1 than the other. For example, the upper surface may be 500 mm high at the lower side 1A and 600 mm high at the upper side 1B. The lower surface 20 of the track panel is flat, but the upper surface 10 is formed with upstands 10A, 10B at the lower and upper sides 1A, 1B of the panel 1 respectively, four plinths 50 and a drainage channel 30 located alongside the upstand 10A at the lower side 1A of the track panel 1.
The upstands 10A, 10B are provided on the upper face 10 of the track panel 1 for preventing the overflow of water, debris and waste onto the side of the formation. The upstands 10A, 10B are, in this example, 200 mm high and 150 mm deep and runs the length of the track panel 1.
The plinths 50 are provided for supporting baseplates 5, rail fasteners (not shown) and rails 2 above the upper surface 10 of the track panel 1, thereby preventing the accumulation of debris, water and waste around the baseplate and rail fasteners and so facilitating cleaning

of the track and reducing corrosion of the rail fastening assembly. By installing a rubber bonded direct fixation fastener (DFF) assembly, in which the baseplate is fixed directly to the slab by anchor bolts, threaded components can be avoided. This assembly will also take out any uneven settlement of the track panels, enabling the resilience of the fastener to be increased. Use of a DFF baseplate assembly also allows adjustment of the vertical and lateral position of the baseplate if the track panel is not correctly installed in exactly the right position.
In this example, the upper surfaces of the plinths 50 are 100 mm below the top of the upstand 10B on the upper side 1B of the track panel 1. The plinths 50 are rectangular in plan, measuring by 550 mm x 1000 mm. The plinths 50 are separated by 300 mm in the direction of the rail 2 and by 1195 mm in the direction perpendicular to the rail 2. Each plinth 50 is located 150 mm from the closest edge of the track panel 1 in the direction of the rail 2. The plinths 50 which are adjacent to the upper edge 1B of the track panel 1 are located 400 mm from the upstand 10B.
As there are no joints between a plinth or sleeper for the track fastener assembly and any in-situ concrete, de-bonding between pre-cast and in-situ concrete is eliminated.
The drainage channel 30 is preferably U-shaped in cross-section, as shown in Figure 3, more preferably semicircular in cross-section. In this example, the opening of the drainage channel 30 at the upper surface 10 of the track panel is 400 mm across and is located 300 mm from the nearest plinths 50 and 100 mm from the upstand 10A.
The track panels 1 are laid such that the drainage channels 30 interconnect and rails 2 can be located on

successive plinths 50. At intervals, for example of approximately 100 metres, instead of a track panel 1, a modified track panel 1' is provided. As shown in Figure 1, in addition to the drainage channel 30, the modified track panel 1' has a T-shaped junction to a further channel 40 which is connected to a sump 3, this being in turn connected by pipes 4A, 4B to other sumps along the track and a main sump (not shown) . The provision of collection sumps every 100 metres enables cleaning out of any blocked pipes.
As shown in Figures 4A and 4B, the fall of the drainage channels 30 is determined by half round clay channels 31 embedded on mortar 32 in the pre-formed drainage channel 30. Different depths of mortar bed 32 are used to give the required fall, for example the mortar bed 32 shown in Fig. 4A is deeper than that in Fig. 4B. The half round clay channels 31 also give a smooth surface for the flow of water and an even fall to the sumps.
Blockage of the drainage channels 30, 40 can be prevented by providing gratings 35, 45 over the drainage channels 30, 40, as shown in Figures 4A, 4B and 4C. A recess 36 may be provide in the upper surface 10 of the track panel 1 over the drainage channels 30, 40 (see Fig. 4C) to locate the gratings 35, 45.
As shown in Figures 5A and 5B, to prevent the penetration of water into the formation, the joint between adjoining track panels is formed by mating male and female connections 60, 65, provided on the bottom part of the track panels 1, 1'. The top part of the track panels 1, 1' is formed so that there is a gap 70 between interlocked track panels, thereby facilitating the introduction of filler material 75, for example bitumen or epoxy grout, to seal the joint against the penetration of water.

In this example, the filler gap 70 is 20 mm wide and 300 mm deep at the lower side 1A of the panel 1. Below this the panel 1 is provided with two pairs of male/female connections 60, 65 at each end.
In some locations, for example, in noise sensitive areas, the track panel could be installed within a pre-cast or cast in-situ trough on elastomeric pads, to reduce noise and vibration. For example, Figure 6 shows a track panel 1 embodying the present invention mounted on elastomeric pads 90 (numbering 8 in all, although only 2 are shown) within a trough 80 of approximately U-shaped cross-section. The depth of the trough 80 beneath the track panel 1 in this example is 350 mm and the sides 85 are 825 mm on the upper side 1B of the track panel 1 and 725 mm on the lower side 1A of the track panel 1, both sides being 250 mm thick.
Track panels embodying the present invention may be laid as follows. Firstly, the existing track is removed and the Bite is excavated down to sound formation. Then a firm hydraulic bounded layer is laid (not shown). The pre-cast track panels 1, 1' are then installed on the hydraulic bounded layer and the joints 70 between the track panels 1, 1' are sealed with filler material 75. A modified track panel 1' is provided every 100 metres having an outlet channel 40 from the drainage channel 30 to a sump 3 connected to the main drain 4A, 4B. The drainage channels 30, 40 are finished by laying half-round clay channels 31, 41, embedded on mortar, in the pre-cast drainage channels 30, 40 to the correct falls. Finally, galvanised grating covers 35, 45 are provided on the drainage channels 30, 40.
If the track panels 1, 1' are to be mounted within a containment trough 80, before the track panels 1, 1' are laid the containment trough 80 is either cast in-situ or a pre-cast trough 80 is installed.

CLAIMS
1. A precast concrete railway track panel having an upper
surface to which railway rails may be secured when the
track panel is in use, wherein the upper surface is
inclined with respect to the lower surface of the track
panel in a direction transverse to the intended direction
of the longitudinal axes of the railway rails and is formed
with a drainage channel which extends across the track
panel along or adjacent to a side of the inclined upper
surface of the track panel which is lowermost.
2. A track panel as claimed in claim 1, wherein the said
drainage channel is provided with channel-shaped inserts,
supported within the channel at a desired longitudinal
inclination for determining the fall of the drainage
channel.
3. A track panel as claimed in claim 1 or 2, wherein the
drainage channel is formed with a further channel which
communicates with the said drainage channel and extends
transversely with respect thereto so as to intersect the
said lowermost side of the inclined upper surface of the
track panel.
4. A track panel as claimed in claim 3, wherein the said
drainage channel and the said further channel intersect at
a T-shaped junction.
5. A track panel as claimed in any preceding claim,
wherein the drainage channel is provided with a grating
thereover for inhibiting the entry of debris into the
drainage channel.

6. A track panel as claimed in claim 3 or 4, or claim 5
when read as appended to claim 3 or 4, wherein the said
further channel is provided with a grating thereover for
inhibiting the entry of debris into the further channel.
7. A track panel as claimed in any preceding claim,
wherein the upper surface of the panel is provided with an
upstand along the said lowermost side thereof for
inhibiting the flow of water from the track panel onto an
underlying foundation.
8. A track panel as claimed in claim 7, wherein the panel
is also provided with such an upstand along a side thereof
which is uppermost.
9. A track panel as claimed in any preceding claim,
wherein the sides of the panel connecting the lowermost
side to the side opposite thereto are shaped so as to have
male and female mating features whereby the panel may be
connected to corresponding female and male mating features
of an adjoining such panel.
10. A track panel as claimed in any preceding claim,
wherein the said upper surface is provided with at least
two spaced-apart plinths for supporting a railway rail
baseplate when the panel is in use.
11. A precast concrete railway track panel substantially as
hereinbefore described with reference to Figures 1 to 6 of
the accompanying drawings.

12. An assembly comprising a track panel as claimed in any
preceding claim, further comprising at least one
elastomeric pad on which the said panel is mounted.
13. An assembly as claimed in claim 12, further comprising
a trough of approximately U-shaped cross-section in which
the said panel is supported on the or each pad.