TECHNICAL FIELD

This invention relates to a rail treatment system for ameliorating buckling of rails on which run trains and other rail-borne vehicles. More particularly, though not exclusively, the invention relates to a composition, a method and an associated apparatus for treating such rails for the purpose of reducing or ameliorating, or perhaps even substantially preventing, thermally-induced buckling thereof, e.g. during hot weather or in hot climates where rails are subjected to unusually high temperatures that may cause their buckling due to longitudinal thermal expansion. The invention relates in particular, though not exclusively, to the application to rails of a thermally insulating anti-buckling composition.

BACKGROUND OF THE INVENTION AND PRIOR ART

In the field of railway engineering it is a well-recognised problem that exposure of metal (e.g. steel) rails to unusually high temperatures, such as during especially hot summer weather or in hot climates, can lead to unusually high levels of longitudinal thermal expansion of a rail, or a particular portion of a rail section’s length, that may be enough to cause transverse buckling of the rail. As well as being a potentially serious safety hazard from the point of view of safe running of a train or other vehicle on the rail, such distortions of a rail’s longitudinal shape can be very disadvantageous in terms of cost and passenger inconvenience, since scheduled trains or other vehicles cannot run on a rail track damaged though buckling, and the job of repairing the relevant portion of the rail track can be time consuming and expensive. Moreover, such problems can be exacerbated if e.g. unusually hot weather conditions are prolonged.

Hitherto this problem of rail buckling has generally been addressed by the use of mechanical devices of various kinds applied to the means of fixture of the rails to their underlying sleeper or basal support or ballast arrangements. However, these known means of addressing the problem of rail buckling having limited efficacy, and since they are often over-engineered and need to be used in large numbers to fully protect long lengths of rails in national rail networks, their costs of deployment can be excessive.

There is therefore a need in the art of rail engineering for an improved and more cost-efficient system for ameliorating the problem of rail buckling, especially thermally-induced rail buckling. It is with a primary object of addressing this need that the present invention has been devised.

Other objects and advantages of the invention or embodiments thereof may be apparent from the further definitions and descriptions which follow below of embodiments of the invention and particular features thereof.

SUMMARY OF THE INVENTION

In various of its aspects the present invention provides a method of treating a rail, especially a rail for the transport therealong of a train or other rail-borne vehicle, for reducing its propensity for undergoing thermally-induced buckling, a composition for treating a rail to reduce thermally-induced buckling thereof, an apparatus for treating a rail with an anti- thermal-buckling composition, a rail treated with such a composition, and a railway or other rail-borne vehicle track comprising one or more such treated rails.

In a first aspect of the present invention there is provided a method of treating a rail, especially a rail for the transport therealong of a train or other rail-borne vehicle, for reducing its propensity for undergoing thermally-induced buckling, the method comprising applying to at least a portion of a surface of the rail a composition comprising particles of a thermally insulating material and a matrix material.

In many embodiments of the above-defined method, the method may comprise applying to the said at least one portion of the surface of the rail at least one, especially one or more, coating layer(s) of the said composition. Thus, in some practical embodiments the application step may comprise applying just one coating layer of the composition to the rail portion, whereas in other practical embodiments the application step may comprise applying a plurality of coating layers of the composition to the rail portion.

In some practical embodiments of the above-defined method the step of applying the thermally insulating composition to the rail may be carried out prior to the rail being installed on a railway or other track, such as during a final stage in the rail’s overall manufacture in a factory.

However, in other, possibly more preferred, practical embodiments of the above-defined method the step of applying the thermally insulating composition to the rail may be carried out on the rail in situ once it has been installed on a railway or other track. Such embodiments may therefore be practised on existing rails of existing railway or other tracks. In a second aspect of the present invention there is provided a composition for treating a rail to reduce thermally-induced buckling thereof, the composition comprising particles of a thermally insulating material and a matrix material.

In many embodiments of the above-defined composition, the composition may be provided for use in the form of a liquid, especially a liquid precursor composition which comprises, in addition to the matrix material and the particles of the thermally insulating material, at least one liquid carrier or dispersant or solvent, and the optimum thermal insulation properties of the composition may be realised upon drying of the precursor composition by evaporation of at least a portion of one or more of the said carrier(s) or dispersant(s) or solvent(s).

Thus, in a third aspect of the present invention there is provided an anti-thermal-buckling composition in situ once applied to at least a portion of a surface of a rail for reducing thermally-induced buckling thereof, wherein the composition comprises particles of a thermally insulating material in a matrix material.

In a fourth aspect of the present invention there is provided an apparatus for treating a rail with an anti-thermal-buckling composition, the apparatus comprising:

(i) application means for applying onto at least a portion of a surface of the rail a precursor composition comprising particles of a thermally insulating material and a matrix material.

In some practical embodiments of the above-defined apparatus which are designed for practising embodiments of the method in which the step of applying the composition to the rail is carried out on the rail in situ once it has been installed on a railway or other track, the apparatus may further comprise:

(ii) transportation means for transporting the apparatus along the rail; and wherein the application means (i) for applying the precursor composition onto at least the portion of the surface of the rail is constructed and arranged to do so as the apparatus is transported along the rail.

In practical embodiments of any of the above-defined apparatuses of this fourth aspect of the invention, the application means (i) may comprise:

(iii) storage means for storing a supply of the precursor composition to be applied to the rail; and

(iv) delivery means for delivering onto the said at least a portion of the rail surface at least one coating layer of the said precursor composition.

In a fifth aspect of the present invention there is provided a rail, especially a rail for the transport therealong of a train or other rail-borne vehicle, which has been treated with an anti-thermal-buckling composition by the application to at least a portion of a surface thereof at least one coating layer of a composition comprising particles of a thermally insulating material and a matrix material. Embodiments of the rail of this fifth aspect may be a rail so treated by any embodiment of the method of the first aspect or with any embodiment of the composition of the second aspect or by use of any embodiment of the apparatus of the fourth aspect.

In a sixth aspect of the present invention there is provided a railway or other rail-borne vehicle track comprising one or more, especially (though not exclusively) a plurality of, rails, wherein the or each rail, or at least one of the plurality of rails (where a plurality is provided), is a rail which has been treated with an anti-thermal-buckling composition by the application to at least a portion of a surface thereof at least one coating layer of a composition comprising particles of a thermally insulating material and a matrix material. Embodiments of the or each rail of the railway or other track of this sixth aspect may be a rail so treated by any embodiment of the method of the first aspect or with any embodiment of the composition of the second aspect or by use of any embodiment of the apparatus of the fourth aspect.

According to the invention, therefore, the treatment of one or more rails by applying to at least a portion of one or more non-running surface(s) thereof a composition, especially a liquid precursor composition, comprising the matrix material and the particles of thermally insulating material, leads to the formation - especially upon the precursor composition’s drying - of a unique thermally insulating coating layer which acts as a heat shield. This heat shield layer prevents undue heating of the rail due to the sun’s rays in hot weather or from a hot ambient environment, thereby reducing the tendency of the rail to undergo excessive thermal expansion, especially in a longitudinal direction, and thus to reduce the propensity for the rail to undergo thermally-induced buckling.

In various embodiments of the invention in its various aspects, the anti-thermal-buckling composition which is applied to the rail may be applied thereto in the form of a liquid precursor composition, e.g. by spraying, or coating using a suitable coating device, or some other surface-application technique. The liquid precursor composition may be applied in the form of at least one coating layer on at least a portion of at least one surface or surface portion of the rail. In some embodiments a single such coating layer of the precursor composition may be applied to the rail. However, in other embodiments a plurality of coating layers may be applied sequentially to the rail, one on top of another, especially with a drying step taking place between the applications of adjacent coating layers, whereby a plural-layer overall coating may be applied to the rail, especially so that the overall coating is built up into a desired or appropriate total thickness.

In many embodiments one or more respective coating layers of the precursor composition may be applied onto at least one side of a web portion of the rail, which is to say at least one side of the upstanding central portion of the rail that carries the width-wise enlarged head of the rail which provides the running surface thereof that contacts the train or other vehicle’s wheels during its travel.

In some embodiments respective coating layers of the precursor composition may be applied to both sides, i.e. to each of the two opposite sides, of the web portion of the rail. In practising such embodiments the precursor composition may be applied to both sides of the rail substantially simultaneously, with the application apparatus being designed accordingly.

In the application of embodiments of the invention to the treatment of twin rails of a conventional railway track, the method and associated apparatus may be designed so as to apply at least one coating layer of the precursor composition to each respective one of at least one side of, especially both sides of, the web portion of each of the two rails. This application of the precursor composition to up to all four sides of the two rails may again be carried out simultaneously for maximum efficiency, with the apparatus being designed accordingly.

In some embodiments of the invention, the composition for treating the rail to form the final anti-thermal-buckling coating composition layer(s) may be provided for use, and applied to the rail, in the form of a liquid precursor composition comprising, in addition to the said matrix material and the said particles of the thermally insulating material, at least one liquid carrier or dispersant or solvent. The precursor composition in its as-provided and ready-for-use form may thus further comprise, in addition to the said matrix material and the said particles of the thermally insulating material, at least one liquid carrier or dispersant or solvent, especially at least one liquid carrier or dispersant or solvent in which are carried or dispersed or suspended the said particles of thermally insulating material, and in which is carried or dispersed or suspended or dissolved the said matrix material.

In some embodiments the particles of thermally insulating material comprise a particulate material comprising expanded glass particles, beads, granules or grains, especially particles (or beads, granules or grains, any of which latter terms may be used interchangeably with “particles” in the context of this invention) of a lightweight expanded recycled glass material. The glass material may be formed predominantly of S1O2. In many such embodiments the particles of expanded glass may be hollow or porous, especially porous with substantially closed pores (or the particles may predominantly be closed-porous in nature). Typically such closed-porous expanded glass particles may be formed by a sintering process, in which a pre-prepared ground recycled glass product is sintered and foamed (i.e. expanded) in a rotary kiln, thereby creating lightweight spheres or oval-shaped bodies with a fine closed cellular pore structure.

In many such embodiments the glass material may be formed predominantly of S1O2, i.e. it may comprise S1O2 in an amount of >approx. 70 % by weight of the total glass material. Optionally, the glass material may comprise minor amounts of one or more oxides or other compounds of any one or more other elements, such as Al, Na, Fe, Ca, Mg, K, Ti, Mn, S, as well as unavoidable impurities or trace amounts of one or more other elements or compounds, e.g. Cl. Where present, any such oxides of other compounds may each be present in an amount, independent of any amount of any other such other oxide, of up to about 1 or 2 or 5 or 10 or 15 % by weight of the total glass material.

In some embodiments the particles of expanded glass may have a particle size (i.e. average diameter or width) in the range of from about 0.1 or 0.2 or 0.3. mm up to about 1 or 2 or 3 or 4 mm, more especially in the approx range of from about 0.5 mm up to about 1 mm.

In some embodiments the particles of expanded glass may have a loose bulk density in the range of from about 150 or 200 to about 300 or 400 kg/m ³ , more especially in the approx range of from about 200 or 225 to about 275 or 300 kg/m ³ , e.g. in the approx range of from about 230 to about 270 or 275 kg/m ³ .

In some embodiments the particles of expanded glass may have a particle density in the range of from about 300 or 350 to about 800 or 950 kg/m ³ , more especially in the approx range of from about 400 to about 600 kg/m ³ , e.g. in the approx range of from about 425 to about 500 or 525 kg/m ³ .

In some embodiments the particles of expanded glass may have a particle crush strength (or crush resistance) in the range of from about 1.4 or 1.5 or 1.6 to about 2.7 or 2.8 N/mm ² , more especially in the approx range of from about 2.0 to about 2.6 or 2.7 N/mm ² (as measured by DIN EN 13055-1).

One example of a suitable particulate expanded recycled glass material for use as the particles of thermally insulating material in embodiments of the invention is the LIA VER (trade mark) Expanded Glass Granulate product, grade 0.5-1 mm, from Liaver GmbH & Co. KG.

Another example of a particulate expanded recycled glass material which may also be suitable for use as the particles of thermally insulating material in embodiments of the invention is the PORAVER (trade mark) Expanded Glass Beads product, grade 0.5-1 mm, from Dennert Poraver GmbH.

Other specific examples of suitable particulate expanded recycled glass materials for use as the particles of thermally insulating material in embodiments of the invention may also be commercially available.

In many embodiments, the particles of expanded glass or other thermally insulating material may be present in the liquid precursor composition for application to the rail in an amount of from about 2 or 3 to about 50 or 60 % by weight of the overall liquid precursor composition, especially in the approx range of from about 3 or 4 or 5 to about 15 or 20 or 30 % by weight of the overall liquid precursor composition.

In some embodiments of the invention the matrix material may be carried or dispersed or suspended or colloidally suspended or dissolved in the liquid precursor composition that is provided for application to the rail.

The matrix material may comprise a resin or binder or polymer material, such as an acrylic- based polymer (e.g. an acrylate polymer) or a polyurethane polymer (e.g. a polymer of an isocyanate and a polyol) or a natural or synthetic latex material (e.g. comprising one or more polymers of monomers such as isoprene, styrene, butadiene, styrene or vinyl acetate).

In some embodiments, the matrix material may be present in the liquid precursor composition for application to the rail in an amount of from about 1 or 2 or 3 or 5 to about 50 or 60 % by weight of the overall liquid composition, especially in the approx range of from about 1 or 2 or 3 or 5 to about 40 or 50 or 55 % by weight of the overall liquid composition.

The liquid precursor composition comprising the matrix material and the particles of thermally insulating material may further comprise one or more other components, which may optionally also contribute to the overall thermal insulating properties of the final insulating layer on the rail, or may at least contribute to the stability of, or other desirable physical properties (e.g. sprayability) of the composition that is applied to the rail.

In particular, in some embodiments the liquid precursor composition may further comprise at least one liquid carrier or dispersant or solvent, especially a liquid carrier, dispersant or solvent which is able to be evaporated under ambient temperature conditions of the rail environment, especially so evaporatable over a time period of from about 30 mins to about 2 or 3 hours. Such a liquid carrier, dispersant or solvent may comprise water. However, alternative such liquid carrier(s), dispersant(s) or solvent(s) may include one or more organic liquids, such as polyvinyl alcohol, and possibly others.

In some embodiments the liquid precursor composition may comprise the water or other liquid carrier, dispersant or solvent component(s) in a total amount of from about 1 or 2 or 5 to about 50 or 60 % by weight of the overall liquid composition, especially in the approx range of from about 1 or 2 or 5 to about 40 or 50 % by weight of the overall liquid composition.

Furthermore, in some embodiments the liquid precursor composition may additionally comprise one or more auxiliary components, such as one or more extender pigments, coalescing agents, agents for improving film-forming properties, or filler materials. Examples of extender pigments, coalescing agents and agents for improving film-forming properties are well-known in the art. Examples of such filler materials may include small (especially nano-scale) particles of a solid material, such as a ceramic, titanium dioxide, etc, e.g. with a particle size in the approx range of from about 1 or 5 or 10 up to about 50 or 100 or 250 or 500 nm, or even up to as much as 1000 nm.

In practising some embodiments of the invention, the precursor composition that is applied to the rail may be provided for use by combining together, e.g. by mechanical mixing, (i) a first component being the particles of expanded recycled glass material or other thermally insulating material, and (ii) a second component being a pre-prepared liquid composition comprising the said matrix material, a liquid carrier or dispersant or solvent, and optionally any above-mentioned auxiliary components such as one or more extender pigments, coalescing agents, agents for improving film-forming properties, or filler materials.

One example of a suitable such second component (ii) liquid composition for use in embodiments of the invention is the MASCOAT SOUND CONTROL-DB (trade mark) sound insulation product (this being a curable water-based acrylic sound damping composition, which lends itself particularly well to application by spraying), from Mascorp Ltd, Houston, Texas USA.

In practising some embodiments of the invention, in order to prepare the above-defined precursor composition by combining together, e.g. by mechanical mixing, the first component (i) (being the particles of expanded recycled glass material or other thermally insulating material) and the second component (ii) (being the pre-prepared liquid composition comprising the said matrix material, liquid carrier or dispersant or solvent, and optionally any of the aforementioned auxiliary components), the respective components (i) and (ii) may be combined together in respective relative amounts that provide the desired or appropriate final %wt amounts of each of the constituent substances or materials in the final precursor composition. Such respective relative amounts of each of those components (i) and (ii) may depend on the individual %wt contents of each respective constituent substance or material in its respective component composition (i) or (ii). However, by way of example, in the case of using MASCOAT SOUND CONTROL-DB in combination with LI AVER Expanded Glass Granulate product, grade 0.5-1 mm, the MASCOAT SOUND CONTROL-DB liquid may be included in an amount of from about 70 to about 95 or 96 or 97 % by weight of the total precursor composition, especially from about 75 or 80 to about 95 % by weight of the total precursor composition, and the LI AVER expanded glass materials may be included in an amount of from about 3 or 4 or 5 to about 30 % by weight of the total precursor composition, especially from about 5 to about 20 or 25 % by weight of the total precursor composition.

In many embodiments the liquid precursor composition may be applied to the rail as a coating layer of generally substantially uniform thickness or depth in its area of application. In some embodiments, the total thickness or depth of the coating layer may be in a range of from about 0.5 or 1 up to about 3 or 4 or 5 mm, especially for example in the region of around 2 mm. For any given practical scenario, however, the precise total coating layer thickness or depth may be selected e.g. in dependence on the degree of thermal insulation that it is desired to attain. Coating layer thicknesses/depths outside the above example mm range may however be used, if desired or if circumstances of a particular rail’s geometry or situation demand it.

In some embodiments the liquid precursor composition may be applied to the rail as a single coating layer, of the overall final required or desired total thickness/depth. However, in other embodiments the liquid precursor composition may be applied in a plurality of sequentially applied individual coating layers, e.g. of around 0.5 mm thick/deep, one on top of another, optionally with a drying step taking place between the applications of adjacent coating layers, whereby a plural-layer overall coating layer may be built up to the above-defined preferred desired or appropriate total thickness/depth.

In practising embodiment methods according to the present invention, the anti-thermal- buckling composition that is applied to the rail may be so applied, especially in the form of a liquid precursor form of the composition, using an apparatus according to the fourth aspect of the invention, as defined above.

In its simplest embodiment form, in the case of embodiment methods in which the step of applying the precursor composition to the rail is carried out before the rail leaves the factory, such apparatus may simply comprise the above-defined application means (i) for applying onto the at least a portion of the surface of the rail the precursor composition comprising the particles of thermally insulating material and the matrix material. That application means may comprise at least delivery means, such as in the form of a spraying device, for applying the precursor composition as one or more coating layers on the rail surface by spraying. Example embodiments of such a spraying device constituting such a delivery means will be discussed further below in conjunction with other embodiments in which the apparatus is designed for applying the coating to the rail in situ.

In more advanced embodiment forms of the apparatus according to the invention, which are designed for the practising of embodiment methods in which the step of applying the precursor composition to the rail is carried out on e.g. an existing rail in situ once it has been installed on a railway or other track, the apparatus may further comprise the above-defined transportation means (ii) for transporting the apparatus along the rail, wherein the application means (i) for applying the precursor composition onto at least the portion of the surface of the rail is constructed and arranged to do so as the apparatus is transported along the rail.

In some such embodiments the transportation means may include:

(ii)(a) at least one, optionally a plurality of, wheel(s) constructed and arranged for mounting the apparatus on one or at least one of a plurality of rails (e.g. both rails of a twin- rail track) so as to be moveable therealong, wherein the or at least one of the said rails is that rail to whose surface the precursor composition is to be applied; and

(ii)(b) drive means constructed and arranged for moving the apparatus along and relative to the rail or rails on which it is mounted.

In some embodiments the drive means may drivably act on the or at least one of the wheels to drivably move the apparatus along and relative to the rail or rails on which it is mounted. However, in other embodiments the drive means may instead drivably act on the or at least one of the rails which carry(ies) the apparatus, in order to drivably move the apparatus along and relative to the rail or rails on which it is mounted.

In some embodiments the drive means may include a motor, e.g. an electric motor, such as an electric motor powered from a battery which may conveniently be provided onboard the apparatus. Optionally a suitable gearing arrangement may be employed between the motor and the driven wheels(s) or rail itself (as the case may be) to provide a suitable speed and/or degree of control of drive of the apparatus relative to the rail or rails on which it is mounted.

Thus, as the drive means drivably moves, e.g. propels, the apparatus along the one or more rails, the application means (i) may be actuatable to apply onto the at least a portion of the surface of the rail - especially at a selected location or region thereof as the apparatus is propelled along the rail(s) - the or a respective one of the one or more coating layer(s) of the precursor composition.

In embodiments where the apparatus comprises a plurality of wheels for mounting the apparatus on a plurality of rails, especially both rails of a twin-rail track, at least one of which may in some instances be an electricity conductor that is used to power the train or other vehicle that customarily uses that track, the apparatus may include suitable electrical insulation means to avoid any short-circuiting occurring, via the apparatus, between those two rails or between one of the rails and another conductor adjacent thereto. Such insulation may be provide for instance as an inherent portion or component of the apparatus itself, e.g. as part of its frame or chassis, or alternatively as part of the mounting of the one or more wheels themselves.

In some embodiments the application means (i) may comprise the above-defined storage means (iii) for storing a supply of the precursor composition, and delivery means (iv) for delivering onto the said at least a portion of the rail surface a suitable amount (i.e. an amount sufficient to form, once dried, the required thickness or depth of the or the respective layer of the final anti-thermal-buckling composition) of the precursor composition.

In practical embodiments the delivery means may be in communication, especially fluid communication, with the storage means, e.g. by any appropriate arrangement of tubing, pipe(s) or suchlike, for allowing precursor composition ready for application to be passed from the storage means to the delivery means. A suitable pump device may be used to promote such transfer of the precursor composition, if desired or appropriate. The storage means may comprise for example one or more tanks, containers or other receptacles in which is/are contained an appropriate supply volume or weight of the precursor composition, which volume or weight may be designed to be sufficient for application of a desired length or area of the precursor composition onto the rail surface during a given coating operation, before needing replenishing.

In many such practical embodiments the one or more tanks, containers or other receptacles may be provided or carried onboard the apparatus.

In some embodiments the delivery means (iv) for delivering onto the said at least a portion of the rail surface the relevant amount of the precursor composition may comprise a spraying device, for applying a or a respective coating layer of the precursor composition onto the rail surface by spraying.

In some such embodiments the spraying device may comprise an airless spraying device. Such an airless spraying device is one in which a vacuum is created upstream of or adjacent a nozzle of the spray head, which draws composition to be ejected from the spray nozzle from the supply thereof, and the composition is then ejected from the nozzle under its own momentum. Such an airless spray device may comprise a jet pump device. Practical examples of such jet pump devices which may be suitable for spraying the precursor composition in embodiments of the invention are well-known and widely commercially available in the art.

In other, alternative, embodiments, e.g. depending on the type of precursor composition being applied onto the rail, it may be possible to employ alternative forms of delivery means, such as one or more roller applicators or even one or more brushes or other coating devices, to apply the coating of the precursor composition onto the rail. Other surface-application delivery means may alternatively be used if desired or appropriate.

Generally speaking, spray devices suitable for use in embodiments of the invention to apply the coating layer(s) of the noise-reducing onto the rail surface may be designed such that they comprise a directional nozzle or head that governs the width and/or spray pattern from a volumetric pump in order to place the composition that is applied in the correct or optimum target area on the rail. Furthermore, the nozzle or head may be designed and manufactured to facilitate the spray application to take into account the flow characteristics, viscosity and other rheological parameters, of the composition that is to be applied. In embodiments of the apparatus in which one or more coating layers of the precursor composition is/are applied to one side only of a or a respective rail, the spraying device may be provided with just one, or one respective, spray head or nozzle, which is arranged and/or configured to face the surface of the or the respective rail onto which the precursor composition is to be applied. However, in other embodiments where the coating of the precursor composition is applied to both sides of a or a respective rail, the spraying device may be provided with a pair of, or a respective pair of, opposed spray heads or nozzles, each one being disposed to or on one respective side of the or the respective rail, especially a respective side of the web portion of the or the respective rail, and facing the respective side surface thereof onto which the precursor composition is to be applied. The spacing from the or the respective rail surface and possibly other spatial parameters of the one or more spray heads or nozzles may be selected or adjusted as is most appropriate to optimise the coating’s application procedure, including for example application parameters such as coating area, thickness, uniformity, integrity, and possibly other application parameters, which precise design details will be well understood and practisable by persons skilled in the art.

Independently of the feature of the apparatus optionally being mounted on both of a pair of rails for being transported therealong as the precursor composition is applied to at least one of the rails, in the case where both of the pair of rails are each to have applied to one or more sides thereof a or a respective coating layer of the precursor composition, the apparatus may comprise the appropriate number and positioning and orientation of spray heads or nozzles, for delivering the precursor composition to where its application to the various rail surfaces or surface portions is needed.

In practical embodiments the various components of the delivery means, as well as any associated hardware of the composition storage and delivery system, may be provided or carried onboard the apparatus.

Indeed, in many embodiments it may be convenient for the apparatus to comprise a chassis or frame or base, on which are mounted the various components and associated hardware of the apparatus, so that the apparatus may be provided as a self-contained unit, trolley or vehicle, in particular a rail-borne unit, trolley or vehicle which can be transported in a driven manner along the one or more rails as it applies the coating of the precursor composition to the relevant surface(s) or surface portion(s) of the one or more rails, especially the relevant side(s) thereof, in a given operation. The overall operation of the unit or vehicle may be controlled by any suitable control system, at least some components of which may for example be remote from the unit or vehicle to allow an operator to control it more efficiently.

In some embodiments of the invention in its broadest terms, the precursor composition comprising the particles of thermally insulating material and the matrix material that is applied to at least a portion of a surface of the rail may be so applied directly onto the surface or surface portion of the rail itself, i.e. without another coating or layer in between it and the rail. Furthermore, in such embodiments the anti-thermal-buckling composition coating or layer that is applied to the rail may constitute the only species of coating/layer material that is applied to the rail.

However, in some other embodiments of the invention, the precursor composition comprising the particles of thermally insulating material and the matrix material that is applied as one or more layers thereof to at least a portion of a surface of the rail may be so applied onto, or over the top of, another at least one coating or layer of a material which has already been pre-applied to that rail surface or portion thereof in a pre-application stage for imparting to the rail some other desirable property or operational characteristic.

For instance, for the purpose of reducing mechanical noise emanating from rail tracks, especially for environmental and amenity reasons but also for helping to reduce noise- induced rail wear over time, a rail may have pre-applied to at least a portion of a surface thereof a noise-damping material comprising a coating of a noise-reducing composition. Such a noise-damping coating composition layer may thus constitute such a coating or layer that has been pre-applied to the rail surface before the application of the anti-thermal- buckling composition of the present invention and over which the anti-thermal-buckling precursor composition of the present invention is applied in these particular embodiments of the present invention.

In such embodiments which employ both an anti-thermal-buckling composition coating or layer according to the present invention and also a noise-damping coating composition coating or layer, it may be more appropriate for the noise-damping coating composition coating/layer to be applied first of all directly to the rail surface, and then the anti-thermal- buckling composition coating/layer of the invention applied on top thereof. In this manner, because it may be more important for the mechanical noise-damping layer to achieve maximum secure adhesion/bonding directly to the rail surface, this ordering of the applications of the two coating/layer species may be more desirable than the opposite ordering. However, it may still be within the scope of these dual-coating/layer embodiments that the anti-thermal-buckling composition coating/layer of the invention is applied first of all directly to the rail surface, and then the noise-damping coating composition coating/layer applied on top thereof.

Accordingly, in such dual-coating/layer embodiments, the coating of the noise-reducing composition may be applied as a coating of generally substantially uniform thickness or depth. In some such dual-coating/layer embodiments, especially in the case of rails of conventional underground railway tracks for instance, the thickness or depth of the coating, which may represent an adequate or desirable or optimum noise-reducing amount, may for example be in a range of from about 1 or 2 up to about 4 or 5 mm. For any given practical scenario, however, the precise coating thickness or depth may be selected e.g. in dependence on the degree of noise-reduction that it is desired to attain. Coating thicknesses outside the above example mm range may however be used, if desired or if circumstances of a particular rail’s geometry or situation demand it.

In other such dual-coating/layer embodiments, however, the coating of the noise-reducing composition may possibly be applied as a coating of a generally substantially non-uniform thickness or depth, such as with a thickness or depth which varies, e.g. by up to about 1 or 2 or 3 or 5 or 10 or 15 or 20 or 30 or 40 or 50 or perhaps even >50 % of its median thickness, passing in one or more directions across the rail surface carrying the coating, such as in a generally vertical or transverse direction relative to the rail’s longitudinal direction.

In many dual-coating/layer embodiments the coating of the noise-reducing composition may be applied generally as a single layer, especially in a single application step or pass. However, in other dual-coating/layer embodiments it may be possible for the coating of the noise-reducing composition to be applied in or as a plurality of layers, wherein each layer is applied in a separate or discrete application step or pass, with the plural layers being applied on top of one another. This plural-layer application technique may be useful for example where a particular thickness of coating is desired to be applied that is difficult to achieve in a single pass or application, or if the overall thickness of the coating desired to be applied is relatively large.

In some dual-coating/layer embodiments within the scope of the present invention the noise- reducing composition may comprise any suitable composition which absorbs vibrations or reduces the amplitude of sonic or other waves that pass through it. Such compositions may be substantially solid or semi-solid once applied to the rail surface, especially once cured or dried/evaporated (as or if their chemistry may dictate). In some dual-coating/layer embodiments the noise-reducing composition may comprise particles of a solid material dispersed in a binder or matrix. Thus, the noise-reducing composition may comprise a binary-phase system. The solid particle phase may comprise nano-particles, i.e. particles of a diameter on the nanometer scale, such as in the range of from about 0.5 or 1 or 5 or 10 up to about 50 or 100 or 250 or 500 nm, or even up to as much as 1000 nm. The particles may be generally substantially regular (or symmetrical) or irregular (or asymmetrical) in shape, and/or may be substantially porous or non-porous. The particles may for example comprise one or more ceramic materials. Alternatively, other solid materials, such as titanium oxide, etc may be suitable instead. The binder or matrix may comprise one or more polymer materials, such as an acrylic-based polymer. The binder or matrix may be selected so as to be substantially semi-solid or highly viscous or exhibit resilient or elastic properties, e.g. so as to exhibit a “jelly”-like consistency that enables it to absorb and only poorly transmit vibrational energy within its volume or structure. To assist this behaviour the noise-reducing composition, especially once it has been formed on the rail surface, may if desired or appropriate comprise a foamed structure, i.e. comprising voids within a framework or network or body of the dual-phase material itself.

For practical purposes, in the practising of many dual-coating/layer embodiments within the scope of the present invention, the noise-reducing composition may be provided and actually applied to the rail in the form of a liquid precursor composition, especially a liquid aqueous or part-aqueous or possibly even non-aqueous precursor composition. The liquid precursor composition may be curable, or dryable or evaporatable, to form the final noise-reducing composition in situ on the rail surface once the precursor composition has been applied thereto. Thus, following application of the precursor composition to the rail any suitable curing period or drying time may be allowed to elapse, e.g. depending on environmental conditions such as temperature and/or humidity, before the final coating of noise-reducing composition is established.

In practical embodiments the liquid precursor composition which is curable or dryable to form the final noise-reducing composition on the rail surface may have any suitable physical or rheological properties to render it suitable for application to the rail by spraying or other surface-application technique that is desired to be used, e.g. roller-coating or even painting using a brush or similar tool.

By way of example, one commercially available precursor composition which has been found to be suitable for application to a rail to form a noise-reducing composition is the curable water-based acrylic sound insulation product known by the trade mark MASCOAT SOUND CONTROL-DB, from Mascorp Ltd, Houston, Texas USA - which happens to be same example commercial product that may be used as one component, together with the particles of thermal insulating material, of the anti-thermal-buckling composition which forms the basis of the present invention.

Other commercially available examples of suitable precursor compositions for imparting suitable noise-reducing properties when applied as a noise-damping coating onto a rail may also be available. One such other example is that known by the trade mark TEMP-COAT SILENT RUNNING (from TEMP-COAT Brand Products LLC, Covington, Louisiana, USA), which is a visco-elastic aqueous acrylic latex-based sound damping coating, and again lends itself particularly well to application by spraying. Other commercially available examples of noise-reducing compositions or precursors therefor which may be suitable for use in these dual coating/layer embodiments of the present invention may alternatively be used.

In various practical embodiments of the present invention - in particular in those embodiments where an anti-thermal-buckling precursor composition of the invention is applied directly to a surface of a rail, or in those dual coating/layer embodiments where a noise-damping coating is pre-applied directly to a rail surface before the anti-thermal- buckling precursor composition of the invention is applied over the top thereof, the overall method of treating the rail may be preceded by one or more additional, preliminary steps for the purpose of preparing and/or priming the surface of the rail ready for the application thereto of the relevant precursor composition that is the first to be applied directly to the rail surface.

Such additional preparative steps may include any one or more of the following:

- a rust- (or corrosion-)removal or rust- (or corrosion-)treatment step, e.g. in which a rust- (or corrosion-)removal or inhibitor or rust- (or corrosion-)treatment composition or agent (for example that commercially available under the trade mark AQUASTEEL, from Aquamarine Chemicals (Bayer-Wood Technologies Ltd)) is applied to the rail or the appropriate surface(s) or surface portion(s) thereof, to remove existing rust or corrosion from the rail(s)’s surface(s) so as to enhance the adhesion and stable application of the first-to- be-applied precursor composition on the rail(s);

- a washing or rinsing step, e.g. in which water or an aqueous or other suitable cleaning or washing liquid (for example that commercially available under the trade mark POWERCLEAN, from Prochem Europe Ltd) is applied to the rail(s) to remove any debris or any rust- (or corrosion-)removal or inhibitor or rust- (or corrosion-)treatment composition or agent remnant thereon arising from the above rust removal or treatment step - such a washing or pre-cleaning step may alternatively or additionally be carried out prior to any rust- (or corrosion-)removal or rust- (or corrosion-)treatment step as above;

- a drying step, e.g. in which air or other gas, e.g. heated air, is blown onto the treated or washed/rinsed rail surface(s) to dry them prior to the first-to-be-applied precursor composition being applied thereto;

- optionally, a priming step, e.g. depending on the chemistry of the first-to-be-applied precursor composition being used and applied, such as by applying to the rail surface(s) which is/are to receive the first-to-be-applied precursor composition thereon an appropriate primer or priming composition or agent, in order to help affix and bond the first-to-be-applied precursor composition on the rail surface(s).

Any one or more of the above preparative steps may be carried out if desired or appropriate before the step of applying the first-to-be-applied precursor composition coating/layer.

In some practical forms of the apparatus according to the present invention, the apparatus may advantageously include appropriate components and other hardware for effecting the relevant one(s) of the above preliminary preparative steps, in addition to performing the main application step(s) of applying the relevant one(s) of the coating(s)/layer(s) of the anti- thermal-buckling precursor composition, or prior to the latter the pre-application of the noise damping precursor composition.

For the above purpose, in some practical forms of the apparatus, the apparatus may be designed to comprise a plurality of discrete modules, sections or units, each of which is designed for performing a particular step of the overall operation as discussed above. The modules, sections or units may be joined together in a linear sequence or array, so that each step of the overall operation may be carried out on a given portion of the one or more rails sequentially as the apparatus travels in a driven manner along the rail(s) and performs the overall rail preparation and rail coating operations as it goes. Accordingly, such a design of apparatus may be termed a “one-pass” apparatus, since it performs all the jobs of both rail preparation and rail coating in a single overall operation whilst travelling in a single direction.

Alternatively, in some other practical forms of the apparatus according to the invention, the apparatus may instead comprise the appropriate components and other hardware to form a single or common spraying or other application arrangement, which is used for effecting each of, or at least two or three or four or more of, the relevant one(s) of the above preliminary preparative steps as well as the anti-thermal-buckling precursor composition coating step (optionally also the noise-damping precursor composition coating step), and its relevant application components may be purged and/or rinsed or cleaned between each such discrete step. This form of the apparatus may thus be able to be made smaller and more compact, if that should be desirable, for example. Accordingly, this design of apparatus may be termed a “multi-pass” (or “plural-pass”) apparatus, since it performs all the jobs of both rail preparation and rail coating in a sequential multi-stage (or plural-stage) overall operation whilst making multiple (or plural) travelling passes, possibly (optionally) in different directions, in the overall treatment of a given length or section of rail(s).

As an alternative to the above single apparatus used a plurality of times for different jobs in the overall operation, in other embodiment apparatuses it may be the case that any appropriate number (especially a plurality of two, three, four, five or possibly even more than five) of like apparatuses are provided as part of a group or series thereof, wherein each apparatus of the group or series is charged with a different job in the overall operation and is set up for carrying out a respective one of the above preliminary preparative steps as well as the relevant precursor composition(s)’ coating step(s). The individual apparatuses of the group or series may thus be deployed either individually or in sequence, one after another. They may even be connected together in a similar manner to the individual modules of the modular form of apparatus discussed above.

Further optional or desirable, although non-limiting, components or features of apparatuses in accordance with various embodiments of the invention, and/or its method of use, may be apparent from the detailed description further below of some specific embodiments of the invention as shown in the accompanying drawings.

Within the scope of this application it is envisaged and explicitly intended that the various aspects, embodiments, features, examples and alternatives, and in particular any of the variously defined and described individual features thereof, set out in any of the preceding paragraphs, in the claims and/or in any part of the following description and/or accompanying drawings, may be taken and implemented independently or in any combination. For example, feature(s) described in connection with one particular embodiment or aspect are to be considered as independently applicable to and utilisable in all embodiments of all aspects, unless expressly stated otherwise or such features are, in such combinations, incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

Some specific embodiments of the present invention in its various aspects will now be described, by way of schematic and illustrative examples only, with reference to the accompanying drawings, in which:

FIGURE 1 is a perspective view of one schematic embodiment of an apparatus for treating a pair of railway rails with an anti-thermal-buckling precursor composition in accordance with an embodiment of the invention, which is in the form of a modular one-pass apparatus, in which a plurality of discrete modules each perform a specific task in the rail preparation, priming, noise-damping-composition-application and anti-thermal-buckling precursor composition application steps in an overall rail treatment operation;

FIGURES 2(a), 2(b), 2(c) and 2(d) are, respectively, enlarged close-up views of portions of the apparatus shown in FIG.1 as labelled therein as ll(a), ll(b), ll(c) and ll(d);

FIGURE 3 is a perspective view of an alternative, somewhat more basic, embodiment of an apparatus for treating one or more railway rails with an anti-thermal-buckling precursor composition in accordance with an embodiment of the invention, which is in the form of a “multi-pass” apparatus which employs a single or common spraying application arrangement to perform each of several individual tasks in the rail preparation, priming, noise-damping- composition-application and anti-thermal-buckling precursor composition application steps in the overall rail treatment operation, with the application components being purged and/or rinsed or cleaned between each discrete step;

FIGURE 4 is a side view of the apparatus of FIG. 3;

FIGURE 5 is a top plan view of the apparatus of FIG. 3;

FIGURE 6 is a rear end view of the apparatus of FIG. 3;

FIGURE 7 is a plan view of an example of the hand controls sub-assembly with which the overall operation of the apparatus of FIG. 3 may be actuated and controlled;

FIGURE 8 is a schematic perspective view of a pair of finished rails of a railway track which have each had a coating of an anti-thermal-buckling composition applied to a side surface thereof using either of the apparatuses of FIG. 1 or FIG. 3.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring firstly to FIGS.1 and 2, these show in schematic terms an apparatus according to one embodiment of the apparatus aspect of the invention, which is designed for applying to each of a pair of rails both an anti-thermal-buckling composition coating or layer according to the present invention and also a noise-damping coating composition coating or layer, the latter coating/layer being applied first of all directly to each surface of the rails and then the anti-thermal-buckling composition coating/layer of the invention applied on top thereof. Thus, this particular embodiment apparatus is designed to treat the rails with a duality of coatings/layers which independently function to impart to the rails their respective individual benefits of noise-damping as well as - crucially, according to this invention - anti-thermal- buckling effects.

The apparatus comprises a plurality of discrete modules, sections or units, each of which is designed for performing a particular step in the overall rail treatment operation, comprising rail cleaning, rail preparation, rail priming, application of a noise-damping composition, and finally - and in accordance with the invention - application of an anti-thermal-buckling composition. The modules, sections or units are joined together in a linear sequence or array, so that each step of the overall operation is carried out on a given portion of the one or more rails sequentially as the apparatus travels in a driven manner along the rails and performs the overall rail preparation and rail coating operations as it goes.

FIGS.1 and 2 show in schematic terms the main components of a more advanced one-pass version of apparatus 1 (e.g. as may be envisaged as a schematic in-production version of apparatus for carrying out anti-thermal-buckling treatment methods according to embodiments of the invention) for applying a coating of an anti-thermal-buckling composition to the sides of the central webs or spines R1S, R2S of each of a pair of rails R1, R2 of a railway track, such that of an underground or overground train network. As shown in FIG. 8, each rail R1 , R2 comprises a respective transversely enlarged head portion R1 F, R2F which provide the respective running surfaces/faces which contact the train wheels when it runs on the track, and each rail R1, R2 is supported on sleepers S in a conventional manner for railway tracks.

The apparatus 1 comprises a linear sequence or array of a plurality of discrete modules 20, 40, 60, 80, each of which is designed to perform a specific step or stage of the overall operation of damping the rails R1 , R2.

The apparatus 1 is mounted on the pair of rails R1 , R2 in a rolling manner via wheels (not explicitly shown, for clarity), and is drivable therealong in the direction of arrow D, relative to the track, with each module 20, 40, 60, 80 being actuatable as the apparatus 1 moves along the track to perform its given job on the relative portions of the rails of the track as it passes along it.

The front module or unit 20, as shown more clearly in the blown-up image portion constituting FIG. 2(c), is designed as a first preparative module which applies a rust-removing composition via a pair of spray heads 26A, 26B to the sides of the spine/web portions R1S, R2S of the respective rails R1 , R2. A supply of the rust-removing composition is carried onboard the apparatus 1 in one or more storage tanks 10, and is conveyed to the spray heads 26A, 26B via respective tubing or hoses 26H. Also carried atop the front module/unit 20 may be provided a compressor 30 and associated equipment for supplying the necessary rust removal composition to the spray heads 26A, 26B. A respective guide roller 24 mounted on a downwardly extending leg 22L of the frame or chassis of the front module/unit 20 rides atop each respective rail R1 , R2 to assist the optimum positioning of the spray heads 26A, 26B relative to the respective rail sides. The spray heads 26A, 26B are mounted on a further downwardly extending foot 22F of a frame or chassis of the module/unit 20 in an optimum spacing from and spatial position relative to the rail spine/web sides to optimise the spray application of the rust-removing composition. Byway of example, one suitable rust-removing composition which has found to be useful for this purpose is the product commercially available under the trade mark AQUASTEEL, from Aquamarine Chemicals (Bayer-Wood Technologies Ltd)). Thus, as the front module/unit 20 travels along the rails R1, R2 with the rest of the apparatus 1, any rust or corrosion on the sides of the rails is able to be removed, thereby cleaning the rails R1 , R2 ready for the next preparative step and later the application thereto of the noise-reducing coating.

The middle module or unit 40, as shown more clearly in the blown-up image portions constituting FIG. 2(d) and 2(a), is designed to perform two further preparative steps.

Firstly, a front portion of the middle preparative module/unit 40 is designed as a second preparative module which cleans the rails by use of a pair of pressurised water jets 46A, 46B mounted so as to face the sides of the spine/web portions R1S, R2S of the respective rails a short distance therefrom. These water cleaning jets 46A, 46B are mounted on a downwardly extending leg 42L of a frame or chassis of the module/unit 40. Carried atop the middle module/unit 40 is a water storage tank 50, which stores a supply of water for supplying the cleaning jets 46A, 46B, and are in fluid communication therewith via appropriate hoses or tubing 46H. Alternatively or additionally, an additional water supply may be provided by one or more other storage tanks, such as one of those 10 on the front module/unit 20. Thus, as the middle module/unit 40 travels along the rails R1 , R2 with the rest of the apparatus 1, the rails R1 , R2 are cleaned, washed and rinsed to a suitable degree ready for the next preparative step and later the application thereto of the noise-reducing coating.

A rear portion of the middle module/unit 40 is designed as a third preparative module which constitutes an air drier module/unit. It utilises a pair of warm or hot air driers 48A, 48B to dry the rails’ sides in readiness for the application thereto of the noise-reducing composition coating. Each air drier 48A, 48B is mounted so as to be spaced a suitable distance away from the respective rail webs’ sides, each being carried on a foot 43F at the lower end of a downwardly extending leg 43L of the frame or chassis of the middle module/unit 40. Thus, as the middle module/unit 40 travels along the rails R1 , R2 with the rest of the apparatus 1, the rails’ sides are dried, leaving them ready to receive thereon the coating of the noise- reducing composition in the final, most important step in the overall operation.

Of course, any other suitable numbers, functions and sequential ordering of front and/or middle modules or units 20, 40, or portions thereof, could be included instead of or in addition to those discussed above, in order to effect other, or other combinations or sequences of, preliminary preparative operations on the rails R1 , R2 before the next module or unit 60 follows with the application of a noise-reducing or damping coating to the sides of the rails R1 , R2 in the next stage of the operation.

Thus, the next module or unit 60, as shown more clearly in the blown-up image portion constituting FIG. 2(b), is designed to perform the application of the coating of the noise- reducing/damping composition to the sides of the rail spine/web portions R1 S, R2S. A supply of an aqueous precursor composition to the noise-reduction coating composition to be formed in situ on the rail sides is carried onboard the apparatus 1 in storage tank 70. By way of example, one suitable noise-reducing precursor composition which has been found to be useful for producing the noise-reducing coating on the rail sides is the product commercially available under the trade mark MASCOAT Sound Control-dB (from Mascorp Ltd, Houston, Texas USA), which is a curable water-based acrylic sound damping coating composition. As other examples of possibly useful such precursor compositions may be mentioned that known by the trade mark TEMP-COAT Silent Running (from TEMP-COAT Brand Products LLC, Covington, Louisiana, USA), which is a visco-elastic aqueous acrylic latex-based sound damping coating. Other commercially available precursor compositions that may also be useful and suitable for use for the purpose of applying a noise-reducing/damping composition to the rails R1, R2 may also be available.

The noise-reducing precursor composition is applied to the sides of the rail spine/web portions R1S, R2S via a pair of dual jet-pump-based spray heads 66A, 66B. These spray heads 66A, 66B are mounted on a downwardly extending leg 62L of a frame or chassis of the module/unit 60 in an optimum spacing from and spatial position relative to the rail spine/web sides to optimise the spray application of the noise-reducing composition precursor composition. The noise-reducing precursor composition is conveyed from the storage tank 70 to the spray heads 66A, 66B via appropriate hoses or tubing 66H. The spray heads 66A, 66B are, being based on jet pumps, termed airless spray devices, and are designed such that they comprise a directional nozzle or head that governs the width and/or spray pattern from a volumetric pump in order to place the precursor composition that is applied in the correct or optimum target area on the rail. Furthermore, each nozzle or spray head 66A, 66B is designed and manufactured to facilitate the spray application to take into account the flow characteristics, viscosity and other rheological parameters, of the precursor composition being applied.

Once the coating of the noise-reducing precursor composition has been applied to each of the respective sides of the spine/web portions R1S, R2S of the respective rails R1 , R2, a suitable drying period (e.g. anywhere from 30 mins to 2 or 3 hours, as appropriate, and depending e.g. on the environmental conditions) may be allowed so as to enable the noise- reducing precursor composition to dry to a suitable extent and thus form the final noise- reducing composition coating/layer on each of the rail spine/web portions R1S, R2S.

The final stage in the overall rail treatment operation is the application to each of the rail spine/web portions R1S, R2S of the coating/layer of the anti-thermal-buckling composition, which is the primary characterising feature of the present invention. This coating/layer is applied by the final, rear module or unit 80, which in its construction and operation may be substantially the same as or closely similar or analogous to that of the penultimate module/unit 60 which applies the noise-reducing coating/layer.

Thus, the final module/unit 80 for applying the anti-thermal-buckling precursor composition comprises an onboard storage tank 90, in which is contained a supply of the anti-thermal- buckling precursor composition comprising (i) a first component being the particles of expanded recycled glass material or other thermally insulating material, and (ii) a second component being a pre-prepared liquid composition comprising the said matrix material, a liquid carrier or dispersant or solvent, and optionally any above-mentioned auxiliary components such as one or more extender pigments, coalescing agents, agents for improving film-forming properties, or filler materials. The two components (i) and (ii) are combined together by suitable mechanical mixing, either before being charged into the tank 90 or afterwards. By way of a practical prototype example embodiment, the component (i) is the LIAVER (trade mark) Expanded Glass Granulate product, grade 0.5-1 mm, from Liaver GmbH & Co. KG (or alternatively the PORAVER (trade mark) Expanded Glass Beads product, grade 0.5-1 mm, from Dennert Poraver GmbH) - present in the precursor composition in an amount of approx. 10 % by weight of the total precursor composition -, and the component (ii) is the liquid composition MASCOAT SOUND CONTROL-DB (trade mark) sound insulation product (this being a curable water-based acrylic sound damping composition), from Mascorp Ltd, Houston, Texas USA - present in the precursor composition in an amount of approx. 90 % by weight of the total precursor composition.

Since the construction and operation of the final, rear module or unit 80 which applies the anti-thermal-buckling precursor composition is substantially the same as (or closely similar or analogous to) that of the penultimate module/unit 60, the parts and components of the final rear module/unit 80 (including their own respective dual jet-pump-based spray heads), as well as their function and manner of operation, substantially correspond to those of the penultimate module/unit 60, as described above in relation to that module/unit and shown more clearly in the blown-up image portion constituting FIG. 2(b) - and so will not need duplicated description again here in relation to their applicability also to the final module/unit 80.

Thus, once the coatings/layers of the noise-reducing composition and also (on top thereof) the anti-thermal-buckling composition have been applied to each of the respective sides of the spine/web portions R1S, R2S of the respective rails R1, R2, the final configuration and appearance of the thus dual-treated rails R1 , R2 is shown in FIG. 8.

In a modification of the apparatus 1 in an alternative embodiment of the present invention in its various aspects, the penultimate module/unit 60 could be omitted altogether, so that no noise-reducing damping coating/layer at all is applied to the rails R1 , R2, and the remaining rear module/unit 80 is used to apply directly to the prepared and primed rails R1 , R2 the coating/layer of the anti-thermal-buckling precursor composition.

T urning now to the embodiment apparatus as shown in FIGS. 3 to 7, here the apparatus 100 is designed as a more basic multi-pass version (e.g. as may be envisaged as a schematic prototype version of apparatus for carrying out anti-thermal-buckling rail treatment methods according to embodiments of the present invention) in which the same apparatus is used to effect each discrete application stage of the overall operation, including the preparative steps of water cleaning and rust removal, the application of the noise-reducing coating precursor composition to the respective rail spine/web sides, and finally the application of the anti- thermal-buckling precursor composition to the respective rail spine/web sides.

In this version of the apparatus, it comprises the appropriate components and other hardware to form a single or common spraying arrangement, which is used several times over for effecting, one discrete step after another, each of the relevant one(s) of the above application steps, with the relevant components being purged and/or rinsed or cleaned between each such discrete step. Accordingly, this version of the apparatus 100 performs all the jobs of both rail preparation and the respective rail coatings in a sequential multi-stage operation whilst making multiple travelling passes along the rails, possibly in different directions, in the overall treatment of a given length or section of the rail track.

In view of the above detailed discussion of the modular construction and operation of the one-pass apparatus of FIGS. 1 and 2, many of the equivalent constructional and operational details of the multi-pass apparatus of FIGS. 3 to 7 will be readily understood by the skilled person in light of the disclosure and descriptions hereinabove. However to facilitate this understanding the various component parts and the constructional or operational features of the apparatus of FIGS. 3 to 7 are summarised by the following self-explanatory list:

110 - solenoid valve (e.g. 12 volt), for actuating release of composition to spray heads,

120F - front lifting/manipulation handle,

120R - rear lifting/manipulation handle

130 - composition feed pipe (connected to solenoid valve 110),

140A, 140B - rear working lights (left and right),

150A, 150B - spray heads (left and right),

150LA, 150LB - mounting legs (left and right) for spray heads,

150HA, 150HB - supply hoses for spray heads (left and right),

160 - drive wheel (driven by electric motor),

170 - idler wheel,

180 - front working light,

190 - battery,

200 - battery securing strap,

210 - operator control unit, including wiring connection box, battery condition indicator, light switches etc,

220 - tension wheels,

230 - stabiliser wheel,

235, 236, 237 - mounting and support struts for mounting of stabiliser wheel to the apparatus, 240 - stabiliser wheel insulating bushes (for preventing electrical short-circuiting between the rails R1 , R2).

An example of the operator control unit 210 is shown in FIG. 7, where the various component parts and constructional or operation features thereof by which the apparatus 100 is controllable can be summarised by the following self-explanatory list:

310 - forward/reverse direction switch, 320 - control cable,

330 - isolator key,

340 - speed controller,

350 - forward/reverse throttle (e.g. 3-step),

360 - warning light,

370 - composition solenoid switch, for actuating composition release from the spray heads as or when required.

It is to be understood that the above description of various specific embodiments of the invention in its various aspects has been by way of non-limiting examples only, and various modifications may be made from what has been specifically described and illustrated whilst remaining within the scope of the invention as defined by the appended claims.

Throughout the description and claims of this specification, the words “comprise” and “contain” and linguistic variations of those words, for example “comprising” and “comprises”, mean “including but not limited to”, and are not intended to (and do not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.