GB2563082A

GB2563082A - Rail damping system

Info

Publication number: GB2563082A
Application number: GB1708870.9A
Authority: GB
Inventors: Phillips Roland; Venables Raymond
Original assignee: Roland Norman Phillips
Current assignee: Roland Norman Phillips
Priority date: 2017-06-02
Filing date: 2017-06-02
Publication date: 2018-12-05
Also published as: GB201708870D0

Abstract

A method of damping a railway rail R1, R2 comprises applying a coating C1 to surface of the rail wherein the coating is of a noise-reducing composition. Also provided is an apparatus 1 for carrying out the method. Also provided is a rail, or a plurality of rails, that have been dampened by the surface application of a coating comprising a noise-reducing composition. The coating may be applied to the rail in situ once it has been installed on a railway track. The coating may be applied to the rail prior to the rail being installed. The coating may be applied by spraying. The coating may be applied onto the rail web, optionally two opposite sides of the rail web. The coating may have a uniform thickness. The coating may have a non-uniform thickness varying between 1 and 50 of its median thickness. The coating may be applied as a single layer, or a plurality of layers. The coating may be formed of a solid material dispersed in a binder or matrix. The particles may be porous or semi-porous, and may comprise ceramic materials.

Description

RAIL DAMPING SYSTEM

TECHNICAL FIELD

This invention relates to a system for the damping of rails on which run trains and other railborne vehicles, and in particular for damping to reduce noise. More particularly, though not exclusively, the invention relates to a method and an associated apparatus for damping a rail, for the purpose of reducing noise emanating therefrom when trains or other vehicles travel along it. The invention relates in particular to the application to a rail of a damping material.

BACKGROUND OF THE INVENTION AND PRIOR ART

In the field of railway engineering it is a well-recognised problem that noise emanating from a rail when a train, tram or other vehicle travels along it is undesirable. Typically noise is generated by mechanical interactions of and between the train or other vehicle’s wheels and the running surface of the rail, and may be caused not only by structural vibrations within the materials of the rail and/or the wheels themselves but also by mechanical vibrations at the interface between the running surfaces of the rail and the wheels. Levels of noise generation can often increase over time as rails undergo wear, especially wear of the nature of corrugations or other surface deformations formed in a rail’s running surface through the mechanical surface-to-surface interactions with the train or other vehicle’s wheels. Rail corrosion can also be another contributory factor to noise generation. Not only is noise an environmental nuisance, but the mechanics of noise generation itself can lead to exponentially increasing levels of further rail wear.

In order to tackle such issues of rail wear and noise generation thereby, it is well-known in the art to periodically employ rail grinders, namely apparatus which physically reshapes a rail’s running surface, in order to restore the rail’s proper profile and remove corrugations or other irregularities from its running surface. Such rail grinders are typically used as part of a regular rail maintenance regime and not only help to reduce noise and the ride of trains or other vehicles riding along the rail but also help to extend the rail’s lifespan.

However, rail grinders are large and expensive items of machinery to manufacture, deploy and maintain. For their use they also require lengths of rail, or tracks comprising one or more rails, to be closed during the grinding operation, which therefore prevents trains or other vehicles running thereon whilst the grinding operation is being carried out, which therefore forces such maintenance operations to be carried out e.g. at night, when trains or other vehicles may not need to run anyway, or even to be carried out less frequently than may be optimal.

In an effort to reduce noise emanating from rail tracks, especially for environmental and amenity reasons but also to help reduce rail wear over time, it is known to employ rail dampers, which are devices that are physically attached by clamping to the side(s) of a rail to act as a mass-spring system which improves the rail’s ability to decouple and/or decay noise-inducing vibrations which occur as a train or other vehicle runs along the rail.

However, such known rail damping devices are at best only partially successful in tackling the problem of noise generation, and they too, like rail grinders, are expensive to install and maintain. They may furthermore have only limited efficacy since in many cases they require “tuning” to a particular rail vibration frequency in order to be optimally effective, and this may itself render such damping devices less effective when typical noise-inducing vibrations may occur over wide or varying frequency ranges, e.g. when different vehicles use a given length of rail track.

Therefore, there is a need in the art of rail engineering for an improved and more efficient system for damping rails against noise generation. This need for an improved noise-damping system manifests itself not only in a need for reducing noise pollution in the environment in the vicinity of rails and railway tracks, but also in a need to reduce rates of noise-induced wear on rails themselves. It is with a primary object of addressing these needs 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

Embodiments of the invention in its various aspects may be understood with reference to the appended claims.

In various of its aspects the present invention provides a method of damping a rail, especially a rail for the transport therealong of a train or other rail-borne vehicle, an apparatus for applying a damping material to a rail, a rail damped by the application thereto of a damping material using the method or the apparatus, and a railway or other rail-borne vehicle track comprising one or more such damped rails.

In one aspect of the present invention for which protection is sought there is provided a method of damping a rail, especially a rail for the transport therealong of a train or other railborne vehicle, the method comprising applying to at least a portion of a surface of the rail a damping material comprising a coating of a noise-reducing composition.

In some practical embodiments of the above-defined method the step of applying the coating of the noise-reducing 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, embodiments of the above-defined method the step of applying the coating of the noise-reducing 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 another aspect of the present invention for which protection is sought there is provided an apparatus for applying a damping material to a rail, the apparatus comprising:

(i) application means for applying onto at least a portion of a surface of the rail a damping material comprising a coating of a noise-reducing composition.

In practical embodiments of the above-defined apparatus which are designed for practising embodiments of the method in which the step of applying the coating of the noise-reducing 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 coating of the noise-reducing 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 the invention the application means (i) may comprise:

(iii) storage means for storing a supply of the noise-reducing composition; and (iv) delivery means for delivering onto the said at least a portion of the rail surface an amount, especially a noise-reducing amount, of the noise-reducing composition.

In yet another aspect of the present invention for which protection is sought there is provided a rail, especially a rail for the transport therealong of a train or other rail-borne vehicle, damped by the application to at least a portion of a surface thereof a damping material in the form of a coating of a noise-reducing composition. The rail of this aspect may be a rail so damped by the method of the first-mentioned aspect or by use of the apparatus of the preceding aspect.

In a yet further aspect of the present invention for which protection is sought 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 damped by the application to at least a portion of a surface thereof a damping material in the form of a coating of a noise-reducing composition. The or each rail of the railway or other track of this aspect may be a rail so damped by the method of the first-mentioned aspect or by use of the apparatus of the preceding-but-one aspect.

In embodiments of the invention the noise-reducing composition may be applied, e.g. by spraying or other surface-application technique, as a coating on at least a portion of at least one surface or surface portion of the rail. In many embodiments one or more respective coatings of the noise-reducing 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 coatings of the noise-reducing 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 noise-reducing 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 damping of twin rails of a conventional railway track, the method and associated apparatus may be designed so as to apply a plurality of coatings of the noise-reducing composition to respective ones of at least one side of, especially both sides of, the web portion of each of the two rails. This application 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 many embodiments the coating of the noise-reducing composition may be applied as a coating of generally substantially uniform thickness or depth. In some such 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 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 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 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 embodiments of the 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 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 up to about 10 or 20 or 30 or 50 or 100 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 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 embodiments of the invention the noisereducing composition may be provided for application to the rail in the form of a liquid precursor composition, especially a liquid aqueous or part-aqueous or possibly even nonaqueous 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 in accordance with embodiments of the invention is that known by the trade mark MASCOAT Sound Control-dB (from Mascorp Ltd, Houston, Texas USA), which is a curable water-based acrylic sound damping coating composition, and lends itself particularly well to application by spraying. Further technical features and properties of this example material are implicitly incorporated in this disclosure by reference thereto.

Other commercially available examples of suitable precursor compositions for imparting suitable noise-reducing properties when applied as a 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. Again, further technical features and properties of this example material are implicitly incorporated in this disclosure by reference thereto.

Other examples of noise-reducing compositions or precursors therefor suitable for use in embodiments of the invention may alternatively be used.

In practising embodiment methods according to the present invention, the coating of the noise-reducing composition, or in many cases the coating of a precursor composition therefor, may be applied to the rail surface using an apparatus which has been specially designed for that purpose.

In its simplest embodiment form, in the case of embodiment methods in which the step of applying the coating of the noise-reducing composition (or its precursor) 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 coating of the noise-reducing composition (or its precursor). That application means may comprise at least delivery means, such as in the form of a spraying device, for applying the composition (or its precursor) as a coating 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 (or its precursor) 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 coating of the noise-reducing composition (or its precursor) 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 coating of the noise-reducing composition (or its precursor) 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 twin8 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 coating of noise-reducing composition (or its precursor) 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 coating of the noise-reducing composition (or its precursor).

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 noise-reducing composition or its precursor composition, and delivery means (iv) for delivering onto the said at least a portion of the rail surface a noise-reducing amount of the noise-reducing composition or its 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 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 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 noisereducing composition or its precursor, which volume or weight may be designed to be sufficient for application of a desired length or area of the composition or its precursor 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 noise-reducing amount of the noise-reducing composition or its precursor composition may comprise a spraying device, for applying a coating of the composition or its 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 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 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 noise-reducing 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 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 a coating of the noise-reducing composition is 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 composition is to be applied. However, in other embodiments where the coating of the noise-reducing 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 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 practiceable 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 coating 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 coating of the noise-reducing composition, the apparatus may comprise the appropriate number and positioning and orientation of spray heads or nozzles, for delivering the 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 noise-reducing 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 practising some practical embodiments of the method of damping a rail in accordance with the present invention, in conjunction with - but prior to - the step of applying the coating of the noise-reducing composition to the one or more rails, one or more additional, preliminary steps may optionally be carried out, especially in order to prepare the one or more rails ready for the application thereto of the noise-reducing composition.

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 rails or rails, 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 noisereducing 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 rusttor 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 noise-reducing composition being applied thereto;

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

Any one or more of the above preparative steps may be carried out of desired or appropriate before the step of applying the coating of the noise-reducing composition.

In some practical forms of the apparatus according to the invention, the apparatus may advantageously include the appropriate components and other hardware for effecting the relevant one(s) of the above preliminary preparative steps, in addition to performing the noise-reducing composition coating step.

For this 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 noise-reducing 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 embodiments it may be the case that any appropriate number (especially a plurality of two, three, four or possibly even more than four) 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 noise-reducing composition coating step. 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 a rail damping apparatus in accordance with 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 and noise-reducing coating application steps in an overall rail damping operation;

FIGURES 2(a), (b), (c) and (d) are respective 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), respectively;

FIGURE 3 is a perspective view of another, different, and somewhat more basic, embodiment of a rail damping apparatus in accordance with 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 and noisereducing coating application steps in the overall rail damping 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 a noise-reducing 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 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 damping methods according to embodiments of the invention) for applying a coating of noise-reducing 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 R1F, 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 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 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 tank(s) 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. By way 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 noisereducing 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 rear module or unit 60 follows up with the application of the noise-reducing coating to the sides of the rails R1, R2 in the final stage of the operation.

Accordingly, the rear module or unit 60, as shown more clearly in the blown-up image portion constituting FIG. 2(b), is designed to perform the critical application of the coating of the noise-reducing composition to the sides of the rail spine/web portions R1S, 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 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 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 compositions that may also be useful and suitable of ruse in embodiments of this invention may also be available.

The noise-reducing composition 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 composition 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 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 composition has 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 treated rails R1, R2 is shown in FIG. 8.

Turning now to the embodiment 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 damping methods according to embodiments of the 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, and finally the application of the noise-reducing coating precursor composition to the respective rail spine/web sides.

In this version of the apparatus 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 rail coating 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 hereinabove. However to facilitate this understanding the various component parts and constructional or operation 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.

Claims

1. A method of damping a rail, the rail being a rail for the transport therealong of a train or other rail-borne vehicle, the method comprising applying to at least a portion of a surface of the rail a damping material comprising a coating of a noise-reducing composition.

2. A method according to claim 1, wherein the step of applying the coating of the noisereducing composition to the rail is carried out on the rail in situ once it has been installed on a railway or other track.

3. A method according to claim 1, wherein the step of applying the coating of the noisereducing composition to the rail is carried out prior to the rail being installed on a railway or other track.

4. A method according to any one of claims 1 to 3, wherein the coating of the noisereducing composition is applied by spraying on at least a portion of at least one surface or surface portion of the rail.

5. A method according to any preceding claim, wherein the coating of the noisereducing composition is applied onto at least one side of a web portion of the rail.

6. A method according to claim 5, wherein the coating of the noise-reducing composition is applied to each of the two opposite sides of the web portion of the rail.

7. A method according to claim 6, wherein the coating of the noise-reducing composition is applied to both sides of the rail substantially simultaneously.

8. A method according to any preceding claim, wherein the coating of the noisereducing composition is applied as a coating of generally substantially uniform thickness or depth.

9. A method according to claim 8, wherein the thickness or depth of the coating is in a range of from about 1 or 2 up to about 4 or 5 mm.

10. A method according to any one of claims 1 to 7, wherein the coating of the noisereducing composition is applied as a coating of a generally substantially non-uniform thickness or depth, optionally wherein the thickness or depth varies by up to about 1 or 2 or

3 or 5 or 10 or 15 or 20 or 30 or 40 or 50 of its median thickness passing in one or more directions across the rail surface carrying the coating.

11. A method according to any preceding claim, wherein the coating of the noisereducing composition is applied either:

(i) as a single layer; or (ii) 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.

12. A method according to any preceding claim, wherein the noise-reducing composition comprises a composition which absorbs vibrations or reduces the amplitude of sonic or other waves that pass through it.

13. A method according to claim 12, wherein the noise-reducing composition is substantially solid or semi-solid once applied to the rail surface, optionally once applied to the rail surface and cured or dried/evaporated.

14. A method according to claim 12 or claim 13, wherein the noise-reducing composition comprises particles of a solid material dispersed in a binder or matrix.

15. A method according to claim 14, wherein the solid particle phase comprises nanoparticles with diameters in the range of from about 0.5 or 1 up to about 10 or 20 or 30 or 50 or 100 nm.

16. A method according to claim 14 or claim 15, wherein the particles are generally either:

(i) substantially regular or symmetrical in shape; or (ii) substantially irregular or asymmetrical in shape.

17. A method according to any one of claims 14 to 16, wherein the particles are generally either:

(iii) substantially porous; or (iv) substantially non-porous.

18. A method according to any one of claims 14 to 17, wherein the particles comprise one or more ceramic materials.

19. A method according to any one of claims 14 to 18, wherein the binder or matrix comprises one or more polymer materials.

20. A method according to claim 19, wherein the binder or matrix exhibits resilient or elastic properties.

21. A method according to any preceding claim, wherein the coating of the noisereducing composition comprises a foamed structure.

22. A method according to any preceding claim, wherein the coating of the noisereducing composition is formed on the rail surface or surface portion by applying thereto a liquid precursor composition therefor.

23. A method according to claim 22, wherein the liquid precursor composition is aqueous or part-aqueous.

24. A method according to claim 22 or claim 23, wherein the liquid precursor composition is 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.

25. A method according to claim 24, wherein following application of the precursor composition to the rail a curing period or drying time is allowed to elapse before the final coating of noise-reducing composition is established.

26. A method according to any one of claims 22 to claim 25, wherein the liquid precursor composition is applied to the rail by spraying.

27. A method according to any preceding claim, wherein one or more additional preparative steps is/are carried out prior to the step of applying the coating of the noisereducing composition to the rail, wherein the one or more additional preliminary preparative steps is/are selected from any one or more of the following:

- a rust- (or corrosion-)removal or rust- (or corrosion-)treatment step, in which a rust(or corrosion-)removal or rust- (or corrosion-)treatment composition or agent is applied to one or more surface(s) or surface portion(s) of one or more rails to remove existing rust or corrosion from the rail(s)’s surface(s) so as to enhance the adhesion and stable application of the noise-reducing composition thereto;

- a washing or pre-cleaning step, in which water or an aqueous or other cleaning or washing liquid is applied to one or more rails to remove any debris or any rust- (or corrosion23 )removal or rust- (or corrosion-)treatment composition or agent remnant thereon arising from a rust removal or treatment step;

- a drying step, in which air or other gas is blown onto one or more treated or washed rail surface(s) to dry them prior to the noise-reducing composition being applied thereto;

- optionally, a priming step, in which a primer or priming composition or agent is applied to one or more surfaces of one or more rails which is/are to receive the noisereducing composition thereon, in order to help affix and bond the noise-reducing composition thereon.

28. An apparatus for applying a damping material to a rail, the apparatus comprising:

29. An apparatus according to claim 28, which is an apparatus constructed and arranged for carrying out a method according to claim 2, wherein the apparatus further comprises:

(ii) transportation means for transporting the apparatus along the rail;

30. An apparatus according to claim 28 or claim 29, wherein the application means (i) comprises:

31. An apparatus according to claim 30, wherein the delivery means (iv) comprises a spraying device.

32. An apparatus according to claim 31, wherein the spraying device comprises an airless spraying device, wherein 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.

33. An apparatus according to claim 32, wherein the spraying device comprises a jet pump device.

34. An apparatus according to any one of claims 29 to 33, as dependent through claim 29, wherein the transportation means includes:

(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 so as to be moveable therealong, wherein the or at least one of the said rails is that rail to whose surface the coating of noise-reducing composition (or its precursor composition, as the case may be) 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.

35. An apparatus according to claim 34, wherein the drive means drivably acts on either:

(i) 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, or (ii) 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.

36. An apparatus according to claim 34 or claim 35, wherein the apparatus comprises a plurality of wheels for mounting the apparatus on a plurality of rails, at least one of which is an electricity conductor that is used to power a train or other vehicle that customarily uses the said rails, and wherein the apparatus includes 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.

37. An apparatus according to claim 36, wherein the electrical insulation means is provided as an inherent portion or component of a frame or chassis of the apparatus, or as part of the mounting of the one or more wheels themselves.

38. An apparatus according to any of claims 30 to 37, as dependent through claim 30, wherein the delivery means is in fluid communication with the storage means.

39. An apparatus according to any of claims 30 to 38, as dependent through claim 30, wherein the storage means comprises one or more tanks, containers or other receptacles in which is/are contained an appropriate supply volume or weight of the noise-reducing composition (or its precursor composition, as the case may be), which volume or weight is designed to be sufficient for application of a desired length or area of the composition (or its precursor composition, as the case may be) onto the rail surface during a given coating operation, before needing replenishing.

40. An apparatus according to claim 39, wherein the one or more tanks, containers or other receptacles is/are provided or carried onboard the apparatus.

41. An apparatus according to any one of claims 31 to 40, as dependent through claim 31, wherein the coating of the noise-reducing composition is to be applied to one side only of a or a respective rail, and wherein the spraying device is 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 coating of the composition is to be applied.

42. An apparatus according to any one of claims 31 to 40, as dependent through claim 31, wherein respective coatings of the noise-reducing composition are to be applied to both sides of a or a respective rail, and wherein the spraying device is 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 and facing the respective side surface thereof onto which a respective one of the coatings of the composition is to be applied.

43. An apparatus according to any one of claims claim 28 to 42, wherein the apparatus is constructed and arranged for being mounted on both of a pair of rails for being transported therealong as the coating composition is applied to each of the rails, and both of the pair of rails are each to have applied to one or more sides thereof a respective coating of the noisereducing composition, and wherein the apparatus comprises the appropriate number and positioning and orientation of a plurality of spray heads or nozzles for delivering the composition to where its application to the various rail surfaces or surface portions is needed.

44. An apparatus according to any one of claims 30 to 43, as dependent through claim 29, wherein the various components of the delivery means, as well as any associated hardware of the composition storage and delivery system, are provided or carried onboard the apparatus.

45. An apparatus according to any one of claims 28 to 44, further comprising 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 which can be transported in a driven manner along one or more rails as it applies the coating of the noise-reducing composition to the relevant surface(s) or surface portion(s) of one or more of those rails.

46. An apparatus according to any one of claims 28 to 44, further comprising means for carrying out any of the additional preliminary preparative steps as defined in claim 27.

47. An apparatus according to claim 46, wherein the apparatus comprises a plurality of discrete modules, sections or units, each of which is constructed and arranged for performing a respective one of the coating and/or any one or more of the defined preliminary preparative steps of an overall damping operation.

48. An apparatus according to claim 47, wherein the modules, sections or units are 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.

49. An apparatus according to claim 46, wherein the apparatus comprises the appropriate components and other hardware to form a single or common application arrangement which is usable for effecting each of the relevant one(s) of the defined preliminary preparative steps, in addition to performing the noise-reducing composition coating step, and its relevant components are purgeable and/or rinseable or cleanable between each such discrete step.

50. A rail for the transport therealong of a train or other rail-borne vehicle, wherein the rail has been damped by the application to at least a portion of a surface thereof a damping material in the form of a coating of a noise-reducing composition.

51. A rail according to claim 50, which is a rail which has been damped by a method according to any one of claims 1 to 27 or by use of an apparatus according to any one of claims 28 to 49.

52. A railway or other rail-borne vehicle track comprising one or more, optionally 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 damped by the application to at least a portion of a surface thereof a damping material in the form of a coating of a noise-reducing composition.

53. A railway or other rail-borne vehicle track according to claim 52, which is a railway or other rail-borne track comprising one or more rails which has/have been damped by a method according to any one of claims 1 to 27 or by use of an apparatus according to any one of claims 28 to 49.