Field of the Invention

The present invention relates to a system for weighing an axle of a wagon travelling along a railway line.

Background of the Invention

A number of systems have previously been developed for weighing railway wagons as they travel along a railway line. To improve weighing precision, it is important that the wagons do not vibrate as they travel over a weighing section of line. In the region of the weighing section, the track bed should preferably be uniformly elastic so as not to exaggerate any vibrations. It may not always be convenient to ensure that the ballast of a foundation is firmly bedded in. Further, existing systems may not facilitate easy assess for a tamping machine to compact ballast in the weighing area.

The railway line may not exhibit any shocks in this region. The influence of leading and trailing wheels is considerable and must be detected in principle by the weighing system. Changes in the rigidity of the track bed may cause any increase in error of weight measurements.

In many cases, weighing systems are incorporated into railway lines as a subsequent measure, whereby the continuous rails remain intact. To install the system, the ballast in the vicinity of the weighing section of line is partly removed; the cross members are installed; and the ballast is replaced. This process generally results in a change in the rigidity of the track bed in the vicinity of the weighing section of line. The larger deformations in the rail in this section are the cause of undesired vibrations of the wagons which render measuring results inaccurate. Even when weighing systems are incoφorated during railway construction, the substantially greater compressive strength of the cross members of the weighing system, as compared to the normal sleepers, may lead to inaccuracies.

In remote areas, ballast of track foundations can be eroded by heavy rain and/or flood waters. In these circumstances, the accuracy of the measurements taken can vary greatly. Further, it may be difficult to transport and install multiple components of heavy weighing systems in remote areas.

Railway maintenance workshops provides a controlled environment for working on all manner of repairs to the train engines and train wagons. The workshops typically include one or more bays, each being adapted to receive a single engine or wagon. The bays may include equipment for balancing engines and wagons. The equipment, such as load detectors, may be bulky and its installation may necessitate not insubstantial works to the existing rail track structure. As such, the known systems may not be suitable for easy reconfiguration to suit the needs of any given train engine or wagon. As such, the steps involved in balancing a train are typically complicated, costly and time consuming. Further, the process may be subject to errors arising from the balancing equipment.

Known balancing apparatus may not be easily adaptable for use in selectively weighing individual wheels of each bogie of an engine or a wagon. Further, known balancing equipment may not be easily adaptable for use in selectively balancing one or both bogies of an engine or a wagon.

It is generally desirable to overcome or ameliorate one or more of the above described difficulties with known systems for weighing trains, or to at least provide a useful alternative. Summary of the Invention

In accordance with one aspect of the invention, there is provided a system for weighing an axle of a wagon travelling on a railway line, including: (a) cross members, each extending between opposed sections of rails of the railway line and a foundation;

(b) a load detector coupled between a section of a first one of said rails and a first one of said cross members, said load detector being adapted to generate a signal representing a weight of said section of said first one of said rails; (c) a computer device adapted to receive the signal generated by the load detector;

(d) bracing members for inhibiting movement of the cross members with respect to each other, wherein the computer device is adapted to generate data representing weight of an axle of a wagon travelling along the railway line based on the signal generated by the load detector when the axle passes over the load detector.

Preferably, the system includes a lateral force sensor operably coupled to a first one of said rails, wherein the lateral force sensor is adapted to generate a signal representing the presence of an axle of a wagon passing over it.

Preferably, the computer device is adapted to generate the data representing the weight of the axle of the wagon on receipt of said signal representing the presence of an axle from the lateral force sensor.

Preferably, said first one of said cross members includes a second load detector coupled to it between a section of a second one of said rails, said second load detector being adapted to generate a signal representing a weight of said section of said second one of said rails; the computer device is adapted to receive the signal generated by the second load detector; and the computer device is adapted to generate the data representing the weight of the axle based on the signal generated by the load detector and the signal generated by the second load detector when the axle passes over the load detector and the second load detector. Preferably, the system includes a second lateral force sensor operably coupled to the second one of said rails, wherein the second lateral force sensor is adapted to generate a signal representing the presence of an axle of a wagon passing over it.

Preferably, the computer device is adapted to generate the data representing the weight of the axle on receipt of said signal representing the presence of an axle from the lateral force sensor and said signal representing the presence of an axle from the second lateral force sensor.

Preferably, a second one of said cross members includes first and second load detectors arranged so as to at least partially bear a weight of respective sections of opposed rails and generate signals representing the weight of said respective sections of the rails.

Preferably, the computer device is adapted to receive the signals generated by the load detectors of the second one of said cross members; and the computer device is adapted to generate the data representing the weight of the axle based on the signal generated by the load detector, the signal generated by the second load detector and the signals generated load detectors of the second one of the cross members.

Preferably, the system includes a third and fourth lateral force sensors operably coupled to respective ones of the rails, wherein each of the third and fourth lateral force sensors is adapted to generate a signal representing the presence of an axle of a wagon passing over it.

Preferably, the computer device is adapted to generate the data representing the weight of the axle on receipt of said signal representing the presence of an axle from the lateral force sensor and said signal representing the presence of an axle from the second; and to stop generating the data representing the weight of the axle on receipt of said signal representing the presence of an axle from the third and fourth lateral force sensors. Advantageously, the bracing members distribute a load of the axle over the cross members and improve the stability of the weighing area. Advantageously, the bracing members and the cross members form a structurally secure foundation to minimise wagon movement, other than in the direction of travel, thereby facilitating higher accuracy with weighing measurements. Advantageously, the bracing members and the cross members obviate difficulties in disconformity with the track bed.

In accordance with another aspect of the invention, there is provided a system for weighing a wheel of an axle of a static wagon in a maintenance workshop that includes a railway track having two spaced apart rail members coupled to a foundation by a plurality of spaced apart fasteners, including:

(a) a weighing section including a first section of rail of one of said rail members extending at least partially between two successive ones of said fasteners,

(b) first and second load detectors coupled between respective sections of said first section of rail and the foundation, said first and second load detectors generating signals representing forces applied to them by said first section rail; and

(c) a computer device adapted to receive the signals generated by the load detectors and generate data representing weight of a wheel supported by said first section of rail, wherein said first section of rail is adapted to move relative to the foundation.

Preferably, wherein opposite ends of said first section of rail are cut free from said one of said rail members.

Preferably, the load detectors are low profile load cells.

In accordance with another aspect of the invention, there is provided a system for weighing each wheel of a bogie of a static wagon in a maintenance workshop that includes a railway track having two spaced apart rail members coupled to a foundation by a plurality of fasteners, including:

(a) a weighing section for each wheel of the bogie including: (i) a corresponding section of rail of one of said rail members extending at least partially between two successive ones of said fasteners; and (ii) first and second load detectors coupled between respective sections of said corresponding section of rail and the foundation, said first and second load detectors generating signals representing forces applied to them by said corresponding section rail; and

(b) a computer device adapted to receive signals generated by the load detectors of each weighing section and generate data representing weight of each wheel of the bogie, wherein, for each weighing section, said section of rail of one of said rail members is adapted to move relative to the foundation.

Preferably, for each weighing section, opposite ends of said section of rail of one of rail members are cut free from said one of said rail members.

Preferably, the load detectors are low profile load cells.

In accordance with another aspect of the invention, there is provided a system for weighing each wheel of each bogie of a static wagon in a maintenance workshop that includes a railway track having a railway track having two spaced apart rail members coupled to a foundation by a plurality of fasteners, including:

(a) a weighing section for each wheel of each bogie of the wagon including:

(i) a corresponding section of rail of one of said rail members extending at least partially between two successive ones of said fasteners; and (ii) first and second load detectors coupled between respective sections of said corresponding section of rail and the foundation, said first and second load detectors generating signals representing forces applied to them by said corresponding section rail; and

(b) a computer device adapted to receive signals generated by the load detectors of each weighing section and generate data representing weight of each wheel of each bogie, wherein, for each weighing section, said section of one of said rail members is adapted to move relative to the foundation.

Preferably, for each weighing section, opposite ends of said section of rail of one of rail members are cut free from said one of said rail members.

Preferably, the load detectors are low profile load cells.

In accordance with another aspect of the invention, there is provided a system for statically balancing a bogie of a wagon in a maintenance workshop that includes a railway track having a railway track having two spaced apart rail members coupled to a foundation by a plurality of fasteners, said system for performing the steps of:

(a) generating data representing weight of each wheel of the bogie using the above described system; and (b) displaying said data representing weight of each wheel of the bogie on a visual display unit.

Preferably, said system for performing the step of adjusting weight distribution over each wheel of the bogie until the weight over each wheel is substantially even.

In accordance with another aspect of the invention, there is provided a system for statically balancing wagon in a maintenance workshop that includes a railway track having a plurality of cross members coupled between a foundation and two spaced apart rail members, said system for performing the steps of: (a) generating data representing weight of each wheel of each bogie of the wagon using the above-described system; and

(b) displaying said data representing weight of each wheel of each bogie on a visual display unit.

Preferably, said system for performing the step of adjusting weight distribution over each wheel of each bogie until the weight over each wheel is substantially even. Brief Description of the Drawings

Preferred embodiments of the invention will now be described by non-limiting example, with reference to the drawings, in which:

Figure 1 is a schematic diagram showing a system for weighing an axle of a wagon travelling on a railway line;

Figure 2 is another schematic diagram of the system shown in Figure 1 ; Figure 3 is a plan view of cross members of the system shown in Figure 1 arranged in a condition of use;

Figure 4 is a plan view of cross members shown in Figure 3 arranged in another condition of use;

Figure 5 is a plan view of an alternative arrangement of cross members of the system shown in Figure 1 ; and

Figure 6 is a flow diagram showing the steps performed by the system shown in Figure 1.

Figure 7 is a schematic diagram showing another system for weighing an axle of a wagon;

Figure 8 is another schematic diagram of the system shown in Figure 7;

Figure 9 is a schematic diagram showing a weighing section of the system shown in Figure 7;

Figure 10 is a screen shot generated by the system shown in Figure 7; and

Figure 11 is a flow diagram showing the steps performed by the system shown in Figure 7.

Detailed Description of Preferred Embodiments of the Invention

The system 10 shown in Figure 1 and 2 is used to weigh an axle 12 of a wagon (not shown) travelling on a railway line 14. The system 10 includes cross members 16a, 16b, 16c, 16d, 16e, 16f each extending between opposed sections of rails 14a, 14b of the railway line 14 and a foundation 20. The system 10 also includes load detectors 22a, 22b, 22c, 22d coupled between respective sections of the rails 14a, 14b and respective cross members 16c, 16d. The load detectors 22a, 22b, 22c, 22d are adapted to generate signals representing the weight of the relevant sections of the first and second rails 14a, 14b.

The system also includes a computer device 24 that is adapted to receive the signals generated by the load detectors 22a, 22b, 22c, 22d; and a plurality of bracing members 26 for inhibiting movement of the cross members 16a, 16b, 16c, 16d, 16e, 16f with respect to each other. The computer device 24 is adapted to generate data representing weight of an axle 12 of a wagon travelling along the railway line 14 based on the signals generated by the load detectors 22a, 22b, 22c, 22d when the axle 12 passes over the load detectors 22a, 22b, 22c, 22d.

The bracing members 26 provide stability for the system 10 for improved accuracy of weight measurements. The bracing members 26 permit the system 10 to be installed on a foundation of ballast whilst maintaining accuracy in weight measurements. The system 10 can generate accurate weight measurements in locations subject to flooding, for example, where the ballast of the foundation can become unstable.

The cross members 16a, 16b, 16c, 16d, 16e, 16f are used to separate rails 14a, 14b from the foundation 20, which may include ballast, concrete, or any other suitable material. Each cross member 16a, 16b, 16c, 16d, 16e, 16f generally passes under opposed sections of the rails 14a, 14b. Furthermore, cross members 16a, 16b, 16c, 16d, 16e, 16f may pass underneath more than two rails, for example, on railway lines of different gauges, where a first rail is generally used for carriages of all gauges and there is provided a plurality of second rails distanced from the first rail relative to the carriage gauge they are designed to support.

Although the system shown in Figures 1 to 3 includes six cross members 16a, 16b, 16c, 16d, 16e, 16f, it will be appreciated that more, or less, cross members may be suitable for particular applications. The cross members 16a, 16b, 16c, 16d, 16e, 16f are generally rectangular, when viewed from above or from the sides, and have a rectangular cross section. However, it will also be appreciated that cross members 16a, 16b, 16c, 16d, 16e, 16f with other shapes and cross-sections may be used. For example, a cross member with semi-circular cross-section or with a depression in the region of the cross member located between opposing rails. In addition, cross members 16a, 16b, 16c, 16d, 16e, 16f are preferably of the same dimensions as standard sleepers, in order to make the exchange of one for the other simple, so that the rails 14a, 14b are of a regular distance from the foundation in the vicinity of the cross members 16a, 16b, 16c, 16d, 16e, 16f and to ensure the rails 14a, 14b are fixed relative to each other as would otherwise be the case if the weighing sleepers were replaced with normal sleepers.

As particularly shown in Figures 3 and 4, the cross members 16a, 16b, 16c, 16d, 16e, 16f are braced together by bracing members 26 so as to inhibit relative translation of the cross members 16a, 16b, 16c, 16d, 16e, 16f with respect to each other. The bracing members 26 improve the rigidity to the system 10, which advantageously reduces inaccuracies due to:

a. Disproportionate distribution of weight of the carriage; b. Local concentrations of weight arising by carriages following slightly different trajectories along rails and exciting vibration of the carriage; and c. Disconformity in the ballast of the foundation due to heavy rain or flooding, for example.

As particularly shown in Figures 3 and 4, the cross members 16a, 16b, 16c, 16d, 16e, 16f are formed in three pairs 28a, 28b, 28c. The cross members 16a, 16b, 16c, 16d, 16e, 16f of each pair 28a, 28b, 28c are separated by three bracing members 26a, 26b, 26c preferably formed integrally there between. Alternatively, the bracing members 26a, 26b, 26c may be coupled between cross members 16a, 16b, 16c, 16d, 16e, 16f by any suitable means including being welded directly to the cross members 16a, 16b, 16c, 16d, 16e, 16f, or being mechanically fastened by bolts onto a tab that is welded onto the cross members 16a, 16b, 16c, 16d, 16e, 16f. It will be appreciated that any combination of such bracing members may be used, without falling outside the scope of the invention.

Bracing members 26a, 26b, 26c of each pair 28a, 28b, 28c of cross members 16a, 16b, 16c, 16d, 16e, 16f are located under the rail and at some point intermediate between the rails 14a, 14b. The bracing members 26a, 26c ensure that the extremities of the cross members 16a, 16b, 16c, 16d, 16e, 16f do not translate in relation to each other. Bracing members 26a, 26c located under the rail provide easy access to the ballast for a tamping machine. As such, the ballast can be easily compacted. In particular, this arrangement is suitable for cross members 16a, 16b, 16c, 16d, 16e, 16f fabricated from highly rigid compounds, as the portions of respective cross members 16a, 16b, 16c, 16d, 16e, 16f, may remain in substantially fixed configuration, with very little flex as a carriage passes thereover. This may improve stability of the rails 14a, 14b on the foundation 20, and the weighing process is preferably more repeatable than may be achieved using other configurations. Such a configuration may allow for more consistent weighing of carriages.

Adjacent pairs 28a, 28b, 28c of cross members 16a, 16b, 16c, 16d, 16e, 16f are coupled together by bracing members 26 formed from opposed flanges 30a, 30b, 30c mechanically coupled together by fasteners such as bolts, for example. Alternatively, the opposed flanges 30a, 30b, 30c of the bracing members 26 of the adjacent pairs 28a, 28b, 28c of cross members 16a, 16b, 16c, 16d, 16e, 16f are coupled together by any other suitable means.

The pairs 28a, 28b, 28c of cross members 16a, 16b, 16c, 16d, 16e, 16f form a stable weighing area for the system 10 when coupled together in the manner shown in Figure 4.

Advantageously, the system 10 is easily transported to locations for installation and is easier to assembly on site. This may be particularly the case in regions where rail conditions are harsh. For example, in areas of high flooding where ballast may be flushed away and foundations are inconsistent. The larger surface of the weighing area covered by the pairs 28a, 28b, 28c, 28d cross members 16a, 16b, 16c, 16d, 16e, 16f advantageously accommodate a greater degree of foundation irregularity during installation and foundation movement after installation. The system 10 is, therefore, effective:

a. On foundations with a large variation in compressive strength; b. Where the number of axles per bogie changes, as this will alter either increase or decrease with mass per axle 12 and consequent force distributions experienced by the rail; and c. Accommodate a larger range of carriage velocities and vibrations.

An alternative arrangement of the cross members 16a, 16b, 16c, 16d, 16e, 16f is shown in Figure 5. In this arrangement, adjacent cross members 16a, 16b, 16c, 16d, 16e, 16f are coupled together by bracing members 26 formed from opposed flanges 30a, 30b, 30c mechanically coupled together by fasteners such as bolts, for example. Alternatively, the opposed flanges 30a, 30b, 30c of the bracing members 26 of the adjacent cross members 16a, 16b, 16c, 16d, 16e, 16f are coupled together by any other suitable means. The flanges 30a, 30c are located at the ends of adjacent cross members 16a, 16b, 16c, 16d, 16e, 16f. The flanges 30a, 30b ensure that the extremities of the cross members 16a, 16b, 16c, 16d, 16e, 16f do not translate in relation to each other. The flanges 30b are located and at some point intermediate between the rails 14a, 14b between adjacent cross members 16a, 16b, 16c, 16d, 16e, 16f. The cross members 16a, 16b, 16c, 16d, 16e, 16f form a stable weighing area for the system 10 when coupled together in the manner shown in Figure 5. Advantageously, the cross members can be easily transported to locations for installation and is easier to assembly on site

The first and third pair 28a, 28c of cross members 16a, 16b, 16e, 16f include fasteners 32 for securing respective sections of the rails 14a, 14b to the foundation 20. The fasteners 32 are of known configuration and are not described here in further detail. The second pair 28b of cross members 16c, 16d, includes modified fasteners 34 for securing respective sections of the rails 14a, 14b to the foundation 20. The modified fasteners 34 include the components of the fasteners 32 together with the load detectors 22a, 22b, 22c, 22d

The load detectors 22a, 22b, 22c, 22d are preferably conventionally calibrated load cells. Alternatively, the load detectors 22a, 22b, 22c, 22d are some other form of pressure transducers or alternative devices. Individual load detectors (not shown) may also be arranged such that they are insensitive to moments of flexion and transverse forces in the rails. Each load detector 22a, 22b, 22c, 22d is coupled to a cross member 16c, 16d at a location intermediate between the cross member 16a, 16b and the rail 14a, 14b. However, the load detectors 22a, 22b, 22c, 22d may alternatively be located at least partially within a housing or cavity of the cross member 16c, 16d.

Each load detector 22a, 22b, 22c, 22d is electrically connected to the computer device 24 which is capable of receiving and interpreting signals generated by the load detectors 22a, 22b, 22c, 22d. In addition, or as an alternative, to a hardwired electrical connection, the load detectors 22a, 22b, 22c, 22d preferably include computer readable memory (not shown) for storing data, relating to the generated signal, for later retrieval. The signal may also be transmitted from the load detector over a network to various devices.

The system also includes two pairs of lateral force sensors 36a, 36b, and 36c, 36d. The first pair of sensors 36a, 36b are coupled to opposed sections of rails 14a, 14b between cross members 16b and 16c. The second pair of sensors 36c, 36d are coupled to opposed sections of rails 14a, 14b between cross members 16d and 16e. Thus, the pair of sensors 36a, 36b are positioned to register the entry and exit of an axle 12 into and out of a weighing area of the load sensors 22a, 22b, 22c, 22d. The lateral force sensors 36a, 36b, 36c, 36d thereby define the weighing area.

The load sensors 36a, 36b, 36c, 36d are operably coupled to respective sections of the rails 14a, 14b. The sensors 36a, 36b, 36c, 36d are adapted to generate a signal representing the presence of an axle 12 of a wagon passing over it. Generally, installation of lateral force sensors 36a, 36b, 36c, 36d involves boring a transverse bore into the rail and coupling the lateral force sensor 36a, 36b, 36c, 36d therewith. Use of lateral force sensors to detect the presence is described in detail in US 6,653,578 and is not described here in further detail. The computer device 24 is electrically coupled to the lateral force sensors 36a, 36b, 36c,

36d and is adapted to generate data representing weight of an axle of a wagon travelling along the railway line on receipt of the signals representing the presence of an axle 12 from the lateral force sensors 36a, 36b, 36c, 36d. Alternatively, the computer device 24 can generate data representing weight of an axle of a wagon travelling along the railway line on receipt of another signal signals representing the presence of an axle 12 from an optical detector, or any other suitable device for detecting the presence of an axle 12. The processes performed by the computer device 24 to generate the weight of an axle 12 of a wagon travelling along the railway line are described in detail below.

With reference to Figure 6, the computer device 24 includes a computer program that performs the following steps to generate the weight of an axle 12:

1. On start up, initialise the system to restore default settings, at step 50. The initialisation process includes the step of clearing registers and memory;

2. The computer device 24 continuously samples the input signal from the first pair of lateral force sensors 36a, 36b;

3. On receipt of a signal from the first pair of force sensors 36a, 36b indicating the presence of an axle 12, the computer device, at step 52, records the time in memory and then samples, at step 54, the input signals received from the load detectors 16a, 16b, 16c, 16d. The computer device 24 stores, at step 56, the sampled results in memory.

4. The computer device 24 continues to sample, at step 54, the input signals received from the load detectors 16a, 16b, 16c, 16d and store them in memory, at step 56, until the input signal from the second pair of lateral force sensors 36c, 36d indicates that the axle 12 is leaving the weighing area. 5. The computer device 24, at step 58, records the time in memory and then generates, at step 60, the speed of the axle by dividing the known distance "X" between the pairs of sensors 36a, 36b and 36c, 36d by the difference between the entry time and the exit time. The computer device stores the speed in memory. 6. The computer device 24 generates, at step 62, the weight of the axle 12 by averaging the stored input signals from the detectors 22a, 22b, 22c, 22d and deducting the known weight of the rails 14a, 14b in the relevant sections.

7. The computer device 24 stores, at step 64, the weight of the axle 12 in memory.

8. The computer device 24 generates, at step 66, data representing the weight of the axle 12 and the speed of the axle 12 for display on a monitor (not shown), for example. The computer device 24 is adapted to generate the weight of a wagon by performing the above-mentioned steps each axle 12 of each bogie of the wagon, and then adding them the weight of each axle 12 together. Similarly, the computer device 24 can generate the entire weight of train by performing the above-mentioned steps for all axles of the train and then the weight of each axle together.

Further details of the purpose and function of particular features are disclosed in US 6,653,578, which is incorporate herein by reference.

The computer device 24 is preferably a microcontroller that having a computer program stored in memory to perform the above-mentioned steps. Alternatively, the computer device 24 may be implemented in any suitable combination of software and hardware and may be an application specific integrated circuit. The computer device 24 is preferably adapted to communicate with one or more remote computer devices 40 by a . communications network 42 using standard communications protocols. The remote devices 40 include personal computers, personal digital assistants, mobile telephones, note books, etc.

The system 100 shown in Figures 7 and 8 is used for statically weighing each wheel 102 of a wagon (not shown), for example, in a maintenance workshop (not shown) that includes a railway track 106 having two spaced apart rail members 112a, 112b coupled to a foundation 1 10 by a plurality of fasteners 109. The fasteners 109 are preferably rail clamps arranged in spaced apart positions along extent of the track 106. In the example shown in Figures 7 and 8, the fasteners 109 couple respective sections of the rail members 1 12a, 112b to cross members 108 extending between the rail members 112a, 1 12b and the foundation 110. In an alternative embodiment, the railway track 106 includes two spaced apart rail members 112a, 1 12b coupled to raised sections (not shown) of the foundation 1 10 by fasteners 109. In this embodiment, the above-described cross members are not present. Rather, the fasteners 109 are rail clamps that couple respective sections of the rail members 112a, 112b directly to the raised sections of the foundation 1 10. The system 100 operates in an analogous way for both of the above-described embodiments. The following description of the system 100 is made, by way non-limiting example, with reference to the railway 106 shown in Figures 7 and 8. However, the system 100 is equally applicable to both of these railway configurations and others.

Further, the system 100 is hereafter described with reference to the wheels 102 of a wagon (not shown). However, the system 100 is equally suitable for use in weighing the wheels of a train engine, or other vehicle that travels on wheels along a railway track.

The system 100 includes a weighing section 114a - 114h for each wheel 102 of each bogie (not shown) of the wagon (not shown). As particularly shown in Figure 9, each weighing section 114a - 114h includes:

a. A first load detector 1 16a coupled between a section 1 18 of one of the rail members 112a, 112b and one of the cross members 108. The first load detector 116a is adapted to generate a signal representing a force applied to it by the section 1 18 of the rail member 112a, 112b; and b. A second load detector 1 16b coupled between the section 118 of the member 112a, 1 12b and another one of the cross members 108. The second load detector 1 16b is adapted to generate a signal representing a force applied to it by the section 118 of the rail member 112a, 112b. The other cross member 108 is preferably the next successive cross member 108 from cross member 108 coupled to the first load detector 116a.

An exemplary load detector 116a, 116b is shown in Figures 10 and 11. The load detector 116a, 1 16b is low profile and is shaped for arrangement between a rail member 1 12a, 1 12b and a corresponding cross member 108. The load detectors 116a, 1 16b are coupled to the cross members 108 by fasteners 121. The load detector 116a, 116b includes first and second load cells 117, arranged to bear the weight of the rail member when the load cell 1 16a, 1 16b is fitted in the manner shown in Figures 7 to 9. As above mentioned, the load detector 1 16a, 116b generates a signal representing a force applied to it by the section 1 18 of the rail member 112a, 112b and transmits this to a computer device 120 via an insulated conductor 119. Alternatively, the load detector 1 16a, 1 16b transmits the signal to the computer device 120 using any other suitable means. For example, the load detector 116a, 1 16b can transmit the signal to the computer device 120 over a wireless network.

The load detectors 116a, 116b are preferably low profile load detectors which make the system 100 easily adaptable for use with an existing rail track structure. Use of the low profile load detectors 116a, 116b allows positioning of the load cells 116a, 116b under the rail without the need for significant civil works.

The load detectors preferably have the following operating parameters:

a. Capacity 15 tonne b. Sensitivity 1.6 +/- 0.003 mv/v

C. Combined error +/- 0.05 FS d. Creep (10 min) +/- 0.05 FS e. Zero balance +/- 1% FS f. Operating Temp -30 to + 70 ⁰ C g. Safe load 200% FS h. Protection Class IP 67 i. Material Alloy steel j- Cable length 12 m

The computer device 120 is adapted to receive signals generated by the first load detector 1 16a and the second load detector 116b of each weighing section 114a - 114h and subsequently generate data representing weight of each wheel 102 of each bogie of the wagon when they are positioned on corresponding sections 1 18 of the rail members 1 12a, 112b. For each weighing section 114a - 114h, the section 118 of the rail member 112a, 1 12b is adapted to move relative to a corresponding cross member 108. For example, for each weighing section 1 14a - 1 14h, opposite ends 122a, 122b of the section 1 18 of the rail member 1 12a, 112b are physically detached from the rail member 1 12a, 1 12b. An isolation gap "X" separates the opposite ends 122a, 122b of each section 1 18 from the rail member 112a, 112b. The distance "X" is preferably lmm or 2mm.

The system 100 also includes a visual display unit 124 for receiving and displaying the data representing weight of each wheel of each bogie over a telecommunications network 146. The visual display unit 124 is preferably a touch screen monitor. Alternatively, the visual display unit 124 is any other suitable display unit. Figure 12 shows a screen shot of an exemplary user interface 123 generated by the computer device 120 and displayed by the visual display unit 124. In the example shown, the user interface includes:

a. Text boxes 126 displaying the weight of each wheel 102 of one bogie of the wagon; b. Text boxes 128 displaying the weight of each axle of one bogie of the wagon; c. A text box 130 displaying the bogie weight; and d. A text box 132 displaying the wagon weight

The user interface 123 shows the wheels 102 of one bogie of the wagon. However, the system 100 is also adapted to generate a user interface displaying the weight of each wheel 102 of each bogie of the wagon.

The user interface 123 also includes the following function buttons:

a. Print 134; b. Store 136; c. Zero 138; d. Exit 140; e. Header 142; and f. Direction 144.

When executed, the print function button 134 instructs the computer device 120 to send the data displayed on the visual display unit to a printer to print a hard copy of the relevant information. The store function button 136 instructs the computer device 120 to send the data displayed on the visual display unit to a database where the information will be stored for later use.

The zero function button 138 facilitates zeroing of the weighing system. Current weight readings for each wheel will be reset to zero. This function may be necessary before a new weighing task starts, for example.

When executed, the exit function button 140 instructs the computer device 120 to stop sending data to the visual display unit 124 and to shut down the device 120.

The header function button 142 opens up a window which allows the user to enter the vehicle/wagon number and the operator name. This information is displayed on the final report print out. The direction function button 144 defines the direction of the wagon from the visual display unit. With reference to Figure 10, the left and right hand sides of the graphical user interface respectively indicate that what is shown is the rear and front of the bogie. When the direction button is pressed, the displayed wagon will be turned around.

The system 100 can be adjusted to suit the needs of any particular application by changing the number and location of weighing sections 1 14a - 1 14h. For example, in an application where it is only necessary to weigh the wheels of a single bogie of a wagon, the system 100 need only include four weighing sections 114a, 114b, 114h , 114g.

The system 100 can be used to statically balance a wagon in the above described maintenance workshop that includes a railway track having a plurality of cross members coupled between a foundation and two spaced apart rail members. To do this, the system 100, is used to perform the steps of:

a. generating data representing weight of each wheel of each bogie of the wagon in the above described manner; and b. displaying the data representing weight of each wheel of each bogie on the visual display unit 124.

Based on the above information, a technician can determine the weight of each wheel of the wagon and adjust the distribution of weight over all of the wheels so that the wagon is balanced.

With reference to Figure 13, the computer device 120 includes a computer program that performs the following steps to generate the weight of each wheel of each bogie of the wagon; the weight of each bogie of the wagon; and the weight of the wagon:

1. On start up, initialise the system 100 to restore default settings, at step 150. The initialisation process includes the step of clearing registers and memory;

2. Sample, at step 152, the input signal from the first and second lateral force sensors 116a, 116b of the first weighing section 114a which represent the weight applied to each load detector 116a, 116b;

3. Add together, at step 154, the weight of each load detector 116a, 116;

4. Subtract, at step 156, the weight of the movable section 118 of the rail 112a, 1 12b from the combined weight of the load detectors 1 16a, 116b; 5. Save, at step 158, the weight in memory;

6. Send, at step 160, the weight to the visual display unit 124 for display on the user interface 123;

7. Repeat steps 2 to 6 for each wheel of the first bogie.

8. Add, at step 162, the weight of all wheels of the first bogie together; 9. Save, at step 164, the combined weight of the wheels, the weight of the first bogie, in memory;

10. Send, at step 166, the weight of the bogie to the visual display unit 124 for display on the user interface 123; and

1 1. Repeat steps 2 to 10 for the second bogie. 12. Add, at step 168, the weight of both bogies together;

13. Save, at step 170, the combined weight of the bogies in memory; 14. Send, at step 172, the weight of the bogies to the visual display unit 124 for display on the user interface 123; and

15. Repeat steps 2 to 14 until the "exit" function button is triggered.

The computer device 120 is adapted to generate the weight of each wheel 102 of the wagon by performing the above-mentioned steps. Similarly, the computer device 120 can generate the entire weight of train by performing the above-mentioned steps for all wheel of the wagon.

The computer device 120 is preferably a microcontroller that having a computer program stored in memory to perform the above-mentioned steps. Alternatively, the computer device 120 may be implemented in any suitable combination of software and hardware and may be an application specific integrated circuit. The computer device 120 is preferably adapted to communicate with one or more remote computer devices 124 by a communications network 146 using standard communications protocols. The remote devices 124 include personal computers, personal digital assistants, mobile telephones, note books, etc.

Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention as hereinbefore described with reference to the accompanying drawings.

Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.