Railway Virtual Track Block System

Abstract

To provide a railroad virtual track block system.SOLUTION: A method of railroad track control includes partitioning a physical track block into a plurality of virtual track blocks, the physical track block defined by first and second insulated joints disposed at corresponding first and second ends of a length of railroad track. The presence of an electrical circuit discontinuity in one of the virtual track blocks is detected, and in response a corresponding virtual track block position code indicating the presence of the discontinuity in the one of the virtual track blocks is generated.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates generally to railway signaling systems, and more particularly to railway virtual track block systems. [Background technology]

[0002] Block signaling is a well-known technique used in railroad operations to maintain spacing between trains and thereby avoid collisions. Generally, railroad tracks are divided into track blocks, and automatic signals (typically red, yellow, and green lights) are used to control train movement between the blocks. For unidirectional tracks, block signaling allows trains to follow each other with minimal risk of rear-end collisions.

[0003] However, conventional block signaling systems suffer from at least two significant disadvantages: First, track capacity cannot be increased without additional track infrastructure, such as additional signals and associated control equipment; and Second, conventional block signaling systems cannot identify broken rails within unoccupied blocks. Summary of the Invention [Means for solving the problem]

[0004] The principles of the present invention are advantageously embodied in a virtual "high density" block system that improves the capacity of existing track infrastructure used by railroads. Generally, by dividing the current physical track block structure into multiple (e.g., four) segments, or "virtual track blocks," train block spacing is reduced to accurately reflect the train's braking capabilities. In particular, train spacing is maintained within a physical track block by identifying train positions relative to virtual track blocks within that physical track block. Among other things, this principle alleviates the need for wayside signals, as train braking distances are maintained within the locomotive instead of through wayside signal flanking. Additionally, by dividing a physical track block into multiple virtual track blocks, broken rail can be detected within an occupied physical track block. The present specification also provides, for example, the following items: (Item 1) 1. A method of railway track control, said method comprising: dividing a physical track block into a plurality of virtual track blocks, the physical track blocks being defined by first and second insulated joints, the first and second insulated joints being located at corresponding first and second ends of a length of railway track; detecting a location of an electrical circuit discontinuity in one of the plurality of virtual track blocks; generating a corresponding virtual track block location code in response to detecting the presence of the electrical circuit discontinuity in the one of the plurality of virtual track blocks; Including, wherein the virtual track block location code indicates a location of the electrical circuit discontinuity in the one of the plurality of virtual track blocks. (Item 2) Item 10. The method of claim 1, wherein the electrical circuit discontinuity is an open circuit indicative of broken track within the one of the virtual track blocks. (Item 3) Item 10. The method of claim 1, wherein the electrical circuit discontinuity is a short circuit caused by a train wheel within the one of the plurality of virtual track blocks. (Item 4) Detecting the presence of the electrical circuit discontinuity in one of the plurality of virtual track blocks includes: detecting a break in a first code transmitted from the first end of the physical track block to the second end of the physical track block; transmitting a second code from at least one of the first and second ends of the physical track block; receiving the second code returned from the electrical circuit discontinuity and determining the location of the electrical circuit discontinuity within one of the plurality of virtual trajectory blocks; Item 1. The method according to item 1, comprising: (Item 5) Item 5. The method of item 4, wherein the first code is carried by a first electrical signal and the second code is carried by a second electrical signal. (Item 6) 1. A railway track control system comprising a plurality of control systems, each control system disposed at a corresponding end of a corresponding physical track block; Each control system is detecting the presence of a train within the corresponding physical track block; determining a position of the train within at least one virtual track block within the corresponding physical track block; transmitting a code identifying the position of the train within the at least one virtual track block within the corresponding physical track block; 1. A railway track control system operable to: (Item 7) 7. The railway track control system of claim 6, wherein each control system is operable to detect the presence of the train within the corresponding physical track block by detecting an interruption in a track signal transmitted by another of the control systems located at an opposite end of the corresponding physical track block. (Item 8) 8. The railway track control system of item 7, wherein the track signal includes a track code. (Item 9) 7. The railway track control system of claim 6, wherein each control system is operable to determine the position of the train within the at least one virtual track block within the corresponding physical track block by transmitting track signals along the corresponding physical track block and receiving the track signals back from the train's wheels. (Item 10) 7. The railway track control system of claim 6, wherein each control system is operable to wirelessly transmit the code identifying the position of the train within the at least one virtual track block. (Item 11) 7. The railway track control system of claim 6, wherein each control system is operable to transmit a code identifying the position of the train, the code having at least one bit corresponding to one of a plurality of virtual track blocks within the corresponding physical track block. (Item 12) 1. A method of controlling a railway track, said method comprising: Dividing each of a plurality of physical trajectory blocks into a plurality of virtual trajectory blocks; Detecting the presence of a train within a physical track block; In response to detecting the presence of a train within a physical track block, determining a virtual track block within the physical track block in which the train resides; transmitting a code identifying the virtual track block on which the train is located; A method comprising: (Item 13) 13. The method of claim 12, wherein detecting the presence of the train within the physical track block includes detecting a change in a state of a track signal transmitted through the physical track block. (Item 14) Item 14. The method of item 13, wherein determining the virtual track block within the physical track block on which the train is located includes transmitting a signal from at least one of a first and a second end of the physical track block and receiving the signal back from a wheel of the train. (Item 15) Item 15. The method of item 14, wherein transmitting the signal from at least one of the first and second ends of the physical track block includes transmitting a code. (Item 16) Item 16. The method of item 15, wherein determining the virtual track block within the physical track block on which the train is located includes transmitting a signal from each of the first and second ends of the physical track block and receiving corresponding return signals from front and rear wheels of the train. (Item 17) 13. The method of claim 12, wherein transmitting the code identifying the virtual track block on which the train is located includes transmitting a code including at least one bit corresponding to each of the plurality of virtual track blocks within the physical track block. (Item 18) 13. The method of claim 12, wherein transmitting the code identifying the virtual track block on which the train is located comprises wirelessly transmitting the code. (Item 19) Detecting the presence of the train within a physical track block includes detecting the presence of the train within first and second physical track blocks, and the method further comprises: determining a virtual track block within each of the first and second physical track blocks in response to detecting the presence of the train within the first and second physical track blocks; and transmitting a code identifying the virtual track block within the first and second physical track blocks in which the train is located; Item 13. The method of item 12, further comprising: (Item 20) 20. The method of claim 19, wherein the first and second physical track blocks are adjacent physical track blocks separated by an isolated joint, and determining a virtual track block within each of the first and second physical track blocks on which the train resides includes transmitting a signal from a single control system to each of the first and second adjacent physical track blocks. [Brief explanation of the drawings]

[0005] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0006] [Figure 1] FIG. 1 is a schematic diagram showing a representative number of unoccupied physical railway track blocks, together with associated signal (control) stations, where each physical track block is divided into a selected number of virtual track blocks in accordance with the principles of the present invention.

[0007] [Figure 2] FIG. 2 is a schematic diagram showing the system of FIG. 1 with a train approaching the rightmost signal station.

[0008] [Figure 3] FIG. 3 is a schematic diagram showing the system of FIG. 1 with a train entering the rightmost virtual track block between the rightmost signal station and the center signal station.

[0009] [Figure 4] FIG. 4 is a schematic diagram showing the system of FIG. 1 with a train positioned within a virtual track block between the rightmost signal station and the center signal station.

[0010] [Figure 5]FIG. 5 is a schematic diagram showing the system of FIG. 1 with a train entering the rightmost virtual track block between the center signal station and the leftmost signal station.

[0011] [Figure 6] FIG. 6 is a schematic diagram showing the system of FIG. 1 with a train positioned within a virtual track block between the center and leftmost signal stations, and a second, following train approaching the rightmost signal station.

[0012] [Figure 7] FIG. 7 is a schematic diagram showing the system of FIG. 1 with a first train moving out of the physical track block between the center signal station and the leftmost signal station and a second train entering the physical track block between the center signal station and the rightmost signal station.

[0013] [Figure 8] FIG. 8 is a diagram illustrating the scenario of FIG. 7 together with the processing of the corresponding message code within any locomotive in the vicinity of at least one of the depicted signal points. DETAILED DESCRIPTION OF THE INVENTION

[0014] The principles of the present invention and their advantages are best understood by referring to the illustrated embodiments depicted in Figures 1-8 of the drawings, in which like numbers refer to like parts.

[0015] Two methods of train detection are disclosed in accordance with the principles of the present invention. One method determines rail integrity in unoccupied blocks. The second method determines train position within occupied blocks in addition to rail integrity. The following discussion describes these methods under three different example scenarios: (1) a system dormant (no trains) within a physical track block, (2) operation with a single train within the physical track block, and (3) operation with multiple trains within the physical track block. In this discussion, Track Code A (TC-A) is an available, open-source electrocode commonly used by railroads and is carried by a signal transmitted over at least one of the rails of the corresponding physical track block. Track Code B (TC-B) is unique to the present principles and provides detection of train position within one or more virtual track blocks within an occupied physical track block, preferably carried by a signal transmitted over at least one of the rails of the corresponding physical track block. TC-A and TC-B may be carried by the same or different electrical signals. Preferably, either TC-A or TC-B is transmitted continuously. Generally, TC-A relies on a first location transmitting a coded message to a second location, or vice versa (i.e., one location exchanging information over the rails). TC-B, on the other hand, is implemented as a reflection of transmitted energy using a transmitter-receiver pair with separate and distinct components. With TC-B, the system monitors the reflection of energy through the train's axles.

[0016] Virtual Track Block Position (VBP) messages represent occupancy data determined from the TC-A and TC-B signals and are preferably transmitted via wireless communication links to computers in nearby locomotives. The following discussion illustrates preferred embodiments, but does not represent all embodiments of the principles of the present invention. TC-A is preferably implemented with transmitter / receiver pairs, with the transmitter and receiver of each pair located at different locations. TC-B is implemented using transmitter / receiver pairs, with the transmitter and receiver of each pair preferably located at the same location. The energy signature from the transmitter is proportional to the distance from the isolated joint to the nearest axle of the train.

[0017] The track segments depicted in Figures 1-8 represent physical track blocks 101a-101d, with physical track blocks 101a and 101d shown partially and physical track blocks 101b and 101c shown fully. Physical track blocks 101a-101d are separated by conventional isolated joints 102a-102c. Signal control stations 103a-103c are associated with isolated joints 102a-102c. Each signal station 103 preferably transmits to the track on either side of the corresponding isolated joint 102, as discussed further below.

[0018] As shown in the legend provided in Figure 1-8, solid arrows represent track code transmission during track occupation by trains using TC-B signals. Dashed arrows represent track code transmission during unoccupied track using TC-A signals.

[0019] In accordance with the present invention, each physical trajectory block 101a-101d is divided into a plurality of virtual trajectory blocks, or "virtual trajectory blocks." In the illustrated embodiment, each of these virtual trajectory blocks represents one-quarter (25%) of each physical trajectory block 101a-101d, although in alternative embodiments, the number of virtual trajectory blocks per physical trajectory block may vary. In FIGS. 1-8, station #1 (103a) is associated with virtual trajectory block A1-H1, station #2 (103b) is associated with virtual trajectory block A2-H2, and station #3 (103c) is associated with virtual trajectory block A3-H3. In other words, in the illustrated embodiment, each station 103 is associated with the four virtual trajectory blocks to the left of its corresponding isolated joint 102 (i.e., virtual trajectory block A1-H2). i -D i ), and the four virtual trajectory blocks to the right of the corresponding isolated joint 102 (i.e., virtual trajectory block E i -H i In this configuration, the virtual orbit blocks overlap (e.g., virtual orbit block E1-H1 associated with station #1 overlaps with virtual orbit block A2-D2 associated with station #2).

[0020] Figure 1 depicts a track segment with no nearby trains. At this point, TC-A is transmitted from station #1 (103a) and received by station #2 (103b), and vice versa. The same is true for station #2 (103b) and station #3 (103c). All three locations each have a corresponding virtual track block A. i -H i Generate and transmit a VBP message of 11111111 corresponding to the unoccupied orbit in (i=1, 2, or 3). Table 1 categorizes the various codes for the scenario shown in Figure 1. [Table 1]

[0021] 2 depicts the same track segment with a single train 104 approaching from the right. At this point, TC-A is being transmitted between station 1 (103a) and station 2 (103b), which generate and transmit 11111111 VBP messages for virtual track blocks A1-H1 and A2-H2, respectively. The same is true from station 2 (103b) to station 3 (103c). However, the right approach to station 3 (103c) is no longer receiving TC-A from the next station to its right (not shown) due to a short circuit caused by a train in physical track block 101d, so station 3 terminates its TC-A transmission to the right. Station #3 (103c) then begins transmitting TC-Bs to the right to determine the degree of occupancy within physical track block 101d (i.e., the virtual track block or blocks on which the train is positioned) that was communicated as virtual track block occupancy. In this case, station #3 (103c) determines that the train is within virtual track block F3-H3 of physical track block 101d and therefore generates a VBP message with 1111 (unoccupied) for virtual track block A3-D3 of physical track block 101c to its left, 1 (unoccupied) for virtual track block E3 of physical track block 101d to its right, and 000 (occupied) for virtual track block F3-H3 of physical track block 101d to its right. Table 2 categorizes the codes for the scenario shown in Figure 2. [Table 2]

[0022] 3 depicts the same track segment, now with a train approaching physical track block 101c between station 2 (103b) and station 3 (103c), while still occupying physical track block 101d to the right of station 3 (103c). At this point, TC-A continues to be transmitted between station 1 (103a) and station 2 (103b), with station 1 (103a) generating a 11111111 VBP message for virtual track block A1-H1 and station 2 (103b) generating a 1111111 VBP message for virtual track block A2-G2. However, station 2 (103b)'s right approach is no longer receiving TC-A from station 3 (103c) due to the short circuit caused by the train in physical track block 101c, and station 2 therefore terminates its transmission of TC-A to the right. Station #2 instead begins transmitting TC-B to the right to determine the extent of the occupied virtual orbit block within physical orbit block 101c.

[0023] In particular, the train is entering virtual track block H2 of physical track block 101c, and station #2 (103b) therefore generates a 0 for virtual track block H2 in its VBP message. Station #3 (103c) now generates and transmits a VBP message of 00000000 for virtual track block A3-H3 due to both sides of isolated joint 102c being shorted in the nearest virtual track block. Table 3 categorizes the codes for the scenario in Figure 3. [Table 3]

[0024] Figure 4 depicts the same track segment, now with the train between Station 2 (103b) and Station 3 (103c). At this point, TC-A continues to be transmitted between Station 1 (103a) and Station 2 (103b), with Station 1 generating a 11111111 VBP message for virtual track block A1-H1 and Station 2 generating a 11111 VBP message for virtual track block A2-D2. Station 2 (103b)'s right approach still has not received TC-A from Station 3 (103c), so Station 2 continues to transmit TC-B to the right to detect the train's virtual track block location within physical track block 101c. When the train is positioned within virtual track block F2-H2, station #2 (103b) generates and transmits a VBP message with 11111 for virtual track block A2-E2 and 000 for virtual track block F2-H2.

[0025] Station #3 (103c) transmits TC-B to the left and TC-A to the right because physical track block 101d is no longer occupied. Specifically, when the train is positioned within virtual track block B3-D3, Station #3 (103c) generates a VBP message with 0000 for virtual track block A3-D3 and 1111 for virtual track block E3-H3. Table 4 categorizes the codes for the scenario in Figure 4. [Table 4]

[0026] Figure 5 depicts the same track segment, but now with a train located within physical track block 101b between station 1 (103a) and station 2 (103b) and within physical track block 101c between station 2 (103b) and station 3 (103c). Station 1 determines the train position to be within virtual track block H1, and station 3 determines the train position to be within virtual track block A3-B3. Both station 1 and station 3 use TC-B signaling to determine the train's virtual track block location. If the train is within virtual track block H1, station 1 (103a) generates a VBP message consisting of 1111111 for virtual track block A1-G1 and 0 for virtual track block H1. Station #2 (103b) generates a VBP message of 00000000 for virtual orbit block A2-H2 due to both sides of isolated joint 102b being shorted in the nearest virtual orbit block.

[0027] Station #3 (103c), on the left approach, still has not received TC-A from Station #2 (103b) and continues to transmit TC-B to the left to determine the train's virtual track block position within physical track block 101c, which in this case is virtual track block A3-B3. Station #3 (103c) similarly transmits TC-B to the right because physical track block 101d to the right is no longer receiving TC-A from the station to its right (not shown). This indicates that a second train is approaching Station #3 (103c) from the right. Station #3 (103c) therefore generates a VBP message with 00 for virtual track block A3-B3, 11111 for virtual track block C3-G3, and 0 for virtual track block H3. Table 5 categorizes the codes for the scenario in Figure 5. [Table 5]

[0028] Figure 6 depicts the same track segment with a first train between Station 1 (103a) and Station 2 (103b) and a second train on the right approach to Station 3 (103c). Using TC-B signaling, both Station 1 and Station 2 determine that the train's virtual track block location for the first train is within virtual track block B2-D2. Therefore, Station 1 (103a) generates a VBP message consisting of 11111 for virtual track block A1-E1 and 000 for virtual track block F1-H1. Station 2 (103b) generates a VBP message with 0000 for virtual track block A2 and 1111 for virtual track block E2-H2.

[0029] Station #2 (103b) on the right approach and station #3 (103c) on the left approach are now transmitting and receiving TC-A signals. Station #3 (103c) continues to transmit TC-B to the right and detects a second train within virtual track block F3-H3 of physical track block 101d. Therefore, station #3 (103c) generates a VBP message with 11111 for virtual track block A3-E3 and 000 for virtual track block F3-H3. Table 6 classifies the codes for the scenario in Figure 6. [Table 6]

[0030] Figure 7 depicts the same track segment, with a first train now located within physical track block 101a between a station to the left (not shown) of station 1 (103a) and station 1, and also within physical track block 101b between station 1 (103a) and station 2 (103b). Station 1 (103a) detects the presence of the first train using TC-B signaling and generates and transmits a VBP message consisting of 00000000 for virtual track block A1-H1 due to both sides of isolated joint 102a being shorted within the nearest virtual track block. Station 2 (103b)'s left approach still has not received a TC-A from station 1 (103a) due to the short circuit caused by the first train, so station 2 continues to transmit a TC-B to the left. Station #2 (103b) similarly transmits TC-B to the right, since physical track block 101c to the right is now no longer receiving TC-A from station #3 (103c) due to the short circuit caused by the second train.

[0031] Specifically, from the TC-B signaling, station #2 detects the first train within virtual track block A2-B2, virtual track block C2-G2 as unoccupied, and the second train within virtual track block H2. Therefore, station #2 (103b) generates and transmits a VBP message with 00 for virtual track block A2-B2, 11111 for virtual track block C2-G2, and 0 for virtual track block H2. The second train is now within physical track block 101c between station #2 (103b) and station #3 (103c), and also within physical track block 101d between station #3 (103c) and the station to the right of station #3 (103c) (not shown). In this case, station #3 (103c) generates a VBP message of 00000000 for virtual orbit block A3-H3 due to both sides of isolated joint 102c being shorted in the nearest virtual orbit block. Table 7 classifies the codes for the scenario in Figure 7. [Table 7]

[0032] Figure 8 depicts combining multiple wayside occupancy indications into one general train occupancy diagram. In the illustrated embodiment, the four virtual track blocks to the left of each station overlap the four virtual track blocks to the right of the adjacent station. The same applies to the right of each station, respectively. When wayside data is aligned as shown in Figure 8 and the logic "or" is applied, train occupancy can be determined relative to the nearest occupied virtual track block. In other words, any train in the vicinity that receives a VBP code can determine the location of any other train in the vicinity without the need for signaling aspects. Table 8 categorizes the codes for the scenario in Figure 8. [Table 8]

[0033] In accordance with the principles of the present invention, determining whether a virtual track block is occupied or unoccupied can be implemented using any one of several techniques. Preferably, existing core logic controllers and track infrastructure are used, and the system interfaces with existing electrocode equipment when determining when a virtual track block is unoccupied.

[0034] In the illustrated embodiment, the system distinguishes between virtual track blocks that are 25% increments of a standard physical track block, although in alternative embodiments, the physical track blocks may be divided into shorter or longer virtual track blocks. Additionally, in the illustrated embodiment, in the event of a broken rail under the train, the core logic controller records the broken rail in the nearest virtual track block (25% increment of the physical track block), sets an alarm for it, and indicates its location.

[0035] Preferably, the system has the capability to detect both the front (front) and rear (rear) axles of the train and to detect and verify track occupancy on approach as well as in advance. This principle is not constrained by any particular hardware system or method for determining train position; any one of several known methods can be used with conventional hardware.

[0036] For example, wheel position can be detected using current transmitted from one end of a physical track block to the other end of the physical track block and shorted by the train's wheels. If current provided from the front of the train detects the front wheels and current provided from the rear of the train detects the rear wheels, then generally, since the impedance of the track is known, the current transmitted from the isolated joint will be proportional to the location of the short along the block. Once train position is known, the occupancy of each virtual track block is also known. Either DC or AC current can be used to detect whether a virtual track block is occupied, but if an AC overlay is utilized, the AC current is preferably below 60 Hz and remains off until the track circuit is occupied.

[0037] Additionally, train location can be detected using conventional rail / highway-grade crossing warning system hardware such as motion sensors. Moreover, non-track-related techniques such as global positioning system (GPS) tracking, radio frequency detection, etc. may also be used to determine train location.

[0038] In the illustrated embodiment, the maximum short circuit sensitivity is 0.06 ohms, the communication format is based on Interoperable Train Control (ITC) messaging, and track circuit health monitoring is based on smooth transitions from 0 to 100% and 100 to 0%.

[0039] In a preferred embodiment, power consumption requirements comply with existing Wayside Interface Unit (WIU) specifications. Logging requirements include occupancy, method for determining occupancy, direction at a particular time, message transmission content and timing, calibration times and results, broken rail determination, error codes, etc.

[0040] Although the embodiment described above is based on a maximum length of 12,000 feet for fixed (i.e., non-moving) track circuits, the maximum length of a track circuit may vary in alternative embodiments. Although the bit descriptions described above are 1 for unoccupied virtual track blocks and 0 for occupied virtual track blocks, in alternative embodiments, the reverse logic may also be used.

[0041] One technique for measuring track position and generating a TC-B is based on current transmitted from one end of a physical track block to the other end of the physical track block and shorted by a train wheel. Generally, since the track impedance is known, the current transmitted from an isolated joint will be proportional to the location of the short along the block. Once the train position is known, the occupancy of each virtual track block is also known.

[0042] While the present invention has been described with reference to specific embodiments, these descriptions are not intended to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will be apparent to those skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the concepts and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

[0043] It is therefore contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the present invention.

Claims

1. 1. A railway track control system for maintaining braking distance in a locomotive, the railway track control system comprising: a plurality of control systems, each disposed at a corresponding end of a corresponding physical track block; Equipped with Each control system is dividing a physical track block into a plurality of virtual track blocks, the physical track blocks being defined by first and second isolated joints, the first and second isolated joints being located at corresponding first and second ends of a length of railway track; positioning a signal control station proximate to each isolated joint, and associating each signal control station with a group of virtual track blocks to the left of a corresponding isolated joint and a group of virtual track blocks to the right of a corresponding isolated joint; providing a first current from a first signal control station in front of the train to detect the front wheels of the train and a second current from a second signal control station in the rear of the train to detect the rear wheels of the train; determining whether the virtual track block is occupied or unoccupied via a core logic controller interfacing with the Electrocode device; Combine multiple virtual track block occupancy indications into one general train occupancy diagram using both the front and rear axles of the train to demonstrate track occupancy; 1. A railway track control system operable to:

2. 2. The railway track control system of claim 1, wherein each control system is further operable to transmit a TC-A signal between a first signal control station and a second signal control station and between the second signal control station and a third signal control station, the second signal control station being located between the first signal control station and the third signal control station.

3. 3. The railway track control system of claim 2, wherein each control system is further operable to short-circuit the TC-A signal within a physical track block such that the second signal control station does not receive a TC-A signal from the third signal control station when a train occupies at least one virtual track block between the second signal control station and the third signal control station.

4. 4. The railway track control system according to claim 2, wherein each control system is further operable to transmit a TC-B signal from the second signal control station towards the third signal control station to determine a degree of occupancy within the physical track block conveyed as a virtual track block occupancy.

5. 2. The railway track control system of claim 1, wherein each control system is operable to determine an electrical discontinuity in the at least one virtual track block within the corresponding physical track block by transmitting a track signal along the corresponding physical track block.

6. 5. The railway track control system of claim 4, wherein virtual track block position (VBP) messages represent occupancy data determined from said TC-A and TC-B signals and are transmitted via a wireless communication link to a computer in a nearby locomotive.

7. 5. The railway track control system according to claim 2, wherein each control system is operable to generate a VBP message indicating that the virtual track block between the first signal control station and the second signal control station is unoccupied and indicating that at least one virtual track block between the second signal control station and the third signal control station is occupied, when a train is located between the second signal control station and the third signal control station.

8. 8. The railway track control system according to claim 2, wherein each control system is operable to generate a VBP message indicating that at least one of the virtual track blocks between the first signal control station and the second signal control station is occupied and indicating that at least one virtual track block between the second signal control station and the third signal control station is occupied, when a train is located between the first signal control station and the second signal control station and between the second signal control station and the third signal control station.

9. 2. The railway track control system according to claim 1, wherein each control system is operable to generate a VBP message indicating that at least one of the virtual track blocks between the first signal control station and the second signal control station is occupied and indicating that the virtual track block between the second signal control station and a third signal control station is unoccupied when a train is located between the first signal control station and the second signal control station, the second signal control station being located between the first signal control station and the third signal control station.

10. 7. The railway track control system according to claim 4, wherein each signal control station, after detecting a short circuit, terminates transmission of the TC-A signal and starts transmitting the TC-B signal to determine the degree of occupancy within the physical track block.

11. 1. A method of railway track control performed by a plurality of control systems, the method comprising: each control system dividing a physical track block into a plurality of virtual track blocks, the physical track blocks being defined by first and second isolated joints, the first and second isolated joints being located at corresponding first and second ends of a length of railway track; each control system positions a signal control station proximate to each isolated joint and associates each signal control station with a group of virtual track blocks to the left of the corresponding isolated joint and a group of virtual track blocks to the right of the corresponding isolated joint; each control system providing a first current from a first signal control station in front of the train to detect the front wheels of the train and a second current from a second signal control station in the rear of the train to detect the rear wheels of the train; each control system determining whether a virtual track block is occupied or unoccupied via a core logic controller interfacing with the Electrocode equipment; Each control system combines multiple virtual track block occupancy indications into one general train occupancy picture, using both the front and rear axles of the train to demonstrate track occupancy. A method comprising:

12. 12. The method of claim 11, wherein each control system is further operable to transmit TC-A signals between a first signal control station and a second signal control station and between the second signal control station and a third signal control station, the second signal control station being located between the first signal control station and the third signal control station.

13. 13. The method of claim 12, wherein each control system is further operable to short-circuit the TC-A signal within a physical track block such that the second signal control station does not receive a TC-A signal from the third signal control station when a train occupies at least one virtual track block between the second signal control station and the third signal control station.

14. 14. The method of any one of claims 12 to 13, wherein each control system is further operable to transmit a TC-B signal from the second signal control station towards the third signal control station to determine the degree of occupancy within the physical orbit block conveyed as virtual orbit block occupancy.

15. 12. The method of claim 11, wherein each control system is operable to determine an electrical discontinuity in the at least one virtual track block within the corresponding physical track block by transmitting a track signal along the corresponding physical track block.

16. 15. The method of claim 14, wherein a virtual track block position (VBP) message represents occupancy data determined from said TC-A and TC-B signals and is transmitted via a wireless communication link to a computer in a nearby locomotive.

17. 17. The method of any one of claims 12 to 14 or 16, wherein each control system is operable to generate a VBP message indicating that the virtual track block between the first signal control station and the second signal control station is unoccupied and indicating that at least one virtual track block between the second signal control station and the third signal control station is occupied, when a train is located between the second signal control station and the third signal control station.

18. 18. The method of any one of claims 12 to 14 or 16 to 17, wherein each control system is operable to generate a VBP message indicating that at least one of the virtual track blocks between the first signal control station and the second signal control station is occupied and indicating that at least one virtual track block between the second signal control station and the third signal control station is occupied, when a train is located between the first signal control station and the second signal control station and between the second signal control station and the third signal control station.

19. 12. The method of claim 11, wherein each control system is operable to generate a VBP message indicating that at least one of the virtual track blocks between the first signal control station and the second signal control station is occupied and indicating that the virtual track block between the second signal control station and a third signal control station is unoccupied when a train is located between the first signal control station and the second signal control station, the second signal control station being located between the first signal control station and the third signal control station.

20. 17. The method of claim 14 or 16, wherein each signal control station, after detecting a short circuit, terminates transmission of the TC-A signal and starts transmitting the TC-B signal to determine the degree of occupancy within the physical track block.

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