Remote Isolation System for a Rail System

Abstract

A remote isolation system (700) for a rail system (200) comprising a rail system component (215A) other than rail traffic energisable by an energy source (23) and a control system (205) for controlling operation of said rail system component (215A) wherein said control system (205) enables isolation of said rail system component (215A) from said energy source (23) to an isolated state when an isolation request for said rail system component (215A) is authorised by the control system (205).

Claims

1. A remote isolation system for a rail system comprising: a rail system component energisable by an energy source; and a control system for controlling operation of said rail system component wherein said control system enables isolation of said rail system component from said energy source to an isolated state when an isolation request for said rail system component is authorised by the control system.

2. A remote isolation system as claimed in claim 1 wherein said control system is configured to enable isolation of the rail system component following receipt of a permissible isolation request input to the control system by an operator.

3. A remote isolation system as claimed in claim 2 including at least one remote isolation station to enable communications with the control system to facilitate isolation on permissible request, said remote isolation station being provided with a control panel having input means to enable an operator to input an isolation request for authorisation by the control system; and an isolation switch for the rail system component.

4. A remote isolation system as claimed in claim 3 wherein said rail system includes a signal equipment room or signal boxes and a remote isolation station is located outside said signal equipment room.

5. A remote isolation system as claimed in claim 3 including at least one mobile remote isolation station.

6. A remote isolation system as claimed in claim 3 including a bypass or over-ride mode wherein said remote isolation system is deactivated and rendered temporarily inoperative to address an isolation system fault.

7. A remote isolation system as claimed in claim 4 including first circuit interrupter(s) which are in series connection with a primary stop/start switch for the rail system component, the first circuit interrupter(s) being controlled to the off or break state by said control system once isolation of the rail system component has been authorised by the control system.

8. A remote isolation system as claimed in claim 7 wherein said remote isolation system includes second circuit interrupter(s) in an energy supply line from the energy source to the rail system component, said second circuit interrupter(s) being under the control of the control system and placed in the off state once isolation is authorised by the control system.

9. A remote isolation system as claimed in claim 8 further comprising a voltage monitoring means to sense and monitor voltage downstream of the first and second circuit interrupter(s).

10. A remote isolation system as claimed in claim 1 wherein isolation includes bridging and automated isolation.

11. A remote isolation system as claimed in claim 1 wherein said rail system component is selected from track switches and overhead aerials to provide power for trains and track supply.

12. A remote isolation system as claimed in claim 1 including track shorting devices to indicate traffic occupied status and provide notification that works are in progress on a section of isolated track.

13. A remote isolation system as claimed in claim 1 including automatic track derailers to derail rail traffic should it approach a section of isolated track.

14. A remote isolation system as claimed in claim 1 including securing means having sensors to continuously monitor and secure isolation system integrity and implement corrective action to address threats to isolation system integrity if detected.

15. A remote isolation system as claimed in claim 14 wherein said control panel is configured to only enable isolation system operation following operator identity verification using an operator identification device integrated with the control panel and remote isolation system.

16. A remote isolation system as claimed in claim 15 wherein said operator identity verification includes verification of operator identification data, such as isolation permit data enabling an operator to perform specific tasks and work in particular areas.

17. A rail system comprising: a control system for controlling rail system operations; a plurality of interconnected rail tracks and associated railway system components energisable by an energy source under control by the control system; and an isolation system for isolating at least one said railway system component from said energy source when authorised by the control system wherein at least one rail track remains operational under the control of the control system during isolation of the rail system component by the isolation system.

18. A rail system as claimed in claim 17 wherein the control system enables the at least one rail track to remain operational dependent on certain permissives being met.

19. A rail system as claimed in claim 17 wherein a permissive relates to safety clearance and, in case of insufficient clearance, the control system places rail track(s) having insufficient clearance out of service.

Description

[0035] The remote isolation system according to the present invention will be more fully understood from the following description of a preferred embodiment thereof made with reference to the accompanying drawings in which:

[0036] FIG. 2 shows a schematic layout of a remote isolation system for turnouts of a rail system in accordance with one embodiment of the present invention.

[0037] FIG. 3 shows a further schematic of the remote isolation system shown in FIG. 2.

[0038] FIG. 4 shows a schematic of a control panel for use in the remote isolation system for the rail system schematised in FIGS. 2 and 3.

[0039] FIG. 5 shows a logic flow chart for a remote isolation procedure for a turnout of the rail system schematised in FIGS. 2 and 3.

[0040] FIG. 6A shows a perspective view of a retaining (keeper) plate securing means for preventing removal or loss of a key actuating device from the turnout isolation switch included in the control panel of FIG. 4 when installed.

[0041] FIG. 6B shows a front left perspective view of the turnout isolation switch box included within the control panel of FIG. 4 in normal running condition.

[0042] FIG. 7 shows a partial front view of the turnout isolation switch box of FIG. 6B with cover removed to show the lock member arrangement in position within the switch box.

[0043] FIG. 8 shows a front left perspective view of the turnout isolation switch box of FIGS. 6B and 7 in an isolated condition and as a manual lock out process proceeds.

[0044] FIG. 9 shows a top perspective view of the turnout isolation switch box later in the lock out process than as shown in FIG. 8.

[0045] FIG. 10 shows a top perspective view of the turnout isolation switch box of FIGS. 6B to 9 with a manual lock out point ready for use.

[0046] FIG. 11 shows a front left perspective view of the turnout isolation switch box with a hasp fitted in a locked out position.

[0047] FIGS. 12A and 12B show detail perspective views illustrating arrangement and movement of a movable lock member for the turnout isolation switch box of FIGS. 6 to 11.

[0048] FIG. 13 is a bottom perspective view of the turnout isolation switch box of FIGS. 6B to 11.

[0049] FIG. 14 shows a key for actuating the turnout isolation switch.

[0050] FIG. 15 shows a logic flow chart for a de-isolation procedure for a turnout of the rail system schematised in FIGS. 2 and 3.

[0051] FIG. 2 shows a rail system 200 for conveying iron ore to a port, which like the afore-described rail system 100, includes a track section 210 comprising two rail tracks here numbered 211 and 213 interconnected through rail system componentsturnouts 215A and 215Bprovided for each track. Rail system 200 operations are controlled by a control system 205 including, among other rail system components, a signal equipment room 207 from where a Traffic Controller supervises the control system 205. Control system 205 is, subject to the following description, a conventional SCADA computer control system 252 used for controlling rail system operations.

[0052] Trains are switched from track 211 to track 213, when required, using paired turnouts 215A, 215B each comprising switches and frogs. Turnouts 215A, 215B operate simultaneously when their corresponding switch motors 215AA and 215BA are energised through electrical supply line 23 by an AC power system. The AC power system typically operates at 110V through electrical contacts 231A and 231B which are housed in substation 230. Activation of the contactors 231A or 231B (i.e. placing them in the off or break state) de-energises the electrical supply to switch motors 215AA or 215BA respectively. A voltage monitor relay 810 senses and monitors electrical energy supply downstream of the contactors 231A, 231B.

[0053] Rail system 200 enables automated remote isolation of rail system components, and in particular turnouts 215A, 215B, through a remote isolation system 700. The remote isolation system 700 includes a number of components including fixed remote or field isolation stations 212 and 214 each having control panels 300 as described below and located outside signal equipment room 207. Remote isolation station 212 is used in the isolation of turnout 215A. Remote isolation station 214 is used in the isolation of turnout 215B. The need for the provision of separate remote isolation stations 212, 214 is premised on the fact that the turnouts 215A, 215B can typically be separated by anywhere from 1,000 m to 5,000 m, though in some cases even greater separation distances may exist. Remote isolation stations 212 and 214 could however alternatively be configured to allow isolation of either turnout if desired.

[0054] It will be understood that remote isolation stations 212 and 214 could be replaced or supplemented by one or more mobile isolation stations, for example in the form of mobile isolation devices such as portable computer devices (in certain applications these potentially being provided as smartphones) or communication devices using wireless communications, as disclosed for example in the Applicant's Australian Provisional Application Nos. 2015902561 and 2015902562 filed on 30 Jun. 2015, the contents of which are hereby incorporated herein by reference. The remote isolation stations 212 and 214 may be powered from the plant grid, other power networks or alternative power sources, conveniently such as via solar power.

[0055] The remote isolation system 700 may also include, as part of its control system, a master controller 250 incorporating a human/machine interface (HMI) here in the form of a touch sensitive screen 251 which displays human interpretable information. The master controller 250 is located within signal equipment room 207. Remote isolation stations 212 and 214 are in communication with the master controller 250 by way of communication line 253, and also with each other by way of communication channels 254 and 255. Communications channels 253-255 may be in any suitable form including hard wired or wireless forms.

[0056] FIG. 3 shows a further schematic of the remote isolation system 700 shown in FIG. 2 further highlighting the control and communications systems. Like numerals are used to indicate elements in FIG. 3 that are common with those described with reference to FIG. 2. First circuit interrupters, being a set of isolation contacts 800, are placed in series connection with a stop/start switch 216A for the switch motor 215AA of turnout 215A. A similar stop/start switch is also provided for the switch motor of turnout 215B with isolation contacts (not shown for ease of illustration). Isolation contacts 800 and switch 216A form part of the control system that controls second circuit interrupter(s) 850.

[0057] Second circuit interrupter(s) 850, in the form of contactor(s), are a critical element of the remote isolation system 700. Isolation contacts 800 are in the form of a plural switch which incorporates self-diagnostics and is designed so that a loss of power results in the contacts 800 moving to the off or break state.

[0058] FIG. 3 shows provision of a digital out (DIG OUT) control line 822 to the stop/start switch 216A not necessarily controlled by the remote isolation system 700, and rather being controlled by rail control system 205. Control line 821 is not relied upon to achieve isolation of turnout 215A though it may be used to sense that a current isolation is in effect. Master controller 250 controls both the isolation contacts 800 and contactors 850 as shown by control lines 822 and 823 respectively.

[0059] Voltage monitor relay 810 senses and monitors the voltage downstream of contactors 800 and 850 and, in particular, whether any power is being supplied to switch motor 215AA of turnout 215A. Voltage monitor relay 810 is a device certified for safety compliance and incorporates self-diagnostics because its role is to ensure that risk of hazardous continued energisation of turnout switch motor 215AA following an authorised isolation is prevented.

[0060] The control panel 300 of either of the remote or field isolation stations 212 and 214 is shown in greater detail in FIG. 4. Panel 300 has a human machine interface (HMI) 300A with a touch screen 365 (though less fragile buttons, switches and other input devices may be used in alternative arrangements) for entering commands including issuing isolation requests to the master controller 250 mmands. A request button 304 is provided for isolation requests. Information can also be presented on screen 365 in respect of any such isolation requests including isolation status and other relevant rail system data. Control panel 300 also includes: [0061] indicator light 302 showing whether or not the remote isolation station 212 or 214 is ready and available for an operator request to isolate switch and frog 215A when required for maintenance purposes; [0062] indicator light 303 to provide zero energy confirmation when voltage monitor relay 810 indicates zero energy in the turnout 215A and its switch motor 215AA; [0063] request isolation button 304 which is activated by an operator (and which illuminates when pressed) for the operator to request isolation and a corresponding request approved indicator light 305; [0064] indicator light block 306 for showing correctness of selection of turnout switch 215A for isolation and system checks proceeding as described below; [0065] indicator light block 307 for showing whether or not the isolation process is complete following system checking; [0066] isolation lockout switch box 350 with isolation lockout switch 355 (here shown with key 357 in a normal or resting position with a flap lock member 291 held captive prior to isolation. Locked out position is shown in FIG. 11 and described below); and [0067] graphics (in the form of arrows and text) illustrating the sequence of steps to be followed in the required isolation procedure.

[0068] Control panel 300 also includes a try step button 309 pressed by the operator after system checks have been passed successfully and isolation has been authorised but before lockout of isolation switch 355. The try start step checks that the turnout switch motor 215AA does not start against expectation of isolation.

[0069] In summary, turnout 215A is isolated for maintenance works by a process involving the following logical sequence of steps: [0070] An operator request at remote isolation station 212 for the control system 205 to approve isolation of the turnout 215A by de-energising its switch motor 215AA; [0071] The isolation being approved if the operator request meets permissives for isolation of turnout 215A (example permissives would include compatibility with the rail access plan with no trains expected on the track section 210 during proposed maintenance time; remote isolation system 700 in healthy condition; permits to isolate and work issued, valid and current (such permits advantageously being issued in accordance with systems as described in the Applicant's Australian Provisional Patent Application Nos. 2015902559 and 2015902564 filed on 30 Jun. 2015, the contents of which are hereby incorporated herein by way of reference)); [0072] Isolation of turnout 215A automatically implemented by the control system 205; [0073] Try step button 309 pressed to invoke a check that isolation of turnout 215A and switch motor 215AA is effective which involves checking that electrical contacts 800,850 are in an isolated state with no voltage downstream of electrical contacts 800,850 as continuously monitored by voltage monitor relay 810; an attempt to restart the switch motor 215AA using try step button 309 or automated processes; and checking that there is no re-energisation of turnout switch 215A and its switch motor 215AA (which may involve continuous monitoring as described in the Applicant's Australian Provisional Patent Application No. 2015902556, the contents of which have previously been incorporated by reference); and [0074] Manual lockout to be done using isolation switch 355 described below if the try start is unsuccessful (as required).

[0075] Operation of the remote isolation system 700 will now be described in further detail with reference to the generalised logic flow chart shown in FIG. 5.

[0076] At step S1, the remote isolation system 700 undergoes a health check for any existing faults and alarms that would prevent an isolation request from being granted, approved or authorised.

[0077] If no relevant faults exist, then step S2 checks whether the remote isolation system is in in a ready state. In the rail system 200 as described, such a ready state would be indicated by the correct positioning of the track turnouts. If step S2 is satisfied, the FIS AVAILABLE status indicator light of light block 302 will glow solid on control panel 300. If not, then a flag or fault message will be generated at the master controller HMI 251 at signal equipment room 207 informing the Traffic Controller of the fault.

[0078] At step S3, an operator situated at remote isolation station 212 pushes the isolation request button 304. This isolation request is forwarded through communication line 253 to the master controller 250 and rail control system 205 and onward to the signal equipment room 207. Indicator light 304 then flashes to indicate registration of the isolation request by the rail control system 205. The isolation request is pending at this stage. Step S3 results in a signal to the signal equipment room 207 which may be displayed for the attention of a Traffic Controller. At the signal equipment room 207, either the rail control system 205itself or the Traffic Controller considers the isolation request and decides whether to authorise it.

[0079] At step S4, a time out timer is started. This timer may be set for any convenient period, for example, 5 minutes. The isolation authorisation process must be completed within this period.

[0080] At step S5, the isolation system awaits grant of an isolation authorisation from the signal equipment room 207 or Traffic Controller who may determine that the isolation will be authorised, possibly after interrogation of the operator to assess whether permissives to isolation have been met. A number of key permissives were described above. The Traffic Controller then confirms authorisation of the isolation request through a human machine interface, for example by pressing an authorisation button. Request Approved indicator light 305 illuminates and then, as the system check steps below proceed, indicator light 306 illuminates to indicate that status.

[0081] Step S6 is then a check that isolation authorisation is granted within the time period set by the timer described for step S4. If not, a timer expire message issues and the process moves to step S19 in which case no isolation proceeds.

[0082] Step S7 is part of the timer loop which checks that authorisation is received within the preset time mentioned for step S4. Thus inaction by the Traffic Controller, or a decision by the Traffic Controller not to grant approval of an isolation request, will result in a time out and moving to step S19 without isolation being implemented.

[0083] At step S8, rail control system 205 checks the status of the voltage monitor 810 as described above. At this stage, the stop/start switch 216A should already be in the off or break state such that contactor(s) 850 are also in the off or break state as shown in FIG. 3. The voltage sensed by the voltage monitor 810 should be practically zero. Provided that a zero voltage status is returned by the voltage monitor 810, isolation contacts 800 are placed in the off or break state, at step S9, creating a further point of isolation. Personnel in the vicinity of remote isolation station 212 and signal equipment room 207 may be alerted of the imminent isolation by a warning system prior to breaking contactors 850 and isolation contacts 800. The warning system may provide visual or audible warnings, advantageously both. Sirens and recorded voice message announcements may also be used, including at remote isolation stations 212 and 214 which include suitable warning sirens and lamps (serviceability of which may be tested by pressing button 300B on control panel 300).

[0084] The system has now been isolated at two points of isolationin the control circuit and the energy supply line 23by isolation contacts 800 and contactors 850all under supervision of rail control system 205. As there may be some delay in the operation of isolation contacts 800, including for safety reasons as above described, steps S10 (open isolation contacts) and S17 provide a timed loop whereby a check is performed to confirm that they are in the off or break state as required for isolation. Isolation contacts 800 are provided with self-diagnostics and are able to report their status to the master controller 250. If the system does not register that the isolation contacts 800 are in the off or break state within the timer period, then a fault flag is generated and the remote isolation system 700 moves to step S19 in which the last known state of the system is maintained.

[0085] If step S10 is passed, indicator light 306 goes off and the checking complete indicator light 307 is made to glow solid or steady at control panel 300 of remote isolation station 212. A similar indicator light may also appear on the control panel of remote isolation station 214 as both stations are communicated with the master controller 250 and rail control system 205.

[0086] Step S11 of the isolation procedure requires the operator to press button 309 on control panel 300 in a try start test step. Once pressed, the isolation system checks for energisation of turnout switch motor 215AA and checking proceeding indicator light 306 re-illuminates.

[0087] Steps S12 and S18 provide a timed loop to check that the try start test, as required by safety guidelines, has been passed (a pass being registered if a fail to start signal issues from rail control system 205). Otherwise, the step will time out and a fail flag will register.

[0088] At step S13, checking complete indicator light 307 again glows solid or steady and at step S14, the operator locks out the isolation switch 350 with a personal lock and hasp 600 as described below.

[0089] The remote isolation of turnout 215A is now complete and secured at step S15. The Traffic Controller is informed of this status through display at signal equipment room 207. Screen 365 of HMI 300A also indicates this status (as with other system status during the isolation process). Maintenance works on turnout 215A may now proceed.

[0090] When maintenance is completed, the turnout 215A is returned to de-isolated state in step S16, a flowchart for de-isolation being described below with reference to FIG. 15.

[0091] FIGS. 6A to 11 and 13 show one possible turnout isolation switch assembly in the form of switch box 350 required for use in isolation of switch and frog 215A. Turnout isolation switch box 350 has a housing 420 which includes isolation switch 355 at the front. Housing 420 includes an upper flange 430, a lock member in the form of flap 291 and a resting portion 440 against which flap 291 is held captive when required and as described further below. Housing 420 is free of apparent lock out points to which a hasp and padlock could be inadvertently fixed using a manual lock out procedure.

[0092] Housing 420 also accommodates, noting its interior as well as exterior, electrical and mechanical components and systems to enable operation of the switch box 350. Power and communications cables are connected through socket 480 (detachable by removing screws 482) as shown in FIG. 13. Access to interior components, for example by removing an access cover 294, is restricted to authorised personnel. Housing 420 has a robust construction being configured and designed as a very solid and robust unit to endure the difficult and often very harsh environmental conditions typical of iron ore rail systems in North Western Australia, for example.

[0093] Turnout isolation switch 350 must co-operate with a switch actuating device here in the form of key 357 whenever remote isolation system 700 is operative, i.e. available to achieve remote isolation of turnouts 215A or 215B. Key 357 is shown in greater detail in FIG. 14 and has an outer portion 357A and a body portion 357C formed with a number of notches 357B in an arrangement suitable for actuation of, and unique to, switch 355.

[0094] For various reasons, including vibration of the switch box 350 or misuse, key 357 could be lost from equipment isolation switch 355. To minimise such risks, the equipment isolation switch box 350 includes at least one securing means to secure the key 357 into co-operation with equipment isolation switch 355 whenever it is operative, not necessarily in isolated condition as will be apparent from description below.

[0095] Such a securing means is provided by retaining (keeper) plate 405 which is designed to prevent removal of key 357 from equipment isolation switch 355 once locked into position. Keeper plate 405 is shown as a separate component in FIG. 6A and includes lower flange 405B and upper flange 405C. Upper flange 405C includes an aperture 405A to accommodate a lock device (padlock 407) to secure the keeper plate 405 to the switch box housing 420. Keeper plate 405 includes an open ended aperture 405D comprising two slot portions 405E and 405F, portion 405F having lesser height than that of portion 405G and the diameter of isolation switch 355. Aperture 405D has a terminal portion 405G at one end of slot portion 405F. The function of these features is described below.

[0096] Keeper plate 405 has dimensions allowing a neat fit between upper surface 440A of magnetic portion 440 (with which lower flange 405B of keeper plate 405 is in contact) and upper flange 430 (with which upper flange 405C of keeper plate 405 is in contact) of switch box housing 420.

[0097] Keeper plate 405 is slid between magnetic portion 440 and upper flange 430 of switch box housing 420. In this position, slot portion 405E is co-located with equipment isolation switch 355 and key 357, having lesser dimension for its body portion 357C than slot 405E and may readily be inserted and brought into co-operation with switch 355. Keeper plate 405 is slid further into a position, as shown in FIG. 6B, where terminal portion 405G of slot portion 405F engages with key portion 357C whilst overlapping with switch 355. The relative dimensions of key portion 357C and slot portion 405F now enable keeper plate 405 to prevent removal of key 355 from switch 357. In this position, aperture 405A of keeper plate 405 aligns with corresponding aperture 415A of upper flange 230 of switch box housing 420 forming a locking point for padlock 407. The keeper plate 405 is now locked into position as shown in FIG. 4. In a further embodiment, aimed at making unauthorised key 357 removal even more difficult, the key 357 may be machined with slots locating and securing it to the keeper plate 405.

[0098] Equipment isolation switch 355 is operable by turning the key 357 between a first NORMAL position in which switch motor 215AA for switch and frog 215A is electrically energised and a second ISOLATE position in which switch motor 215AA is without power (i.e. de-energised) enabling maintenance works on the switch and frog.

[0099] However, whilst turning the key 357 from the NORMAL position to the ISOLATE position is a necessary step in establishing an isolation states when authorised by master controller 250, this alone does not provide a sufficient condition for the remote isolation system 700 to properly isolate switch motor 215AA and switch and frog 215A. The isolation switch 350 must also be locked out, in this case by a manual lock out procedure. Further, such a manual lockout is not provided for by turnout isolation switch 350 unless a lockout point is provided by co-operating a locking device with switch 350 under the control of master controller 250. Authorisation of manual lock out by master controller 250 requires the correct remote isolation procedure sequence to be completed as summarised hereinabove.

[0100] More specifically, the locking device for turnout isolation switch 350 has two lock members, the first being formed by cut out or slot 291C located in a fixed position of a top flange 430 of the switch housing 420. Slot 291C alone cannot accommodate a locked padlock or hasp as required for regulatory isolation. The second lock member is constituted by a plate or flap 291 and a cut out or slot 291B provided at one end of flange 292 which corresponds with the cut out or slot 291C when the flap 291 is raised to cover the isolation switch 355. Flap 291 includes a slot 293 arranged centrally thereof which can correspond with the key 357 when the flap is in a raised position. Cut-out 291B, slot 293 and flap 291 are likewise designed to alone not support attachment of a padlock or hasp 600 used in the remote isolation system 700.

[0101] The flap lock member 291 (and in particular its slot 291B) and 291C will only be allowed to co-operate to form a lock out point 297 (as best depicted in FIG. 10) through co-operation if authorised by the master controller 250, and this will only occur if the correct remote isolation procedure, as previously described, is followed.

[0102] As shown in FIGS. 6B and 7, the turnout isolation switch box 350 and particularly the isolation switch 355 are in a resting state with flap 291 and slot 293 (for accommodating the key 357 when in an isolated position) open and held captive against resting portion 440 of switch box 350 through a solenoid operated magnetic interlock as described below.

[0103] When isolation is authorised following correct procedure and key 357 is turned to the ISOLATE position (as shown in FIG. 8), flap 291 is released from its captive position enabling it to rotate about its hinge 291A and flap shaft 310. This happens because a magnetic lock preventing rotation of hinge 291A is de-magnetised, on isolation, due to deactivation of flap solenoid 301. This enables flap 291 to rotate upward in clockwise direction (as indicated by FIGS. 8 to 10, 12A and 12B) and finally into the locking position as shown in FIGS. 10 and 11.

[0104] Further detail of the solenoid operated magnetic interlock is shown in FIGS. 7, 12A and 12B. In a resting position, flap solenoid 301 is energised by power supply to the switch box 350. A plunger portion of the flap solenoid 301 is consequently located within a receptacle 319 of striker/positioning block 317 and this acts as a lock on rotation of flap shaft 310. Flap 291 is held captive. Proximity sensors 315 monitor the position and generate an alarm signals if the flap 291 moves unexpectedly from the captive position. On isolation, the plunger portion of flap solenoid 301 is released from receptacle 319 of striker/positioning block 317. The lock is released and flap shaft 310, hinge 291A and flap 291 are allowed to rotate in direction R into the locking position against the action of flap shaft return spring 318. Proximity sensors 315 also operate continuously to detect this situation.

[0105] In locking position, flap 291 covers the isolation switch 355 whilst providing for a portion 358 of key 357 to extend through slot 293. When this occurs, slots 291B and 291C co-operate to form an aperture or lockout point 297 through which a hasp 600 is securely and correctly accommodated for lockout, as shown in FIG. 11. This prevents movement or removal of key 357 from isolation switch 355. More than one operator can lockout and hasp 600 includes a number of apertures 600A allowing other hasps or personal locks to be applied.

[0106] The master controller 250 of the remote isolation system 700 properly deactivates flap solenoid 301 enabling lockout as above described only when an unsuccessful try step (i.e. attempt to re-energise turnout switch 215A) is completed. Until that point, flap 291 is held captive in its resting position as shown in FIGS. 6B and 7.

[0107] Sensors, such as proximity sensors, are used to monitor the position of the key 357 in turnout isolation switch 355 and ensure that various components (most notably the key 357 and the flap 291 (through proximity sensors 315)) are correctly positioned in a resting or NORMAL (energised) or locked out or ISOLATE condition. Corrective action may be initiated if deviation from the correct position is indicated. Alert signals may also be generated by the master controller under such circumstances. Sensors can also be used to indicate tampering with the hasp 600 such that corrective action may be initiated if any such tampering is detected.

[0108] On correct de-isolation, flap 291 is rotated back into its resting position to again be held captive against resting block 440 through operation of the solenoid actuated magnetic interlock.

[0109] The turnout isolation switch 355 is only operable when the key 357 is engaged with it. The key 357 must be removed from the key switch 355 when deactivation of the turnout isolation switch 350 is required. Control system or authorised personnel approval would be required prior to such removal which, even then, is only permitted when the isolation switch 355 is in a NORMAL condition. Furthermore, key removal is not permitted without additional validation steps if key switch 355 is in an ISOLATE condition. Deactivation would typically require other tasks to be completed before a remote isolation system is safely and completely removed from service.

[0110] It will be understood that other isolation switch designs could be used together with the rail isolation system described above. An alternative isolation switch assembly, including a securing means to maintain key 357 in co-operation with isolation switch 355 as described in the Applicant's Australian Provisional Patent Application No. 2015902554 filed 30 Jun. 2015, the contents of which are hereby incorporated herein by way of reference, could also be used.

[0111] Following isolation of turnout switch 215A as above described, the rail control system 205 remains operational allowing one of the tracks 213 to remain operationalsubject to conditions in the form of permissives as described belowduring maintenance on turnout switch 215A which shuts down operations on track 211. This improves rail system 200 productivity and availability as can be demonstrated by the following simple example. In a scenario where the rail system 200 conveys saleable iron ore product, that iron ore product can now continue to be transported on one track during maintenance thus reducing the loss of revenue encountered using prior isolation and approval procedures. Importantly, this benefit is also achieved through a remote isolation system that is fully compliant with applicable mining regulations and industry standards.

[0112] As an additional safety measure, the isolation system may include track shorting devices 260 to indicate traffic occupied status, for example providing notification that works are in progress on a section of isolated track 211 to those concerned such as drivers of approaching trains. Automatic track derailers 270 are also included in the rail system to derail rail traffic should it approach a section of isolated track 211 where maintenance work may be taking place.

[0113] As alluded to above, whether the rail control system 205 enables track 213 remains operational may depend on certain permissives being met. For example, one permissive may relate to safety clearance between interconnected tracks 211 or a possibly operational rail track 213 and a work area including a section of track 211 isolated by the isolation system. In case of insufficient clearance, the rail control system 205 may place both rail tracks 211 and 213 out of service for the duration of the maintenance works.

[0114] The de-isolation procedure for the remote isolation system 700 then follows the logic flow diagram of FIG. 15. At step S20, the master controller 250 confirms firstly that an isolation is active. Once confirmed, the operator removes hasp 600 from the lock out point 297 of isolation switch 350 at step S21. Key 357 is then turned to the resting or NORMAL position. This action is sensed at turnout isolation switch 350 and a signal is sent to the master controller 250 to indicate that de-isolation has been requested. The operator is now no longer able to operate the turnout isolation switch without proceeding back to step S1 as previously described with respect to FIG. 5.

[0115] At step S22 a check is performed to confirm that the turnout isolation switch 350 is back to the resting state. If so confirmed, the system proceeds to step S23 which is intended to prevent an uncontrolled start by ensuring that the stop-start switch 216B is in the off position so that re-activation of isolation contacts 800 will not result in an activation of contactors 850 and thereby a re-energisation of turnout switch motor 215AA. If step S23 is failed, a flag is raised and the isolation system holds its current state.

[0116] If step S23 is passed, the system moves to step S24 (close isolation contactors) at which the isolation contacts 800 are activated to a closed, or make, state. S25 then indicates that the de-isolation is now complete and that the rail control system 205 and Traffic Controller can re-activate the turnout 215A for normal operation according to normal procedures.

[0117] As is evidenced from the above discussion, the Applicant's remote isolation system alleviates the need for extensive participation of isolation personnel and rail controllers to enable an isolation in a rail system 200 to be effected. The remote isolation system implemented on the rail system 200 can remotely isolate power to specific track points once power to adjacent tracks has been enabled or disabled as specific circumstances may warrant. Notably, where an isolation officer would typically be required to place a bridge in a related control circuit so as to not have the isolation lock out an adjoining or adjacent track 213, the remote isolation system of the present invention can do this automatically. That is, the remote isolation system, as described, can place a bridge in the related control circuit so that the adjacent track remains available for rail use, unlike the situation with current rail isolation arrangements. It should however be noted that the remote isolation system does not exclude use of bridging at the same time as automated remote isolation in rail system 200 where necessary.

[0118] Modifications and variations to the remote isolation system disclosed in the present specification may be apparent to the skilled reader of this disclosure. Such modifications and variations are deemed within the scope of the present invention.

[0119] For example, the isolation lockout switch 355 need not be operated using a key 357 as described above. The isolation lockout switch 355, and control panel 300 (and indeed other components of the remote isolation system 700) could be configured to only enable operation following operator identity verification using operator identification devices integrated with the control panel or remote isolation system as described in the Applicant's Australian Provisional Patent Application Nos. 2015902559 and 2015902564, the contents of which have previously been incorporated herein by reference. Such operator identification devices may receive operator identification data either directly and/or from an operator identification means. A range of operator identification devices and operator identification means could be used, the latter class conveniently including smart devices such as smart cards and smart phones. A smart card identification system could be implemented using a card reader 299 located at remote isolation stations 212 and 214.

[0120] Operator identification data would be stored in both the control system and any operator identification means, for example a smart card, following a conventional process and such data could include, or be tied to, isolation permits to work at remote isolation stations 212 and 214 and in particular locations or work areas around the track section 210. Smart card validity could be checked in the field. This option reduces the risk of accidental or deliberate misuse of the remote isolation system 700. Such benefits further help increase safety and reduce lost production for maintenance.