Rail Vehicle Detection System Flashcards
Rail Vehicle Detection System
a system of safeworking infrastructure used in axle counter territory and continuously track-circuited territory in the Rail Network
Rail Vehicle detection track
a portion of track formed into an electric circuit where current is carried through the rails and used to detect the presence of trains
Track circuits
used in the operation and control of points and signalling equipment
Electronic operation of rail vehicle detection system
The computer system that operates the safeworking infrastructure
Describe how the computer system operates the safeworking infrastructure
takes instructions fed from the Network Control Officer and track circuitry information to operate points/switches, signals and level crossings throughout the Rail Network
Benefits of a computer system controlling rail vehicle detection system
Will not allow conflicting rail movements to be set up accidentally, will always provide a failsafe outcome should a computer fail in service
The computer system for safeworking is protected via
redundant electronics and an Uninterruptable Power Supply (UPS) to ensure that the system remains fully operational during a blackout or loss of service power from the city supply
Describe how a track circuit signal displays “clear”
The rail block immediately ahead of the signal must be unoccupied so that the electric signal can be sent down each rail and the signal relay will energise to make the signal show
Describe how a track circuit signal displays “STOP”
When a train’s wheelset occupies a circuited part of the block, the energising batter/power supply is interrupted and causes the signal relay to ‘drop out’, allowing the red signal to become illuminated
Functionality of Rail Vehicle detection is provided by an electronic system and includes the setting of routes and points, including through
setting of signals, auto re-clearing of signals, over ride controls, blocking, train description and Automatic route setting based on timetables
Automatic route setting
where the paths for trains are set in accordance to the timetable or train path with alarms to the operators when it is not possible to maintain timetable order
The system information is used to
monitor correct sequence of track circuit occupancy or loss of train/points or switch mechanism detection under trains. Also provides information to other computer based systems.
Train Description
presented through coloured bars which denote the degree of early or late running of a train. Will show all static and dynamic information regarding that piece of infrastructure or rolling stock
Braking distance depends on
gradient, train type, line speed set by the “Cheif Engineer of Track”
The Rail Vehicle Detection system uses continuous track circuiting or axle counters to
detect the presence of rail traffic in a block and prevent following rail traffic entry into occupied blocks
The Rail Vehicle detection system is used on
single lines (for bidirectional movements), double lines (for bidirectional or unidirectional movements)
Entry to and exit from sections is authorised by
controlled signals
Controlled signals are operated by
signalling equipment controlled by Network Control Officers or Axle counters/track circuits
Automatic signals are operated by
continuous track-circuiting
If the Rail Vehicle Detection system of Safeworking fails,
A method of special working may be introduced
Interlocking of axle counters, track circuits, points and protecting signals prevents a running signal from displaying a proceed indication unless
the block beyond the signal is not occupied, there are no conflicting routes set, the points are correctly set
Authority to enter a block and proceed through a block is given by
clearance of the signal that controls the entry
With Proceed authorities, drivers must
Obey signals, pass signals at STOP only in accordance with Rule NSG 608, ANSG 608 or CNSG 608 “Passing signals at STOP” depending on the relevant track owners specific equipment
Clearing of the relevant signal gives
a proceed authority
Qualified Workers must switch a signal box or local control panel in or out of operation only with
the authority of the Train Controller, the agreement of the Network Controll officers responsible for controlled signals that will be affected, the agreement of the Protection Officer, if a work on track authority has been issued for the affected portion of the line
A signal box/local control panel must not be switched in while
rail traffic is closely approaching the location as this could return the signals to STOP
A signal box/local control panel must not be switched in or out for
management of rail traffic if rail traffic is travelling under manual block working conditions on the affected portion of line
Manual block working
manually prevents rail traffic entries into occupied blocks
Manual block working must be used if
it is specified in other Network Rules, a train has been advertised as a block train, rail traffic does not reliably operate track-circuits, the Network Control Officer needs to block work rail traffic, the signalling system is not/might not be operating correctly
Signals passed at stop during basic block working must
be passed in accordance with NSG 608 passing signals at STOP
Signal
A trackside piece of infrastructure that provides the Train Crew a visual indication of the status of the track ahead of the intended movement
What are signals used for
used to facilitate the safe and efficient movement of trains.
The design of the signalling system provides
safe separation between trains provided the system is working within its designed parameters
At some signalled locations, starting or home/starting signals governing entry to Train Order or Token territories may display
a pulsating white light
Trackside signals are used to
authorise through movements from one signal to the next
Trackside signals may be passed only in accordance with
Network Owner Rule 606 (Responding to signals and signs), Network Owner rule 608 (Passing signals at stop)
In the New South Wales rail network, running signals provide information about
the route for which a signal is cleared
In colour light signalled territory, a cleared signal indicates the condition of the route or block immediately beyond the signal by
the combination of lights displayed, a route indicator, a lower turnout unit
Lower quadrant semaphor running signals have
large arms to control main line movements or medium arms to control diverging movements
Types of Controlled/Absolute signals
Outer home or accept, Home, Starting, Home/starting, Distance
Types of Automatic or Permissive signals
Automatic, distant
Outer home or Accept signal
A controlled signal used to control entry to the block ahead, but not otherwise protect points or other identified risks
Home Signal
Used to protect points and other identified risks (some home signals are kept permanently at stop)
Starting signal
Used to authorise departure from a controlled area
Home/Starting signal
Functions as home and starting signal
Distant Signal (Controlled)
May show clear or caution and cannot be used to protect the portion of line to the next signal, however there are in some instances where controlled distant signals can show stop and can be used to protect the portion of line to the next signal
Automatic (permissive) Signal
Protects the block ahead. Displays a PROCEED indication only if the block ahead is unoccupied
Distant signal (automatic)
May show clear or caution and cannot be used to protect the portion of line to the next signal, however there are in some instances where controlled distant signals can show stop and can be used to protect the portion of line to the next signal
Controlled signals are operated by
signalling equipment controlled by Network Control Officers or a combination of track circuits, or axle counters and signalling equipment controlled by network control officers
Controlled signals can display a PROCEED indication only if
points in the route are in the correct position, there are no conflicting routes set, In Rail Vehicle Detection territory the block ahead is unoccupied
Controlled signals at attended locations are
absolute signals
Absolute signals that are Controlled signals at attended locations
Double light colour light, single light colour light, Lower quadrant semaphore signal
Double light colour light signal
Pair of Vertical lights
double light and single colour light signals become automatic when
An A sign or illuminated A light is on or near the signal
Single light colour light signal
marker light vertically below main signal nights
Automatic signals become absolute signals if they
are so designated by an instruction sign, are interlocked with trackside monitoring equipment that sets them at STOP or can be switched between automatic and controlled operation
Double light colour light signals with staggered light cases are
automatic signals, distant signals
Double light colour light signals with vertical in line light cases are
controlled signals or Automatic signals if an A is fitted or an A light is lit
Single light colour light signals with a staggered marker light are
automatic signals or distant signals (single)
Auomatic single light colour lights have a red marker light. The marker light is lit if
the signal is at stop or the main light fails
Single colour light distant signals that cannot indicate STOP have
a yellow marker light that is lit if the main light fails
Some distant signals indicate stop if
the line between the distant signal and the next signal is occupied or the distant signal fails
Distant signals that can indicate STOP have a red marker light that is lit if
the signal is at STOP or the main light fails
Distant signals may have a signal identification sign with
the same signal identification as the signal ahead. The identification sign includes the word DISTANT
Single colour light signals with an in line red marker light are
controlled signals or automatic signals if an A sign or an A light is lit (single)
The marker light on a single colour light signal is lit if
the signal is at stop or the main light fails
A proceed indication for a turnout route is displayed by
a diagonal row of yellow lights on the turnout unit. The row of lights is angled up towards the turnout route
Co-acting signals
may be used to provide information about the running signal indication if a running signal may be obscured from a driver’s view
Co-acting signals may have
a plate showing CO-ACTING, INDICATOR, or an abbreviation; a signal identification sign with the same details as those on the primary signal
An intermediate signal, known as a repeater signal, may
be provided at some locations to give a driver better information about the indication of the next signal
Shunting Signals
Controlled signals operated by Network Control Officers or other Qualified Workers, Used to authorise shunting movements
Shunting signals must only be passed in accordance with
rule NSG 606 responding to signals and signs. Only within the next section, must not be a through movement
If a colour light shunting signal controls movements over more than one route
a route indicator is usually provided
Subsidiary Signals
a small colour light or small semaphore signal placed below running lights. If it displays proceed, the running signal displays stop
General purpose shunting signals are placed
beside running lines, within shunting yards
Calling on signals
Shunting/subsidiary signals attached to home signals, authorise a movement past the running signal, indicate that the points in the route are locked, but do not indicate that the line ahead is clear
Intermediate shunting signals
shunting signals that are placed between two running signals, facing in the same direction as the running signals. May be used to authorise a shunting movement
When the first running signals displays a PROCEED indication, the intermediate shunting signal
displays PROCEED for the running movement
Shunt repeater sign
designates a shunt repeater signal
Shunt repeater signals
are placed as subsidiary signals below controlled running signals, show that the shunting signal below the next running signal displays a PROCEED indication
For calling on, the signals will display
A steady small yellow light
Shunt ahead signals
fitted as subsidiary signals to starting signals or home/starting signals, authorise a shunting movement past that signal, but must not be used as authority to proceed through a section
For shunt ahead, the signals will display
A small flashing yellow light
Dead end signals
fitted as subsidiary signal to home or home/starting signals only, are on brackets placed on the same side as the route for the authorised movement (usually a dead end siding), authorise a shunting movement from the running line to a dead end siding, may be used for movement from a running line to a yard or loop
Describe Running signal indications
The legal PROCEED and STOP indications shown by colour light and semaphore signals in the Rail Network showing from Least restrictive (Highest/Top) aspect to most restrictive (lowest/bottom?) aspect
Describe a clear PROCEED, next signal displays a PROCEED indication
Single: Green
Double: Green/Green
Lower Quadrant: Angled down, Green
Preliminary Medium indication
a Green light over a pulsating yellow light, indicating that the signal ahead is displaying medium
Purpose of a preliminary medium indication
to assist drivers in identifying the turnout signal when multiple warnings are provided in areas of high speeds and/or close signal spacing
Indication for Double: Green/Pulsating yellow
PROCEED, next signal displays at least MEDIUM indiciation
Indication for Single: pulsating yellow
Medium PROCEED, next signal displays at least a CAUTION or CAUTION TURNOUT indication (PY)
Indications for Double: Green/Steady yellow
Medium PROCEED, next signal displays at lead a CAUTION or CAUTION TURNOUT indication (G/SY)
Indications for Single: Red/ Triple Pulsating yellow at angle
Medium turnout PROCEED on turnout route, next signal displays at least a CAUTION or CAUTION TURNOUT indication (R/TPY)
Indications for Double: Yellow/Yellow
Medium turnout PROCEED on turnout route, next signal displays at least a CAUTION or CAUTION TURNOUT indication (Y/Y)
Indications for Single: Steady yellow
Caution PROCEED, next signal may be at STOP (Y)
Indications for Double: Green/Red
Caution PROCEED, Next signal may be at stop (G/R)
Indications for Single: Red/ Triple steady yellow at angle
Caution turnout PROCEED on turnout route. Next signal may be at STOP (R/)
Indications for Double: Yellow/Red
Caution turnout PROCEED on turnout route. Next Signal may be at stop (Y/R)
Indications for Single Lower Quadrant: Red over white/green
Caution turnout PROCEED on turnout route. Next signal may be at STOP (LQ)
Indications for Single: RED, red green
Low Speed PROCEED ready to stop at next signal (Rrg)
Indications for Double: RED/RED, green
Low speed PROCEED ready to stop at the next signal (Double)
Indications for Single: RED, red, Close up green
Close up PROCEED ready to stop at the next signal (line ahead may be occupied) (Single)
Indications for Double: RED/RED, close up green
Close up PROCEED ready to stop at the next signal (line ahead may be occupied) (Double)
Single colour Indication for Stop
RED, red
Double colour indication for STOP
RED/RED
Single lower quadrant indication for stop
Horizontal RED
Describe the starting or home/starting signals that govern the entry to Train Order or Token Territories
Display a pulsating WHITE aspect in lieu of a GREEN aspect and traffic is authorised to depart the signalled location only if the crew is in possession of the correct authority for the section
Colour light repeater signals
take the same form as colour light running of shunting signals. Might show a less restrictive indication than the repeated signal
Indication of Vertical/staggered “" white lights on a repeater signal
PROCEED. Next signal shows PROCEED
Indication of Horizontal white lights on a repeater signal
PROCEED, next signal shows STOP
Restricted speed
a speed that allows rail traffic to stop short of an obstruction within the distance of clear line that is visible ahead
Controlled Speed
a speed that allows rail traffic to stop short of an obstruction within half the distance of clear line that is visible ahead
In single and double colour light signalled territory, multi lamp route indicators on running signals, in most cases, the
turnout route
If the signal displays a PROCEED indication, the route indicator shows
Letters usually related to the name of a line. And numbers, usually referring to the number of a station platform or a designation of track within a yard
Route indicators on shunting signals or co-acting signals may show
a running line turnout route or a shunting route
Turnout repeaters
placed at safe braking distance from points to give advance warning that a turnout route is set
If the running signal below the turnout repeater displays STOP, CAUTION or LOW SPEED, a turnout repeater does not illuminate because
the repeater indication will not be applicable for the following signal
Mail line indicators
show the condition of points and level crossing. Are identified by a black letter on a white reflective diamond attached to the indicator post. DO NOT that the line is clear or give authority to be in the section in Train Order/Token Territory
If main line indicators are able to display a STOP indication, they may be passed at STOP only in accordance with
Rule NSG 610, ANSG610, CNSG 610 passing indicators at stop
indication of a pulsating white light on a main line indicator
Points are set for the main line, and warning equipment at a level crossing is in working order
indication of a steady yellow light on a main line indicator
The next main line indicator may be at STOP
indication of a steady red light on a main line indicator
STOP. Points may not be set for the main line, or warning equipment at a level crossing may not be operating to warn road traffic
indication of a steady red light with angled white lights on a main line indicator
Points are set for the turnout
Main line indicator repeaters are identified as
‘REPTR’ under the same black letter as the main line indicator being repreated
Indication of a pulsating white light on a main line indicator repeater
the main line indicator being repeated is not at STOP
Indication of a steady yellow light on a main line indicator repeater
The main line indicator being repeated may be at STOP
Point indicators
used to indicate the position of points
Catch point indicators
show the position of catch points
Point indicators and catch point indicators may be
colour light or mechanical
Indication of a colour light point indicator set at Red
the points are not set
Indication of a colour light point indicator set at white arrow
the points are set and locked for the route indicated by the direction of the arrow
Mechanical point indicators (arrow type) with an illuminated white arrow indicate
the route is set, but does not indicate whether points are locked
If the mechanical point indicator (bar type) shows a Horizontal (STOP) white bar, it indicates
the points are unlocked, or are not set in normal position. The crew must stop and check the position of the points
If the mechanical point indicator (bar type) shows an angled (45 degree) white bar, it indicates
The points are set and locked in NORMAL position.
If the U indicator is lit
the controlling signal box is unattended and points beyond the home/starting signal are locked in NORMAL position
If the starting or home/starting signal directly protects a Type F level crossing, illumination of the U indicator shows
that the warning equipment is in working order
Illuminated white/orange warning lights are provided at
locations where workers on track have a restricted view of approaching rail traffic. If rail traffic approaches, the lights go out
Illuminated white crossing lights, sometimes combined with audible warning devices as additional alarms are
provided at pedestrian crossings restricted to used by rain workers. If rail traffic approaches, the lights go out and alarms are activated in time for workers to go to, or remain in a safe place
Dead end lights
small red lights to indicate the end of dead end sidings. The lights display STOP indications only.
If it is possible for a dead end light to be mistaken as a running signal at STOP, a
white light above the red light is used to distinguish it from a running signal
Guards indicators
Indicators placed over the platform if it is possible for the signal at the exit end of a platform to be obscured from a guard’s view
A guard’s indicator will show a lunar white or blue light if
the exit end signal displays a PROCEED indication
Yard Limit signs
define the limits of yards, define the end of a section and in train order territory define the yard limits of a train order location
Drivers must respond to YARD LIMIT signs in accordance with
rule NSG 606 responding to signals and signs and Rule NTR 418 Yard Limits
A location may be a
Signal, STOP sign, Main line indicator, YARD LIMIT sign
Location signs are used to indicate
approach to a location. In signalled territory they give additional warning of approach to a signal
Location signs are placed
no more than 3000m before the location and at a safe braking distance from the location
Train crew must respond to Landmark and Location signs in accordance with
Rule NSG 606, ANSG 606, CNSG 606 Responding to signals and signs
Describe a landmark sign
Triangular Reflective yellow sign with the middle cut out
Describe a location sign
Triangular Reflective yellow sign, usually with the location listed beneath
Shunting Limit signs
indicate the limit to which a shunting movement may be made on a running line, have white text on a red reflective or illuminated background
STOP signs
may be passed only if authorised, have white text on a red reflective background
Clearance posted
usually located between two converging lines to show the clearance limit
Some clearance posts have
a reflective background or a white light that must be illuminated at night or in conditions of low visibility
Catch point signs
indicate that there are catch points ahead, have white text on a red reflective background, are provided where catch points are not protected by a fixed signal or indicator
Derail signs
indicate that there is a derail device ahead, have white text on a red reflective background
Derail signs are provided if
movements can be made towards derail devices, the devices are not protected by a fixed signal or an indicator
Train crew controlling shunting must remove derail devices before
authorising shunting movements beyond a derail sign
Narrow track warning signs are placed in locations where there is restricted clearance between
vehicles on adjacent lines, the track and other infrastructure or buildings
Workings performing shunting at locations with narrow track clearances must
not stand between a moving vehicle and a vehicle standing on an adjacent track
Worksite warning signs
Placed on the departure end of a platform to indicate than an inner HandNetwork Control Officer is located ahead
Describe worksite warning sign placement in the ARTC and CRN network
must be placed at the departure end of the last platform on approach, in a position where it can be clearly seen by the driver of the approaching train to maintain awareness of a inner HandNetwork Control officer ahead
Describe worksite warning sign placement in the Railcorp network
Located beyond the departure end of a platform to allow the driver to see the sign while stopped at the platform.
Distant warning signs
Black and white diagonally striped sign, used during pilot staff working if there is no signal within 2000m of a STOP sign being used to protect points or a crossover
Prohibitive signs
if a signal carries a prohibitive sign, Train crew must follow the directions on the sign
Slip site signs
signals are interlocked with slip detectors to respond to landslips
Describe how slip detectors work
Track circuitry is connected to the rail line to monitor track movement. Any movement of the track geometry will result in activation of an electronic sensor to put signals into the STOP position and alert the Network Controller of possible track defects
Tonnage sign
might be fitted on or near a signal placed before a rising grade so the train is not stopped at a signal on a portion of track that is particularly steep
Purpose of a tonnage signal
ensures that the signal where the rising grade of concern exists will at least show a caution and therefore a train should not have to stop at that signal where starting the train may be a challenge due to the trailing tonnage
For prescribed trains, tonnage signals are
absolute
In regards to tonnage signs, if the T indicator is lit
drivers of prescribed trains may ignore the instructions on the TONNAGE sign
Starting or home/starting signs
some starting or home/starting signals in bidirectional train detection territory have prohibitive signs fitted to them
Distant signal/repeater signal signs
distant signals and colour light repeater signals than can display STOP have signs with black text on a white reflective background
Intermediate sidings signs
signals that protect intermediate sidings must be passed only in accordance with the instructions on the sign
Absolute signal signs
signals fitted with an absolute signal sign must not be passed at STOP without the Network Control Officer’s authority
Token Territory signs
show that a token, such as a Train Staff or Electric Staff is necessary to occupy the section ahead
Train Order working signs
show the beginning and end of the territory where a Train Order is required. These signs are placed at the interface to the RVD boundary
End signalled authority signs
show that there is a set of manual lever operated non-interlocked points to enter a siding, loop or yard. Must not pass without the correct authority for the area
End signalled authority signs have
white text on a red background in the upper half and white text on a black background in the lower half
Block joint signs
show the locations of insulating block joints between separate track circuits of track circuited line, have white text on a red reflective background. Rail traffic may be required to stand clear
Single light signal signs
show a change of signal type in used. May be from or to double light, train order or token territory
Signal Identification signs
are fixed to running signals and some shunting signals and have letters and/or numbers that uniquely identify the signal
Odd numbers on signal identification signs indicate
down direction signal
Even numbers on signal identification signs indicate
Up direction signal
Signal designation signs
provided for some signals and are fitted either to the signal post or to a wall near the signal
Accept signal signs
Signs fitted to some accept signals showing the name of the controlling location or the word ACCEPT
