Signals Flashcards
What are the types of two-position signals? (2)
- light
- disc
What are the classes of two-position signals? (5)
- disc
- dwarf
- distant
- calling on
- home
What do two-position home signals protect? (5)
Stations
Signal boxes
Sidings
Level crossings
Junctions
Two-position signal:
What does a home signal at the stop position indicate? (4)
Points – unknown
Track ahead – may or may not be occupied
Speed – stopped
Next signal – unknown
Two-position signal:
What does a home signal at the proceed position indicate? (4)
Points – set
Track ahead – clear
Speed – track speed or what is required
Next signal – unknown
Two position signal:
If the calling on signal is at normal, what does the light look like?
It is extinguished.
How many tracks does a calling on signal apply to?
Only ONE
What train movements do disc signals control? (4)
Running line to running line
Running line to siding
Siding to siding
Siding to running line
Can a two-position signal be placed on the same post as other classes of signal?
Yes – particularly disc signals.
What does a disc signal (or a two-position dwarf) at STOP indicate? (4)
Points – may not be set
Track ahead – may be occupied
Speed – stopped
Next signal – unknown
What does a disc signal (or a two-position dwarf) at PROCEED indicate? (4)
Points – are set
Track ahead – may be occupied
Speed – ‘precautionary speed being able to stop short of any obstruction’
Next signal – unknown
What train movements to two-position dwarf signals control? (4)
Running line to running line
Running line to siding
Siding to siding
Siding to running line
What two aspects does a dwarf signal on the same post as a home signal (ie a siding dwarf) display?
Normal (extinguished) and proceed (yellow light)
How are multiple two-position signals on the one post read?
Left to right, then top to bottom
1 3
2 4
What are the types of three-position signals?
Only one – light
What are the classes of three-position signals, and how are they differentiated? (3)
Home (placed vertically)
Automatic (staggered)
Dwarf (one light at a time)
What do three-position home signals protect? (5)
Stations
Signal boxes
Sidings
Level crossings
Junctions
What are the controlled three-position signals?
Home and dwarf (controlled by signaller)
What is the uncontrolled three-position signal?
Automatic (controlled by passage of trains)
Do uncontrolled home signals exist?
Yes – particularly in the MURL. To do with the authority needed to pass at stop.
What is the primary purpose of automatic signals?
To expedite the passage of trains
Which train movements does a three-position dwarf signal control? (4)
Running line to running line
Running line to siding
Siding to siding
Siding to running line
Which classes of signal are ‘absolute’, and what does this mean?
Home, dwarf, and disc signals are absolute (normally controlled signals)
This means a driver cannot authorise themselves to pass these signals at stop
Which class of signals are ‘permissive’, and what does this mean?
Automatic (ie uncontrolled)
Means a driver, following Rule 1 s 3, may authorise themselves to pass these signals at stop
What are marker lights and why are they used?
Permanent red lights on a three-position signal. They are used when the signals are ONLY going to indicate either normal or medium speed, so are fitted in either the A or B position rather than a light that changes.
What does a Clear Normal Speed signal indicate? (4)
Points – are set
Track ahead – is clear
Speed – track speed
Next signal – at proceed
What does a Normal Speed Warning signal indicate? (4)
Points – are set
Track ahead – is clear
Speed – track speed (whilst able to stop at next signal)
Next signal – at STOP
What does a Reduce to Medium Speed signal indicate? (5)
Points – are set
Track ahead – is clear
Speed – normal track speed
BUT – speed must be 40km/h before the next fixed signal
Next signal – at proceed
What does a Clear Medium Speed signal indicate? (4)
Points – are set
Track ahead – is clear
Speed – 40km/h
Next signal – at proceed
What does a Medium Speed Warning signal indicate? (4)
Points – are set
Track ahead – is clear
Speed – 40km/h (while being able to stop at next fixed signal)
Next signal – at STOP
What does a Stop signal indicate? (4)
Points – may not be set
Track ahead – may be occupied
Speed – STOPPED (reverser set to OFF in Comeng, off/neutral in a Siemens or X’Trap)
Next signal – unknown
What does a Low Speed Caution signal indicate?
Points – are set
Track ahead – may be occupied
Speed – maximum 15km/h
Next signal – unknown
What is the ‘normal’ position of a low speed caution signal?
When the yellow light is extinguished – obey the aspect on the home signal.
What train movements does a low speed caution aspect control? (4)
Running line to running line
Running line to siding
Siding to siding
Siding to running line
Can a low speed caution signal be used for train movements into a bi-directional portion of track?
No.
What does an illuminated 65 or 80 on a three position signal indicate?
The presence of high speed points.
What does an illuminated 65 or 80 on a three position signal change?
The maximum speed for a Clear Medium Speed aspect – whatever is indicated by the illuminated lights.
(NOTE: when lights aren’t illuminated, Medium speed reverts back to 40km/h)
What does a Clear Medium Speed signal with an illuminated 65 indicate?
Points – are set
Track ahead – clear
Speed – 65km/h
Next signal – at proceed
What does an illuminated letter ‘A’ on a three-position home signal indicate? (3)
That the signaller has ‘switched out’
The signal in question is functioning as an automatic signal.
The points are set for the main line.
What is another word for a signal box being ‘switched out’?
‘Fleeting’ mode
What indicator is there that a signal box has ‘switched out’?
A ‘Signal Box Closed’ sign displayed in a visible location
When a signal box is ‘switched out’, is it considered attended or unattended?
Unattended
What aspects can be displayed by a three-position dwarf? (3)
Stop
Low Speed Caution
Clear Low Speed
What does a Stop aspect from a three-position dwarf signal indicate? (4)
Points – may not be set
Track ahead – may be occupied
Speed – STOPPED
Next signal – unknown
What does a Low Speed Caution aspect from a three-position dwarf signal indicate? (4)
Points – are set
Track ahead – may be occupied
Speed – maximum 15km/h
Next signal – unknown
What does a Clear Low Speed aspect from a three-position dwarf signal indicate? (4)
Points – are set
Track ahead – clear
Speed – maximum 15km/h
Next signal – at proceed
What is the purpose of a banner indicator?
To indicate aspect of signal when the signal itself is blocked from view.
Is a banner indicator a signal?
No.
What should you do if a banner indicator is defective (ie one or both lights failing to display an indication)?
Report to appropriate Controller.
Proceed as if next fixed signal is at STOP
What does a round white light on a banner indicator signify?
That the next signal has a marker light in that position.
What aspects can a banner indicator show?
Red – horizontal line
Yellow – diagonal line
Green – vertical line
Where are repeating signals, and what is their purpose?
Around Frankston.
Used to signify the change from two-position signal use to three-position signals.
What is a block section of track?
The portion of track from signal box to signal box.
What is a track section of track?
Smaller portions of track within block sections, demarcated by automatic signals.
What are the three aspects displayed on a repeating signal?
Warning (next signal at stop)
Proceed (next signal at Normal Speed)
Reduce to Medium (same meaning as other three-position signals)
