1. Signals (Two and Three Position Signals) Flashcards
The two basic aspects that two-position Home, Dwarf and Disc signals will display?
- Stop
- Proceed
What aspects can Siding Dwarf and Calling On signals display?
- Normal
- Proceed
What are the two types of Two Position Signals?
- Light Type
- Disc Type
What are different classes of Two Position Signals? (5)
- Disc
- Dwarf
- Distant
- Home
- Calling On
In regards to a Two Position Signal, what does the ‘Type’ describe?
The physical construction of the signal
Two Position Home Signals are fixed at and protect:
- Stations
- Signal Boxes
- Sidings
- Level Crossings
- Junctions
All Two Position Home Signals are what ‘type’ of signal?
Light type
What colours can a Two Position Home Signal display and what do they mean?
- Green = proceed
- Red, purple and blue = stop
What can a position at Stop also be referred to?
Position at Danger
If a Two Position Home Signal is at Stop, what four pieces of information can be extrapolated?
- The laying of points is unknown
- The track ahead may be occupied
- The driver may not proceed past the signal unless authorised
- The driver won’t know the aspect of the next signal
What information is being conveyed if a Two Position Home Signal is at ‘Proceed’? (4)
- The points, if any, are set for the next move
- The track ahead is clear to the next fixed signal
- Proceed at track speed as required
- Signal aspect ahead is unknown and driver must be prepared to stop if required
Does a Two Positron Home Signal indicate what the next signal aspect will be?
No
Are Distant Signals considered Two Position or Three Position signals?
Two Position signals
Where are Calling On Signals located
On the Up line from Stoney Point to Frankston
What is the point of a Calling On Signal?
It allows a train to enter an occupied section of track, where normal signals would inhibit the manoeuvre
True or false: A single Calling On signal can apply to multiple tracks.
False – a Calling On signal will only apply to the same track as the Home Signal above it
What does a Calling On Signal at Normal indicate?
You cannot proceed
What does a Calling On Signal at Proceed indicate?
You can proceed cautiously past the signal being able to stop short of any obstruction
What to do if both Home and Calling On signals are displaying Proceed at the same time?
It must be treated as irregular – treat both signals at their safest aspect (i.e. stop)
Describe a Disc Signal
A red, circular target that can be turned to the side
Where are Disc Signals used to control movements? (4)
- Running line to running line
- Running line to siding
- Siding to siging
- Siding to running line
Where can a Disc Signal be placed? (3)
- On the ground
- On a post with other discs
- On a post with other classes of signal
Can a two-position signal be on a post with other classes of signals?
Yes
What two aspects may a Disc Signal display?
- Stop
- Proceed
What is being communicated if a Disc Signal is at the Stop (or Danger) position? (4)
- Points may not be set for next move
- Track ahead may be occupied
- Driver must not proceed unless authorised
- Driver will not know upcoming aspects, if applicable.
What is being communicated if a Disc Signal is at the Proceed position? (4)
- Points are set for the move
- Track may be occupied
- Proceed at “reduced speed cautiously” being prepared to stop short of any obstruction
- The next signal aspect is unknown, driver must be prepared to stop
What must we be cautious of when passing a Disc Signal at proceed?
The line we are entering may be occupied or obstructed
What is the defined speed for a Disc Signal at proceed?
There is none, though sidings are a maximum of 15km/h
Two Position Dwarf Signals control train movements from: (4)
- Running line to running line
- Running line to siding
- Siding to siding
- Siding to running line
What colour indicated STOP on a Dwarf Signal?
Red, Blue or Purple
What two aspects can a Siding Dwarf indicate, and how are they indicated?
- Normal (do not proceed) – light is extinguished
- Proceed – light is yellow
What colours can a Two-Position Dwarf signal display?
Red, Blue, Purple, Green and Yellow
What is being communicated if a Light-Type Dwarf is at Stop (Danger)? (4)
- Points for next move may not be set
- Track ahead may be occupied
- Driver must not proceed unless authorised
- Driver will not know aspect of next signal
What is being communicated if a 2-position Light-Type Dwarf Signal is at Proceed? (4)
- Points are set for next move
- Track ahead may be occupied
- Proceed at “reduced speed cautiously”, being prepared to stop short of any obstruction
- The signal aspect in advance is unknown and the driver must be prepared to stop if necessary
What is indicated if there are four Two-Position Dwarf Signals on the same post?
That four routes are available from that post
Is there a defined speed for proceeding past a Two Position Dwarf Signal?
No, though driver must operate train in manner that will allow them to stop short of obstructions
How is a Two-Position Dwarf Signal identified when it is placed on the same post as a Home Signal?
With a sign clearly indicating the word SIDING beneath the dwarf
When a Two-Position Dwarf is placed on the same post as a Home Signal, what two aspects can the Dwarf signal show?
- Normal (do not proceed) – extiguished
- Proceed – yellow
What movement are Two-Position Dwarfs used for when placed on the same post as a Home Signal?
It can only be used for moves into a siding – never for the same movement as the Home Signal
Can both a Home Signal and the Siding Dwarf both display “Proceed” simultaneously?
No – it must be treated as irregular and driver must treat both signals at their safest aspect (i.e. stop the train)