Three Positions - Two Positions Signals Flashcards
Three Positions Signals - Name the type?
Light
Three Positions Signals - Name the Class?
Home, Automatic and Dwarf
Three Positions Signals - How Many colour combinations?
Home: 7 (includes the Low Speed Caution)
Automatic: 6
Dwarf: 3
How many lights can you show at a time on Dwarf Signal?
Only 1
What are the colours displayed on Dwarf Signals?
Red, Yellow, Green and Purple
What are the colours displayed on Home and Automatic Signals?
Red, Yellow and Green
How many aspects does a Dwarf three position Signal have?
3
What are the aspects for Dwarf Signals and their respective colour(s)?
3 Position
Red or Purple - STOP aspect
Green - CLEAR LOW SPEED
Yellow - LOW SPEED CAUTION
2 Position Red or purple - STOP aspect Green - Proceed Siding dwarf illuminated - Proceed Siding dwarf extinguished - Normal
What are the 4 questions you need to ask to describe the aspect of a signal?
PTSN
P = Points - Are they set or not?
T = Track Ahead - Is the track clear or occupied?
S = Speed - What is the track speed?
N - Next Signal? What does it tell me about the next signal (either stop or proceed aspect)?
What are the advantages of having Track circuits and Automatic signals in a block section of the track?
- Allows more trains
- Allows more track sections to be included within a block section protected by Home Signals
How are Home Signals controlled?
By Signallers
How are Automatic Signals controlled?
By the passage of trains.
Describe a Clear Normal Speed signal and explain what it means
Green light above Red light.
- Points, if any, are set
- Track ahead is clear up to the next fixed signal
- Speed is track speed
- Next signal will display a proceed aspect
Describe a Normal Speed Warning signal and explain what it means
Yellow light above Red light.
- Points, if any, are set
- Track ahead is clear up to the next fixed signal
- Speed is track speed BUT you need to reduce speed in preparation for:
- Next signal will display STOP
Describe a STOP Signal and explain what it means
Two red lights above each other.
- Points may or may not be set
- Track ahead may or may not be occupied
- Speed is STOP - DO NOT PROCEED
- Next signal: Driver doesn’t know
Describe a Reduce to Medium Speed signal and explain what it means
Yellow light above a green light.
- Points are set
- Track ahead is clear up to the next fixed signal
- Speed is track speed for this section BUT you must be at 40km/h by the time you reach the next fixed signal
- Next signal will most likely be a Clear Medium Speed or Medium Speed Warning (40km/h for this section)
Describe a Clear Medium Speed signal and explain what it means
Red light above a green light.
- Points are set
- Track ahead is clear up to the next fixed signal
- Speed is Medium speed (40km/h) for the entire length of this section up to next fixed signal
- Next signal will display a PROCEED aspect
Describe a Medium Speed Warning signal and explain what it means
Red light above a yellow light.
- Points are set
- Track ahead is clear
- Speed is Medium speed (40km/h) for the entire length of this section up to next fixed signal BUT you must reduce speed and prepare for:
- Next signal will display STOP
Can you have a Low Speed Caution Signal aspect on an automatic signal?
No. Only on Home Signal (yellow below two red lights) and Dwarf (Yellow light)
Describe a Low Speed Caution signal on a home signal and explain what it means
A yellow light below 2 red lights. Only found on Home Signals. - Points are set - Track ahead may or may not be occupied - Speed is MAX 15km/h - Be prepared to stop - Next signal: Driver doesn't know
Is it possible to have a green light above a yellow light on a home or automatic signal?
No (unless we haven’t learned that one yet!)
Only yellow above green = Reduce to Medium Speed aspect
What are Low Speed Caution aspects used for?
Running line to siding
Running line to running line: mostly used for the purpose of forming a 6 car train with two 3 car trains.
When can a Low Speed Caution aspect NEVER BE USED?
It can never be used for train movement into a bi-directional section of the track
What train movements do Dwarf Signals control?
R-R: Running line to running line
R-S: Running line to siding
S-R: Siding to running line
S-S: Siding to siding
What do Home signal protect - Where are they fixed?
SSSLJ S: Stations S: Sidings S: Signal boxes L: Level Crossings J: Junctions
Can you pass a Home Signal at STOP?
Complicated question, the standard Metro Academy answer is “NO, Except..”
I refer you to exceptions to pass abs/atc cards 😎