Signalling Flashcards
What is the principle of Absolute Block signalling?
One train, One section, One time
What does it mean for a signal to be showing as “off”?
Showing permission to proceed
How do you identify a distant semaphore
Yellow with a fishtail and black chevron
How do you identify a Stop semaphore
Red with a white stripe
What does a raised semaphore mean?
Proceed/off
What does the home signal signify
The beginning of station limits
What does a Section semaphore signify?
The beginning of a block section
What is the area between a distant and home signal known as?
Service Braking Distance
You see a black and white semaphore; what does that mean?
Its the back of a semaphore, coloured different so as to not confuse
How long is the Clearing Point?
Around 400 metres
What does a white diamond shaped sign on a signal post mean?
The area is track circuited
What does a white diamond shaped sign with a T on a signal post mean?
The area is track circuited and there is a telephone here
What does IBH stand for and what is it?
Intermediate Block Home signal
Its an extra stop signal provided on long stretches of track
What sign signifies an IBH signal?
White rectangle with a vertical black line doen middle
Theres a light signal with a black sign with a white triangle in it in an Absolute Block area; what does it mean?
Its an intermediate block distance signal
Who controls the IBH signal?
The signaller at the rear
Where would you find a fixed distant signal?
At a location such as dead ends or loops where the next signal will always show ‘caution’
How do you identify a subsidiary signal?
Its a smaller semaphore or light signal located below a full size signal
A subsidiary signal is raised and showing a C; what does this mean?
“Calling On”
Train can proceed at caution as the line ahead is likely occupied, such as a station platform where more than one train is allowed in the section
A subsidiary semaphore is raised and showing an ‘S’ what does this mean?
Shunt
Proceed at caution and carry out your shunt manoeuvre, only going as far as necessary
How to read Stepped Semaphore signals
Highest signal refers to the main route
Lower signals relate to the routes to the left or right of the main route
How to read Stacked semaphore signals
Highest signal refers to the route furthest left
Lower signals relate to progressive routes to the right
What is the principle of Track circuit Block (TCB) signalling?
One train - One Signal Section - One at a time
What is the area between signals called in TCB?
Signal Block
What is used to separate each signal block?
Insulating Block Joints
What is the sequence for a 4 aspect signal?
Green proceed
Double yellow preliminary caution
Single yellow caution
Red Danger/Stop
What do the Yellow lights mean
Double yellow Prelimary caution: expect to find the next signal as single yellow/caution
Single yellow Caution: expect to find the next signal as red/danger
What does a green signal mean?
Proceed: expect to find the next signal at green too
What is the 3 aspect sequence
Green Proceed
Single yellow Caution
Red Danger/Stop
How do 2 aspect signals work
The signal can only show red or green
Each stop signal will have its own distant signal which will show yellow or green.
Train has to pass through the Signal Section in order for earlier lights to change
What sign does an automatic signal have?
White rectangle with black horizontal stripe through middle
Signal number may also be shown
What is an automatic signal?
A signal controlled by the passage of a train through its section using the track circuit only
How to identify a controlled signal?
Black plate with white writing showing signal number
What is a controlled signal?
A signal controlled by a signal box (manually operated)
How to identify a semi-automatic signal?
White rectangular plate with black horizontal stripe through the middle and semi above the stripe
May also show signal number
What is a semi-automatic signal?
A signal that is usually controlled by the passge of a train via track circuit but can also be controlled by a signal box
How to identify a distant signal ID plate
Black signal plate with white writing, has a white triangle and/or R
On a Position Light, what would a danger signal look like?
One red and one red light lit (horizontal)
Two red lights lit (horizontal)
What does a Proceed signal look like on a Position Light and what does it mean?
Two white lights lit at a diagonal (45°) angle
Means peoceed cautiously to next stop signal or buffer stop if no signal ahead.
Be prepared to stop at any obstruction.
When a main aspect light has an associated Position Light which is not lit, what must you do?
Obey whatever signal is shown on the main aspect light
What does it mean when a main aspect light is showing Red,but position light is lit with two diagonal white lights?
Premissive Working- proceed past the red signal cautiously but be prepared to stop at next signal or obstruction (like the C subsidary semaphore)
How to identify a Limit of Shunt sign (3)
Illuminated white square with red **LIMIT OF SHUNT
Illuminated white circle with red LIMIT OF SHUNT
Position light with no top light showing two horizontal red lights (permanently on)
How many junction indicators could a signal have associated with it?
6
How many lights must be illuminated on a junction signal?
At least 3 illuminated lights (should be five)
What does it mean if a main signal is at proceed but junction indicator is not illuminated?
Proceed on main route
What do flashing yellow lights signify on a main aspect?
2 flashing yellow: prepare to find the next signal at 1 flashing yellow
1 flashing yellow: prepare to find next signal at 1 solid yellow and junction indicator lit
What does 1 steady yellow light and lit junction indicator mean
Prepare to find next signal at danger after the junction
What is the sequence for a 4 aspect system ahead of a junction?
Proceed (green)
Flashing preliminary caution (double yellow)
Flashing caution (single yellow)
Steady caution (single yellow) with junction indicators
Danger/stop (red)
What is the sequence for a 3 aspect system with an upcoming junction?
Proceed
Flashing caution
Steady caution with junction indicator
Danger/stop
What does a Banner Repeater do?
Shows advanced warning of what an upcoming signal is showing (if its obstructed by a bend etc)
What does a Banner Repeater look like?
Lights showing:
White circle with horizontal black line (danger)
White circle with diagonal black line (proceed)
Green circle with horizontal black line (proceed on a 3 aspect banner repeater)
How to identify a banner repeater
ID plate will have a BR on it
3 aspect as above but with ‘burger’ symbol on it
What is a co-acting signal and how to identify?
Signal lights placed beside the main signal in a more visible location
Has CA on ID plate
What does a SPAD indicator look like?
Two flashing red lights, middle solid red light with STOP on it and blue outline
What must you do if you see an illumiated SPAD indicator
Stop
Press red buttom
Report to signaller
How would you recognise a signal that is not in use?
Lights: covered in a black bag with white X
Semaphore: has a white X attached
If a signal is showing more than one colour at once, what to do?
Assume it should be the most restrictive signal (danger/stop)
Report as malfunction
Whay are the examples of Signal Irregularities (4)
Signal reversion
Signal not displayed correctly
Signal missing/broken
Wrong route offered
What must we do if we notice a signal irregularity?
Stop the train/do not move the train
Inform the signaller
Driver completes their forms
When can you enter a single track section without a token or staff? (MAPES)
Modified working
Assisting a train
Pilot in operation
Engineering possession
Shunting
What does PILOT stand for and how to identify one?
Person In Lieu Of Token
Red armband with PILOT in white text
