Signals Flashcards
What is the main purpose of signalling
To ensure there is one one train in one section at any one time.
What are the two main types of signals
Colour light signals
Semaphore signals
What are the two main systems used to trigger colour light signalling
Track circuits
Axel counters
What does a single red light mean
Danger
Do not pass
What does a single green light mean
Proceed, Clear
What does a single yellow light mean
Caution,
Expect the next signal to be red (danger)
What does a pair of yellow lights mean
Preliminary caution
Expect the next signal to be caution
When dispatching a train, what does a single or double yellow light mean
Proceed
All aspects apart from red mean proceed, unless the red is fitted with an active position light
On ground position signals, which light formation indicates Proceed
Two white lights displayed at 45 degrees
When dispatching, what does a blank Off indicator mean
Stop
What does a Banner repeater look like and what are the 3 stages
White circle with black line through the middle.
Horizontal line is Stop
Line at 45 degrees is restrictive proceed (same as double or single yellow)
Line at 45 degrees with a green circle is Proceed
How do you recognise a co-acting signal
It is a lower level duplication of the main signal
The signal plate has the suffix letters CA
What stations would you see a RA indicator
London or Manchester
What are the RA indicators used for
Platform staff use them to convey the ready to start signal to the driver
This replaces the buzz buzz
In a colour light signal area, how do you identify a distant signal
A black signal plate with a white triangle on it
How do you identify a “not in use” signal
The signal will be covered and have a white cross displayed
How do you identify an automatic signal
It has a white plate with a black horizontal bar through the middle
How can you identify a semi automatic signal
It has a white plate with a horizontal black bar through the middle and the word SEMI above the bar
How are automatic signals operated
By the passage of trains, using either track circuits or axel counters
What does SPAD stand for
Signal Passed At Danger
What does a red horizontal semaphore signal mean
Stop
What does a distant semaphore signal look like
Yellow arm with black chevron (yellow light at night)
What is the part of the line called between the Home signal and the Section signal
Station Limits
(There’s not always a station within the station limits)
What is the part of the track called between the Section signal and the following Home signal (which includes the distance signal)
Block section
What does a red semaphore signal at 45 degrees mean
Proceed / off
What does a distant semaphore signal look like
Yellow board with a fish tail and black chevron
What does a semaphore shunt signal look like
White round disc with red bar across the middle
Horizontal for danger
45 degrees (with green light at night) for proceed at caution as far as the line is clear
Semaphore Route indicators are used at locations of diverging routes
Which signal relates to the main line
The highest signal
Signal 1 relates to the route on the far left and then successive routes to the right
Route indications by stacked shunting signals, which signal relates to which track
Signal 1 at the top of the stack relates to the route on the far left
As you work down it relates to successive routes to the right
(Top to bottom, Left to right)
What are the two main route indicators in colour light signalling
Junction indicators (feathers)
Route indicator box (theatre box)
What does a flashing yellow light mean
This is telling the driver that the route ahead has been set
When can you disregard the main aspect of a signal
Only if the main aspect is fitted with a Subsidiary / Position light or you are working under special rules
How can you identify a controlled signal
A black plate with the signal identification number on it
How do you identify a Distant colour light signal
A distant signal cannot show a stop aspect.
Can be identified by a white triangle or the letters R or RR on the identification plate
How do you identify an Intermediate block signal
White signal plate with vertical black line through.
What is the sequence of three aspect signalling
Green = proceed = top
Yellow = caution = middle
Red = stop = bottom
What is the sequence of four aspect signalling
Green = proceed = second from top
Double yellow = preliminary caution = top & second from bottom
Yellow = caution = second from bottom
Red = stop = bottom
What does the “end of emergency special working” sign look like
Yellow square with black EW on crossed diagonally with red line
What is the hand signal for Stop
Both hands straight up in the air,
Red flag during daylight
Red light during darkness or poor visibility
What is the order of signals in absolute block signalling
Distant
Home
Section
In absolute block signalling whats station limits
The part between the first home and the section signal controlled by the same signal box
How many stop signals can 1 signal box control
5
4 home and 1 section
If the distant signal is showing off, what position is the home and section signal in
Both the home and section signal must be off for the distant to be off
What’s the part called between the distant signal and the first home signal
Service breaking distance
Where is the AWS magnet in semaphore absolute block signalling
180 metres before the distant signal
What is CP in semaphore absolute block signalling
Clearance point,
The train has to pass 440 yards past the signal before the next signal can be pulled off
What is the 20/20 rule
Be slowing down to 20 mph at least 200m before the signal and be able to stop 20 m before the signal
What does the white diamond attached to a signal post mean
Track circuits fitted
Why might track circuits be fitted to a semaphore signal
Because it’s out of view of the signal box, so to let the signaller know when the train has arrived
What does the back of a semaphore stop and distant signal look like
Stop signal is white with black line
Distant signal is white with black chevron
In absolute block signalling, which signals can have AWS magnets
Only the distant signal
If you are unsure if a semaphore signal is off or on what should you do
Stop the train before the signal, secure the train and call the signaller
What part of absolute block is classed as the block section
From section signal, box A to the first home signal, box B
What does IBS stand for
Intermediate block section
How do you identify an IBS stop signal
The ID plate will be a white rectangle with a black line top to bottom
Which signal box controls any additional distant or stop signals in an IBS area
The signal box prior
What’s does IBS achieve
It splits up a long block section into smaller sections letting more trains travel through whilst keeping one train in one section at any one time
What does a subsidiary semaphore signal look like
A smaller signal arm which is either white with red line top and bottom or completely red
When on will show either a red, white or no light
When off will show a green light
Some have a letter C or S
Where would you find a subsidiary semaphore signal
If used they are always attached underneath the main signal
What is a subsidiary semaphore signal used for
When showing the off aspect you are signalled past the main signal aspect at danger under authority of the subsidiary signal
If stopping at any signal what must you do
Switch on DRA and have full service brakes applied
What does the C or S mean when the subsidiary semaphore is in the off position
C = calling you on
S = shunting
What do shunting discs look like
White circle with red line through the middle and red and green lights.
Works the same as a subsidiary signal
Can you carry passengers when being signalled past a shunting disc
No
How must you drive after passing an off distant signal or any subsidiary signal
At caution, at a speed which allows you to stop before a train, obstruction or buffers
What is a small semaphore signal arm
It’s a stop signal that controls movement into a loop or No-block line.
Once cleared you must proceed at caution
How do stepped diverging route indicators work
The highest signal relates to the main route
Lower signals relate to progressive routes to left or right
What is the advantage of a directing distant signal
A directing distant signal relates to the signal controlling the junction signal, which enables you to keep moving and not come to a near stand before clearing the junction signal
How are stacked shunting signals read
Top to bottom
Left to right
Why would you find a distant and stop signal on the same signal post
This happens when the block sections are small, these signals are controlled by different signal boxes
When might you find an outer and inner distant signal
When the block sections are close together and outer then inner distant signal may be used to increase breaking distance
How do you know if a semaphore signal is not in use
It’s marked with a large white cross
Where might you find a distant board
On approach to
A colour light stop signal
A semaphore stop signal
A stop board
A points indicator
A buffer stop
What do shunting signals that don’t show red look like
Either black or white discs with a thick yellow line through the middle.
Moves to diagonal and can show green light for clear
Can also be 3 light in black triangle
What is a co-acting signal
A lower down version of the main aspect signal positioned on the same post for visual purposes
What is a fringe box
A signal box which controls colour light and semaphore signals going from track circuits to AB.
How is permission given to move over points worked from a signal box
Verbally
Day light = arm raised above head
Night = white light moved quickly twisting wrist
When clear of points, if no shunter give the signaller one short blast of horn
Can you shunt outside the home signal
Only with the signallers permission
Who controls good loops and good line
Good loop = one signaller, on TCB it’s one section
Good line = two or more signallers, on TBC it’s more than one section.
