06 - Three Position Signals

Question 1

What are the types of three position signals?

Answer 1

There is only light type.

A- Top light
B- Bottom Light
C- Only on specific signals (Low speed caution)

Question 2

What are the classes of three position signals?

Answer 2

Home - Two lights placed vertically, default position is stop.

Automatic - Two lights placed stagged, default position is proceed.

Dwarf - Shows one colour at a time, default position is stop.

Question 3

What do home signals protect?

Answer 3

Stations
Signal Boxes
Sidings
Level Crossings
Junctions

Question 4

What is the primary purpose of Automatic signals in a long section of track?

Answer 4

The primary purpose is to expedite the passage of trains, dividing long sections of track into shorter sections to allow more trains to travel in a signal direction.

Question 5

Dwarf signals control train movements to and from?

Answer 5

Running line to running line
Running line to siding
Siding to running line
Siding to siding.

Question 6

What colours may a 3 position dwarf signal display?

Answer 6

Red
Purple
Blue
Yellow 
Green

Question 7

What is a green over red signal and what does it mean?

Answer 7

Clear Normal Speed.
The points if any are set for the move
The track ahead is clear to the next signal
The speed for the track section is track speed
The next fixed signal will be a proceed aspect

Question 8

What is a Yellow over Red Signal and what does it mean?

Answer 8

Normal Speed Warning
The points if any are set for the move
The track ahead is clear
The speed for the track section is track speed but you must be prepared to stop before the next signal
The next signal will be displaying a stop

Question 9

What is a Yellow over Green signal and what does it mean?

Answer 9

Reduce to medium

The points if any are set for the move
The track ahead is clear
The speed for the track section is track speed but you must reduce to 40 before the next fixed signal
The next signal will be showing a medium aspect.

Note some signals have a provision for speeds higher than 40, example reduce to medium with a 65 light.
If you see the next signal change to an improved aspect you do not need to decrease your speed.

Question 10

What is a Red over Green signal and what does it mean?

Answer 10

Clear medium speed

The points if any are set for the move
The track ahead is clear
The speed for the track section is 40 until the next fixed signal.
On ATC sections the speed restriction only applied until the whole of your train has cleared the points
The next signal is at proceed.

Question 11

What is a Red over Yellow signal and what does it mean?

Answer 11

Medium Speed warning

The points if any are set for the move
Track ahead is clear
The speed for the track section is 40 but you must be prepared to stop before the next fixed signal.
The next signal will be displaying stop.

Note: Even on ATC track, the speed restriction applies for the whole track section.