Through the medium of animation with voice-over, this video introduces part 3 of Cōnsilium Aquīs Sulis's course on GB Mainline Signalling.

Through the medium of animation with voice-over, this video covers the following topics:
- what is a lockout device
- application of lockout devices
- cancellation of lockout devices
- types of lockout device.

Through the medium of animation with voice-over, this video covers the following topics:
- what is shunting
- shunting in depots and sidings
- shunting on the main line
- ground frames.

Through the medium of animation with voice-over, this video covers the following topics:
- what is a slot
- slots between adjacent signalling control areas
- slots for level crossings
- shunter’s releases.

Through the medium of animation with voice-over, this video covers the following topics:
- what is Automatic Route Setting (ARS)
- ARS sub areas
- Train Operated Route Release (TORR).

Through the medium of animation with voice-over, this video covers the following topics:
- what are station duties and train dispatch
- the roles of guards and platform dispatch staff
- platform indicators and plungers
- Driver Only Operation.

Through the medium of animation with voice-over, this video covers the following topics:
- what is a level crossing
- level crossing protection
- interlocking of level crossings
- level crossing telephones
- level crossing risk assessment.

Through the medium of animation with voice-over, this video covers the following topics:
- measuring tracks
- platform and tunnel controls
- preceding signals
- trip wires.

Through the medium of animation with voice-over, this video covers the following topics:
- the challenge of resetting axle counters
- aspect restrictions
- Engineering Possession Reminders (EPRs)
- Special Train Reminders (STRs)

Through the medium of animation with voice-over, this video covers the following topics:
- Colwich controls
- Insill locking
- Huddersfield controls
- preset shunt signals.

Through the medium of animation with voice-over, this video covers the following topics:
- historical background
- Interoperability Directive
- Technical Specifications for Interoperability (TSIs)
- European Train Control System (ETCS)
- European Rail Traffic Management System (ERTMS).

Through the medium of animation with voice-over, this video summarizes part 3 of Cōnsilium Aquīs Sulis's course on GB Mainline Signalling.