How the Channel Tunnel Operates: Trains, Control Systems, and Maintenance

The Channel Tunnel (Eurotunnel) operates a sophisticated shuttle system for passengers and vehicles between Folkestone (UK) and Calais (France).

Rolling Stock

• Trainsets: Two Class 92 dual-voltage electric locomotives (25 kV AC / 1.5 kV DC) hauling 18 double-deck shuttle carriages.
• Shuttle Types: Passenger Shuttle (PS), Vehicle Shuttle (VS), High Vehicle (HV), Exceptional Vehicle (EV).
• Power Switch: Automatic changeover between UK and French electrification systems in the tunnel.

Signalling: ETCS Level 2

European Train Control System Level 2 with in-cab moving-block signalling. Allows closer headways, higher capacity, and computerised diagnostics. Trains receive continuous speed/authority updates from trackside equipment.

Maintenance Regime

Train Maintenance

• Routine: During turnaround at terminals (embarking/disembarking).
• Daily Major Checks: UK stock at Dollands Moor (Folkestone); French stock at Fréthun.

Tunnel Infrastructure Maintenance

• Service Tunnels: Two smaller tunnels flank the main bores. Used by Tunnel Inspection Vehicle (TIV) and Rail Traction Maintenance Train (RTMT) for track, catenary, and environmental monitoring.
• Drainage: Gravity drainage via boreholes to galleries; 24 pumping stations with submersible pumps as backup.
• Ventilation: Fresh air intakes at portals (Cheriton, Shakespeare Cliff, Sangatte); exhaust shafts at Folkestone, Guston, Fréthun. Air warmed and directed through ducts to service tunnel.
• Fire Safety: 250 L/s water delivery via 8 km pipe network; 12 emergency cross-passages (every 375 m); 19 service-to-safety gallery passages (every 1 km); 26 emergency stop/evacuation points with sealed doors to service tunnel; evacuation doors every 15 m in service tunnel.

This integrated system ensures high reliability, safety, and capacity for ~400 train movements daily.