Eurostar Class 373 trainsets were built for the launch of international high-speed passenger service through the Channel Tunnel in the 1990s.
The design was derived from French TGV technology but adapted for operation across different national railway systems.
The trainsets used power cars at each end with articulated passenger cars between them.
Engineering had to account for British loading gauge, continental electrification systems, signaling differences, and Channel Tunnel safety requirements.
The long trainsets were designed so portions could be separated in an emergency, a feature tied directly to tunnel operating rules.
Eurostar services linked London with Paris and Brussels, replacing much of the former air-and-ferry travel market between the cities.
Before completion of Britain’s dedicated high-speed line, Class 373 trains used conventional British tracks at lower speeds between London and the tunnel.
High Speed 1 later allowed full high-speed operation from London St Pancras to the tunnel.
Newer Class 374 trainsets have replaced many Class 373 assignments, but preserved and remaining examples document the first generation of Channel Tunnel passenger operation.
For TransitSatellite, Class 373 should be presented as a specific trainset type, while Eurostar itself is the service and operating brand that has used multiple equipment generations.