Each network supplies half the required power, but each is capable of supplying all of the power necessary for the whole system. The cantenaries supply the traction power necessary for the shuttle trains and the through trains. The overhead power lines supply 25 kV - one of the most powerful 25kV cantenary systems in existence. All the control and communications systems are carried in three fibre-optic cables. These high capacity cables transmit digitally all the data for rail traffic management, and all the electrical and mechanical plant data in the tunnels.
All trains using the tunnels have electric traction, so there is no engine exhaust pollution.
The service tunnel vehicles have diesel engines designed to give very low emissions. Air is pumped into the service tunnel from ventilation buildings at Shakespeare Cliff and Sangatte. The service tunnel acts as the supply duct for normal ventilation. Air handling units located above the doors of the cross-passages every 375 metres, control the flow of air from the service tunnel to the railway tunnels. The drainage system of five pumping stations permits the removal of water from the tunnels.