AERODYNAMIC PHENOMENA IN TUNNELS AS CRITERIA FOR THE PREPARATION OF PROJECTS AND THE CONSTRUCTION OF TUNNELS ON NEW LINES

Aerodynamic phenomena are particularly important when drawing up projects and building tunnels through which trains will travel at high-speeds. The most dangerous phenomena are sudden changes in pressures, since these can have an effect on passenger comfort and, in extreme cases, can endanger the safety of passengers and train crew. The increase of air resistance in long tunnels can prevent trains from running at maximum speeds which are normally possible. Moreover, when trains pass through long tunnels, difficulties can arise with engine ventilation in motive power units and with air-conditioning in passenger compartments.