Centrifugal - and jet - fan ventilation in the tunnels, along with other safety features, were in themselves massive undertakings. Land had to be acquired from more than 42,000 different landowners, a colossal legal exercise.
बोगद्यांमधील केंद्रोत्सारी व जेट - पंखांनी संवातन तसेच इतर सुरक्षा उपाय हीच मुळात मोठ्या मुश्‍कीलीची कामे होती.