CORRESPONDENCE. THE CONSTRUCTION OF THE MERSEY TUNNEL.

Keywords: TUNNELS, CONSTRUCTION, MERSEY TUNNEL, TUNNELLING, CARS, EXHAUSTS, GAS, CARBON MONOXIDE, NOXIOUS, VENTILATION, AIR, DUCTS, PITOT, TUBES, ANEMOMETERS, CEMENTATION, FLOW, VELOCITY, INSTRUMENTATION, MERSEY, BIRKENHEAD, LIVERPOOL, UK