What tunnel runs under the Hudson River and has a ventilation system innovated by Ole Knutsen Singstad?
Ole Singstad Ole Knutsen Singstad (June 29, 1882 – December 8, 1969) was a Norwegian-American civil engineer who innovated the ventilation system for the Holland Tunnel (which subsequently became commonly used in other automotive tunnels) and advanced the use of the "Sunk-tube" method of underwater vehicular tunnel building, a system of constructing the tunnels with prefabricated sections.
Queensway Tunnel The Queensway Tunnel is a road tunnel under the River Mersey, in the north west of England, between Liverpool and Birkenhead. It is often called the Birkenhead Tunnel, to distinguish it from the Kingsway Tunnel, which serves Wallasey and the M53 motorway traffic.