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.
Bolmen Water Tunnel The Bolmen Water Tunnel (Swedish: "Bolmentunneln" ) is a water supply tunnel, 82 km long. It goes from the lake Bolmen in Kronoberg County to the province of Skåne, all in Sweden, and it serves around 700,000 people with drinking water. It has a cross section area of 8 m², a diameter of almost 3 m. About 2 m³/s is transported through the tunnel, although the capacity is 6 m³/s. The tunnel was built during the period 1975 to 1987.