What tunnel runs under the Hudson River and has a ventilation system innovated by Ole Knutsen Singstad?
Holland Tunnel The Holland Tunnel is a highway tunnel under the Hudson River between Manhattan in New York City and Jersey City, New Jersey. Its two tubes carry eastbound and westbound Interstate 78. In New Jersey, it is also designated NJ 139. An integral conduit within the New York Metropolitan Area, it opened in 1927 as the first of two vehicular tunnels under the river, the other being the Lincoln Tunnel. Both are operated by the Port Authority of New York and New Jersey.
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.