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.
North Hudson County Railway The North Hudson Railway Company built and operated a streetcar system in Hudson County and southeast Bergen County, New Jersey before and after the start of the 20th century. It was founded by Hillric J. Bonn who became the first President in 1865 and served for 26 years until his death, and eventually taken over by the Public Service Railway. In its endeavors to overcome the formidable obstacle of ascending the lower Hudson Palisades, or Bergen Hill, it devised numerous innovative engineering solutions including funicular wagon lifts, an inclined elevated railway, an elevator and viaducts.