The Hudson River Vehicular Tunnel is now known as the Holland Tunnel. The proposal for a Hudson River crossing began as early at 1906 first as a bridge crossing but because of cost became a tunnel crossing. A proposed bridge was estimated to cost $50 million and a tunnel cost $10 million. The New York State and New Jersey Interstate Bridge and Tunnel Commissions decided on building a tunnel in 1919. The problem of ventilation was a big issue and much experimental testing was done. The University of Illinois was engaged to do experimental tests to determine the amount of power required to operate the ventilation system. Yale University determined the effect of carbon monoxide poisoning and the U.S. Bureau of Mines built a large scale model (400 ft. long) of a tunnel in Pittsburgh, Pennsylvania. George S. Rice, chief mining engineer and Arthur C. Willard, consulting ventilation engineer became consultants on the ventilation experiments. Clifford M. Holland, New York States chief engineer was put in charge of the tunnel building but he died in 1924 before the break through of the tube bores coming two directions: from Jersey City, N.J. and from Canal Street in Manhattan. Holland’s successor Milton Freeman died five months later, the tunnel was finished under the third chief engineer Ole Singstad. Singstad innovated the ventilation system for the Holland Tunnel comprising four ventilation buildings, two on each side of the Hudson with 84 immense fans providing a change of air every 90 seconds. He advanced the use of “Sunk-tube” method of underwater vehicular tunnel ventilation. Arthur C. Willard was professor of Heating and Ventilating (1913-1934), head of the Department of Mechanical Engineering (1920-1934, acting dean of the College of Engineering and director of the Engineering Experiment Station (1933-1934) and president of the University of Illinois (1934-1946). The tunnel was opened in 1927, considered an “eighth wonder of the world” at the time and named for Clifford M. Holland. The Holland Tunnel is 8,372 feet long eastbound from Jersey City to Manhattan and 8,558 feet long westbound from Canal Street to 12th & 14th Streets in Jersey City. There are two tubes, nine lanes, each tube is12.5 feet tall with reinforced 2.5 feet thick cast iron rings to support the tube walls lined in tiles. The Holland Tunnel tube dimensions became the standard for all subsequent vehicular underwater tunnels. In 1984 the Holland Tunnel was named a National Historical Civil and Mechanical Engineering Landmark.