The Hudson River Vehicular Tunnel was authorized in 1919 with the promise that it could double the daily traffic load across the river. Construction began in 1920 under Chief Engineer Clifford M. Holland, then a 37-year-old engineer who had built subway tunnels under New York's East River.

Plans called for two parallel tubes. The north tube would be 8,558 ft long and the south tube 8,371 ft. Both would have have an inside diameter of 29.5 ft. The tunnels were driven through the Hudson riverbed by shields working in both directions that were launched from pneumatic caissons. Each shield was pushed forward by 30 hydraulic jacks that had a total force of 6,000 tons. The tubes were lined with 2.5-ft-wide cast iron rings. (ENR 5/8/24 p. 788).

But it was the Holland's ventilation design that became a breakthrough. In shorter tunnels, ventilation was handled by flowing air in one end and out the other. Applied to tubes as long as those under the Hudson, this would have required an unacceptable 75-mph gale. Engineer Holland's solution was a system with one duct running beneath each tube's roadway and one above. Forty-two huge fans would draw fresh air in the lower duct at 3.6 million cu ft per minute and distribute it into the roadway through slots spaced 10 to 15 ft apart along the curbs. Another 42 fans draw air and exhaust fumes into the upper duct through similar slots at the ceilings and expel it into the open air.<

An early construction problem occurred on the New York side, where there was a potential blowout of compressed air because only 14 ft of cover existed. A bed of rocks demanded careful blasting operations. Much of the shields' progress was made by pushing through silt.

Holland spent most of his waking hours overseeing all tunnel design and construction. But in October 1924, he suffered what was termed a nervous breakdown. Three weeks later, he was dead of a heart attack at age 41. Within two weeks, his project was formally named the Holland Tunnel. But Milton Freeman, the engineer of construction who succeeded Holland, was himself dead five months later. Ole Singstad saw the project through to completion in 1927.

Engineering School Blues
The need to turn out well-rounded engineering school graduates isn't just a modern-day issue. Nearly 75 years ago, Engineering News-Record opined about how to "humanize" schools and infuse them with "business training" and "culture" (ENR 9/23/25 p. 371). The magazine noted that while technical skill is critical to employers who "demand not an apprentice, but a junior engineer," it also contended that schools also have a responsibility "to give the student that broader training in human affairs...which it is freely admitted engineers, as a class, lack." ENR speculated that covering all that ground might be tough in a four-year degree and noted that schools were already experimenting with longer programs. "Is it too much to ask that a professor once in a while depart from the theory of the rigid frame to tell how an inspector threw a roughneck foreman off the job--that is if the professor ever got close enough to engineering life to know a roughneck foreman?"

Historic Church Gets Big Lift
Construction of New York City's subway in caused cracks in the foundation of Trinity Church, which had been stable and crack-free since its completion in 1846 (ENR 10/22/25 p.669). The rear end of the brownstone church had settled about 11/4 in., the result of underpinning required to build a retaining wall between the churchyard and Trinity Place to permit subway excavation for the subway. This reinforcement technique generated the largest underpinning operation ever to be undertaken using hydraulic jacks. The chancel and western end of the church were underpinned using a jack with 5,000-psi pressure and 92 piles made of varying lengths of steel tubing that were forced down into hardpan and underlying Manhattan schist.

Jazzed Up Over Bid Spreads
ENR coined the term "jazz bidding," likening erratic construction bids to the new music of the day that some found equally irrational (ENR 9/29/27 p. 493). The analogy described the wide spread of bids for a water-supply tunnel in Mendoza, Argentina., which ranged from $1.2 million to $2.8 million. The million-dollar-plus difference "indicates a sickness in the contracting body. There is no justification...for a 100% variation in prices."