Construction
The contractors were Starrett Brothers and Eken, which were composed of Paul and William A. Starrett and Andrew J. Eken. The project was financed primarily by Raskob and Pierre du Pont, while James Farley's General Builders Supply Corporation supplied the building materials. John W. Bowser was the construction superintendent of the project, and the structural engineer of the building was Homer G. Balcom. The tight completion schedule necessitated the commencement of construction even though the design had yet to be finalized.
Demolition of the old Waldorf–Astoria began on October 1, 1929. Stripping the building down was an arduous process, as the hotel had been constructed using more rigid material than earlier buildings had been. Furthermore, the old hotel's granite, wood chips, and "'precious' metals such as lead, brass, and zinc" were not in high demand, resulting in issues with disposal. Most of the wood was deposited into a woodpile on nearby 30th Street or was burned in a swamp elsewhere. Much of the other materials that made up the old hotel, including the granite and bronze, were dumped into the Atlantic Ocean near Sandy Hook, New Jersey.
By the time the hotel's demolition started, Raskob had secured the required funding for the construction of the building. The plan was to start construction later that year but, on October 24, the New York Stock Exchange experienced the major and sudden Wall Street Crash, marking the beginning of the decade-long Great Depression. Despite the economic downturn, Raskob refused to cancel the project because of the progress that had been made up to that point. Neither Raskob, who had ceased speculation in the stock market the previous year, nor Smith, who had no stock investments, suffered financially in the crash. However, most of the investors were affected and as a result, in December 1929, Empire State Inc. obtained a $27.5 million loan from Metropolitan Life Insurance Company so construction could begin. The stock market crash resulted in no demand for new office space; Raskob and Smith nonetheless started construction, as canceling the project would have resulted in greater losses for the investors.
A structural steel contract was awarded on January 12, 1930, with excavation of the site beginning ten days later on January 22, before the old hotel had been completely demolished. Two twelve-hour shifts, consisting of 300 men each, worked continuously to dig the 55-foot (17 m) deep foundation. Small pier holes were sunk into the ground to house the concrete footings that would support the steelwork. Excavation was nearly complete by early March, and construction on the building itself started on March 17, with the builders placing the first steel columns on the completed footings before the rest of the footings had been finished. Around this time, Lamb held a press conference on the building plans. He described the reflective steel panels parallel to the windows, the large-block Indiana limestone facade that was slightly more expensive than smaller bricks, and the building's vertical lines. Four colossal columns, intended for installation in the center of the building site, were delivered; they would support a combined 10,000,000 pounds (4,500,000 kg) when the building was finished.
The structural steel was pre-ordered and pre-fabricated in anticipation of a revision to the city's building code that would have allowed the Empire State Building's structural steel to carry 18,000 pounds per square inch (120 MPa), up from 16,000 pounds per square inch (110 MPa), thus reducing the amount of steel needed for the building. Although the 18,000-psi regulation had been safely enacted in other cities, Mayor Jimmy Walker did not sign the new codes into law until March 26, 1930, just before construction was due to commence. The first steel framework was installed on April 1, 1930. From there, construction proceeded at a rapid pace; during one stretch of 10 working days, the builders erected fourteen floors. This was made possible through precise coordination of the building's planning, as well as the mass production of common materials such as windows and spandrels. On one occasion, when a supplier could not provide timely delivery of dark Hauteville marble, Starrett switched to using Rose Famosa marble from a German quarry that was purchased specifically to provide the project with sufficient marble.
The scale of the project was massive, with trucks carrying "16,000 partition tiles, 5,000 bags of cement, 450 cubic yards [340 m3] of sand and 300 bags of lime" arriving at the construction site every day. There were also cafes and concession stands on five of the incomplete floors so workers did not have to descend to the ground level to eat lunch. Temporary water taps were installed so workers did not waste time buying water bottles from the ground level. Carts running on a small railway system transported materials from the basement storage to elevators that brought the carts to the desired floors where they would then be distributed throughout that level using another set of tracks. The 57,480 short tons (51,320 long tons) of steel ordered for the project was the largest-ever single order of steel at the time, comprising more steel than was ordered for the Chrysler Building and 40 Wall Street combined. According to historian John Tauranac, building materials were sourced from numerous, and distant, sources with "limestone from Indiana, steel girders from Pittsburgh, cement and mortar from upper New York State, marble from Italy, France, and England, wood from northern and Pacific Coast forests, [and] hardware from New England." The facade, too, used a variety of material—most prominently Indiana limestone but also architectural terracotta, brick, and black granite from Sweden.
By June 20, the skyscraper's supporting steel structure had risen to the 26th floor, and by July 27, half of the steel structure had been completed. Starrett Bros. and Eken endeavored to build one floor a day in order to speed up construction, achieving a pace of four and a half stories per week; prior to this, the fastest pace of construction for a building of similar height had been three and a half stories per week. While construction progressed, the final designs for the floors were being designed from the ground up (as opposed to the general design, which had been from the roof down). Some of the levels were still undergoing final approval, with several orders placed within an hour of a plan being finalized. On September 10, as steelwork was nearing completion, Smith laid the building's cornerstone during a ceremony attended by thousands. The stone contained a box with contemporary artifacts including the previous day's New York Times, a U.S. currency set containing all denominations of notes and coins minted in 1930, a history of the site and building, and photographs of the people involved in construction. The steel structure was topped out at 1,048 feet (319 m) on September 19, twelve days ahead of schedule and 23 weeks after the start of construction. Workers raised a flag atop the 86th floor to signify this milestone.
Work on the building's interior and crowning mast commenced after the topping out. The mooring mast topped out on November 21, two months after the steelwork had been completed. Meanwhile, work on the walls and interior was progressing at a quick pace, with exterior walls built up to the 75th floor by the time steelwork had been built to the 95th floor. The majority of the facade was already finished by the middle of November. Because of the building's height, it was deemed infeasible to have many elevators or large elevator cabins, so the builders contracted with the Otis Elevator Company to make 66 cars that could speed at 1,200 feet per minute (370 m/min), which represented the largest-ever elevator order at the time.
In addition to the time constraint builders had, there were also space limitations because construction materials had to be delivered quickly, and trucks needed to drop off these materials without congesting traffic. This was solved by creating a temporary driveway for the trucks between 33rd and 34th Streets, and then storing the materials in the building's first floor and basements. Concrete mixers, brick hoppers, and stone hoists inside the building ensured that materials would be able to ascend quickly and without endangering or inconveniencing the public. At one point, over 200 trucks made material deliveries at the building site every day. A series of relay and erection derricks, placed on platforms erected near the building, lifted the steel from the trucks below and installed the beams at the appropriate locations. The Empire State Building was structurally completed on April 11, 1931, twelve days ahead of schedule and 410 days after construction commenced. Al Smith shot the final rivet, which was made of solid gold.
The project involved more than 3,500 workers at its peak, including 3,439 on a single day, August 14, 1930. Many of the workers were Irish and Italian immigrants, with a sizable minority of Mohawk ironworkers from the Kahnawake reserve near Montreal. According to official accounts, five workers died during the construction, although the New York Daily News gave reports of 14 deaths and a headline in the socialist magazine The New Masses spread unfounded rumors of up to 42 deaths. The Empire State Building cost $40,948,900 to build (equivalent to $678 million in 2024), including demolition of the Waldorf–Astoria. This was lower than the $60 million budgeted for construction.
Lewis Hine captured many photographs of the construction, documenting not only the work itself but also providing insight into the daily life of workers in that era. Hine's images were used extensively by the media to publish daily press releases. According to the writer Jim Rasenberger, Hine "climbed out onto the steel with the ironworkers and dangled from a derrick cable hundreds of feet above the city to capture, as no one ever had before (or has since), the dizzy work of building skyscrapers". In Rasenberger's words, Hine turned what might have been an assignment of "corporate flak" into "exhilarating art". These images were later organized into their own collection. Onlookers were enraptured by the sheer height at which the steelworkers operated. New York magazine wrote of the steelworkers: "Like little spiders they toiled, spinning a fabric of steel against the sky".