The Gateway Arch, also known as the Gateway to the West, is an integral part of the Jefferson National Expansion Memorial and the iconic image of St. Louis, Missouri. It was designed byFinnish-American architect Eero Saarinen and structural engineer Hannskarl Bandel in 1947. It stands 630 feet (192 m) tall, and is 630 feet (192 m) wide at its base, making it the tallest monument in the world. Construction of the arch started on February 12, 1963 and was completed on October 28, 1965. The monument opened to the public on July 10, 1967.
The cross-sections of its legs are equilateral triangles, narrowing from 54 feet (16 m) per side at the base to 17 feet (5.2 m) at the top. Each wall consists of a stainless steel skin covering a sandwich of two carbon steel walls with reinforced concrete in the middle from ground level to 300 feet (91 m), with carbon steel and rebar from 300 feet (91 m) to the peak. The interior of the Arch is hollow and contains a unique transport system leading to an observation deck at the top. The interior of the Arch also contains two emergency stairwells of 1076 steps each, in the event of a need to evacuate the Arch or if a problem develops with the tram system.
The base of each leg at ground level had an engineering tolerance of one sixty-fourth of an inch (0.40 mm) or the two legs would not meet at the top.
During construction, both legs were built up simultaneously. When the time came to connect both legs together at the apex, thermal expansion of the sunward facing south leg prevented it from aligning precisely with the north leg. This alignment problem was solved when the St. Louis Fire Department sprayed the south leg with water from firehoses until it had cooled to the point where it aligned with the north leg.
From the visitor center one may move to either base (one on the north end and the other on the south end) of the Arch and enter the tramway much as one would enter an ordinary elevator, through narrow double doors. The north queue area includes displays which interpret the design and construction of the Gateway Arch; the south queue area includes displays about the St. Louis riverfront during the mid-19th century.
Passing through the doors, passengers in groups of five enter an egg-shaped compartment containing five seats and a flat floor. Because of the car shape, the compartments have sloped ceilings low enough to force taller riders to lean forward while seated (for this reason it’s recommended that the tallest of the five passengers in the car sit in the center seat facing the door). Eight compartments are linked to form a train, meaning that both trains have a capacity of 40, and that 80 people can be transported at one time. These compartments individually retain an appropriate level by periodically rotating every 5 degrees, which allows them to maintain the correct orientation while the entire train follows curved tracks up one leg of the arch. The trip to the top of the Arch takes four minutes, and the trip down takes three minutes. The car doors have narrow windows, allowing passengers to see the interior stairways and structure of the Arch during the trip.
Near the top of the arch, the rider exits the compartment and climbs a slight grade to enter the arched observation area. Thirty-two small windows (16 per side) measuring 7 by 27 inches (180 mm × 690 mm) allow views across the Mississippi River and southern Illinois with its prominent Mississippian culturemounds to the east at Cahokia Mounds, and the City of Saint Louis and St. Louis County to the west beyond the city. On a clear day, one can see up to thirty miles (48 km).
A time capsule containing the signatures of 762,000 St. Louis area students was welded into the keystone before the final piece was set in place.
Eleven light aircraft have been successfully flown beneath the arch, the first on June 22, 1966 when the arch had been completed for less than a year.
In 1980, Kenneth Swyers tried to parachute onto the Gateway Arch, planning to jump off to land on the ground. Instead, he slid all the way down one leg to his death. The pilot, Richard Skurat, had his pilot certificate suspended for 90 days.
In 1984, David Adcock of Houston, Texas, began to scale the arch by means of suction cups on his hands and feet, but he was talked out of continuing after having climbed only 20 feet (6.1 m). The next day he successfully scaled the nearby 21-story Equitable Building in downtown St. Louis.
It was declared a National Historic Landmark in 1987.
On September 14, 1992, it was rumored that John C. Vincent of New Orleans successfully scaled the outside of the Arch with suction cups during the night, and performed a BASE jump from the top with a parachute at 7 a.m. No evidence surfaced to support his claim, and it was speculated by Park Rangers that Vincent was lowered from a helicopter onto the top of the Arch, from which he parachuted. He was jailed three months for the stunt.
On July 21, 2007, approximately 200 people were trapped in the trams or at the top of the Arch after an electrical problem occurred with the tram system. All were returned to the ground either by being taken down stairs to a service elevator, or by waiting for power to be restored. A second electrical problem caused one tram to be taken out of service the following day.
Here’s a link to the official website of the Gateway Arch – http://www.gatewayarch.com/Arch/