page_title: Gateway Arch
section_title: Physical characteristics
hierarchical_section_title: Gateway Arch / Characteristics / Physical characteristics
caption_attribution_description: Testing out the zoom. It works
context_page_description: The Gateway Arch is a 630-foot monument in St. Louis, Missouri, United States. Clad in stainless steel and built in the form of a weighted catenary arch, it is the world's tallest arch, the tallest man-made monument in the Western Hemisphere, and Missouri's tallest accessible building. Built as a monument to the westward expansion of the United States, and officially dedicated to "the American people," the Arch, commonly referred to as "The Gateway to the West" is the centerpiece of Gateway Arch National Park and has become an internationally recognized symbol of St. Louis, as well as a popular tourist destination.
  The Arch was designed by Finnish-American architect Eero Saarinen in 1947; construction began on February 12, 1963 and was completed on October 28, 1965 at an overall cost of $13 million. The monument opened to the public on June 10, 1967.
  It is located at the site of St. Louis's founding on the west bank of the Mississippi River.
context_section_description: Both the width and height of the arch are 630 feet (192 m). The arch is the tallest memorial in the United States and the tallest stainless steel monument in the world.
  The cross-sections of the arch's legs are equilateral triangles, narrowing from 54 feet (16 m) per side at the bases to 17 feet (5.2 m) per side 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 to the peak. The arch is hollow to accommodate a unique tram system that takes visitors to an observation deck at the top.
  The structural load is supported by a stressed-skin design. Each leg is embedded in 25,980 short tons (23,570 t) of concrete 44 feet (13 m) thick and 60 feet (18 m) deep. Twenty feet (6.1 m) of the foundation is in bedrock. The arch is resistant to earthquakes and is designed to sway up to 18 inches (46 cm) in either direction, while withstanding winds up to 150 miles per hour (240 km/h). The structure weighs 42,878 short tons (38,898 t), of which concrete composes 25,980 short tons (23,570 t); structural steel interior, 2,157 short tons (1,957 t); and the stainless steel panels that cover the exterior of the arch, 886 short tons (804 t). This amount of stainless steel is the most used in any one project in history. The base of each leg at ground level had to have an engineering tolerance of ¹⁄₆₄ inch (0.40 mm) or the two legs would not meet at the top.
caption: The windows of the observation deck are located around the apex of the arch.
exif: {"Image Make": "Canon", "Image Model": "Canon PowerShot S3 IS", "Image Orientation": "Horizontal (normal)", "Image XResolution": "180", "Image YResolution": "180", "Image ResolutionUnit": "Pixels/Inch", "Image DateTime": "2006:07:03 00:47:47", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "187", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "180", "Thumbnail YResolution": "180", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "2863", "Thumbnail JPEGInterchangeFormatLength": "3796", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExposureTime": "1/160", "EXIF FNumber": "63/10", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2006:07:01 19:15:46", "EXIF DateTimeDigitized": "2006:07:01 19:15:46", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "3", "EXIF ShutterSpeedValue": "117/16", "EXIF ApertureValue": "85/16", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "29/8", "EXIF MeteringMode": "Pattern", "EXIF Flash": "80", "EXIF FocalLength": "72", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2816", "EXIF ExifImageLength": "2112", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "Interoperability RelatedImageWidth": "2816", "Interoperability RelatedImageLength": "2112", "EXIF InteroperabilityOffset": "2698", "EXIF FocalPlaneXResolution": "112640/9", "EXIF FocalPlaneYResolution": "2112000/169", "EXIF FocalPlaneResolutionUnit": "2", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Manual", "EXIF DigitalZoomRatio": "1", "EXIF SceneCaptureType": "Standard"}