page_title: Stealth ship
section_title: Shaping
hierarchical_section_title: Stealth ship / Shaping
caption_attribution_description: English: Detail of the Forbin, a modern frigate of the French navy. The faceted appearance reduces radar cross-section for stealth. Français&#160;: Vue d'une des cheminées du Forbin Русский: Французский эсминец «Форбин», дымовая труба правого борта
context_page_description: A stealth ship is a ship which employs stealth technology construction techniques in an effort to ensure that it is harder to detect by one or more of radar, visual, sonar, and infrared methods.
  These techniques borrow from stealth aircraft technology, although some aspects such as wake and acoustic signature reduction are unique to stealth ships' design. Though radar cross-section reduction is a fairly new concept many other forms of masking a ship have existed for centuries or even millennia.
context_section_description: In designing a ship with reduced radar signature, the main concerns are radar beams originating near or slightly above the horizon (as seen from the ship) coming from distant patrol aircraft, other ships or sea-skimming anti-ship missiles with active radar seekers. Therefore, the shape of the ship avoids vertical surfaces, which would perfectly reflect any such beams directly back to the emitter. Retro-reflective right angles are eliminated to avoid causing the cat's eye effect. A stealthy ship shape can be achieved by constructing the hull and superstructure with a series of slightly protruding and retruding surfaces.  Furthermore, round shapes on the ship are eliminated or covered up, examples include smokestacks and gun turrets. Also, cavities that present a horizontal face are to be eliminated since they act like a trap and are very visible to radar.  To get around these limitations many ships use features such as panels that cover reflective surfaces or use alternate designs of hardware. Also, every effort must be made to have the smallest gaps on the ship as possible.  Common hull shapes include tumblehome hull designs which slope inward from the waterline, and SWATHhulls which allow for better stability when using a tumblehome hull.  These RCS design principles were developed by several navies independently in the 1980s using work done on aircraft RCS reduction as the starting point.
  The currently developed U.S. Zumwalt-class destroyer — or DD(X) — is the US version of a stealth ship. Despite being 40% larger than an Arleigh Burke-class destroyer the radar signature is more akin to a fishing boat, according to a spokesman for Naval Sea Systems Command;  sound levels are compared to the Los Angeles-class submarines.  The tumblehome hull reduces radar return and the composite material deckhouse also has a low radar return.  Water sleeting along the sides, along with passive cool air induction in the mack reduces infrared signature. Overall, the destroyer's angular build makes it "50 times harder to spot on radar than an ordinary destroyer.
  The Swedish Navy's Visby class corvette is designed to elude visual detection, radar detection, acoustic detection, and infrared detection. The hull material is a sandwich construction comprising a PVC core with a carbon fibre and vinyl laminate. Avoidance of right angles in the design results in a smaller radar signature, reducing the ship's detection range.
  Britain's Type 45 anti-air warfare destroyer has similarities to the Visby class, but is much more conventional, employing traditional steel instead of carbon fiber. Like Visby, its design reduces the use of right angles.
  Taiwan's' Tuo Chiang-class stealth corvette are a class of fast stealth multi-mission corvettes currently in service with the Republic of China (Taiwan) Navy. The ships is designed to have a low radar cross-section and evade radar detection making it difficult to detect the ship when operating closer to the coastline 
  Sea Shadow, which utilizes both tumblehome and SWATH features, was an early U.S. exploration of stealth ship technology.
caption: Detail of Forbin, a modern frigate of the French navy. The faceted appearance reduces radar cross-section for stealth.
exif: {"Image ImageDescription": "", "Image Make": "SONY", "Image Model": "DSC-W180", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image DateTime": "2009:09:21 15:19:12", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "318", "Image CustomRendered": "Normal", "Image ExposureMode": "Auto Exposure", "Image WhiteBalance": "Auto", "Image SceneCaptureType": "Standard", "Image Saturation": "Normal", "Image Sharpness": "Normal", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 51, 48, 48, 0, 0, 0, 2, 0, 2, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Make": "SONY", "Thumbnail Model": "DSC-W180", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail DateTime": "2009:09:21 15:19:12", "Thumbnail JPEGInterchangeFormat": "12854", "Thumbnail JPEGInterchangeFormatLength": "7390", "EXIF ExposureTime": "1/800", "EXIF FNumber": "27/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2009:09:21 15:19:12", "EXIF DateTimeDigitized": "2009:09:21 15:19:12", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "3", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "55/16", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "31/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2736", "EXIF ExifImageLength": "3648", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed"}