inverted bow

{{Short description|Bow whose furthest forward point is not at the top}}

File:A (ship) at Sorrent 2012 3.jpg cruising at Sorrento, Italy in 2012.]]

File:Vu1912.JPG, a dreadnought type ship with inverted bow, flagship of the Austro-Hungarian navy in 1912.]]

In ship design, an inverted bow (occasionally also referred to as reverse bow) is a ship's or large boat's bow whose furthest forward point is not at the top. The result may somewhat resemble a submarine's bow. Inverted bows maximize the length of waterline and hence the hull speed, and often have better hydrodynamic drag than ordinary bows. On the other hand, they have very little reserve buoyancy and tend to dive under waves instead of piercing or going over them.

Inverted bows were popular on battleships and large cruisers in the early 20th century. They fell out of favour, as they were extremely wet at high speeds and in heavy seas, but have made a comeback on modern ship design.

Examples

=Motor Yacht "A" =

The 390 ft luxury motor yacht M/Y "A" has an inverted bow, along with a tumblehome hull design.

File:Well intervention vessel Sarah.JPG vessel Sarah with X-Bow.]]

=Ulstein X-Bow=

The Ulstein X-Bow (or just X-BOW) is an inverted ship's bow designed by Ulstein Group to improve handling in rough seas, and to lower fuel consumption by causing less hydrodynamic drag.Five (TV channel) television program Megastructures, 12.45 to 1.45 pm Friday 29 January 2010 It is shaped somewhat like a submarine's bow.{{cite web |url=http://www.thehandandeye.com/blog/2-2-2015-x-bow-innovating-an-old-industry |title=X-Bow: Innovating an old industry — The Hand & Eye |website=www.thehandandeye.com |url-status=dead |archive-url=https://web.archive.org/web/20150926093426/http://www.thehandandeye.com/blog/2-2-2015-x-bow-innovating-an-old-industry |archive-date=2015-09-26}}

File:Bourbon Orca in Stavanger 2012.jpg in 2006.]]

File:Siem_Moxie_ship_R01.jpg

The MV [http://ulstein.com/references/bourbon-orca Bourbon Orca], design AX104, is an Ulstein A-Series anchor handling tug supply vessel (AHTS) built for Bourbon Offshore Norway, the Norwegian division of the French Groupe Bourbon,[http://www.shipoftheyear.com/ship-of-the-year-2006/ship-of-the-year-2006 Ship Of The Year 2006.] {{Webarchive|url=https://web.archive.org/web/20150128133153/http://www.shipoftheyear.com/ship-of-the-year-2006/ship-of-the-year-2006/ |date=2015-01-28 }} Accessed: 24 January 2015. and was the first ship built with the Ulstein X-bow in 2006. She was awarded Ship of the Year 2006, both by Skipsrevyenhttp://ulstein.com/news/2006/2006-ahts-bourbon-orca-ship-of-the-year {{Webarchive|url=https://web.archive.org/web/20210514102817/https://ulstein.com/news/2006/2006-ahts-bourbon-orca-ship-of-the-year |date=2021-05-14 }} 2006: AHTS Bourbon Orca - Ship of the Year and Offshore Support Journal. In 2007, the Bourbon Orca design model was included in the London Science Museum's display of innovative technology. The vessel's operator claims that the design achieves higher speed and a calmer motion in head, rough seas.[https://web.archive.org/web/20110708085554/http://www.bourbon-online.com/medias/dossierdepresse/Press-Kit-BOURBON-vessels-built-in-China.pdf A series of four Ulstein designed inverted bow PSV vessels] page 16-17 Bourbon (company), 24 June 2010. Accessed: 11 March 2011. Originally developed for offshore oil and gas vessels, the design has entered new segments such as yachts, cruise vessels, offshore wind and fisheries. In 2017, a US cruise company ordered the first four X-BOW cruise ships for arctic ice conditions,{{Cite web|url=http://www.seatrade-cruise.com/news/news-headlines/sunstone-china-group-to-build-4-6-expedition-cruise-ships.html|title = SunStone, China group to build 4+6 expedition cruise ships in Shanghai|date = 17 March 2017}} and Lindblad Expeditions also ordered two such expedition cruise vessels.{{Cite web|url=http://www.seatrade-cruise.com/news/news-headlines/it-s-official-lindblad-inks-newbuild-deal-with-ulstein.html|title = It's official: Lindblad inks 1 + 2 newbuild deal with Ulstein|date = 7 November 2017}}

The number of X-BOW vessels contracted and or delivered reached the 100 mark in 2017.{{cite web |url=https://www.offshorewindindustry.com/news/x-bow-cracks-100-vessels-mark |title=X-BOW cracks the 100 vessels mark |website=www.offshorewindindustry.com/ 16 January 2016. Accessed: 7 July 2022}} Later developments from the X-BOW are the X-STERN {{Cite web|url=https://ulstein.com/innovations/x-stern|title=X-Stern®|date=16 March 2020 }} and TWIN X-STERN {{Cite web |url=https://www.theexplorer.no/solutions/two-sterns-provide-fuel-savings-and-maximum-manoeuvrability/ |title=Two sterns provide fuel savings and maximum manoeuvrability |access-date=2022-07-07 |archive-date=2022-06-28 |archive-url=https://web.archive.org/web/20220628020426/https://www.theexplorer.no/solutions/two-sterns-provide-fuel-savings-and-maximum-manoeuvrability/ |url-status=dead }} hull line designs.

=Zumwalt-class destroyer=

The bow of the {{Sclass|Zumwalt|destroyer|0}} stealth guided missile destroyer for the United States Navy is also inverted. It has a wave-piercing tumblehome hull form whose sides slope inward above the waterline.{{Cite web|title=Full Page Reload|url=https://spectrum.ieee.org/the-electric-warship|access-date=2020-11-10|website=IEEE Spectrum: Technology, Engineering, and Science News|date=31 July 2013|language=en}}

References

[http://www.marinelog.com/index.php?option=com_k2&view=item&id=25285:video-ulstein-delivers-second-wind-service-vessel&Itemid=257 Ulstein delivers second wind service vessel]

External links

[http://ulstein.com/innovations/x-bow X-BOW]
[http://www.ulstein.com Ulstein Group]
[https://ulstein.com/pdf/Creative-enthusiasm_90-years.pdf Ulstein Group History book] {{Webarchive|url=https://web.archive.org/web/20161103215737/https://ulstein.com/pdf/Creative-enthusiasm_90-years.pdf |date=2016-11-03 }}
[http://www.bourbonoffshore.com/sites/default/files/documents-associes/pdf/ahts-bourbon-orca.pdf pdf 'Bourbon Orca']

Category:Shipbuilding