Editing Ceremonial ship launching (section)

==Methods==
There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching". The oldest, most familiar, and most widely used is the end-on launch, in which the vessel slides down an inclined [[slipway]], usually [[stern]] first. With the side launch, the ship enters the water broadside. This method came into use in the 19th century on inland waters, rivers, and lakes, and was more widely adopted during World War II. The third method is [[float-out]], used for ships that are built in basins or [[dry dock]]s and then floated by admitting water into the dock.<ref name="FAQ108"/>

If launched in a restrictive waterway, drag chains are used to slow the ship speed to prevent it striking the opposite bank.<ref>Basic Ship Theory Volume 1, Fifth Edition

Butterworth-Heinemann; 5 edition | November 21, 2001 | {{ISBN|0750653965}}</ref>

===Stern-first===
[[File:USS Johnston (DD-557) sliding down the building ways at the Seattle-Tacoma Shipbuilding Corporation shipyard, Seattle, Washington, 25 March 1943 - Original.tif|thumb|Destroyer {{USS|Johnston|DD-557}} slipping into the water stern-first during her launch from the [[Seattle-Tacoma Shipbuilding Corporation]] shipyard on 25 March 1943]]
[[File:Arizona launch party.jpg|thumb|right|Stern-first launch of the battleship {{USS|Arizona|BB-39}} in 1915 at the [[Brooklyn Navy Yard]]]]

Normally, [[slipway|ways]] are arranged perpendicular to the shore line (or as nearly so as the water and maximum length of vessel allows) and the ship is built with its [[stern]] facing the water. Where the launch takes place into a narrow river, the building slips may be at a shallow angle rather than perpendicular, even though this requires a longer slipway when launching.{{efn-lr|The [[National Shipyard]]s at [[Chepstow]] are an example.}} Modern slipways take the form of a reinforced concrete mat of sufficient strength to support the vessel, with two "barricades" that extend well below the water level taking into account [[tide|tidal]] variations. The barricades support the two launch ways. The vessel is built upon temporary cribbing that is arranged to give access to the hull's outer bottom and to allow the launchways to be erected under the complete hull. When it is time to prepare for launching, a pair of standing ways is erected under the hull and out onto the barricades. The surface of the ways is greased. ([[Tallow]] and [[whale oil]] were used as grease in sailing ship days.)<ref name="statestreet">{{Cite book| author-link = State Street Corporation – State Street Trust Company| author = Walton Advertising and Printing Company, Boston.| title = Some ships of the clipper ship era, Their builders, owners, and captains| publisher = Printed for the State Street Trust Company| year = 1913| location = Boston, MA| page = 18}}</ref> 
A pair of sliding ways is placed on top, under the hull, and a launch cradle with bow and stern poppets is erected on these sliding ways. The weight of the hull is then transferred from the build cribbing onto the launch cradle. Provision is made to hold the vessel in place and then release it at the appropriate moment in the launching ceremony; common mechanisms include weak links designed to be cut at a signal and mechanical triggers controlled by a switch from the ceremonial platform.

On launching, the vessel slides backwards down the slipway on the ways until it floats by itself.<ref>[https://books.google.com/books?id=pigDAAAAMBAJ&q=Popular+Science+1931+planeHowBiggest&pg=PA36 Ship Was Safely Launched, February 1933, Popular Science] slipway and launching of French passenger liner Normandie in 1933 – excellent drawing and illustrations showing basics of process</ref>

===Sideways===
[[File:Launch of USS St. Louis at Marinette Marine, Wisconsin (USA), on 15 December 2018 (181215-N-N0101-198).JPG|alt=|thumb|Sideways launch of littoral combat ship {{USS|St. Louis|LCS-19}} in 2018]]
Some slipways are built so that the vessel is side-on to the water and is launched sideways. This is done where the limitations of the water channel would not allow lengthwise launching, but occupies a much greater length of shore. ''[[SS Great Eastern|The Great Eastern]]'' designed by [[Isambard Kingdom Brunel|Brunel]] was built this way, as were many [[landing craft]] during [[World War II]]. This method requires many more sets of ways to support the weight of the ship.

===Air-bag===
{{main article |Airbag launching}}
Sometimes ships are launched using a series of inflated tubes underneath the hull, which deflate to cause a downward slope into the water. This procedure has the advantages of requiring less permanent infrastructure, risk, and cost. The airbags provide support to the hull of the ship and aid its launching motion into the water, thus this method is arguably safer than other options such as sideways launching.<ref>{{cite web|url=http://max-groups.com/ship-launching-airbags-best-ship-launching-method/|title=Ship Launching Airbags, the best ship launching method?|work=Max Groups Marine|date=25 October 2016 |url-status=live |archive-url=https://web.archive.org/web/20230417091651/https://max-groups.com/ship-launching-airbags-best-ship-launching-method/ |archive-date= Apr 17, 2023 }}</ref> These airbags are usually cylindrical in shape with hemispherical heads at both ends.