Double bottom

Double bottom
Single hull, Double bottom, and Double hull ship cross sections. Green lines are watertight; black structure is not watertight

A double bottom is a ship hull design and construction method where the bottom of the ship has two complete layers of watertight hull surface: one outer layer forming the normal hull of the ship, and a second inner hull which is somewhat higher in the ship, perhaps a few feet, which forms a redundant barrier to seawater in case the outer hull is damaged and leaks.

The space in between the two bottoms is often used as storage tanks for fuel or ballast water, though fuel storage in the double bottom is not allowed for newbuilt ships since 2007, due to MARPOL_73/78.

Double bottoms are significantly safer than single bottoms. In case of grounding or other underwater damage, most of the time the damage is limited to flooding the bottom compartment, and the main occupied areas of the ship remain intact. For this reason, double bottoms have been required in all passenger ships for decades as part of the Safety Of Life At Sea or SOLAS Convention.

An even more extensive protection is available as a double hull, where the second hull layer extends up the sides of the ship as well as in the bottom.

A double bottom also conveniently forms a stiff and strong girder or beam structure with the two hull plating layers as upper and lower plates for a composite beam. This greatly strengthens the hull in secondary hull bending and strength, and to some degree in primary hull bending and strength.

See also


Wikimedia Foundation. 2010.

Нужна помощь с курсовой?

Look at other dictionaries:

  • Double Bottom — A charting pattern used in technical analysis. It describes the drop of a stock (or index), a rebound, another drop to the same (or similar) level as the original drop, and finally another rebound. The double bottom looks like the letter W . The… …   Investment dictionary

  • double-bottom — /dub euhl bot euhm/, n. See tandem trailer (def. 1). * * * doubˈle bottˈom or double bottom lorry noun An articulated lorry pulling a second trailer (also drawbar outfit) • • • Main Entry: ↑double …   Useful english dictionary

  • double bottom — A term used in technical analysis to refer to the drop of a stock s price, a rebound, and then a drop back to the same level as the original drop. Bloomberg Financial Dictionary double top, bottom A bar chart formation that signals a possible… …   Financial and business terms

  • double bottom — In chartist analysis, the situation in which the prices of a security fall, then rise, then fall again to the same level, producing a W pattern on a graph. This pattern is thought to indicate that the security has much support at the price at the …   Big dictionary of business and management

  • double bottom — noun 1. : the space in a ship between the inner bottom and the shell plating 2. : a market decline on the stock exchange characterized by two successive low points and regarded by chart readers as a prelude to a recovery compare double top …   Useful english dictionary

  • double bottom — Compartments at the bottom of a ship between inner bottom and the shell plating, used for fresh water, ballast water, fuel oil, etc …   Dictionary of automotive terms

  • double bottom — having two bottoms, having a false bottom (of a suitcase, briefcase, etc.) …   English contemporary dictionary

  • double-bottom — /dub euhl bot euhm/, n. See tandem trailer (def. 1). * * * …   Universalium

  • DOUBLE BOTTOM — Кривая цены отобразила букву W, в которой цена опустилась дважды и остановилась на (или возле) таких же низах …   Малая энциклопедия трейдера: глоссарий к книге

  • DOUBLE BOTTOM — (двойное дно) достижение ценой минимального уровня дважды; показывает уровень цен, при котором сохраняется устойчивый спрос на валюту и где в игру вступают быки; …   Глоссарий финансовых и биржевых терминов

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”