Talk:Double hull

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[edit] CONTRADITIONS IN ARTICLE

It has been widely reported after the Valdez spill, and many other non-Exxon spills, that double hull tankers are now required world-wide. If that's the international law, there's nothing I can do about it. A criminal is defined as some entity or person who willfully violates a law, or the spirit of a law. That's not my definition of international treaty law. Arguing against a treaty is fine, but denying the treaty obligations already made is criminal.

The main reasons given at the beginning of the article for double hull ships are totally ignored when the section on oil tankers begins. This is illogical and impossible to reconcile. For example, it is stated that double hulling any ship provides another level of structural strength. Why would we not want tankers to have stronger hulls as well? The explosive gas problem of double hulls doesn't exist on anything but tankers, hunh??? Do you guys know that any ship carries more than enough fuel to leak into its double hull, and any other compartment below deck, regardless of whether it's a tanker or not. If explosions on double hull ships were a problem, they wouldn't do that to passenger ships which all have double hulls, now would they? If explosions are a problem, then provide better ventilation to those areas and more frequent inspections, gas monitors, etc. The reason the industry doesn't want double hulls is because they're not willing to spend the money or maintain the hulls of their ships, and are, technically speaking, criminals.

Imagine if the FAA starting ordering all the mechanics to stop inspecting the wings spars of all airliners since it's too expensive and difficult. Saving bucks is what they're trying to argue for. Double hull ships are considerably more expensive than single hull ships. Recently, a few river tankers broke up coming from the Ukraine headed for the black sea. I think it was 3 or four in one storm with considerable loss of life. Perhaps double hulling would not have helped those wretched sailers. Perhaps it would've. P5g4xn (talk) 00:33, 18 February 2008 (UTC)

[edit] Exxon Valdez

Regarding this section, I don't think the word 'ironic' is used properly. --Bigdavesmith 00:39, 27 May 2007 (UTC)

I added a citation tag to the claim that a double-hull would not have prevented the spill. As far as I can tell, although few claim the spill would have been prevented, a report by the Coast Guard estimated that leakage would have been reduced by at least 25% and as much as 60% if the vessel were built with a double-hull. So although the statement is (probably) true, it doesn't seem to tell the whole story, so perhaps a non-neutral tag would be appropriate.

I'm reading an article from late 2000 right now that cites a 25% figure, but if anyone can find something more recent and more complete, that'd be great. Or if someone could explain to me how the article does tell the whole story, that'd be great, too. I don't know much about it, but I've always heard and read that a double-hull would have helped.

http://www.sabew.org/sabewweb.nsf/e0087b5460c4a721862569c2005fa85a/c55130a3122cde2486256ae2005cf6b5!OpenDocument (December 2000)

http://www.adn.com/evos/stories/T99032456.html (May 1999)

http://www.adn.com/evos/stories/EV425.html (originally published 1989)

68.9.205.10 19:53, 31 March 2006 (UTC)

[edit] Citations

Old uncited-tagged passages may be removed at any time. You are NOT to revert these deletions UNLESS the requested source is provided. This is wiki policy, not up for debate. Georgewilliamherbert, you say the passages you reverted are "correct, though uncited". Truth is NOT crtiteria for inclusion in Wikipedia; citation is. Alvis 06:38, 14 June 2007 (UTC)

Um, no. WP:RS doesn't mean that everything in the encyclopedia has to be cited or removed. The {{fact}} tag just means that someone doubted it, and would like it sourced. That doesn't mean that anyone can apply such a tag to arbitrary WP text, and then remove the text if it's not cited. Everyone is expected to use good judgement. Georgewilliamherbert 19:45, 14 June 2007 (UTC)
Wikipedia:Verifiability states "Any edit lacking a source may be removed, but editors may object if you remove material without giving them a chance to provide references." This tag existed for four months. If you had a problem with the tag, the proper procedure would have been to find a source for it, not throw a fit when the article's being cleaned of uncited passages. I see you've gone and found cites for some of the passages now. THAT'S what you do when you don't like the tags littering the article, NOT reverting legitimate clean-up. Alvis 02:32, 15 June 2007 (UTC)
And I quote:
Material that is challenged or likely to be challenged needs a reliable source, which should be cited in the article.
Challenging something merely because it's not sourced is abuse of WP:V. Unless you have a reason to disagree with the article, you shouldn't be deleting things.
Speaking of which, what is your disagreement with the Mid-deck tankers comment? Georgewilliamherbert 03:34, 15 June 2007 (UTC)
Someone ELSE challenged it, no one responded to the challenge, so it's GONE. My only problem is that it's uncited. To quote Jimmy Wales "I can NOT emphasize this enough. There seems to be a terrible bias among some editors that some sort of random speculative 'I heard it somewhere' pseudo information is to be tagged with a 'needs a cite' tag. Wrong. It should be removed, aggressively, unless it can be sourced." Alvis 05:49, 15 June 2007 (UTC)

[edit] Third opinion

I've got a few points of view on this. First, it often takes someone threatening to delete something to get something done. Bottom line is: Get those sources on, before the facts are gone for good. Sourcing the material in question is hands down the best way to resolve this. That said, perhaps the deleter could move the information to the talk page, rather than completely deleting. This would give time to source, and would avoid loss of information, while still encouraging people to cite their sources. Wrad 06:00, 15 June 2007 (UTC)

Thanks for stepping in. You provide a good alternative; for the tagged passages that GWH hasn't provided sources for, I'll start a section on the talk page in case another editor can find them. Alvis 06:06, 15 June 2007 (UTC)

[edit] Citation needed

If you are able to provide a citation for passages listed below, please do so, and re-integrate the cited passage into the article:

Many in the Shipping Industry consider the Mid-Deck Tanker to be a much more efficient and safer design.[citation needed]

[edit] Purpose

Let's not forget that the primary purpose of double hulls is actually not protection, but elimination of dual-purpose tanks. In a single-hull tanker, the tanks store ballast when empty, so a lot of oil washes into the sea just in normal operation. Double-hull oil tankers use interhull space as ballast tanks.

Besides, there are chemical tankers, with sufficient space to actually prevent spills. Double-hulls, if using corrugated bulkheads, can also have "clean" tanks, easy to wash, for multiple products. So I suggest we find some source and add this info. Double hulls aren't just a safety measure. CP/M comm |Wikipedia Neutrality Project| 21:39, 14 June 2007 (UTC)

No, the reason for double hulls is to protect. Tankers haven't used multipurpose tanks for many decades, since the oil released by doing so became controversial in the 70s. IMO regulations in the 70s and 80s required separate ballast and cargo tanks for oil tankers; the Exxon Valdez, for example, had port and starboard ballast tanks along half of the hull sides, alternating with cargo tanks. Georgewilliamherbert 22:32, 14 June 2007 (UTC)
In part, this was a reason. However, it was not protection, but tank separation requirement which made double hulls practical [BTW, regulations differed quite a bit between countries]. A major issue of double hull structure is wasted interhull space; its use for the imminent dedicated water tanks was the major push making double-hull oil tankers economically feasible enough. Protection was a factor, but not the only one. Where it really is, e.g. chemical tankers, the 20% double hull width standard is used (40% sides only). In oil tankers, only the requirements for ballast tank size determine the double hull width. CP/M comm |Wikipedia Neutrality Project| 12:16, 16 June 2007 (UTC)

Howdy all

Quick note - (I'm new to this!) I note that the text says 'double hulls are significantly safer'. I'd like to see an authoritative statement for that. All the professional maritime sources I've ever spoken to are pretty unanimous that double hulls make things WORSE! There's even a study to that effect from the European Martime Safety Agency.

Cheers

Jimmec (talk) 13:30, 16 January 2008 (UTC)

[edit] Question

[edit] Question

Is double hull used in merchant ships?