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A Solution to the Inherent List on Nimitz Class Aircraft Carriers

A Solution to the Inherent List on Nimitz Class Aircraft Carriers

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1.3.7 Ballast Additi<strong>on</strong><br />

1.3.7.1 Water Ballast<br />

Special preparati<strong>on</strong> would be required for all tanks or voids using locked-in water ballast<br />

<str<strong>on</strong>g>to</str<strong>on</strong>g> correct <str<strong>on</strong>g>the</str<strong>on</strong>g> starboard inherent list. The sp<strong>on</strong>s<strong>on</strong> voids, in particular, are coated with epoxy over<br />

an inorganic zinc primer; this is suitable for installati<strong>on</strong> of water ballast, but <strong>on</strong>ly for a period of<br />

up <str<strong>on</strong>g>to</str<strong>on</strong>g> five years if it is intact. Preparati<strong>on</strong> of <str<strong>on</strong>g>the</str<strong>on</strong>g> sp<strong>on</strong>s<strong>on</strong> voids for installati<strong>on</strong> of water would<br />

require inspecti<strong>on</strong> and possibly repair of <str<strong>on</strong>g>the</str<strong>on</strong>g> existing coating systems. Ano<str<strong>on</strong>g>the</str<strong>on</strong>g>r problem with<br />

using water as a source of ballast is that it is difficult <str<strong>on</strong>g>to</str<strong>on</strong>g> provide a sufficient amount of water<br />

ballast in a space judicious manner in order <str<strong>on</strong>g>to</str<strong>on</strong>g> provide enough permanent list correcti<strong>on</strong>.<br />

Although water is an inexpensive material, utilities would have <str<strong>on</strong>g>to</str<strong>on</strong>g> be relocated <str<strong>on</strong>g>to</str<strong>on</strong>g> o<str<strong>on</strong>g>the</str<strong>on</strong>g>r spaces<br />

and <str<strong>on</strong>g>the</str<strong>on</strong>g> tanks <str<strong>on</strong>g>the</str<strong>on</strong>g>mselves cannot be partially filled.<br />

1.3.7.2 Solid Ballast<br />

For purposes of this project, lead was not c<strong>on</strong>sidered as an opti<strong>on</strong> due <str<strong>on</strong>g>to</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> tremendous<br />

handling expenses and associated carcinogenic problems. Instead, a pumpable slurry of ir<strong>on</strong>-ore,<br />

known as Perma Ballast®, was examined as a possible source of solid ballast. Ballast<br />

Technologies Inc. (BTI) has been a provider and installer of Perma Ballast® since 1983. Their<br />

product is widely acknowledged <str<strong>on</strong>g>to</str<strong>on</strong>g> be <str<strong>on</strong>g>the</str<strong>on</strong>g> quickest and most cost-effective method of ballast<br />

installati<strong>on</strong>. All materials, including <str<strong>on</strong>g>the</str<strong>on</strong>g> fluid used <str<strong>on</strong>g>to</str<strong>on</strong>g> install <str<strong>on</strong>g>the</str<strong>on</strong>g> ballast, are naturally occurring,<br />

n<strong>on</strong><str<strong>on</strong>g>to</str<strong>on</strong>g>xic, n<strong>on</strong>-corrosive and envir<strong>on</strong>mentally safe. No gases or vapors are generated and no<br />

special handling is required up<strong>on</strong> installati<strong>on</strong> or removal.<br />

Minimal vessel modificati<strong>on</strong> is required <str<strong>on</strong>g>to</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ship, <str<strong>on</strong>g>the</str<strong>on</strong>g>reby providing savings <str<strong>on</strong>g>to</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

shipyard. Jobs are not generally subc<strong>on</strong>tracted out, <str<strong>on</strong>g>the</str<strong>on</strong>g>reby cutting out <str<strong>on</strong>g>the</str<strong>on</strong>g> middle man and<br />

making this product more competitive. Prior <str<strong>on</strong>g>to</str<strong>on</strong>g> installati<strong>on</strong>, engineers and key pers<strong>on</strong>nel inspect<br />

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