A Solution to the Inherent List on Nimitz Class Aircraft Carriers

Departments of Ocean Engineering and Civil and Environmental Engineering on May 07, 2004. - 159 с.Перечень заложенных решений на авианосцах класса Нимиц. На англ. яз.Nimitz class aircraft carriers possess an inherent list to starboard that their list control systems (LCS) are typically unable to correct while under Combat Load Conditions. As a result, it has become necessary to use fresh water ballast in a number of inner bottom voids and damage control voids to augment the LCS. Maintaining liquid ballast in damage control voids is unacceptable, as it reduces the design counter flooding capability of the ship, and thus reduces ship survivability. In order to restore the ships operational flexibility and achieve the necessary/desired list correction, this study determines the effect of adding solid ballast to a series of voids/tanks identified on the 2^nd, 4^th, and 8^th decks.
Based on ballast density, tank location and capacity, ease of ballast installation, minor tank structural modifications, and a decision making cost analysis, solid ballast was determined to be the most advantageous for use in correcting the inherent list on the Nimitz class aircraft carriers. Fresh water ballast was also examined as a possible alternative, but not as extensively due to the large quantity of water required and its limited ability to achieve a list correction.Abstract.
Acknowledgements.
Table of Contents.
List of Figures.
List of Tables.
List of Appendices.
Introduction.
Motivation.
Background.
Past Research.
Stability.
Survivability.
Displacement Limits.
KG Limits.
Present Options.
Continue to operate using inner bottom and DC voids.
Add a list control tank on the port side.
Move or exchange compartment spaces.
Convert a current DC void(s) to a JP-5 tank(s) and pump last.
Future ship alterations and modifications.
Re-examine current List Control System.
Ballast Addition.
Water Ballast.
Solid Ballast.
Option Selection.
Preliminary Analysis and Results.
Tank Selection.
Modeling Analysis Performed.
Preliminary Decision-Making Cost Estimation.
Structural Analysis.
Structural Modifications.
Modifications to the 2^nd Deck.
Modifications to the 4^th Deck.
Modifications to the 8^th Deck.
Final Analysis and Results.
Final POSSE Results.
Final Cost Estimation.
Ease of Removal.
Evidence Perma Ballast® is non-corrosive.
Conclusion.
Recommendations.
References.
List of Figures.
Stresses in rectangular plates under uniform lateral pressure.
2^nd Deck Compartment 2-165-8-V.
2^nd Deck Compartment 2-165-8-V, transverse section.
4^th Deck Compartment 4-165-4-V.
8^th Deck Compartment 8-225-6-V.
List of Tables.
CVN 68 Class Delivery Data and Class Predictions as of 11/17/03.
Deck Location Cost Comparison.
Required Structural Modifications for 2-165-8-V.
Required Structural Modifications for 4-165-4-V.
Required Structural Modifications for 8-225-6-V.
Final Cost, Weight Addition, and Change in KG Comparison.
List of Appendices.
Appendix A: Tank Location Study.
Appendix B: Preliminary POSSE Modeling Results.
Appendix C: Preliminary Cost Estimation Data and Worksheets.
Appendix D: Preliminary Cost Comparison.
Appendix E: Complete Structural Analysis.
Appendix F: Final POSSE Modeling Results.
Appendix G: Final Cost Estimation Data and Worksheets.