Unique Replacement Method Developed for the U.S. Navy’s Newest Gas Turbine Powered Warship

The Navy’s newest big-deck Amphibious Assault Ship, LHD 8 Makin Island, is currently under construction and scheduled for delivery in late 2008. LHD 8 utilizes a gas turbine propulsion system that replaces the steam propulsion system used on the previous seven ships of the class. LHD’s are similar in design to aircraft carriers with a full length flight deck and island to the starboard side. Additionally the LHD 8 machinery spaces are directly below storage decks for mission equipment. Because of internal arrangements and the convoluted routes of the intake ducting the traditional method of removing the gas turbines through the superstructure via shore side crane was not possible. The LHD 8 will utilize a method of change out from within the ship. The paper will discuss the design considerations involved in developing this changeout method as well as a review and discussion of the physical changeout demonstration conducted by the shipbuilder. The paper will discuss the design development process such as the environmental qualifications of ship hardware, ship integrity and survivability, special tooling developed for LHD 8, differences from the traditional changeout methods as well as the US Navy’s maintenance philosophy for this ‘first-of-class’ ship design. Included in the paper will be ship drawings, photos and diagrams of the change out hardware, removal routes, special tooling and support equipment.