An operational effectiveness analysis of legacy and future mine countermeasures systems using discrete event simulation

This paper conducts an operational analysis of legacy and future mine warfare systems using discrete event simulation. The research focuses on a comparative analysis of the MCM-1 Avenger ship, supported by the MH-53E helicopter, and the Littoral Combat Ship, supported by external unmanned systems, in active, defense mine countermeasures operations. The paper develops architectural representations of the functional activities associated with mine countermeasures operations, as well as architectural representations of past, current, and potential future physical entities involved in minehunting and mine neutralization. Those architectural representations are used as the basis for the development of two distinct discrete event simulation models, one corresponding to legacy (MCM-1 Avenger) operations and another corresponding to future (Littoral Combat Ship) operations. The results of the simulation are analyzed using statistical regression. The regression results indicate that the key performance drivers for both the legacy and future systems show considerable overlap, and also suggest that the legacy assets meet or exceed the performance of future assets in several measures of effectiveness. The simulation model for the future assets is reconsidered to develop recommendations regarding alterations to the future force that enable the future force to exceed the operational performance of the legacy force.

Preserving Logistical Support for Deployed Battle Groups in Hostile Environments

The U.S. Navy's at-sea replenishment system is a mobile supply line designed to support the deployed carrier task force (CTF)/cruiser/destroyer (CRUDES) surface action group (SAG) and forward deployed units while at sea. In the Pacific, the main component of the mobile supply line, the combat logistics force (CLF) ship, has become a possible target with the development of the anti-ship ballistic missile. With the ability to target and disable a CLF, an enemy can now disable a deployed CTF/CRUDES fleet by eliminating its required resources. With the goal of preserving the CLF's capabilities to perform its mission while avoiding ASBM threat, the authors consider the possibility of utilizing a “mini-CLF” to shuttle fuel between CLFs operating in a safe environment and warships operating in a threat zone. The authors perform two analyses: they (1) analyze the feasibility of using the Littoral combat ship/joint high-speed vessel, reconfigured as a shuttle to transport resources, and (2) analyze requirements for development of a new class of ships to support the CTF/CRUDES SAG while deployed in the Pacific.

Shock-Qualified Stern Tube Seal with Improved Capabilities and Reduced Total Ownership Cost

Stern tube seals are a critical component in a ships propulsion system, sealing the shafts penetration through the hull. Stern tube seals can result in a significant maintenance burden when they are unable to handle the operational conditions of the vessel. Current systems are also lacking a capability to be able to operate through a primary seal failure, something that should be critical to the United States Navy. The United States Navy’s Independence-class littoral combat ship (LCS) has challenging operational conditions including the need to survive shock loads, high shaft speed and significant galvanic corrosion potential. Through a five-year effort the authors developed a stern tube seal for LCS that could handle the challenging operational conditions and provide the Navy with new critical capabilities such as the ability to operate propulsion systems through a primary seal failure without the use of packing and to extend maintenance windows to reduce vessel downtime and associated cost. This paper will present the limitations and challenges of existing stern tube seals, followed by the design improvements developed by the authors to improve performance and reliability while also reducing the total ownership cost for the U.S. Navy.

Selection and Development of the World’s Most Power-Dense Gas Turbine Module for the New Korean Frigate

The MT30 marine gas turbine has been developed specifically for 21st century naval propulsion using modern techniques and methods. Design and development of the MT30 began in 1999 and has since been qualified for naval service following extensive testing. Since then the engine has rapidly been adopted by progressive navies, in both its mechanical and electrical power generation configuration. The Lockheed Martin Littoral Combat Ship (LCS) is one of a new class of United States Navy (USN) fast combatants which has been at sea for more than six years and is powered by the MT30. A combined MT30-driven generator was selected for the new USN DDG1000 Zumwalt class of destroyer and has also been successfully installed into the Royal Navy’s Queen Elizabeth Class aircraft carrier. Most recently, the MT30 Compact Package has been selected to power the Royal Navy’s Type 26 Global Combat Ship which will be built by BAE Systems. The MT30 Compact Package has been designed with the aim of powering modern warship programmes, with the result that it is currently the World’s most power dense in-service marine gas turbine. This is an important factor in naval propulsion where delivering a high power output in a compact space is essential. In addition to the programmes stated above, the MT30 Compact Package was selected for the new Republic of Korea Navy’s (RoKN) frigate programme with a single-GT CODLOG hybrid arrangement consisting of propulsion motors and a Diesel-electric system. As a result, Rolls Royce was selected by the RoKN to deliver the MT30 Gas Turbine Unit and, from a preliminary Rolls-Royce compact package design, the engine and machinery division of Hyundai Heavy Industry (HHI-EMD) has developed the Compact Package for the New Korea Frigate. The MT30 GT was delivered to the HHI-EMD facility in 2014 with the surrounding Compact Package built at HHI-EMD before onward delivery to Daewoo Shipbuilding and Marine Engineering (DSME) where construction of the first frigate will take place. This paper provides the rationale for selection of the MT30 Compact Package for the New Korea Frigate Programme and also describes the development of the MT30 Compact Package; aspects of the design process, construction of the Compact Package and the factory acceptance test conducted at the HHI-EMD facility.

Concept Exploration Methods for the Small Surface Combatant

In 2014, the Small Surface Combatant Task Force completed an innovative study on alternate proposals to procure a capable and lethal small surface combatant. Modified Littoral Combat Ship (LCS) concepts, new design concepts, and existing design concepts were examined. This paper describes the set-based design approach employed to conduct this study.