bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineered Approach to Effective Maintenance Management
Authors: CIERI ANTHONY M. , ELFONT MARK M.
Published: March 2009

The Assessment of Equipment Condition (AEC) Program at the Naval Ship Systems Engineering Station has been providing shore based support to assess the condition of shipboard equipment. This paper examines some of the limitations of the existing process. The paper offers an engineered approach to provide condition assessment on board ship and the shore side support necessary to maximize the effectiveness of the total ship maintenance process. The recommended approach uses existing technology and current hardware and software applications. Included in the approach is the use of microcomputer machinery work stations with expert system software, and a central Condition Maintenance Information System with the capability to provide work packages based on condition assessment and to trend the effectiveness of maintenance decisions. The paper identifies a phased implementation with a limited pilot program prior to fleet wide involvement.
New Techniques in Weapon Firing Cutout Zone Design
Authors: GEORGE EVERETT
Published: March 2009

Weapon pointing and firing zones are critical operational parameters which directly affect the safety and capability of weapon performance and ship mission. These zones are normally implemented in the weapon system and restrict areas of weapon movement and function allowing clearance for ship structure during weapon performance. The primary purpose of the zones is to ensure topside safety by preventing the weapon from firing into surrounding ship structure. Weapon pointing and firing zones are also used to integrate weapon and other shipboard equipment functions to avoid interference conflicts.

The Naval Surface Warfare Center (NAVSWC) is the technical direction agent which designs weapon pointing and firing zones for every large caliber gun mount and rotating missile launcher on U.S. Navy ships. Because of the increasing complexity of topside operations and applications in computer technology, new methods are being developed to support NAVSWC weapon zone design efforts.

This paper first summarizes present techniques in NAVSWC weapon zone analysis and design. The second part of the paper describes methods under development using graphic computer systems to conduct safety analyses for weapon zone design. The paper concludes with a review of future weapon cutout system improvements.
Total Quality Management and its Application to F‐14 Depot Maintenance
Authors: ROBBINS THOMAS , SHEN TERRY W.T. , WILBAT BRUCE B.
Published: March 2009

Understanding the concepts of quality costs through the reduction of waste and process variation is fundamental to the TQM philosophy. The evolution in U.S. quality control demands a shift from the traditional method of auditing the finished product and improving quality by fixing problems to a method of auditing processes. Likewise, TQM demands proper use of statistical process control and continuous training of management and the work force to ensure continuous improvement and productivity.

This paper discusses how the Naval Aviation Depot (NADEP) Norfolk, Virginia, as an example of U.S. industry, employed the new management philosophy of TQM to reduce costs and boost productivity and efficiency. A specific application of TQM is highlighted with the preparation and implementation of the F‐14 aircraft maintenance competition program. As part of this effort, the Norfolk depot's challenge was to streamline operations to minimize the cost of scheduled maintenance on a delivered F‐14, while simultaneously maintaining quality. The competition against private industry for the aircraft workload provided unique opportunities to use TQM to make cultural changes throughout the depot. Norfolk would demonstrate that quality products are more a function of employee knowledge and interaction than the application of traditional quality control technology.
Improving the Ship Design, Acquisition and Construction Process
Authors: RYAN J. CHRISTOPHER , JONS OTTO P.
Published: March 2009

In the spring of 1990, the NavSea Chief Engineer initiated a project to improve the design, acquisition and construction (DAC) of U.S. Navy ships. The project's objectives are to reduce the time and cost of acquiring and operating Navy ships while improving their quality. unlike previous studies on the subject, the project utilizes a rigorous process analysis approach and attempts to use quantitative measures as the basis for recommending improvements.

The paper is, of necessity, a status report on the progress of this project. Topics covered include: the DAC process; a look at the current state of ship acquisition time, cost, and quality; the methodology for process improvements; and early findings.
VSCF Cycloconverter Ships Service Power Equipment
Authors: HULTGREN KENNETH J.
Published: March 2009

Propulsion derived ships service (PDSS) power systems offer significant potential savings to the Navy by eliminating the need for independent diesel and gas turbine‐generator sets to produce ships service power. With PDSS, both the propulsion system and generator are driven by the main engine(s) to reduce fuel consumption, equipment weight and space, and maintenance costs.

Shaft driven power takeoff (PTO) ship systems have been the forerunners of PDSS on commercial vessels, but the Navy's more stringent requirements for wide speed range and high power quality are beyond PTO's limited capabilities. Newer technologies are needed that are more versatile. This paper concentrates on the high frequency generator/cycloconverter (HFG/CCV) based variable speed constant frequency (VSCF) system, which brings inherent advantages to PDSS application. These include additional savings in size and weight via use of compact high frequency equipment, a wide electrical speed range, and stable, clean DoD‐Std‐1399 Type I ships power.

HFG/CCV‐based systems up to 3000 kW capacity over a 3‐to‐1 electrical speed range are described, as are alternative PDSS hybrid systems where a speed range expander gear is employed. This enables the use of either smaller, narrow range PDSS equipment, or wider propulsion ranges between PDSS beyond 3‐to‐1. PDSS equipment layout drawings are included for engine room evaluation, along with a detailed weight and space comparison between PDSS, a T‐AO 187 PTO System, a stand‐alone gas turbine generator set, and a diesel turbine‐generator set to show the savings that can be achieved by HFG/CCV‐based PDSS systems.
Electronic Warfare Testing Utilizing an Improved AN/ULM‐4 Test Range
Authors: WHITE LAWRENCE C.
Published: March 2009

Electronic warfare (EW) systems aboard surface ships have become increasingly complex and currently face multiple simultaneous threats. The primary shipboard EW system in the United States Navy is the AN/SLQ‐32 system, which is designed to provide detection and active jamming against incoming missile threats. The AN/ULM‐4 test range has been utilized to conduct operational readiness testing of this system for many years. Numerous deficiencies of the AN/ULM‐4 have been identified and documented.

The complexity of current EW systems has demanded that the capabilities of the AN/ULM‐4 test range be significantly improved. The redesign of the AN/ULM‐4 to correct these deficiencies is presented. This redesign represents a significant increase in test range capability which has been debated and discussed for over ten years. Particular attention is paid to effects certain design constraints had on the decision making process during the course of the redesign.
Royal Australian Navy Readiness Based Sparing
Authors: SANDERS REGINALD
Published: March 2009

In 1985, the Royal Australian Navy made a commitment to using readiness based sparing in support of their Seahawk project For the first time, sparing decisions at all supply locations were to be determined simultaneously with a single focus on equipment readiness. To meet this challenge, an advanced readiness sparing model was designed and developed. In addition to a robust multi‐echelon/multi‐indenture capability, the model was fitted with many new and unique features. For example, it recognized commonality of parts not only within an aircraft configuration but also across different aircraft types with common supply support. It allowed for variable operating tempos and readiness goals for deployed and non‐deployed aircraft, and it provided a supply and maintenance representation flexible enough to accurately model the RAN's real world support structure.
Structural Reliability Assessment with Ambiguity and Vagueness in Failure
Authors: AYYUB BILAL M. , LAI KWAN‐LING
Published: March 2009

Engineering projects and designs are commonly developed in a systems framework that includes different types of uncertainty. In general, uncertainty can be of either the ambiguity or vagueness type. The theory of probability and statistics has been extensively used in engineering to deal with the ambiguity type of uncertainty. The theory of fuzzy sets and systems has been used to model the vagueness type of uncertainty in many engineering applications. In this paper, the role of fuzzy sets in engineering systems is described using a selected example area that deals with vagueness in failure definition as used in solving structural reliability problems. The reliability of a structure is commonly based on an explicit definition of failure, making structural reliability dependent on this definition. The vagueness in the perception of damage and failure introduces another class of uncertainty, in addition to the commonly realized and modeled class of uncertainty, i.e., ambiguity. In this study, a methodology for reliability assessment of structures based on a fuzzy definition of failure is developed. The significance of the contribution is in providing the reliability of the structure over a damage spectrum.
Propulsion Powered Electric Guns: A Comparison of Power System Architectures
Authors: DOYLE TIMOTHY J. , GRATER GUY F.
Published: March 2009

Alternative power system architectures and interface technologies for driving high energy pulsed loads from the propulsion equipment of surface combatants are compared. Gas turbine mechanical and gas turbine Integrated Electric Drive (IED) propulsion trains are considered as prime power sources. Focus is on the energy path between the ship's prime power and the pulsed load, comparing system candidates on a size, weight and component cost basis. A capacitor based Pulse Forming Network (PFN) supplying an Electro‐Thermal (ET) Gun is utilized as the common load for all configurations. Results indicate that dedicated auxiliary generators driven from propulsion gas turbine engines is the preferred method of powering electric gun PFNs from ship drivetrain equipment. Auxiliary generator‐based systems are compact and lightweight over a wide power range, are equally attractive with both electric and mechanical drive trains and demonstrate retrofit potential to the current fleet.
A Methodology for Evaluation of Ship Fire Safety
Authors: SPRAGUE CHESTER M. , RICHARDS ROBERT C. , BLANCHARD LCDR. MARC A.
Published: March 2009

The overall fire safety of a ship is not obvious. It is dependent on many factors including the vast number of fire scenarios that are possible. A means is required to evaluate a ship for the many types of fires it may be subjected to. The analysis should show what would happen if various alternatives such as protected cable trays, better fire boundaries, or improved fire detection had been used. The Ship Fire Safety Engineering Methodology (SFSEM) provides an integrated framework for analyzing fires on ships in comparison to established fire safety objectives. It accounts for all relevant aspects; the behavior of fire, the effectiveness of passive design features, automated suppression systems, barrier materials, flame spread paths, and manual firefighting.

The Ship Applied Fire Engineering (SAFE) computer programs implement SFSEM and evaluate the probability of spaces and barriers limiting a fire. The evaluation is conducted on a compartment‐by‐compartment basis. It incorporates the fire growth hazard with the probabilities of ignition, automated fire suppression, manual fire suppression, and barrier effectiveness. SAFE calculates the probable paths of fire spread based on time durations. SFSEM/SAFE has been used successfully in a design application and in a retrofit situation.
An AI‐based Decision Support System for Naval Ship Design
Authors: CHOU YU‐CHAO , BENJAMIN COLIN O.
Published: March 2009

Naval ship design is a complex, iterative decision‐making process that requires not only qualitative reasoning and quantitative computations, but also effective handling of massive amounts of information. The development of a systematic procedure in the form of an interactive Decision Support System (DSS) incorporating artificial intelligence (AI) techniques can assist in improving the design process.

The DSS reported in this paper integrates conventional naval ship design application software with an expert system. Modeling techniques such as a spreadsheet, a database management system, and graphic display capability are incorporated as well. This DSS facilitates “what‐if” analysis of design problems and assessment of the trade‐offs between performance and cost.

The DSS will aid rapid generation of design alternatives and facilitate their evaluation. A final recommendation is made based on multiattribute decision analysis using the straightforward points allocation method and the analytic hierarchy process. During a typical consultation process, the user is prompted for inputs to the naval ship design process and is provided with a wide range of reports in graphical and numerical form.

During a structured system evaluation, the DSS displayed considerable accuracy, flexibility, speed, user‐friendliness, and cost‐effectiveness. The reliability and validity of the system were also confirmed. These evaluation procedures provide a replicable methodology for verification and validation of this type of AI‐based decision support system.
Test of Closed‐Loop Degaussing Algorithm on a Minesweeper Engine
Authors: WINGO ROBERT A. , HOLMES JOHN J. , LACKEY MILTON H.
Published: March 2009

A closed‐loop degaussing technique for MCM (mine countermeasure) class vessels has been developed and tested on a minesweeper engine. The system was designed to accurately predict and degauss the off‐board magnetic field signatures from measurements taken on‐board a non‐magnetic hull naval vessel. Calibration procedures for an on‐board to off‐board signature prediction algorithm have been investigated. An onboard sensor configuration, that requires only four single axis gradiometers, has been shown to accurately predict the magnetic signatures of the full‐scale engine.
The Type 23 Frigate—Britain's ASW Frigate for the Nineties
Authors: McKENZIE KENNETH J. , MOORES NIGEL
Published: March 2009

The Type 23 frigate is a design which has provided a highly capable warship at an affordable cost, both in acquisition and, by driving down the manpower costs, in operation. This paper aims to outline the procurement strategy, hull form, structural and machinery fit, signature control, manpower and production factors which have combined to influence the design and construction of the ships, a class whose primary aim is ASW. Although the paper does not specifically address weapon fit or combat system design, these issues have been significantly affected by the more fundamental design factors which, taken together, have contributed in large measure to the overall fighting capability of the class.
Industrialization of the Spray Forming Process for Military Applications
Authors: MORAN ANGELA LEIMKUHLER
Published: March 2009

Spray forming is a single step gas atomization/deposition process which yields ferrous and non‐ferrous near net shape preforms. It has proven to be a viable, cost effective alternative to conventional metal working technology for the production of material preforms with properties surpassing those of their cast and wrought counterparts. Current Navy programs are aimed at optimization of the process, certification of the spray formed products and industrialization of the technology. This includes the development of robust, real‐time sensors interfaced with an automated fuzzy logic controller and expanded motion control system. The system will have the capability to manufacture low cost, improved performance, non‐symmetric components currently producible only by casting or forging. In addition commercially available spray formed piping from foreign sources is currently being evaluated and certified for near term use in the fleet. Industrialization efforts are underway to establish domestic capabilities as there are no commercial facilities in the United States to date. The Navy has just initiated a manufacturing technology program, the intent of which is to develop a commercial plant in the United States capable of producing large military components. This paper will describe the process and program status. Results and comparative data will be presented and potential new applications discussed.
Tomahawk Nitrogen Pressurization Maintenance—Why?
Authors: CIARULA THOMAS A. , NERADKA VINCENT F.
Published: March 2009

This paper discusses the data that were recorded during a three‐month accelerated humidity test of two Tomahawk all‐up rounds (AURs), one pressurized with dry nitrogen in accordance with the current practice, and the other left unpressurized. Temperature and humidity were recorded inside the canisters and missiles. Data analysis consisted of psychrometric calculations to determine the moisture intrusion into these missiles during the test. The work was carried out in support of a technical effort directed at changing the storage and stowage environmental protection of the Tomahawk missile.
Navy Maintenance Support—Why Three Levels?
Authors: II EBEN E. BARNETT
Published: March 2009

As the Services are defining their roles and missions to meet the perceived world threats well into the next millennium, the Navy and Air Force seem to be embarking on two different philosophies of life cycle maintenance support.

The Air Force is adopting a two‐level policy, while the Navy stands firm on its three‐level policy. This has caused a lot of people to ask the obvious—why?
Maintenance Engineering for Maintenance Managers
Authors: JACOBS KENNETH S.
Published: March 2009

Maintenance engineering is defined in JCS Pub 1 as the “application of techniques, engineering skills, and effort, organized to ensure that the design and development of weapons systems and equipment provide adequately for their effective and economical maintenance.” The requirement for effective maintenance engineering is clear as the Navy transitions into an environment of changing force structure and reduced maintenance resources.

Maintenance engineering is needed commencing with conceptual design and continuing throughout ship life until inactivation or strike. Maintenance professionals must exercise this capability as good stewards of ship material readiness despite changing levels of maintenance resources. Evidence suggests effective maintenance engineering may not be in widespread use however, which prompts discussion of means that can be taken to revitalize and maintain this capability within the ship engineering community. While the current capability needs to be strengthened, action must also be taken to make maintenance engineering part of the culture instilled in future generations of decision makers.

This paper focuses attention on the need for effective ship maintenance engineering. It describes action taken by NavSea to strengthen this capability in today's environment. It also suggests action to provide this capability to tomorrow's decision makers. It is intended to stimulate thought that will lead to more effective development and use of this important capability in the challenging times of maintenance change that lie ahead.
Naval Architecture
Authors: BROWN DAVID K.
Published: March 2009

This article reviews the warship design process, starting with the requirement. In real life, the requirement will inevitably be a mixture of functional statements and specified hardware with some topics mentioned, if at all, at a trivial level. Though inevitable, lack of clarity in the requirement makes it very difficult to select the best option. The conflict between cost and survivability leads to unstable areas in which there is no viable design.

The design process is not sequential as usually represented but can only be described as a multidimensional web of interacting closed loops. These interactions are represented by functions which are nonlinear and often discontinuous, contributing to an unstable solution. The closed loops can be broken using experience, diminishing at all levels today, and by the use of formal standards.

Many of the most significant interactions concern the layout of the ship and its resistance to enemy attack. It is suggested that many topics, such as cost, depend more on the zoning philosophy and compartmentation of the ship than directly on length. The “architecture” of the warship greatly affects its effectiveness and its through life cost, justifying “Naval Architecture” as the title of the profession.
Statistical Quality Control and Navy Ship Repair
Authors: STIMSON WILLIAM A.
Published: March 2009

Since the end of the Cold War, there have been demands in the United States to step down defense costs. One effect of these demands is a shift in accent within the U.S. Navy from acquisition to maintenance in order to make ships and ship systems last longer. Inevitably, this will mean more work for the ship repair industry, public and private.

At the same time, the Navy is concerned about quality improvement in its industrial base and is encouraging the use of strategies generally known as Total Quality Management. However, the characteristics of Navy ship repair challenge many of the TQM methods that work so well in manufacturing. Government contracts restrict such quality strategies as single sourcing and just‐in‐time inventory. Government quality assurance requirements rely heavily upon final inspection. Navy business methods such as fragmentation of the work package among independent performers and constant and universal interface between customer and performer impede cohesive control. Finally, Navy ship repair, unlike the automaton factory, requires labor intensive, high skill, non‐rote craftsmanship across many thousands of low volume activities.

The quality objective is this: to measure, control, and improve the processes of ship repair in order to reduce variation from target values and to provide customer satisfaction. This can be done through statistical process control adapted to job shop operation. This paper describes how SQC methods can be applied to production, logistics, quality control, and test programs in order to control the critical path and quantify the quality character of the shipyard. Control is maintained through a closed loop management model which uses key state variables for process measurement. Quality is determined by characteristic curves and quantified by process control limits.
Combat System Engineering: A Return to Fundamentals
Authors: MITTURA ANDREW , KARP MITCHEL S.
Published: March 2009

The Navy's focus has shifted from global war scenarios to preparedness for the prospect of involvement in regional, littoral contingencies and conflicts. Operationally, shipboard personnel will need the ability to shift focus from the combat system multimission roles to that of only a single mission. From a development perspective, combat systems must accommodate a continual infusion of technology in a budget constrained environment. Combat system architecture is the single most important feature affecting combat system flexibility, from both an operational and developmental aspect.

There is a fundamental partitioning of combat system functions into detect, command, and engage in a horizontal integration approach that enhances this needed flexibility. This fundamental partitioning is currently applied to individual weapon systems, but not to combat systems as a whole. Instead, self‐contained weapon systems are often developed and then vertically integrated to form a combat system, causing reduced flexibility.

The battle organization is the principal driving requirement for combat system architecture. This paper shows that the battle organization is best supported by a horizontally integrated combat system of detect, command, and engage. It concludes that a horizontally integrated combat system architecture of detect, command, and engage should be a candidate for future combat systems.
Ship Impact Studies
Authors: SIMS PHILIP J.
Published: March 2009

A major role of the naval architect is assessing the value of future equipments and costs of requirements to the Navy. The means of doing this is a series of ship feasibility studies. Setting R&D priorities or establishing the requirements for a new ship class often means 40 to 100 of these studies. The paper presents, in an appendix, the titles of a sample series of impact studies from the early stage design of the DDG‐51: 7 baselines with a total of 52 excursions. The amount of work is so demanding that the nature of the process itself is often obscured by the massive amount of output.

There is no “universal” system impact; the ship impact assigned to something is dependent on a series of factors. It depends on what baseline ship is chosen, if the ship is near a machinery step function, in what order the questions are asked, what the subsystems of that ship are, whether a knee in the curve has been reached, fleet operational preferences, the fact that savings are not cumulative and inherent flaws in the process.

The paper discusses how changes in basic ship architecture alter the results of ship impact studies. A second appendix describes three generations of destroyers (CL‐51, DD‐963 and the DDG‐51) of similar displacement but with radically different ship impact responses.

The variable nature of ship impact results is why “savings” of systems which are widely advertized in technical society papers and new‐system‐advocate pitches are sometimes not found in procurement ship studies. The users of the ship impact studies (the OpNav requirement writers and the R&D investment selectors) should understand the strengths and weakness of assessing ship impact. They should also understand the need to prepare design tools in advance and the need to study the impact on future ship concepts rather than existing ships.
Performance Testing of Shipboard Electronic Systems
Authors: HARDER GEORGE , MARTIN ROBERT A.
Published: March 2009

Performance evaluation of shipboard electronic systems entails debugging the systems in a laboratory environment, placing them in service and relying on system operators to provide feedback. General testing can be performed at selected sites by system designers, but each site where equipment is to be installed can offer unique problems. It is impossible to predict all the scenarios. Unique problems are more the rule than the exception when equipment is destined for Navy ships. Ship deployments make for difficult logistics when sending test teams to evaluate system failures. So, out of necessity, if newly installed equipment receives the proper inputs and generates the proper outputs, it is accepted and becomes the sailor's responsibility to maintain. In cases where documentation is ambiguous or incomplete, it is left to the sailor's ingenuity to continue testing and training on equipment. This is generally obtained through computer simulations and back‐to‐back testing which can provide results for ideal conditions, but does not take the dynamics of interference into account. Remote site testing is the only way to get a true representation of equipment performance and training problems. Electronic system operators on board Navy vessels are fortunate, they have help. There exists an organization available near major naval ports worldwide whose existence is to test electronic systems performance. The testing utilizes electronic systems as they would normally be configured for operations. This organization is the Shipboard Electronic System Evaluation Facility (SESEF).
Development of a Standard Family of Composite Material Centrifugal Pumps for Naval Surface Ships
Authors: SUITT DENNIS , GIRONA FRANCISCO
Published: March 2009

This paper discusses a program to develop a family of standard design, low‐pressure, composite material centrifugal pumps for Navy surface ship applications. The need for and the benefits derived from the development of this standard family of centrifugal pumps is discussed. Foremost of the projected benefits is a savings of 25% in acquisition and provisioning costs as well as significant reduction in integrated logistic supply costs. Additional benefits detailed are the reduction of maintenance requirements and improvements in serviceability expected from pumps manufactured from composite materials.

A program to evaluate commercial composite pumps to determine compliance with Navy design requirements is detailed. The design criteria for the standard family of composite pumps is provided as is the status of a competitively awarded contract for this design. Contained within the discussions of the contract status is a description of efforts to provide state‐of‐the‐art sealing for the new pumps. The paper also addresses the manner in which the standard design composite pumps will be introduced to the fleet.
Fast Attack Craft—A Comparative Analysis
Authors: BROWER KENNETH S. , KEHOE JAMES W.
Published: March 2009

The paper reports the results of a comparative naval architecture analysis of three modern fast attack craft (FAC). They include the Russian Tarantul, Israeli Sa'ar 4.5, and U.S. PGG‐511. The analysis covers ship performance, speed and range; general arrangements; hull form; hull structure; propulsion; auxiliary systems and outfitting; habitability; and weight, deck area, and volume allocation. The combat systems are identified, but only addressed in terms of the impact of their weight and volume on the design of the ship. The actual military effectiveness of each FAC is not addressed, but is discussed in terms of lessons to be learned in light of the new world order and renewed U.S. interest in littoral warfare.
Underwater Inspection for Welding and Overhaul
Authors: MITTLEMAN JOHN , SWAN LISA
Published: March 2009

Significant progress has been made in making underwater ultrasonic thickness gauging and magnetic particle inspections available to the fleet. Under sponsorship from the Naval Sea Systems Command, Director of Ocean Engineering, Underwater Ship Husbandry Division (NavSea 00C5), the Coastal Systems Station has developed complete hardware packages supporting these two nondestructive test methods, and has introduced them to military inspectors at a shore intermediate maintenance activity, a destroyer tender, and a naval shipyard. Performance trials conducted prior to taking the systems to the field have been accepted by NavSea, Ships' Concepts Group, Materials Subgroup, Metals Division (NavSea 5142) as evidence that these inspections can reliably be performed underwater. Avenues for certifying specially trained divers and inspectors are being developed; for the first time the Navy will have all of the elements in place for underwater inspections satisfying the requirements of Mil‐Std‐271 (Requirements for Nondestructive Testing Methods) and the Naval Ships' Technical Manual Chapter 074.

Underwater ultrasonic thickness gauging has also been slated for use in the fleet, as data from laboratory and field trials have consistently shown that reliable results can be obtained by a team comprising a certified topside inspector and a diver. In tests performed at the Ship Repair Facility (SRF), Yokosuka, underwater readings were compared to those taken in dry dock by SRF inspectors, and independently by contract inspectors. On the basis of approximately 800 locations, differences between the data sets were found to be randomly distributed, with a standard deviation on the order of 0.02“. This level of accuracy is largely sufficient to distinguish plate which will need replacement during overhaul, or plate which is thick enough to weld on.
Acquisition Reform and Best Product Procurement: An Engineering View
Authors: Fisher David A. , Skolnick Alfred
Published: March 2009

ABSTRACT  The military services are being moved in the direction of performance‐based specifications and standards. They are being steered against dictating “how to” produce an item since such action forecloses on the ability to gain access to components or technology that may have a commercial equivalent. Why should the engineering community embrace the new approach? Aside from the obvious weight of it being approved policy, therefore currently mandated, it warrants examination because it is the correct approach at this time when applied to appropriate products.

Military specifications and standards are to be displaced then, by acceptable alternative contractor design solutions. Industry bidders will be allowed to propose the particular design details, permitting procurement flexibility by contractually citing only system level or interface requirements, both physical and functional. Hopefully, this can broaden the industrial base and increase competition with reduced costs to follow. Conceptually, the approach appears both performance‐sensible and cost‐attractive (there are, of course, consequent risks) but how does implementation proceed? Is it possible to pursue the goals envisioned along paths that are not in themselves experimental? Can the American postulate, minimal loss of life and limb to U.S. military people, continue to be honored? Experience and track record elsewhere imply encouraging possibilities in select situations—useful prospects are identified and discussed in practical terms.
Application of Open Systems Standards to DoD Avionics
Authors: Roark Chuck , Kiczuk Bill
Published: March 2009

ABSTRACT  The DoD is transitioning to open systems standards as a means to reduce cost. Key aspects of this thrust are: (1) the development and cataloging of a preferred set of standards which can be uniformly interpreted and applied across DoD programs; (2) the ability to develop target independent software which can be affordably retargeted to rapidly evolving commercially based hardware; and (3) a method for transitioning emerging standards and products to programs with minimum risk.
Nondestructive Evaluation of Navy Structural Components Using Barkhausen Noise Analysis
Authors: Jo J. , Caudill G. , Santos R.
Published: March 2009

ABSTRACT  This paper presents the use of Barkhausen noise analysis (BNA) to nondestructively evaluate residual stresses in (1) shot‐peened Almen strips made of 1070 steel, (2) a 4340 landing gear piston, and (3) a D6AC steel bulkhead. BNA output and X‐ray stress values were compared and correlated for each of the components mentioned above. Almen strips were compared in the range of Almen intensity 2A‐17A. BNA was consistent with X‐ray diffraction measurements in the Almen strips and the landing gear piston. Quantitative analysis of stress characteristics between the two techniques was also discussed for the D6AC bulkhead.
Combat System Maintenance Central (CSMC)
Authors: SACKETT WILLIAM H. , DORMAN MARSHALL L.
Published: March 2009

Combat system maintenance central (CSMC) is an innovative manned space concept. New to the Navy, it is proving to be a major asset to the AEGIS cruisers and destroyers. “The primary mission of the CSMC is to provide an organized environment for the coordination and control of operability testing and maintenance, and the collection, evaluation, and timely dissemination of combat system operational readiness information. CSMC grew from a minimal size, “broom closet” concept (see Figure 1) to one of a critically manned operating area. The growth and evolution of the concept was a major challenge. Several iterations were subjected to intensive design reviews until the CSMC concept was finally fully approved by the Navy (see Figure 2). Combat System contractor personnel working closely with NavSea PMS 400, Aegis program office, personnel were responsible for the development of the CSMC. The space was configured to meet and has met all operational requirements imposed.
Seawolf Submarine Ship Control System: A Case Study of a Fault‐Tolerant Design
Authors: DAUGHAN MICHAEL G.
Published: March 2009

During the several decades since the previous U. S. Navy submarine design, the enhanced capabilities of computers and miniaturization of components has permitted the incorporation of more advanced control features in the same or less space than occupied by previous systems. Also during this period, fault‐tolerant architectures, which typically employ coordinated redundancy to yield highly reliable and available systems, have been deployed on space platforms, aircraft, and other critical applications. The Seawolf submarine utilizes a fault‐tolerant ship control system, which will be the most sophisticated ship control system deployed by a U. S. Navy submarine to date.
Establishing the Fundamentals of a Surface Ship Survivability Design Discipline
Authors: BALL ROBERT E. , CALVANO CHARLES N.
Published: March 2009

This paper describes a conceptual structure of ship survivability definitions and concepts and deals with the need to incorporate a total‐ship approach to surface ship combat survivability as part of the philosophy used to guide a ship's design. Included are:

* A discussion of the increasing emphasis placed on ship survivability during the ship system development process.

* Definitions of the different aspects of ship survivability, in order to suggest a coordinated and coherent understanding of their relationships.

* A discussion of the value of making survivability considerations an integral part of the ship design philosophy, to ensure a requirements‐based systems approach to all of the ship's required attributes, including survivability.
Well Deck Deploy able Naval Combatants
Authors: BOSWORTH CDR. MICHAEL , BLACK SCOTT , MEYER JOHN R.
Published: March 2009

Small, fast surface combatants have not proven as popular to United States Naval planners as they have to planners of other navies. This paper examines the impact of this on the rate of progress of various alternative hull forms, and several reasons for this reluctance are postulated. The authors suggest that the primary reason for so few fast, small U.S. combatants is that the U.S. has a proven requirement for warships that can deploy across an ocean and remain there with only sea‐delivered support for months. These warships must also be prepared to fight for extended periods of time at long distances from friendly shores. The authors recommend the use of alternative hull forms as deployable vehicles supported by a larger vessel with a floodable well deck. Various alternative hull forms are briefly discussed and several are selected for more in‐depth investigation for the postulated deployable vehicle multimission requirement. Two example craft with the same set of missions are described in more detail; the multimission deployable vehicle‐surface effect ship (MDV‐SES) and the multimission deployable vehicle‐hybrid hydrofoil (MDV‐HH). These two concept level designs are described by the respective leaders of the design teams that produced David Taylor Research Center Departmental Reports in the fall of 1990. Each ship displaces on the order of 400 long tons (full load), has a speed in excess of 40 knots, has a crew of 10 to 16 depending upon the mission module embarked, and can land, refuel and rearm a LAMPS III helicopter. Conclusions are drawn from the completed design work and recommendations for further study are put forth.
Contrarotating Electric Drive for Attack Submarines
Authors: DUTTON JEFFREY L.
Published: March 2009

This paper addresses certain issues relating to the viability of contrarotating (CR) electric drive for attack submarines. Topics include CR propulsion's potential benefits, electric drive advantages, and combining contrarotation with electric drive engine room concepts. CR propellers provide propulsive coefficient (PC) increases compared to open‐type and performance‐enhanced single propellers. The maximum submarine propulsion plant power capacity could therefore be reduced with this PC increase, potentially resulting in a smaller, lighter propulsion plant. This paper concludes, however, that contrarotation shows no propulsion plant weight savings against electric drive attack submarines with performance‐enhanced single propeller designs. Weight improvements in the power generation plant and certain steam plant and electric plant systems are offset by weight increases from the additional shafting and bearing requirements for the CR shaft. Contrarotation is currently more advantageous for nonnuclear ships, where significant fuel savings are achievable with its higher PC.
Methods For Ship Military Effectiveness Analysis
Authors: RAINS DEAN A.
Published: March 2009

Ship design and technology selections can be based on complete systems analysis results if one is willing to perform military effectiveness analysis. In the past, these selections have been based on ship size and performance analysis alone, but with improved techniques, comprehensive system analysis on ships can be performed. System analysis is most illuminating because it factors in threat, ship size, cost, weaponry, signatures, vulnerability, decoys/jamming and availability. The purpose of this paper is to explore military effectiveness methodology, develop key relations and show some useful results. The techniques proposed can be used in elaborate computer models for in‐depth studies or in simplified linear relations to gain understanding of the interrelation of the variables and result trends.
Medium Speed Diesel Propulsion Reduction Gearing
Authors: PHINNEY JOHN M.
Published: March 2009

Current interest in medium speed diesel propulsion for maritime vessels is driving a third generation of reduction gear designs.

The first generation flourished in the 1930s and looked remarkably like those proposed today. However, by comparison, they were designed with low power density; used lightly loaded gear teeth and bearings; had to cope with poorly filtered and blended lubricants; used relatively inaccurate manufacturing techniques, and were based on inaccurate analysis of operating conditions.

The second generation, starting in the late 1960s and continuing through 1980, had the benefit of the rational AGMA gear design method, Raimondi and Boyd's work on bearing design, and sophisticated techniques for alignment and vibratory analysis. Power and loading levels increased and many variations of equipment were tried: reversing engines, reversing gears, and reversing propellers. Individually, each, was successful and we now have the benefit of two decades of operating experience for this design generation.

This paper will explore the design principles of the gear/engine/propeller/auxiliary equipment package to define the guiding parameters for the third generation based upon the lessons provided by the experience gained in the two previous generations.
A Steam‐Augmented Gas Turbine with Reheat Combustor for Surface Ships
Authors: URBACH HERMAN B. , GARMAN RICHARD W. , KNAUSS DONALD T. , WATTS JERRY W. , DWAN TERRENCE E. , MITCHELL EUGENE E. , HOWES ENSIGN CORY
Published: March 2009

The steam‐augmented gas turbine (SAGT) concept has attracted attention because of its benign level of NOx emission, its increased fuel efficiency, and significant, cost‐effective increments of output power, particularly when moisture injection is increased to levels approaching 50% of air flow. Such high levels of moisture consumption distinguish the SAGT engine from commercial steam‐injected gas turbines where steam flow may be less than 15% of air flow. At the high 50% levels, the SAGT burner would operate near stoichiometric combustion ratios with specific powers exceeding 570 hp‐sec/lb.

In a previous study, an intercooled, steam‐augmented, gas‐turbine concept was examined for its applicability in the Navy's DDG‐51 class ship environments, which achieves efficiencies approaching the Navy's intercooled regenerative (ICR) engine, and an impressive compactness that arises from the high specific power of steam and low air consumption.

A newer SAGT engine concept, described herein, dispenses with the intercooler, but adds a low‐pressure reheat combustor. At the most efficient operating points, the efficiency of this new reheat SAGT engine at 43% exceeds the efficiency of the ICR engine, while exhibiting the compactness of the previous SAGT concept. Tabular and graphical simulation data comparing the baseline engine, with the ICR and other engine simulations, show that the maximum efficiency of the new SAGT engine occurs at powers required for cruising speeds. Since a DDG operates near cruise conditions for the majority of its mission time, a SAGT plant uses less fuel than the ICR plant. Moreover, since it eliminates the intercooler, developmental work on member elements, largely derivable from off‐the‐shelf components, is reduced. Even with conservative cost estimates, the SAGT plant is quite competitive on a first‐acquisition cost basis with the current gas turbine in the fleet.
Main Propulsion Power Take‐Off Configuration for an ETC Gun Pulsed Power Generator
Authors: PETTERSEN KENNETH E. , BIELITZ CHARLES L. , CIANCI JOHN
Published: March 2009

Electro‐Thermal Chemical (ETC) Gun technology will increase the range and capabilities of existing CIWS and 5 inch guns. Because of their faster, yet more controllable acceleration, ETC guns will allow for the utilization of smart munitions and, in the case of the 5 inch guns, increase range to beyond 50 nautical miles.

This paper examines five power take‐off (PTO) gear configurations from a surface ship class main reduction gears (MRG's) which drive a nominal 10 Megawatt (MW) Pulsed Power (PP) generator. The PP generator is utilized to charge a capacitor‐based pulsed forming network (PFN) which, in turn, provides an electrical pulse to the cartridge of a munition at the breech of an ETC gun upon demand. The PTO gear and resultant placement of the generator will be the major focus of this paper.

Major issues that will be examined will include space constraints within the main engine and auxiliary machinery rooms, gear sizing, survivability, shock and vibration, the penetration of watertight bulkheads with high speed shafting and equipment accessibility. Also, design guidelines for the PP generator will be provided. Special emphasis will be placed on the connection of the PTO gear to the MRGs.
An Assessment of Current Warship Damaged Stability Criteria
Authors: SURKO STEPHEN W.
Published: March 2009

Current damaged stability criteria for the design of warships is outdated. The U.S. Navy criteria, consolidated in Design Data Sheet (DDS) 079–1, was developed over four decades ago, based largely on World War II battle damage experience. The validity of this standard is assessed with regards to the method in which it is assigned, its historical basis, and assumptions of wind and sea conditions.

In general: combatant ships with a length greater than 300 feet must be able to withstand a shell opening of 15 percent along the waterline, while auxiliary ships must be able to withstand a shell opening of 12.5 percent. A warship's ability to withstand underwater damage is determined by an analysis of reserve buoyancy (floodable length) and damaged stability.

A comparison of the design standards used by various navies reveals great similarities and some notable differences. Contemporary weapon threats and increased operational demands have changed the traditional ship design equation. The Ship Operational Capabilities Study has emphasized the need for modern ships to be able to fight hurt. Fortunately, a review of combatant ship model testing demonstrates that ships can be made more survivable. DDS 079–1 should be modified to incorporate some stability criteria developed by other nations, and impose more demanding environmental conditions.