Eliminating the Sterntube in New Deep Sea Ship Construction

2018 ◽  
Author(s):  
George A. Thomson ◽  
Kenneth Ogle
Keyword(s):  
Deep Sea ◽  
Cost Reduction ◽  
Propulsion Systems ◽  
Ship Building ◽  
Ship Construction ◽  
Material Cost ◽  
Design Changes ◽  
Fundamental Design

With water lubricated shafts, the point of sealing the shaft needed to be positioned for access and that required a connecting tube to the sealing gland location. With oil lubricated bearings, a tube was required to contain the oil. As more ships are now being fitted with water lubricated bearings, the need for the ubiquitous stern tube becomes questionable. This paper will address the potential for fundamental design changes to vessel construction from the perspective of material cost reduction and the simplification of ship-building procedures, based on elimination of the stern tube. As propulsion systems evolve into increasingly complex packages this initiative toward simplification may have appeal.

Sensitivity Analysis of Relative Worth in Empirical and Simulation-Based QFD Matrices

2008 ◽  
Author(s):  
Robins M. Kalapurackal ◽  
Shun Takai
Keyword(s):  
Cost Reduction ◽  
Quality Function Deployment ◽  
Development Process ◽  
Rating Scales ◽  
Rating Scale ◽  
Calculation Scheme ◽  
Product Development Process ◽  
Customer Requirements ◽  
Design Changes ◽  
Simulation Based

Quality function deployment (QFD) is one of the most popular tools used in the product development process. It relates customer requirements to product requirements and enables engineers to determine which product requirement is more important than the others in satisfying customers. Some of the benefits of QFD are cost reduction, fewer design changes at the start of production, and improved communication among engineers. QFD applications use various approaches (i.e., worth calculation schemes and rating scales) to calculate the worth of requirements. The purpose of this paper is to study the change in the relative worth (normalized worth) of product requirements yielded by different rating scales and calculation schemes. We studied empirical and simulation-generated QFD matrices to determine how calculation schemes and rating scales influence the relative worth of requirements. Two representative scales and two calculation schemes are used to find the most and least sensitive cases, and the influence of the number of rows and columns in the relative worth of requirements. From the results, we identified the least sensitive and most sensitive combination of calculation scheme and rating scale. We also learned that QFD matrices become less sensitive to changes in rating scale and calculation scheme as the number of columns increases.

Design, Manufacture, and Testing of Large Reduction Gears for Diesel Ship Propulsion Systems

1990 ◽  
Vol 27 (01) ◽  
pp. 30-41
Author(s):  
Peter Gold ◽  
K. Heinz Watzlawek ◽  
Zbigniew J. Karaszewski
Keyword(s):  
Carrying Capacity ◽  
Cost Reduction ◽  
State Of The Art ◽  
Reduction Gear ◽  
Large Reduction ◽  
Propulsion Systems ◽  
Ship Propulsion ◽  
The Past ◽  
Long Life

The dramatic increase in both the size of ships and the power of propulsion systems over the past 15 years has led to a desire for shorter machinery spaces and lighter equipment in order to provide additional cargo carrying capacity. Many equipments and reduction gears in particular have experienced a growing number of problems due to compact designs with reduced scantlings. Consequently, high-horsepower and low-rpm gear units were developed that resulted in incompatibility of machinery and ship. Those marginal designs combined with manufacturing inaccuracies were in most cases the result of overzealous cost reduction programs. This paper presents some of the elements of a state-of-the-art reduction gear evolution cycle that will result in successful gear operation and continued long life.

Design Improvements of the EJ 200 HP Compressor: From Design Verification Engine to a Future All Blisk Version

2001 ◽  
Author(s):  
O. E. Kosing ◽  
R. Scharl ◽  
H. J. Schmuhl
Keyword(s):  
Cost Reduction ◽  
Pressure Ratio ◽  
Weight Ratio ◽  
Control Unit ◽  
Tip Clearance ◽  
Growth Potential ◽  
Design Verification ◽  
Design Changes ◽  
Combat Aircraft ◽  
Specific Thrust

The EJ 200 engine powers the Eurofighter / Typhon combat aircraft and is being built by the four nations UK (RR), Germany (MTU), Italy (FIAT AVIO) and Spain (ITP). The engine is capable of 60 kN dry thrust and 90kN reheat thrust with a 15% built in growth potential. The specific thrust to weight ratio is ≈ 10 and the overall pressure ratio 26. MTU’s 33% work - share package contains the development of the three stage LP Compressor, the five stage HP Compressor and the Digital Engine Control Unit. This paper concentrates on the five stage axial HP Compressor. It describes the major design changes from the very first design verification engine (DVE) to a future all blisk version. It first provides a brief historical overview of the major design improvements which are then discussed in detail. The rotor concept is discussed with respect to life, weight, material and repair. The development of the casing to improve the tip clearance behaviour, the containment and the protection against titanium fire is outlined. The stator concept is described in connection with an intense cost reduction program. The HP Compressor has successfully completed testing and flight clearance has been approved for all standards. Thus far the HPC has accumulated more than 16500 hours total engine experience and over 1040 Eurofighter flights. The production engine manufacturing is in progress, with the first engine to be delivered in March 2001.

scholarly journals Indirect Material Cost Reduction by Eliminating Manual Derailing Process through Process Simplification

2021 ◽  
pp. 1-12
Author(s):  
Christopher L. Dela Cruz ◽  
Patricio Cabading Jr. ◽  
Melanie Paglicawan
Keyword(s):  
Cost Saving ◽  
Cost Reduction ◽  
New Product ◽  
Material Consumption ◽  
Product Integration ◽  
Organizational Goals ◽  
Assembly Plant ◽  
Material Cost ◽  
Line Processes ◽  
The Cost

This paper will discuss how to reduce (IDM) Indirect Material consumption for derailing process by eliminating the manual derailing method as part of cost saving project. It involves the removal of cutter blade used for derail.Cost improvement was one of organizational goals of the company for 2019. This drive can be supported by analyzing Indirect Material spending and process simplification at assembly plant. At assembly End-Of-Line processes, derail cutter blade was one of the top Indirect Material spending at singulation and there is an opportunity to reduce if not eliminated the cost consumption of derail cutter blades through process simplification. Increasing volume in Quad-Flat-No lead (QFN) packages and new banner products being develop by New Product Integration NPI, Q1’20 means increase in IDM consumption per process. The challenge is to drive a process simplification that will reduce IDM to save cost by start of Q2’20. DMAIC methodology was used to improve the process of derailing process.

Ingalls Machine Readable Material Transactions

2015 ◽  
Author(s):  
Hal Todd ◽  
Penny Fairley
Keyword(s):  
Material Transaction ◽  
Cycle Time ◽  
Cost Reduction ◽  
License Plate ◽  
End User ◽  
Material Identification ◽  
Transaction Data ◽  
Ship Construction ◽  
Machine Readable

To face challenges associated with reduced shipbuilding budgets and the need for increased material availability, the Machine Readable Material Transaction was proposed, accepted and is currently in development at Ingalls Shipbuilding. Machine Readable Material Transaction is the processes and tools required to provide a machine readable identification (i.e. license plate) and scanning capability for tracking and identifying individual items, containers of material, and loose materials at various locations and workflows throughout the shipyard. The effort facilitates: * reduced cycle time of material transactions by moving from paper driven processes to electronic driven processes * increased accuracy by minimizing the manual entry of material transaction data by utilizing scanning technology and bar-coding * reduced re-buys by locating lost, damaged or cannibalized material * retention of material identification and history during consumption by capturing: * “what” is the material * “when” was it received or last moved * “where” was its last known location * “why” was it moved, and * “who” was the last person to touch it The purpose of the effort is to ensure visibility, traceability, and accountability for material (purchased and fabricated) from receipt through delivery to the end user. This paper discusses the use of these processes and tools to support U.S. Navy ship construction modernization and cost reduction goals at Ingalls Shipbuilding.

Sensitivity of Relative Worth in QFD Matrices to Rating Scales and Worth Calculation Schemes: An Empirical Study

2007 ◽  
Author(s):  
Robins M. Kalapurackal ◽  
Shun Takai
Keyword(s):  
Cost Reduction ◽  
Quality Function Deployment ◽  
Rating Scales ◽  
Rating Scale ◽  
System Development ◽  
Customer Requirements ◽  
Journal Articles ◽  
The Past ◽  
Design Changes ◽  
System Requirements

In the past several decades, Quality Function Deployment (QFD) has gained its popularity among engineers as a tool to relate (map) customer requirements (inputs) to system requirements or system components (outputs), and to calculate relative worth of these requirements and components. The benefits of QFD in system development include cost reduction, fewer design changes after the start of production, and improved communication among engineers. Despite the observed benefits, the needs for QFD research have been addressed by researchers. These research needs include decision-making process in QFD, rating scales used in QFD matrices, and calculation schemes for calculating the worth of outputs (e.g., system requirements) from the importance of inputs (e.g., customer requirements). The purpose of this paper is to empirically study sensitivity of the relative worth and rank of outputs in QFD matrices to rating scales and worth calculation schemes. We collected QFD matrices from journal articles and textbooks; then calculated the changes of relative worth and the rank of outputs when one type of rating scale and/or worth calculation scheme was changed to the other. The results suggest that the relative worth and rank of outputs are relatively insensitive to rating scales and worth calculation schemes in the QFD matrices studied in this paper.

THE 1973 IMCO CONVENTION: A TANKER OPERATOR'S VIEWPOINT

1975 ◽  
Vol 1975 (1) ◽  
pp. 15-21
Author(s):  
William O. Gray
Keyword(s):  
Status Report ◽  
International Convention ◽  
Design Changes ◽  
The Many ◽  
Oil Tankers ◽  
Detailed Nature ◽  
Fundamental Design ◽  
Technical Studies

ABSTRACT The International Convention for the Prevention of Pollution from Ships, 1973, drafted in London under IMCO auspices last fall is undoubtedly the most comprehensive and potentially promising step yet taken to prevent pollution to the seas by ships. While this convention is now open for ratification by nations, its very detailed nature has already caused studies to commence to identify the steps which must be taken to assure its practical and timely implementation. This paper reviews first the essential provisions of the convention, stressing the technological elements relating to oil tankers. These elements include ships’ operational and equipment features, as well as fundamental design changes for new tankers ordered after December 31, 1975. In addition, questions of reception facilities ashore will be considered. The paper will include a status report in regard to each of these matters as of the date of this conference, rather than a recap of the many technical studies already done prior to the IMCO 1973 convention. While Exxon studies on this subject must form the basis of the paper, to the extent possible, activities of various industry groups and governments toward bringing the IMCO 1973 convention effectively into force will be covered as well

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