SAWE Technical Papers

@inproceedings{3741,

title = {3741. Finding the Balance Between Accuracy and Practicality in Deadweight Survey},

author = {Colin MacFarlane and Manuela Bucci},

url = {https://www.sawe.org/product/paper-3741},

year  = {2020},

date = {2020-07-01},

booktitle = {2020 SAWE Tech Fair},

pages = {24},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virtual Conference},

abstract = {Deadweight audits are exercises required to calculate the vessel lightweight by deduction from the actual ship weight. Depending on the size of the vessel, they can take a few hours to several days. Minimising the duration of the exercise should be prioritised since accuracy of the result is connected to avoidance of changes in the recorded vessel's configuration during the audit. This leads to a compromise between precision and the accuracy that can be achieved: estimating the weight of the deadweight based on experience is the quickest method, weighing everything with calibrated scales is the most precise. An intermediate solution is to find the deadweight partly with estimates, partly with weighing.Experience with all three of these methods showed that accuracy can be achieved even if relatively poor resolution is accepted, if some precautions are taken when recording the weights.This paper presents three study cases and the calculation of uncertainty in the deadweight that derived from the different approaches. The uncertainty and the time spent to complete the audit are used to define an efficiency estimator to rate the deadweight audit.The conclusion is a method to upgrade data recording that allows production of a more meaningful result.},

keywords = {08. Weighing, 13. Weight Engineering - Marine, 21. Weight Engineering - Statistical Studies, 35. Weight Engineering - Offshore},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3739,

title = {3739. Rotorcraft Mass Assessment in an Integrated Design Framework},

author = {Dominik B. Schwinn and Peter Weiand},

url = {https://www.sawe.org/product/paper-3739},

year  = {2020},

date = {2020-07-01},

booktitle = {2020 SAWE Tech Fair},

pages = {15},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virtual Conference},

abstract = {Mass estimation is an essential discipline in the design process of aeronautical vehicles. The maximum take-off mass determines most other design parameters and should therefore be estimated sufficiently precise from the beginning. In the conceptual design phase fast analyses are required in order to allow trade-off studies. In general, this phase is dominated by the use of analytical and statistical methods. At the end of this design stage, a basic external layout has been elaborated and basic design parameters have been determined.During the subsequent preliminary design stage, physics based higher fidelity methods are applied to further elaborate the design and to establish an internal configuration. The constantly increasing computational power allows comparably fast analyses in this design stage that may alter the configuration established in the conceptual design stage.Particular challenges in this design approach arise with unconventional configurations, such as compound rotorcraft, or with different propulsion systems to be integrated, for instance electric or hybrid systems, because of a lack of sufficient statistical data.The German Aerospace Center (DLR) has established the integrated design environment IRIS (Integrated Rotorcraft Initial Sizing) to allow an assessment of virtual rotorcraft configurations. It covers the conceptual and parts of the preliminary design stage and uses the data model CPACS (Common Parametric Aircraft Configuration Schema) for the parametric rotorcraft description.Component masses in IRIS are estimated using various statistical methods during the conceptual design stage. Finite Element (FE) methods are applied in the preliminary design phase to allow a more precise estimation of the structural mass which may influence the maximum take-off mass and therefore the performance characteristics calculated in the conceptual design stage.This paper introduces the design environment IRIS, and in particular the PANDORA framework (Parametric Numerical Design and Optimization Routines for Aircraft) which is used for the statistical estimation of the rotorcraft component masses and the structural sizing process to determine the fuselage mass.},

keywords = {10. Weight Engineering - Aircraft Design, 21. Weight Engineering - Statistical Studies, 24. Weight Engineering - System Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3737,

title = {3737. Use of Mass Growth Allowance to Dynamically Manage Mass Risk},

author = {Zaid Karajeh},

url = {https://www.sawe.org/product/paper-3737},

year  = {2020},

date = {2020-07-01},

booktitle = {2020 SAWE Tech Fair},

pages = {6},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virtual Conference},

abstract = {Management of mass budgets and the associated risks in the aerospace industry has positive impacts that affect delivery and launch of spacecraft. This paper presents a novel feedback control method to manage mass risk over the course of spacecraft design and production. The control method uses a dynamic upper and lower boundary formed as a function of heritage spacecraft mass risk. Spacecraft that deviate above the upper bound fall out of compliance and should trigger action. By observing how the risk mass varies over time with respect to the boundaries, scheduling risks could be identified preserving launch date and potentially acting as a cost saving effort for the spacecraft manufacturer.},

keywords = {19. Weight Engineering - Spacecraft Estimation, 26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3730,

title = {3730. Path to be an Engineer},

author = {Brittany Johnston},

url = {https://www.sawe.org/product/paper-3730},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {6},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {This is an unconventional Society of Allied Weight Engineers (SAWE) student conference paper that gives insight of how a person can have the will power to navigate on a journey of obtaining a new career. Becoming an engineer is far from easy, but it is possible to obtain. I take that possibility with positivity that enables me to make the great strides that I must complete. This paper gives insight to who I am and why I must make this change.},

keywords = {06. Inertia Measurements},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3729,

title = {3729. Application of SAWE Course 'Developing Basic Parametric Methods' to Nacelle Weight Estimating},

author = {Doug Fisher},

url = {https://www.sawe.org/product/paper-3729},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {17},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {This paper details how the learning contained in SAWE course 'Developing Basic Parametric Methods' was applied at Collins Aerospace for estimating nacelle weights of new commercial and business jet aircraft. Collins has decades of experience developing nacelles and a large database of historical weight data, but has not effectively leveraged that data into better weight estimating tools. Learning from this course was applied to develop improved methods of estimating the weight of nacelles for new product proposals. This has allowed us to not only provide better weight estimates but also better understand the limits of our data and estimating methods.},

keywords = {10. Weight Engineering - Aircraft Design, 11. Weight Engineering - Aircraft Estimation, 21. Weight Engineering - Statistical Studies},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3728,

title = {3728. Investigation on the Mass Properties of Cars},

author = {Giorgio Previati},

url = {https://www.sawe.org/product/paper-3728},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {14},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {The knowledge of the mass properties (center off gravity location and inertia tensor) of cars is crucial for the analysis of their dynamic performances. The measurement of such properties is not always performed and their value is estimated by 3D models off some empirical formula. In this paper, the mass properties off cars are investigated by analyzing the measurements performed at tthe Politecnico di Milano. The measurements have been realized by the InTenso+ test rig off the Politecnico di Milano in the period from 2000 to 2018. The test rig is basically a multi-bar pendulum carrying the body under investigation and oscillating from well-known initial conditions. By means of a proper mathematical procedure, the mass properties of the body are accurately measured in a very short testing time.The obtained measures are statistically analyzed and correlations are found with easily accessible vehicle data. On the basis of such correlations, formulae are proposed to have a quick and reasonable estimation of the most relevant mass parameters (center of gravity, heights and diagonal terms of the inertia tensor) of any vehicle.},

keywords = {05. Inertia Calculations, 06. Inertia Measurements},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3727,

title = {3727. Trifilar Pendulum: Non-small Oscillations and Calibration},

author = {Giorgio Previati},

url = {https://www.sawe.org/product/paper-3727},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {16},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {The trifilar pendulum is a well-known and established technique for the measurement of the moment of inertia of rigid bodies. For such application, the motion off the pendulum, which is inherently nonlinear, is considered linear. As consequences, only small oscillations and pendula with long cables with respect to their distance should be employed for the measurement. However, in some application either to use non- small oscillation angles or to use pendulum with relative short cables have to be employed. In these cases, the motion cannot be considered linear and some error in the measurement could arise.This paper aims to analyze the nonlinear motion off the pendulum. A formula is analytically derived for the calibration of the pendulum for non-small rotation angles. A sensitivity analysis is proposed to highlight the advantages of the proposed approach to the measurement of the moment of inertia of relatively smalll and compact bodies, such as tires and engines, and to full scale vehicles and airplanes.},

keywords = {06. Inertia Measurements},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3726,

title = {3726. Toolchain Integration For Space Habitat Design},

author = {Maxwell DeVoe and Ariel Tokarz and Samuel Park},

url = {https://www.sawe.org/product/paper-3726},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {Space habitat design is an iterative process that requires multiple revisions before a final product can be ascertained. Completing a project can prove cumbersome and time consuming, thus straining an organization's resources. To counteract this issue, there was a desire to automate steps within the design process to improve the efficacy of the iterative aspect while also decreasing time spent developing designs. This paper will detail the main processes that were automated within the NASA LaRC Vehicle Analysis Branch environment. Examine is a custom Microsoft Excel-based spreadsheet that was used to consolidate parameter calculations within an encapsulated environment. IDEA is a model based systems engineering software that enables fast and efficient modifications to a CAD model, allowing for greater flexibility in the design process. To improve efficiency, the two design tools were linked to ensure fast and user-friendly data flow between them. The tools are controlled within a SysML application, consolidating the linkage into one interface for the user. This paper will detail the process of linking the tools together as well as the processes being executed within the individual tools themselves.},

keywords = {12. Weight Engineering - Computer Applications, 34. Advanced Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3725,

title = {3725. HERMES: Hazard Examination and Reconnaissance Messenger for Extended Surveillance},

author = {Alexander Sandoval and Alexis Sotomayor and Brandon Santori and Brindan Adhikari and Colin Chen and Junzhe He and Katelyn Griego and Marcos Mejia and Michely Tenardi and Quinter Nyland},

url = {https://www.sawe.org/product/paper-3725},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {The University of Colorado at Boulder Aerospace Engineering Senior Projects Team HERMES (Hazard Examination and Reconnaissance Messenger for Extended Surveillance) is currently designing, building, and testing a child scout rover (CSR). This is the fourth installment in the Jet Propulsion Laboratory's (JPL) Fire Tracker System. The Fire Tracker System is designed to operate in forest fire-prone areas for early fire identification. HERMES aims to improve the Fire Tracker System by navigating through a forest like environment to a location of interest (LOI) while determining a viable path for the Fire Tracker System's previous installment, a large less maneuverable mother rover. To do this, the CSR must traverse over obstacles up to 2.4 inches in height, vertical discontinuities (9 inches wide by 2.4 inches deep), over leaves, dirt, grass, and up or down 20 degree inclined slopes in both open and wooded area. Additionally, the CSR must drive forward and in reverse, as well as perform 360 degree turns in place. To complete these mission objectives, the CSR uses a sensor suite for obstacle and discontinuity detection, a two-motor configuration with a drivetrain and gearbox powering 6 wheels for traversing obstacles, and a moving linear mass stage that shifts the CSR's center of mass to enable traversing over discontinuities. While on a mission, the CSR will have the capability to detect any discontinuities using two downward angled, single beam LiDAR sensors. If a discontinuity is detected, the CSR will stop and notify the user at the ground station. The user at the ground station then commands the CSR into a semi-autonomous discontinuity traversal mode, where the CSR utilizes two ultrasonic sensors mounted on the bottom of the CSR to determine whether it is over a discontinuity or flat ground. These sensors signal the software to move the linear mass stage to shift the center of mass depending on the CSR's position over the discontinuity. The unique challenge of crossing discontinuities, and the solution, is discussed in this paper.},

keywords = {03. Center Of Gravity, 31. Weight Engineering - Surface Transportation, 33. Unmanned Vehicles},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3724,

title = {3724. Methods and Processes for Robust Mass Properties Management in the Automotive Industry with a Main Focus on Mass Uncertainties},

author = {Marcus Stegmiller and Albert Albers},

url = {https://www.sawe.org/product/paper-3724},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {The mass of an automobile represents a crucial parameter for development because it influences the design of the automobile as well as decisive purchasing characteristics such as driving dynamics, fuel consumption and range. The dimensioning effect of the automobile mass has so far led to the definition of challenging and fixed mass targets. Since the automotive industry is characterized by high cost pressure, product complexity (e.g. due to modular and platform strategies, supplier chains and manufacturing constraints), increasing product range and volatile boundary conditions (e.g. due to regulation) automobile masses are permanently changing during development. This can no longer be robustly controlled by fixed mass targets. In practice, this often results in late missed mass targets, which lead to heavy and costly countermeasures.Therefore, the specific requirements of the automotive industry demand a highly developed mass properties management (MPM). This paper presents such a MPM through a practice oriented and flexible methodology. The methodology is based on existing MPM approaches (including SAWE practices) and adapted to the automotive industry. It consists of a mass target framework enriched by a mass prognosis tool, an economic evaluation method for automobile mass scenarios, methods for identifying lightweight design measures and a phase-adequate determination of mass uncertainties. The methods are strongly based on the approach of PGE - Product Generation Engineering, which says that products are developed in generations and therefore information can be reused.This paper deals in particular with the determination of mass uncertainties. Five types of mass uncertainties are identified, compared to the SAWE mass change codes and quantified on the basis of real automobile projects. Since the uncertainties provide transparency on mass potentials and risks, a suitable approach corridor for mass target guidance is derived from them. Furthermore, approaches are presented how mass uncertainties can be interpreted as quality indicators of current MPM processes and how the entire method can be automated. Finally, the mentioned methods above are combined to form a process to derive and manage robust mass targets, buffers and design masses for automobile development.},

keywords = {31. Weight Engineering - Surface Transportation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3721,

title = {3721. A Weight and Center of Gravity Instrument for Measuring Manned Spacecraft},

author = {Dan Otlowski},

url = {https://www.sawe.org/product/paper-3721},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {23},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {Rocketry dynamics equations prescribe that the mass properties of spacecraft, particularly the spacecraft's mass and center of gravity (CG), be carefully choreographed throughout the launch, mission execution, and recovery stages. Mission design carefully selects CG locations for each of the spacecraft modules alone and in combinations, making CG verification an important step toward ensuring mission success. Measuring the CG of large spacecraft presents many of the typical problems associated with measuring CG of smaller objects. Some of these issues are commonly: constructing a measuring system with known geometry, maintaining the repeatability of said geometry under a wide array of load conditions, selecting force transducers with sensitivity appropriate to the verification tolerance, preserving that sensitivity throughout the measurement, and devising a method to relate the spacecraft's datum to the instrument's datum. A purpose-built, mass properties measurement solution that addresses all of these issues is the topic of this paper. In this paper, we will describe the form of the instrument, detail enabling technologies, explain performance drivers, and summarize our results.},

keywords = {09. Weighing Equipment},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3720,

title = {3720. A Practical and Proactive Way of Managing Weight & Center of Gravity Uncertainty Using the Successive Principle},

author = {Runar Aasen},

url = {https://www.sawe.org/product/paper-3720},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {One of the challenges in mass properties is how to handle the uncertainty in an early stage estimate of weight and center of gravity (CG) and its impact throughout the life of the project. Risk is sometimes defined as the product of consequence multiplied by uncertainty, and for many shipbuilding projects the consequence of missing the mark on either the weight or CG can be dramatic. That makes reducing uncertainty essential to avoiding a high-risk project.Dr. Steen Lichtenberg started as early as the 1970's to develop a method for proactive management of uncertainty using the successive principle. The method is a practical way to manage opportunities and risk. The underlying philosophy states that realism in forecasts requires a qualitative phase as well as a quantitative phase. In the qualitative phase, an analysis group of people should be established, while the quantitative phase should establish a basic structure of main items, followed by a systematic detailing process and an action plan.While the method typically handles uncertainties related to the economics of large projects, this paper will look at how the principles and processes involved can be applied to the weight and CG challenges during ship design and construction. A general introduction to the successive principle will be given, the basic applications will be presented, and discussions and examples of use cases will be included. The goal is to add another tool to the toolbox of the weight engineer to help secure successful projects.},

keywords = {21. Weight Engineering - Statistical Studies},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3719,

title = {3719. Modernising Ship Stability: Lightship Evolution Diagnostics with In-Service Stability},

author = {Manuela Bucci and Colin MacFarlane},

url = {https://www.sawe.org/product/paper-3719},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {24},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {Lightship mass and center of gravity are the basis for assessing ship regulatory stability and the maximum payload that the ship can load results from this assessment. Knowing the ship mass and centre of gravity is therefore of utmost importance for both commercial and safety reasons.It is known that, over time, both these quantity change. At present, changes in the lightship are addressed by five-yearly audits that may lead to an inclining experiment - the traditional way to measure ship mass and centre of gravity. The time gaps are filled with estimates based on weight control which can be shown to be a 'random walk' process. This means that, temporarily, undetected worsening of the ship stability might occur.Draught measurement provides immediate feedback of the accuracy of the estimate of weight change, provided draught sensors are adequately maintained. Evidence of change in the vertical position of the lightship center of gravity is not, however, obvious.In-service stability measurements, integrated into the vessel's operational routine, directly estimate the vessel VCG and can diagnose changes in the lightship vertical moment using statistical process control techniques. Changes in the progression of mean values of Deadweight and Lightship vertical moment are used instead of records of weight changes to build a model of ship stability over time with uncertainty on the mean value decreasing with increasing number of measurements. Weight control remains important to characterize the changes and discrepancies from the loading program can be used to identify sensor failures, defective estimates of cargo deadweight and Lightship changes.This paper briefly reviews conventional techniques (referring to previous Conference papers). It then discusses attempts to perform conventional inclinings at sea and the difficulties in obtaining precision, before setting out the methods of in-service stability assessment, techniques for analysis of the results and finally the control limits that can be used to trigger further investigation. The technology is suitable for autonomous vessels.},

keywords = {13. Weight Engineering - Marine, 21. Weight Engineering - Statistical Studies},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3718,

title = {3718. Center of Buoyancy and Center of Gravity Measurement of a Submersible Vehicle},

author = {James Blair},

url = {https://www.sawe.org/product/paper-3718},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {16},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {Stability of submersible vehicles is dependent on the relationship between the center of gravity and center of buoyancy locations on the object. Improper relationships between the two can reduce performance and adversely affect the mission goals of the vehicle. Measuring these values can reveal variations from the designed values that may have been introduced during the manufacturing or assembly process. These values can also change in modular submersible vehicles which allow swapping or modifying components based on the needs of their mission. Errors associated with an improper relationship may not arise until sea testing, which may lead to the need for vehicle disassembly in order to shift or change ballast weights of the submersible.This paper examines a measurement system designed to measure the center of gravity and the center of buoyancy of a submersible object using a hanging weight and center of gravity instrument. The method demonstrated is applicable for vehicles ranging from a few pounds to upwards of 15 tons. With proper fixturing, the machine is capable of measuring center of buoyancy and center of gravity in all 3 axes, which can help determine lateral, longitudinal, and directional stability of a part. This paper outlines a process for measuring submersible vehicles (with negative or slightly positive buoyancy) to determine weight, buoyant force, center of gravity, and center of buoyancy.},

keywords = {13. Weight Engineering - Marine, 21. Weight Engineering - Statistical Studies},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3717,

title = {3717. Evaluating a CoG Envelope Using a Probabilistic Approach},

author = {Robert J. Hundl},

url = {https://www.sawe.org/product/paper-3717},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {15},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {In the Energy and Chemicals Construction Industry, many onshore projects are using modular construction. This type of construction requires that the modules be transported from the fabrication yard to the project site. The fabrication yard may be distant from the project site, thus requiring a combination of ocean transportation and land transportation. To verify the design, the structural analysis uses a given design weight limit and center of gravity (CoG) envelope for the various modes of transportation. The size of the CoG envelope can influence the strengthening requirements for the structure during the transportation phases. CoG envelopes are typically set as a percentage of the module length and width. In special cases, a probabilistic approach could be used to reduce the typical CoG envelope size for reducing the amount of strengthening requirements while also quantifying the risk to the project for reducing the size of the CoG envelope.},

keywords = {13. Weight Engineering - Marine, 21. Weight Engineering - Statistical Studies, 35. Weight Engineering - Offshore},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3716,

title = {3716. A Methodology of Determining Parametric Equations from Data with a Worked Example},

author = {David Laurence Hansch},

url = {https://www.sawe.org/product/paper-3716},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {25},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {The method of using multiple regression to determine parametric weight equations is discussed. A worked example based on 1930s to 1940s US submarines is given. In an appendix, the resulting equations are used for comparative naval architecture with contemporary British and German designs.},

keywords = {21. Weight Engineering - Statistical Studies},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3715,

title = {3715. Negligible Weight Quantification for Surface Ship Weight Surveys},

author = {Greg Roach},

url = {https://www.sawe.org/product/paper-3715},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {12},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {Shipboard weight surveys are routinely performed for surface vessels across the spectrum of marine industries from small pleasure craft to large surface combatants. These surveys are typically part of a vessel's stability test (weight survey & inclining experiment) usually required as part of the vessel's delivery/acceptance or during its service life to confirm the safety of the vessel and/or crew/passengers has not been compromised from post-delivery modifications or inevitable weight & KG growth. These stability tests may take a few days to a few weeks, with a large portion of the effort attributed to the weight survey itself. Further, a large portion of the survey consists of inventorying smaller items which typically constitute a relatively small portion of the overall weight nor may have any appreciable impact to the overall results of the stability test.To date (to the author's knowledge), no official guidance or recommendation(s) exists on what or how to quantify as negligible weight(s) for the purposes of a weight survey. This guidance, if available, may reduce the time required for survey and save considerable time and resources without appreciably changing the end result and/or conclusion.With limited availability/diversity of actual ship survey data, the analysis will focus on the required precision of the stability test based on accepted requirements documentation. This analysis will consider the size of the vessel which directly impacts the design's sensitivity to weight, as well as the practicalities associated with the existing practices of shipboard surveys such as availability of the vessel or qualified personnel. In addition, industry guidance on human engineering design will be used to establish 'rules of thumb' for determining item weights and/or their potential impact to the results to aid in shipboard surveys.},

keywords = {13. Weight Engineering - Marine, 25. Weight Engineering - System Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3714,

title = {3714. Weight and Design Data for World War II - Era United States Military Aircraft},

author = {Dudley M Cate},

url = {https://www.sawe.org/product/paper-3714},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {39},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {Sources of weight data for World War II-era U.S. military aircraft recently were located in the U.S. Federal Archives. The data is to the level of detail found in a short group weight statement. To the author's knowledge, the weight data has not heretofore been publicly available. It was felt to be worthwhile to electronically tabulate the data and then make it available via the SAWE.The paper begins with an introduction that identifies the groundrules and constraints associated with the material in the paper. The rest of the paper presents both weights and weight fractions for the weight empty groups and the useful load items for a wide range of aircraft. The aircraft are arranged by type (fighter, bomber, etc.), military service (Army or Navy), and, in general, chronologically by model (P-40, P-39, P-47, etc.). Also included for each aircraft are the weights of alternate fuel and payload items. For most of the aircraft, the weight empty and gross weight obtained from the archived data are validated by comparing them with weights found in open sources. Values for some of the weight-related design attributes for each aircraft are provided. Accompanying this data is a brief discussion of weight-related considerations for each aircraft.The large number of aircraft for which data are included presents a clear picture of how group and total weights and weight fractions changed with time (e.g., from the pre-war Boeing P-26 to the post-war Lockheed P-80). The data also permit comparison of the differences between, for example, radial-engined and in-line-engined fighters, between Army and Navy fighters, between Navy dive bombers and torpedo bombers, and between biplane and monoplane trainers, to mention just a few of the possibilities.},

keywords = {10. Weight Engineering - Aircraft Design, 30. Miscellaneous},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3713,

title = {3713. Inspiring Future Mass Properties Engineers: NASA's Orion Ascent Abort-2 Flight Test and the Office of Stem Engagement},

author = {Anne Weiss and Rosemary L. Smith},

url = {https://www.sawe.org/product/paper-3713},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {32},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {In response to the National Academy of Engineering's 2004 report, Educating the Engineer of 2020, and two subsequent National Science Foundation research studies examining effective strategies for educating the next generation of engineers, U.S. K-12 general education and undergraduate engineering programs have undergone numerous reforms. Instead of concentrating solely on technical knowledge (e.g., statics, mechanics, fluid dynamics, etc.), formal and informal teachers should now also enhance their instructional practices through interdisciplinary, interactive and immersive experiences that meet students where they are and equip them with 21st-century workforce skills such as collaboration, ability to consider societal and global contexts, and technical writing and public speaking. To support educators' efforts and NASA's Orion Ascent Abort-2 flight test, education specialists in the Langley Research Center's Office of STEM Engagement partnered with the Flight Test Management and Public Affairs Offices to create a line of instructional products that help teachers and students to make connections between NASA-unique assets, STEM content, and careers in mass properties engineering. Using a mixed-methods research design, this paper documents initial results of that unique, highly collaborative interdisciplinary process: an educator professional development digital badge and a flipped classroom unit with standalone video interview. Although full-scale assessment has yet to occur, preliminary data indicates that responses from students, educators and the public to these resources have been overwhelmingly positive. Future ideas include webinars targeting K-12 teachers as well as virtual-reality technology 'field trips' for students - additional tools for achieving the goal of inspiring tomorrow's mass properties engineers.},

keywords = {30. Miscellaneous},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3711,

title = {3711. A Century of Submarine Mass Properties},

author = {David Tellet},

url = {https://www.sawe.org/product/paper-3711},

year  = {2019},

date = {2019-05-01},

booktitle = {78th Annual Conference, Norfolk, VA},

pages = {41},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Norfolk, Virginia},

abstract = {This paper takes a chronological look at submarine milestones during the last century and discusses how the evolution of submarine design affected mass properties engineering including weight control processes, management of mass properties, technical authority, and stability and buoyancy requirements. The paper discusses how the movement of submarine design from boats that can submerge to submarines designed for near constant submergence changed performance requirements including mass property limits. It discusses how the Cold War and nuclear power influenced submarine design and how this affected mass properties requirements and practices including deliberate margin depletion and reduction in service life margins. The paper includes some thoughts on future submarine designs and how those may affect mass property management practices.},

keywords = {13. Weight Engineering - Marine},

pubstate = {published},

tppubtype = {inproceedings}

}