@conference {3687, title = {3687. An Updated Initial Parametric Weight Equation Compendium}, booktitle = {76th Annual Conference, Montreal, Canada}, year = {2017}, month = {05/2017}, pages = {50}, publisher = {Society of Allied Weight Engineers, Inc.}, organization = {Society of Allied Weight Engineers, Inc.}, address = {Montreal, Canada}, abstract = {

When developing the initial weight estimate for a new vessel, the weight engineer or naval architect can produce his or her estimate either by scaling from a known, similar vessel, or by taking the weights of each portion of the vessel from parametric equations or by some combination of these two methods. The preferred source of a parent vessel to scale from or the data from which a parametric equation is derived is the past vessels designed by the naval architect{\textquoteright}s own firm; however, sometimes the firm may not have suitable designs in its portfolio to base a new design weight estimate upon. This paper seeks to collect as many previously published parametric weight equations for as wide a collection of vessel types as possible in order to provide a convenient reference for the times the naval architect{\textquoteright}s own data is insufficient to complete a weight estimate.

This paper is not intended to be the definitive source of parametric weight equations, rather, the goal is to collect a critical mass of equations across the range of vessel types to start the conversation on the relative merits of the various equations and hopefully elicit new up-to-date equations from others. Ideally discussers will add equations based on their own data in addition to discussing the merits of those collected here. The end goal is the production of a SNAME T\&R Bulletin, however much additional validation, updating and discussion is required to take the current paper to the point where it could be considered as a true draft for such a bulletin.

In all cases, the reader is encouraged to consult the original source and attempt independent validation before using any of the equations collected herein.

}, keywords = {13. Weight Engineering - Marine}, url = {https://www.sawe.org/papers/3687/buy}, author = {Hansch, David} } @conference {3688, title = {3688. Uncertainty Analysis Applied to Two Historic Inclining Experiments}, booktitle = {76th Annual Conference, Montreal, Canada}, year = {2017}, month = {05/2017}, pages = {55}, publisher = {Society of Allied Weight Engineers, Inc.}, organization = {Society of Allied Weight Engineers, Inc.}, address = {Montreal, Canada}, abstract = {

Uncertainty analyses were performed on the inclining experiments of two historic passenger liners to determine the drivers of the lightship weight and KG uncertainty. These analyses were further used to determine potential areas to improve the experimental uncertainty as well as areas of the test that can be relaxed without significantly reducing the certainty of the test results. The largest driver in the uncertainty of lightship KG was found to be the uncertainty in displacement as inclined. It is recommended that whenever possible a wedges method of displacement correction be employed to minimize the uncertainty of the test. The wedges method based on actual keel deflection is ideal, but even the parabolic wedges method offers a significant advantage over the 3{\textfractionsolidus}4 hog or sag correction method.

}, keywords = {21. Weight Engineering - Statistical Studies}, url = {https://www.sawe.org/papers/3688/buy}, author = {Hansch, David} } @conference {3511, title = {3511. The Use of Inferential Statistics in Ships{\textquoteright} Stability Analysis}, booktitle = {69th Annual Conference, Virginia Beach, Virginia}, year = {2010}, month = {05/2010}, pages = {17}, publisher = {Society of Allied Weight Engineers, Inc.}, organization = {Society of Allied Weight Engineers, Inc.}, address = {Virginia Beach, Virginia}, abstract = { A deterministic approach is traditionally performed for damage stability analysis on Navy ships, while commercial, ABS accredited, ships use Safety of Life At Sea (SOLAS) and International Maritime Organization (IMO) probability studies. SOLAS and IMO analyses provide an attained subdivision index, but do not allow the designer to determine the actual KG value required to survive damage a certain percentage of the time. In a deterministic approach one would have to analyze all cases to determine the passing percentage. The use of inferential statistics will allow one to determine the KG required for a ship to survive damage a certain percentage of time, or the percentage of cases that will meet the analyzed stability criteria at a particular KG, without having to analyze every damage case, and provides more detail than an attained subdivision index, as with SOLAS and IMO requirements.}, keywords = {13. Weight Engineering - Marine, 21. Weight Engineering - Statistical Studies}, url = {https://www.sawe.org/papers/3511/buy}, author = {COOLEY, MELISSA and DIGGS, MICHAEL and Hansch, David} } @conference {3399, title = {3399. Weight Distribution Method of Determining Gyradii of Ships}, booktitle = {66th Annual Conference, Madrid, Spain}, year = {2007}, month = {5/28/2007}, pages = {21}, publisher = {Society of Allied Weight Engineers}, organization = {Society of Allied Weight Engineers}, type = {13. WEIGHT ENGINEERING - MARINE}, address = {Madrid, Spain}, abstract = {A new method of calculating the radii of gyration of a ship via numerical integration of the weight distribution is proposed. This new method eliminates the need for shape factors or actual individual moments of inertia to be entered with each data entry. Additionally, this method avoids many of the potential pitfalls associated with the traditional weight times distance squared method that occur as a design matures or legacy data is used in a modified repeat ship class. Furthermore, a method of approximating the weight distribution of a ship from a Work Breakdown Structure (WBS) based weight estimate is presented. Sample calculations showing the validity of the weight distributions and radii of gyration are included. }, keywords = {13. Weight Engineering - Marine}, url = {https://www.sawe.org/papers/3399/buy}, author = {Hansch, David} }