Technical Resource Library

In 1995, The National Council of Examiners for Engineering and Surveying (NCEES) approved the offering of a national examination for professional licensure of naval architects and marine engineers (NAME) with The Society of Naval Architects and Marine Engineers as the sponsoring organization. A survey of the Society’s membership was conducted to determine the range of subject matter of importance to practice in this field and an examination specification was developed and published. In the October, 1998 and April, 1999 issues of Marine Technology and SNAME NEWS, articles were presented by the then President, Jose Femenia, discussing various aspects of the examination for Professional Engineer Licensure in Ship Design Engineering (SDE),. The first Principles and Practice Examination was given on October 29, 1999. In 2001, the name was changed and thenceforth is identified as Naval Architecture-Marine Engineering (NAME). In an effort to assist the Society’s membership in their exam preparation, some study materials were developed and presented on the SNAME Web Site that are concerned with some subject areas of the examination specification (the examination specification was published in the Marine Technology issue Volume 35, Number 4, of October, 1998). Since 2001, an annual examination has been administered in April of each year by the various licensing jurisdictions authorized to offer a Principles and Practices examination in this field of licensure. During 2005 and 2006, a second survey of the naval architecture and marine engineering field was conducted to assess needed changes in requirements for abilities, knowledge and practices. Based on this survey, a revised examination specification was developed and implemented in April of 2008.

T&R 3-47 -- This guide covers sea trials of self-propelled surface ships displacing 300 tone or more, powered by fossil fuel and driven by stem turbine, gas turbine, diesel engine or electric motors. It does not cover dock trials or tests or demonstrations which can be conducted dockside, which are covered in SNAME T&R Bulletin 3-39, Guide for Shop and Installation Tests.

T&R 3-39 --  This guide presents information for a shop and installation test of each type of equipment and system normally found on commercial ships. This guide does not cover sea trial tests, which are covered in SNAME CODE FOR SEA TRIALS - 1973.

This paper describes a novel adjustable-length trimaran design for service as a high-speed sealift vessel. Different numerical hydrodynamic tools were exercised to assess the performance of the vessel. An extensive model test program that included powering and seakeeping experiments was conducted to elucidate utility of the numerical predictions.

The objectives for this thesis were to design a modern stern for the series 60 (0.60 CB) Model, to compare the resistance characteristics of the original and modern sterns, and to analyze the wake patterns of the models to determine their effect on propeller induced vibrations. The modern stern was designed to closely represent sterns built today. Analysis of resistance and wake survey results showed that the modern stern made a significant improvement in resistance, hull efficiency, shaft bearing vibrations, hydrodynamic vibrations, and cavitation performance.

This paper describes The Glosten Associates' performance of stability evaluations on 16 vessels of the University-National Oceanographic Laboratory System (UNOLS) fleet. These evaluations established a consistent baseline to aid in managing missionspecific weight change for each vessel to ensure the satisfaction of stability requirements. This dedicated and diligent weight management is essential for ensuring that vessels remain within a safe stability zone while not exceeding reasonable service life allowance

In order to clarify the existence and amount of a required propulsion power reduction possible with the efficient use of the Ballast-Free Ship concept on a Seaway-size bulk carrier, additional experimental and computational hydrodynamics studies were undertaken during the past year. Experimental studies performed in the University of Michigan Marine Hydrodynamics Laboratory (MHL) are described. Computational fluid dynamics (CFD) investigations performed using Star-CCMþ at both model and full scale are also presented.

This paper outlines the design, assessment, and installation of a prototype ballast water treatment system for a double-hull tank ship. The IMO has established a timetable by which vessels must be equipped with ballast water treatment systems that meet a prescribed performance standard. Tank ship installations are particularly challenging because ballast piping is typically located in spaces defined by classification society rules as hazardous. These same rules do not readily allow the treatment equipment and piping to communicate with these spaces. The treatment system described in this paper has been demonstrated, through a risk assessment, to meet applicable classification society rules. Planned full-scale testing intends to show the operational safety, efficiency, and biological efficacy of this promising technology

This technical note evokes directionally nonuniformloading field effects on exposures of marine objects and structures in service under environmental conditions. The note firstly reveals the statistical variability of distributions of probabilities and the entropy concept of uncertainty of systems of events for identification, ordering and presentation of probabilistic seasonal nonuniformities of wind wave loading fields. This paper provides diagram of variability of wind wave directions and the chart of ocean-wide directional nonuniformities compiled from the Global Wave Statistics (GWS). It also
considers seasonal loading field distributions of wind wave heights against wave directions as well as methods for calculation and presentation of directional exposabilities of marine objects and structures. The study introduces two methods for favorable placement and selection of sustainable directions of marine objects and structures exposed seasonally to nonuniform wind wave loading fields based on criteria for minimal average exposure and on robust uniform exposures during service period. The note elaborates examples of favorable placement of a marine object on six piles near the east Brazilian coast and of an oil tanker in the Gulf of Mexico. The note at the end illustrates the use of the multiple-criteria approach either to support decisions about optimal placement and sustainable headings to waves or for avoidance of unfavorable directional field effects and their combination on marine objects and structures.

There is limited long term service experience with the modern generation of large container carriers and hence there is great interest in improving our understanding of the performance of these vessels. In an effort to assess the actual structural service performance of a large container carrier, a comprehensive full-scale measurement system was developed to measure the wave environment, ship motions and structural response. The system was installed on an 8063 TEU container carrier built in 2006, and the first year measurement campaign has successfully been completed. This paper presents a summary of noteworthy observations during the first year’s voyage records which includes ship motion, wind and wave conditions, and hull girder strains and derived hull girder bending and torsional moments. The observed vibratory responses of the hull girder are also presented.