ASTM F1321-14(2021)

Standard Guide for Conducting a Stability Test (Lightweight Survey and Inclining Experiment) to Determine the Light Ship Displacement and Centers of Gravity of a Vessel

SIGNIFICANCE AND USE
4.1 From the light ship characteristics one is able to calculate the stability characteristics of the vessel for all conditions of loading and thereby determine whether the vessel satisfies the applicable stability criteria. Accurate results from a stability test may in some cases determine the future survival of the vessel and its crew, so the accuracy with which the test is conducted cannot be overemphasized. The condition of the vessel and the environment during the test is rarely ideal and consequently, the stability test is infrequently conducted exactly as planned. If the vessel is not 100 % complete and the weather is not perfect, there ends up being water or shipyard trash in a tank that was supposed to be clean and dry and so forth, then the person in charge must make immediate decisions as to the acceptability of variances from the plan. A complete understanding of the principles behind the stability test and a knowledge of the factors that affect the results is necessary.
SCOPE
1.1 This guide covers the determination of a vessel’s light ship characteristics. In this standard, a vessel is a traditional hull-formed vessel. The stability test can be considered to be two separate tasks; the lightweight survey and the inclining experiment. The stability test is required for most vessels upon their completion and after major conversions. It is normally conducted inshore in calm weather conditions and usually requires the vessel be taken out of service to prepare for and conduct the stability test. The three light ship characteristics determined from the stability test for conventional (symmetrical) ships are displacement (“displ”), longitudinal center of gravity (“LCG”), and the vertical center of gravity (“KG”). The transverse center of gravity (“TCG”) may also be determined for mobile offshore drilling units (MODUs) and other vessels which are asymmetrical about the centerline or whose internal arrangement or outfitting is such that an inherent list may develop from off-center weight. Because of their nature, other special considerations not specifically addressed in this guide may be necessary for some MODUs. This standard is not applicable to vessels such as a tension-leg platforms, semi-submersibles, rigid hull inflatable boats, and so on.  
1.2 The limitations of 1 % trim or 4 % heel and so on apply if one is using the traditional pre-defined hydrostatic characteristics. This is due to the drastic change of waterplane area. If one is calculating hydrostatic characteristics at each move, such as utilizing a computer program, then the limitations are not applicable.  
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 14-Jan-2021
• ICS: 47.020.01 - General standards related to shipbuilding and marine structures
• Technical Committee: F25 - Ships and Marine Technology
• Drafting Committee: F25.01 - Structures

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F1321 − 14 (Reapproved 2021) An American National Standard
Standard Guide for
Conducting a Stability Test (Lightweight Survey and
Inclining Experiment) to Determine the Light Ship
1
Displacement and Centers of Gravity of a Vessel
This standard is issued under the fixed designation F1321; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
INTRODUCTION
This guide provides the marine industry with a basic understanding of the various aspects of a
stability test. It contains procedures for conducting a stability test to ensure that valid results are
obtained with maximum precision at a minimal cost to owners, shipyards, and the government. This
guide is not intended to instruct a person in the actual calculation of the light ship displacement and
centersofgravity,butrathertobeaguidetothenecessaryprocedurestobefollowedtogatheraccurate
dataforuseinthecalculationofthelightshipcharacteristics.Acompleteunderstandingofthecorrect
procedures used to perform a stability test is imperative to ensure that the test is conducted properly
and so that results can be examined for accuracy as the inclining experiment is conducted. It is
recommended that these procedures be used on all vessels and marine craft.
1. Scope applicable to vessels such as a tension-leg platforms, semi-
submersibles, rigid hull inflatable boats, and so on.
1.1 This guide covers the determination of a vessel’s light
1.2 The limitations of 1 % trim or 4 % heel and so on apply
ship characteristics. In this standard, a vessel is a traditional
hull-formed vessel. The stability test can be considered to be if one is using the traditional pre-defined hydrostatic charac-
teristics.Thisisduetothedrasticchangeofwaterplanearea.If
two separate tasks; the lightweight survey and the inclining
experiment.The stability test is required for most vessels upon one is calculating hydrostatic characteristics at each move,
such as utilizing a computer program, then the limitations are
their completion and after major conversions. It is normally
conducted inshore in calm weather conditions and usually not applicable.
requires the vessel be taken out of service to prepare for and
1.3 The values stated in inch-pound units are to be regarded
conduct the stability test. The three light ship characteristics
asstandard.Nootherunitsofmeasurementareincludedinthis
determined from the stability test for conventional (symmetri-
standard.
cal) ships are displacement (“displ”), longitudinal center of
1.4 This standard does not purport to address all of the
gravity(“LCG”),andtheverticalcenterofgravity(“KG”).The
safety concerns, if any, associated with its use. It is the
transverse center of gravity (“TCG”) may also be determined
responsibility of the user of this standard to establish appro-
for mobile offshore drilling units (MODUs) and other vessels
priate safety, health, and environmental practices and deter-
which are asymmetrical about the centerline or whose internal
mine the applicability of regulatory limitations prior to use.
arrangement or outfitting is such that an inherent list may
1.5 This international standard was developed in accor-
develop from off-center weight. Because of their nature, other
dance with internationally recognized principles on standard-
special considerations not specifically addressed in this guide
ization established in the Decision on Principles for the
may be necessary for some MODUs. This standard is not
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1
This guide is under the jurisdiction of ASTM Committee F25 on Ships and
Barriers to Trade (TBT) Committee.
Marine Technology and is the direct responsibility of Subcommittee F25.01 on
Structures.
2. Referenced Documents
Current edition approved Jan. 15, 2021. Published February 2021. Originally
2.1 ASTM Standards:
approved in 1990. Last previous edition approved in 2014 as F1321–14. DOI:
10.1520/F1321-14R21. E100Specification for ASTM Hydrometers
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F1321 − 14 (2021)
3. Terminology
3.1 Definitions:
3.1.1 inclining experiment, n—involves moving a series of
weights, in the transverse direction, and then measuring the
resultingchangeintheequilibriumheelangleofthevessel.By
using this information and applying basic naval architecture
principles, the vessel’s vertical cent
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F1321 − 14 F1321 − 14 (Reapproved 2021) An American National Standard
Standard Guide for
Conducting a Stability Test (Lightweight Survey and
Inclining Experiment) to Determine the Light Ship
1
Displacement and Centers of Gravity of a Vessel
This standard is issued under the fixed designation F1321; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
INTRODUCTION
This guide provides the marine industry with a basic understanding of the various aspects of a
stability test. It contains procedures for conducting a stability test to ensure that valid results are
obtained with maximum precision at a minimal cost to owners, shipyards, and the government. This
guide is not intended to instruct a person in the actual calculation of the light ship displacement and
centers of gravity, but rather to be a guide to the necessary procedures to be followed to gather accurate
data for use in the calculation of the light ship characteristics. A complete understanding of the correct
procedures used to perform a stability test is imperative to ensure that the test is conducted properly
and so that results can be examined for accuracy as the inclining experiment is conducted. It is
recommended that these procedures be used on all vessels and marine craft.
1. Scope
1.1 This guide covers the determination of a vessel’svessel’s light ship characteristics. In this standard, a vessel is a traditional
hull-formed vessel. The stability test can be considered to be two separate tasks; the lightweight survey and the inclining
experiment. The stability test is required for most vessels upon their completion and after major conversions. It is normally
conducted inshore in calm weather conditions and usually requires the vessel be taken out of service to prepare for and conduct
the stability test. The three light ship characteristics determined from the stability test for conventional (symmetrical) ships are
displacement (“displ”), longitudinal center of gravity (“LCG”), and the vertical center of gravity (“KG”). The transverse center of
gravity (“TCG”) may also be determined for mobile offshore drilling units (MODUs) and other vessels which are asymmetrical
about the centerline or whose internal arrangement or outfitting is such that an inherent list may develop from off-center weight.
Because of their nature, other special considerations not specifically addressed in this guide may be necessary for some MODUs.
This standard is not applicable to vessels such as a tension-leg platforms, semi-submersibles, rigid hull inflatable boats, and so on.
1.2 The limitations of 1 % trim or 4 % heel and so on apply if one is using the traditional pre-defined hydrostatic characteristics.
This is due to the drastic change of waterplane area. If one is calculating hydrostatic characteristics at each move, such as utilizing
a computer program, then the limitations are not applicable.
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this
standard.
1
This guide is under the jurisdiction of ASTM Committee F25 on Ships and Marine Technology and is the direct responsibility of Subcommittee F25.01 on Structures.
Current edition approved May 1, 2014Jan. 15, 2021. Published May 2014February 2021. Originally approved in 1990. Last previous edition approved in 20132014 as
ε1
F1321 – 13F1321 – 14. . DOI: 10.1520/F1321-14.10.1520/F1321-14R21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F1321 − 14 (2021)
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical
...