ASTM F1808-03(2019)

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.
Designation: F1808 − 03 (Reapproved 2019) An American National Standard
Standard Guide for
Weight Control Technical Requirements for Surface Ships
This standard is issued under the fixed designation F1808; 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.
1. Scope 3. Terminology
1.1 This guide provides recommended weight control tech- 3.1 Definitions:
nical requirements for surface ships and discusses different
3.1.1 agreed weight and center of gravity estimate, n—an
types of weight estimates, reports, and weight control proce-
estimate of light ship weight and centers of gravity data,
dures. It contains a weight classification that will assist in
mutually agreed upon between the owner and the shipbuilder
achieving uniformity by standardizing the weight-reporting
shortly after award of the shipbuilding contract, based on the
system.
shipdesigninformation,forexample,specifications,drawings,
and so forth, available at the time of award.
1.2 This guide is applicable to ships designed and con-
structed in inch-pound units of measurement and to ships
3.1.2 as-built weight and center of gravity estimate, n—a
designed and constructed in SI units of measurement. When-
detailed final estimate of light ship weight and centers of
everinch-poundunitsareshownorreferredtointhetext,orin
gravity data, adjusted for inclining experiment results, reflect-
example formats included in this guide, it is to be understood
ing the as-built ship including the net effect of contract
that corresponding SI units may be substituted if applicable to
modifications.
a ship designed and constructed in SI units, provided that
3.1.3 center of gravity, n—the point through which the
whichever system is used, it is consistently used in all weight
resultant of all gravitational forces on a ship or a component
control reporting documentation for the ship.
passes.Thelocation,abalancepoint,atwhichtheentireweight
1.3 This international standard was developed in accor-
of a ship may be considered to be concentrated.
dance with internationally recognized principles on standard-
3.1.4 deadweight, n—the total carrying capacity of a ship
ization established in the Decision on Principles for the
including weight of cargo, fuel, lubricating oil, fresh water in
Development of International Standards, Guides and Recom-
tanks, stores, passengers and baggage, and crew and their
mendations issued by the World Trade Organization Technical
effects.
Barriers to Trade (TBT) Committee.
3.1.5 inclining experiment, n—a procedure performed on a
2. Referenced Documents
completed, or almost completed, ship to establish experimen-
2.1 ASTM Standards:
tally the light ship values of the displacement and the vertical,
F1321Guide for Conducting a Stability Test (Lightweight
longitudinal, and transverse positions of its center of gravity
Survey and Inclining Experiment) to Determine the Light
(see Guide F1321 for detailed procedures).
Ship Displacement and Centers of Gravity of a Vessel
3.1.6 independent weight and center of gravity estimate,
F1332Practice for Use of SI (Metric) Units in Maritime
n—the estimate of light ship weight and centers of gravity
Applications (Committee F25 Supplement to IEEE/
3 performed by the shipbuilder shortly after award of the
ASTM SI 10) (Withdrawn 2017)
shipbuilding contract based on the ship design information
available at the time of award. When compared with the
This guide is under the jurisdiction of ASTM CommitteeF25 on Ships and
owner’s estimate and upon resolution of differences, an agreed
Marine Technology and is the direct responsibility of SubcommitteeF25.01 on
upon weight and center of gravity estimate will result.
Structures.
Current edition approved Dec. 1, 2019. Published January 2020. Originally
3.1.7 light ship weight, n—theweightoftheshipwithallits
approved in 1997. Last previous edition approved in 2013 as F1808–03 (2013).
equipment and outfit, including permanent (fixed) solid or
DOI: 10.1520/F1808-03R19.
liquid ballast, spare parts that are carried on board, water in
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
boilers at operating levels, machinery including Marine Sani-
Standards volume information, refer to the standard’s Document Summary page on
tation Device units in working condition, lubricating oil in all
the ASTM website.
machinery, but not in storage tanks, and liquids in all piping
The last approved version of this historical standard is referenced on
www.astm.org. systems.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1808 − 03 (2019)
3.1.8 longitudinal center of gravity (LCG), n—the point Sections S1–S4 describe the specific weight control technical
throughwhichthegravitationalforcesonashippass,measured requirements for U.S. Navy surface ships.
longitudinally from amidships, measured from the forward
5. Significance and Use
perpendicular,orinsomecases,measuredfromtheaftperpen-
dicular.
5.1 It is important to know the amount of weight and its
location before the ship is built to be sure that when it is built
3.1.9 transverse center of gravity (TCG), n—the point
it will have positive stability. Only through detailed weight
throughwhichthegravitationalforcesonashippass,measured
estimating in the design stage and during construction can one
transversely, port or starboard, from the ship’s centerline.
beensuredthatpositivestabilitywillbeachievedandretained.
3.1.10 vertical center of gravity (KG or VCG), n—the point
throughwhichthegravitationalforcesonashippassmeasured
6. Procedure
vertically from the keel (K) or the ship’s baseline.
6.1 Aspecified number of calendar days, that is, 30, 45, 60,
3.1.11 weigh; to weigh, v—as commonly understood in
or 90 after date of award, as specified by the owner, the
everyday usage and in the maritime industry, and as used
shipbuilder should submit for agreement an independent
throughout this guide, means to determine by measuring the
weight and center of gravity estimate. This estimate should
mass of.
describe the weight and centers of gravity of the ship in
comprehensive detail and should include summaries and work
3.1.12 weight, n—as commonly understood in everyday
sheets showing the detailed work performed, for example,
usageandinthemaritimeindustry,andasusedthroughoutthis
calculations and estimates based on the design information,
guide, is synonymous with mass. In this guide, weight in
drawings, specification, and so forth. Appendix X1 contains
inch-pound units is measured in pounds and in long tons of
suggestedformsfortheindependentestimate,anditincludesa
2240 lbs; and in SI units (metric), weight is measured in
suggested weight classification system for the estimate. Terms
kilograms and in metric tons of 100 kg. Refer to Practice
used in the weight classification are defined in the Maritime
F1332 for conversion factors to convert inch-pound quantities
Administration Publication, Classification of Merchant Ship
toSI(metric)quantitiesforunitsofweight,moment,moments
Weights.
to trim, and so forth.
6.2 A mutual agreement between the shipbuilder and the
3.1.13 weightclassification,n—thesystemusedinlightship
owneronthelightshipweightandcentersofgravityshouldbe
weight estimating for grouping materials, equipment, or com-
reached as quickly as possible after award of the shipbuilding
ponents of the ship in a structured order to facilitate compari-
contract. Agreement action should consist of a review of
son and to ensure completeness.
shipbuilder’s independent weight and center of gravity esti-
3.1.14 weight group, n—one of the three major elements of
mates and comparison with the owner’s estimate. Upon reso-
light ship weight as used in the weight classification, that is,
lution of differences, an agreed upon weight and center of
hull structure, outfit, and machinery.
gravity estimate will result. Thereafter, the shipbuilder should
beresponsibleforobtaininginthecompletedvesseltheagreed
4. Summary of Guide
upon weight and center of gravity characteristics adjusted for
4.1 Determination of Weight and Moment Data—The authorized departures from the contracted ship design, re-
weight and moment data for all components and material and flected in the agreed upon estimate.
their overall effect on the ship’s weight, center of gravity, list,
6.3 Departures from the contracted ship design, reflected in
and trim should be determined. As ship design or ship
the agreed upon estimate, which affect the light ship weight
construction drawings are prepared and as material is selected,
and centers of gravity, should not be undertaken until the
acquired, or received, the weight and centers of gravity of all
shipbuilder has submitted to the owner his estimate of the
itemsthatcomprisetheshipshouldbedeterminedandreported
effectonweightandcentersofgravityoftheshipandobtained
in the weight estimates and reports. These data may be
written approval to proceed with the department. Departures,
obtained by estimation or calculation during preliminary and
which have a total impact on any weight group of less than a
contract design, by a combination of estimation or calculation
specified percentage, that is, 0.01, 0.02, 0.03, or 0.04% of the
of ship construction drawings, and by actual weight determi-
light ship weight, may be considered negligible and will not
nation of items during detail design and construction.
require written approval with respect to weight.
4.2 Weight Reporting and Control—The procedures for
6.4 The shipbuilder should submit periodically, as agreed
weight reporting and control, regardless of the level of
upon, to the owner, a tabulation of approved departures and
reporting, are described in Section 6 and apply for commercial
their cumulative effect on weight and centers of gravity of the
ships.The method and frequency of weight reporting can vary
agreed light ship estimate. In addition, when submitting plans
depending on the specific ship design, as well as the technical
that involve departures from the type of construction in the
requirements set forth in the contract. The extent and level of
contractedshipdesign,reflectedintheestimate,theshipbuilder
weight control also can vary depending on the specific ship
design.Althoughtheweightcontroltechnicalrequirementsfor
U.S. Department of Transportation, Maritime Administration Classification of
commercial ships usually are less demanding than those for
Merchant Ship Weights, January 1985. Available from the U.S. Maritime
U.S. Navy surface ships, the need for a mechanism to control
Administration, Office of Ship Construction, MAR 720, 400 Seventh St., SW,
the weight of a ship still exists. Supplementary Requirement Washington, DC 20590.
F1808 − 03 (2019)
should itemize such departures and their effect on light ship 7. Keywords
weight and centers of gravity in his periodic reports. A final
7.1 light ship; ship acquisition; weight control; weight
report should be submitted at the time of delivery adjusted to
estimate; weight report
bringtheestimatedlightshipweightandcentersofgravityinto
reasonable agreement with the inclining experiment results.
SUPPLEMENTARY REQUIREMENTS
The following supplementary requirements shall apply only when specified by the purchaser in the
contract or purchase order. These requirements normally are invoked for U.S. Navy Surface Ships.
S1. Special Government Requirements between the accepted weight estimate (AWE) or the allocated
baseline weight estimate (ABWE) and the delivered ship as
S1.1 Government Documents, Drawings, and
inclined.
Publications—The following government documents,
S2.2 accepted weight estimate (AWE), n—theAWE defines
drawings, and publications form a part of this guide to the
the weight and centers of gravity of a ship that was awarded
extent specified herein. Unless otherwise specified, the issues
are those cited in the solicitation. under a specification-type contract using the information that
S1.1.1 Naval Sea Systems Command (NAVSEA) Docu- was available at the time of contract award. It establishes
contractual values for weight and KG and is the baseline for
ments:
0900-LP-039-9020 Ship Work Breakdown Structure for detail design and construction.
Nuclear Propulsion Plant (U)
S2.3 acquisition margins, n—acquisition margins are
S9040-AA-IDX-010/SWBS 5D, Expanded Ship Work
weight and KG allowances included in the weight estimate to
Breakdown Structure, Vol I
cover the inherent limits of precision and the undefined
S9040-AA-IDX-020/SWBS 5D, Expanded Ship Work
variationsofcomponentweightandcentersofgravitythattake
Breakdown Structure, Vol II
placethroughoutthedesignphasesandduringtheconstruction
S1.2 Nongovernment Publications—The following docu-
of a ship. To provide for adequate weight control and configu-
ment(s) form a part of this guide to the extent specified herein.
ration control, acquisition margins are divided into five ac-
Unlessotherwisespecified,theissuesofthedocuments,which
counts: preliminary design margin, contract design margin,
are DOD adopted, are those listed in the issue of the Depart-
detail design and building margin, contract modification
ment of Defense Index of Specifications and Standards
margin, and government-furnished material (GFM) margin.
(DODISS) cited in the solicitation. Unless otherwise specified,
S2.4 actual weight, n—actual weight is the value obtained
theissuesofdocumentsnotlistedintheDODISSaretheissues
by a measurement of material on an accurate scale or other
of the documents cited in the solicitation (see S4.1).
weighing device.
S1.2.1 ANSI Document:
S2.5 allocated baseline weight estimate (ABWE), n—the
X3.4 Code for Information Interchange
ABWE is the contractor’s definition of the weight and centers
NOTE S1—Nongovernment standards and other publications normally
ofgravityofashipthatwasawardedunderaperformance-type
are available from the organizations that prepare or distribute the
contract at the time of hull and propulsion configuration
documents.Thesedocumentsalsomaybeavailableinorthroughlibraries
or other informational services. approval. It is the baseline for detail design and construction.
S1.3 Order of Precedence—In the event of a conflict S2.6 baseline weight estimate (BWE), n—the BWE is any
between the text of this guide and the references cited herein, designated weight estimate that is used as a starting point in a
the text of this guide takes precedence. Nothing in this guide, design phase for comparative analysis with subsequent weight
however, supersedes applicable laws and regulations unless a estimates. Before contract award, the final estimate of each
specific exemption has been obtained.
designphaseisusuallythebaselineestimateforthesucceeding
phase.After contract award, theAWE orABWE usually is the
S2. Terminology baseline estimate for the remainder of detail design and
construction.
S2.1 accepted ship report (ASR), n—the ASR is the docu-
S2.7 bidder’s independent weight estimate (BIWE), n—the
ment that demonstrates the contractor’s performance with
regard to weight control. The ASR highlights the differences bidder’s (or offeror’s) independent weight estimate is prepared
by each potential contractor in response to a solicitation. It is
the bidder’s evaluation of the ship design based on the ship
specifications, drawings, and data that comprise the contract
Available from the Navy Ships Parts Control Center (SPCC), Code 709,
package.
Mechanicsburg, PA 17055.
Available from Naval Sea Logistics Center, Code 623, PO Box 2060,
S2.8 calculated weight, n—calculated weight is weight
Mechanicsburg, PA 17055-0795.
7 computed from ship construction drawings and vendor draw-
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. ings.
F1808 − 03 (2019)
S2.9 capacity load condition (Condition E), n—thecapacity progressinachievinghisrequirementtodelivertheshipwithin
load condition is the ship complete and ready for service in contractual values (see S3.3.4.6).
every respect. It is light ship (ConditionA) plus the following
S2.18 current weight, n—current weight consists of the
variable loads: maximum number of officers, crew, and pas-
most accurate data available on the date of a given weight
sengersthatcanbeaccommodatedandtheireffects;maximum
estimate or report. The summary of current weight is fre-
stowageofammunitioninmagazinesandreadyservicespaces;
quently a combination of estimated, calculated, and actual
full allowance of aircraft and vehicles (fully fueled with full
values.
allowance of repair parts and stores); maximum amount of
S2.19 design and weight data sheet, n—the design and
provisionsandstoresthatcanbecarriedintheassignedspaces;
weight data sheet is a one-page summary that includes group
and maximum capacity of liquids in tanks. Fuel and lube oil
level weight data, hull characteristics data, displacement, and
shall be not greater than 95% of tank capacity, unless such
stability characteristics data, load data, and machinery data.
tanks are compensating. Compensating tanks shall be consid-
S2.20 detail design and building margin, n—detail design
ered filled with 95% fuel and 5% salt water. Maximum
andbuildingmarginisaweightandKGallowanceincludedin
amounts of cargo and supplies, other than for ship’s own use,
the weight estimates and reports to account for design changes
shall be included to the full capacity of the assigned spaces.
as a result of ship construction drawing development; growth
Thisloadconditionshallbenotgreaterthanthelimitingdrafts.
of contractor-furnished material; omissions and errors in the
S2.10 category, n—category is a fundamental unit of ma-
AWE or ABWE, as well as differing shipbuilding practices,
chinery weight classification for nuclear-propelled ships in
omissions and errors in the ship construction drawings; un-
accordance with NAVSEA 0900-LP-039-9020.
known mill tolerances; outfitting details; variations between
S2.11 category system, n—category system is a system of
the actual ship and its curves of form; and similar differences.
machinery weight classification for nuclear-propelled ships in
This margin is to compensate for all contractor-responsible
accordance with NAVSEA 0900-LP-039-9020.
differences between theAWE orABWE and the results of the
S2.12 contract data requirements list (CDRL) (DD Form
inclining experiment, as well as tolerances for experimental
1423), n—a CDRL is a contract form listing all data items
variation in the inclining experiment. This weight and KG
selected from an authorized data list to be delivered under the
allowance is budgeted and included in the feasibility,
contract. It includes the format, content, frequency, submittal,
preliminary, and contract design phases, but no portion of this
and distribution requirements.
marginistobeconsumedbeforeawardofthedetaildesignand
S2.13 contract design margin, n—the contract design mar-
construction contract. Values for these margins are to be
gin is a weight and KG allowance included in the weight
selected by the offeror and included along with rationale for
estimate to account for increases associated with design
theirbasisinBIWEsorPABWEs.Thefinalmarginallowances
development during the contract design phase. This margin is
arethensubjecttonegotiationbetweenthegovernmentandthe
included in the feasibility and preliminary design phases. No
contractor that was selected for detail design and construction.
portion of this margin is consumed before the start of contract
The design and building weight margin shall be located at the
design.
same center of gravity as the summation of weight groups one
S2.14 contract design weight estimates (CDWE), n—the
through seven.
CDWE is the weight estimate of the light ship, full load, and
S2.21 electronic media, n—electronic media is used to
any other specified loading condition prepared during the
transfer detailed weight and moment data that complies with
contract design phase.
the Navy standard weight estimate format and is used by
S2.15 contract modification margin, n—the contract modi-
NAVSEA to prepare Navy weight estimates and reports (see
fication margin is a weight and KG allowance included in the
Annex A1).
weight estimates and reports to account for increases associ-
S2.22 estimated weight, n—estimated weight is based on
atedwithcontractmodificationsissuedduringthedetaildesign
preliminary data and is subject to revision when more accurate
and construction phase. This margin is included in the
information is available, such as when more detailed drawings
feasibility, preliminary, and contract design phases. For
are developed or when components are actually weighed.
performance-type contracts, this margin is also included in
S2.23 expanded ship work breakdown structure (ESWBS),
detail design and building phase. No portion of this margin is
consumed before award of the detail design and construction n—ESWBS is a five-digit functional classification system in
accordancewithNAVSEAS9040-AA-IDX-010/SWBS5Dand
contract.
S9040-AA-IDX-020/SWBS 5D (Vol I and II). For weight
S2.16 contract modification summary, n—the contract
reporting purposes, only the first three digits of this system
modification summary is a complete listing of the weight and
apply. The fourth and fifth single digit classification levels are
momenteffectsofapprovedcontractchanges.Thisinformation
usedtoincorporatethefunctionsthatsupportmaintenanceand
is included as an appendix to the quarterly weight reports, the
repair needs.
accepted ship report, and the final weight report.
S2.17 contractor-responsible condition, n—the contractor- S2.24 feasibility study weight estimate, n—the feasibility
studyweightestimateisacompilationoftheship’sweightand
responsible condition is the full-load condition without the
effects of contract modifications, changes in GFM, and other centerofgravitydatathatresultinlightship,fullload,andany
other specified loading conditions. This estimate is prepared
allowable changes after the establishment of the AWE or
ABWE. This condition is used to measure the contractor’s during the feasibility study design phase.
F1808 − 03 (2019)
S2.25 final weight report (FWR), n—a FWR is a detailed S2.31 inch-pound units, n—inch-pound units comprise a
finalreportofweightandmomentdataforallrequiredloading system of units using pounds, long tons, ft, ft-lbs, and ft-tons
for reporting mass properties data. These weight and moment
conditions. This report accurately reflects accumulated values
for estimated, calculated, and actual weight data for the detail data are carried to the nearest pound and ft-lb at all detail
levels.Inaddition,summariesareconvertedandreportedtothe
design, including the net effect of changes to GFM and
nearest one-hundredth of a long ton and to the nearest ft-ton.
adjudicated and unadjudicated contract modifications.
All levers are carried to the nearest one-hundredth of a foot.
S2.26 full load condition (Condition D), n—the full-load
S2.32 KG, n—KG is defined as the height of the ship’s
condition is the ship complete and ready for service in every
vertical center of gravity as measured from the bottom of the
respect. It is light ship (Condition A), plus the following
keel (includes keel thickness). When using SI units, care must
variable loads: authorized complement of officers, crew, and
be taken not to confuse the naval architectural symbol KG, in
passengers and their effects; full allowances of ammunition in
uppercase letters, with the SI symbol, kg, in lowercase letters
magazines and ready service spaces; full allowance of aircraft
(which represents the SI unit kilogram).
and vehicles (fully fueled with full allowance of repair parts
S2.33 light ship condition (Condition A), n—the light ship
and stores); full supply of provisions and stores for the periods
condition is the ship complete, ready for service in every
specifiedinthedesigncharacteristics;fullpotablewatertanks;
respect, including permanent solid and liquid ballast, onboard
lube oil tanks to 95% of capacity; fuel tanks to 95% capacity,
repair parts, and liquids in machinery at operating levels,
or in the case of compensating tanks, 95% fuel and 5% salt
without any items of variable load.
water; sewage collecting, holding, and transfer tanks to 25%
S2.34 longitudinal lever, n—the longitudinal lever is the
capacity; anti-roll tanks to operating levels; and all other
perpendicular distance from a transverse plane through the
liquids in tanks to required capacity in accordance with
ship’slongitudinalreferencetothecenterofgravityofanitem.
characteristics and liquid-loading instructions. The
The longitudinal reference is located at the forward
ammunition, stores, fuel, and other liquids referred to previ-
perpendicular, unless otherwise specified by the design con-
ously are for the ship’s own use. Cargo (liquid and solid) is
tract or Ship Specification Section 096.
included in the amounts normally carried or to the specified
S2.35 mass properties data, n—mass properties data are
portion of the full capacity of the assigned spaces.
those physical characteristics that define the magnitude,
S2.27 government-furnished material (GFM) margin,
location, and distribution of weight in the ship. They include
n—theGFMmarginisaweightandKGallowanceincludedin
weight, centers of gravity location, moments, and weight
the weight estimates and reports to account for increases
moments of inertia.
caused by the growth in GFM during the detail design and
S2.36 metric units, n—metric units comprise a system of
construction phase. This margin is included in the feasibility,
basic measures that are defined by the International System of
preliminary, and contract design phases. For performance-type
Unitsbasedon“LeSystemeInternationald’Unites(SI)”ofthe
contracts, this margin is also included in detail design and
International Bureau of Weights and Measures.
building phase. No portion of this margin is consumed before
S2.37 moment, n—a moment is the product of a weight and
award of the detail design and construction contract.
its lever. For example, the longitudinal moment of an item is
S2.28 government-furnished material summary, n—the
the product of the weight of the item multiplied by its
GFM summary is a complete listing of weight and center of
longitudinal lever.
gravity data for material and equipment that will be provided
S2.38 percent completion, n—percent completion is the
by the government. The baseline GFM summary, which is
ratioofthecurrentweight,lessthecurrentestimatedweight,to
includedaspartoftheAWEorABWE,reflectstheScheduleA
the current weight, expressed as a percentage.
portionofthecontractatthetimeofcontractaward.TheGFM
S2.39 performance-type contract, n—a performance-type
summary is continuously updated as the detail design weight
contract is the vehicle for ship acquisition resulting from a
estimates mature and the ScheduleAis modified.Also, where
description of operational and mission requirements. Since the
the contract permits, the GFM summary can include other
shipbuilder usually has substantial latitude in determining ship
government-responsible equipment, such as equipment desig-
size and configuration, a PABWE or ABWE is used in this
nated as standard for the class, directed procurement, and so
situation.
forth.
S2.40 pitch moment of inertia, n—moment of inertia about
S2.29 group, n—group is a fundamental unit of ship
the transverse axis through the ship’s center of gravity.
classification, identified by one numeric digit or an alphabetic
S2.41 preliminary allocated baseline weight estimate
designator.Forweightestimatesandreports,agroupisthefirst
(PABWE), n—the PABWE is the potential bidder’s (or offer-
character of the three-digit system. The summation of weights
or’s) estimate of the weight and center of gravity of the ship in
and moments for all of the three-digit elements that begin with
response to a solicitation for a performance-type contract.
thenumberoneisthetotalforGroupone,andsimilarlyforthe
S2.42 preliminary design margin, n—preliminary design
other groups.
margin is a weight and KG allowance included in the weight
S2.30 gyradius,n—thegyradiusforroll,pitch,oryawisthe
estimates to account for increases associated with design
square root of the quotient of the ship’s weight moment of developmentduringthepreliminarydesignphase.Thismargin
inertiaabouttheroll,pitch,andyawaxes,respectively,divided
is included in the feasibility design phase. No portion of this
by the ship’s displacement. margin is consumed before the start of preliminary design.
F1808 − 03 (2019)
S2.43 preliminary design weight estimate, n—preliminary S2.48 specification-type contract, n—a specification-type
design weight estimate is the weight estimate of the light ship, contract is the vehicle for ship acquisition resulting from a
full load, and any other specified load condition prepared Navy controlled contract design. The products of the contract
during the preliminary design phase. design,whichusuallybecomepartoftheshipbuildingcontract
S2.44 quarterly weight report (QWR), n—a QWR is a and therefore the basis for the BIWE, include items such as:
periodicassessmentofdisplacement,drafts,trim,list,GM,and midship section drawing, lines drawing, table of offsets,
KG as the weight estimate matures during detail design and general arrangement drawings, the shipbuilding specifications,
construction. and special requirements like not-to-exceed weight and KG
S2.45 roll moment of inertia, n—moment of inertia about values.
the longitudinal axis through the ship’s center of gravity. S2.49 standard longitudinal station breakdown, n—the
S2.46 service life allowances, n—service life allowances standard longitudinal station breakdown is a system consisting
are weight and KG budgets included in the design to accom- of 22 stations designated by the lettersAthrough X (excluding
modate changes as a result of both authorized (for example, I and O). Station A is the only station forward of the forward
ship alterations) and unplanned growth (for example, paint, perpendicular (FP). Station X is the only station aft of the aft
personalbelongings,andsoforth)duringtheship’soperational perpendicular (AP). Stations B through W extend from the FP
lifetime, which tends to increase displacement and impact to the AP, and each comprises ⁄20 of the length between
stability. perpendiculars.
S2.47 SI units (International System of Units), n—SI units S2.50 three-digit system, n—The three-digit system is a
(see Practice F1332) comprise a system of units using kilo- meansofclassifyingmasspropertiesdatainastructuredorder.
grams (kg), metric tons, metres (m), kg/m, and metric ton-m Everyitemthatcomprisesthecompletedshipisincludedinthe
for reporting mass properties data.All levers are carried to the weight estimates and reports grouped in accordance with the
nearestone-hundredthofam.Theweightandmomentdataare three-digit system. Unless otherwise specified, the three-digit
carried to the nearest kg and kg/m at all detail levels. In system for weight estimates and reports is the same as the first
addition, summaries are converted and reported to the nearest three digits of the ESWBS. An example of this numerical
one-hundredth of a metric ton and to the nearest metric ton-m. ordering is shown in Fig. S2.1.
FIG. S2.1 Example of a Three-Digit System Format
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S2.51 transverse lever, n—transverse lever is the perpen- the products obtained by multiplying the weight of each item
diculardistancefromtheverticalcenterlineplaneoftheshipto bythesquareofitsdistancefromthereferenceinertiaaxis(see
the center of gravity of an item. S3.3.2.3).
S2.52 vertical lever, n—vertical lever is the perpendicular S2.57 weight reporting, n—weight reporting is the prepara-
distance from a horizontal plane through the molded baseline tion and submission of the most accurate and current weight
of the ship to the center of gravity of an item. and moment data available at designated intervals throughout
S2.53 weight control, n—weight control is all of the neces- the design and construction phases.
sary actions, such as predicting, estimating, calculating, S2.58 yaw moment of inertia, n—moment of inertia about
weighing, reporting, analyzing, evaluating, and reversing ad- the vertical axis through the ship’s center of gravity.
verse trends to ensure that a ship’s weight and moments are
S3. Procedures
consistent with its naval architectural limits for displacement,
strength, stability, list, trim, and performance, such as speed, S3.1 General Report Requirements—The contract will in-
endurance, and seakeeping. voke this guide and specify technical data to be prepared,
S2.54 weight control plan, n—a weight control plan out- including modifications and exceptions. The CDRL will
lines the procedures that will be followed to meet contractual specify requirements for deliverables, such as data to be
weight control responsibilities (see S3.3.3.5).
submitted, frequency of submission, number of copies, and
S2.55 weight distribution, n—a weight distribution is a recipients. The general requirements for the weight estimates
weight summary by the standard longitudinal station break-
and reports listed in this standard are specified in S3.1.1
down and is used to develop shear forces and bending through S3.2. The interface of weight estimates and reports is
moments. depicted in Fig. S3.1.
S2.56 weight moment of inertia, n—weight moment of S3.1.1 Loading Conditions—Weight estimates and reports
inertia about any reference axis through the ship’s center of shall contain loading conditions for light ship, full load, and
gravityisthesummationofthemomentofinertiaofeachitem contractor responsibility, unless otherwise specified by the
about its own axis (parallel to the reference inertia axis), plus contract. The light ship condition includes a summary of
FIG. S3.1 Interface of Weight Reporting During Design and Construction
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one-digit groups and the remaining acquisition margin. These surface effect of liquids in tanks), list, trim, and drafts above
values are combined to result in the light ship weight, centers the bottom of the keel at the perpendiculars and midship. Figs.
ofgravity,andassociatedmoments.Thelightshipconditionin
S3.2-S3.4 provide examples of typical loading conditions.
the FWR shall be adjusted to correlate with inclining experi-
S3.1.2 Margins—Acquisition margins shall be included in
ment data. Building margin is used to account for irreconcil-
the estimates and reports. Throughout the design cycle, the
able differences between the FWR and the inclining experi-
appropriate margin account shall be adjusted concurrently to
ment. Building margin is the only acquisition margin account
compensate for departures from the original estimates. This
that is permitted in the FWR. Other margin accounts, such as
computation permits the maintenance of a constant design
detail design margin, will either be fully depleted or if
baselineuntilthebudgetedmarginaccountisexceeded.Weight
remainders exist they should be deleted from the FWR. The
margins shall be located at the same centers of gravity as the
full-load condition is computed by adding specified items of
ESWBS current one-digit totals. Fig. S3.5 provides a typical
variable load to the light ship condition and reflects the actual
example.
ship that is planned for delivery. The contractor-responsible
S3.1.3 Reasons for Changes—Weight estimates and reports
condition is the full-load condition without the effect of
shall include an addendum that explains each cause of signifi-
contractmodifications,bothadjudicatedandunadjudicated;the
cant change in weight or moment within every three-digit
net weight change and associated moment changes from
element. Unless otherwise specified, a significant change is a
baselinevaluesofcurrentGFMitemsthatwereincludedinthe
1% or greater difference from an element’s previous estimate.
originalScheduleAorweresubsequentlyaddedtoScheduleA
A brief narrative of the ship’s condition relative to its naval
through a change in acquisition responsibility; and other
architectural or contractual limits shall be included in this
allowable changes beyond the control of the contractor (see
section. If any of these limits is in jeopardy, recommendations
S3.3.4.6). This condition is used to assess contractual perfor-
for reversing the adverse trend are also required.
mance. In addition to the total weight, centers of gravity, and
associated moments, each loading condition also shall display S3.1.4 Table of Contents—The estimates and reports shall
KG, metacentric height (uncorrected and corrected for the free contain a table of contents.
FIG. S3.2 Example of Light Ship Condition Format
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FIG. S3.3 Example of Full-Load Condition Format
S3.1.5 Special Coding—An explanatory note and remarks classified or proprietary material shall be downgraded by
section shall be included to define special coding symbols, deletingclassifiedorproprietaryportionsthatdonotimpairthe
such as material codes, GFM indicators, and reasons for usefulness of the document.
change indicators. S3.3 Detailed Requirements:
S3.1.6 Lever Symbol—Vertical levers shall be indicated by S3.3.1 Predetail Design Phase—Estimates, reports, and
a“–”forbelowthebaselineanda“+”orablankforabovethe supplemental documents for these design phases shall be
baseline. Longitudinal levers shall be indicated by an “F” or a prepared in accordance with S3.3.1.1 through S3.3.2.10, as
“–” for forward of the reference plane and an “A,” a “+,” or a applicable, unless otherwise specified.
blank for aft of the reference plane. Transverse levers shall be S3.3.1.1 Weight Estimates and Reports—Weight estimates
indicated by a “P,” a “+,” or a blank for port and an “S” or a and reports prepared during these phases consist of baseline
“−” for starboard. weight estimates, interim reports, and final design weight
S3.1.7 Reporting System Units—Estimates, reports, and estimates. These estimates and reports contain detailed infor-
other specified mass properties documentation and data shall mation appropriate to the design phase, loading conditions for
be reported in either inch-pound or metric units as specified in light ship and full load, and are summarized in tabular form as
the contract. follows:
S3.1.8 Paper—Estimatesandreportsshallbemachinewrit- (1)Three-digit system number and title.
ten on 8 ⁄2- by 11-in. paper, and protected by hard covers, but (2)Current weight.
notpermanentlybound.Theoriginalorreproduciblecopyshall (3)Current vertical lever.
be suitable for microfilming. (4)Current vertical moment.
S3.1.9 Supporting Documents—Background information, (5)Current longitudinal lever.
studies, directives, correspondence, and all detail calculations (6)Current longitudinal moment.
pertaining to weight and moment data, including density (7)Current transverse lever.
factors, shall be made available to the Navy upon request. (8)Current transverse moment.
S3.2 Classified Reports—Weight reports containing classi- The mass properties data included in these estimates and
fied data shall be marked in accordance with the security reports are based on the engineering products available before
requirements contained in the contract. Whenever possible, the date of the document.
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FIG. S3.4 Example of Contractor-Responsible Condition Format
S3.3.1.2 Baseline Weight Estimates—The initial estimate (6) The current status of margins, loads, full-load
for a given design phase is designated the baseline weight displacement,KG,list,andtrim.Thechangescorrespondingto
estimate. The baseline weight estimate consists of the light the total net change calculated for (4) and (5) shall be shown
ship, full load, and any other specified loading condition. The for margins, loads, and full-load displacement.
estimate shall be titled Baseline Preliminary or Baseline (7)Abrief narrative providing rationale for any significant
Contract Design Weight Estimate. The requirements for the changes since the previous report and classified by the groups
estimate are as specified in S3.3.1.1. in which the changes occurred.
S3.3.1.3 Interim Reports—Weight estimates produced at S3.3.1.4 Final Design Weight Estimate—The final estimate
specified intervals during a given design phase are designated produced during a design phase is designated as the final
interim weight reports. The interim report summarizes the design weight estimate. This estimate will reflect the final
current weight and moment status of the design and highlights weightandmomentdataforlightship,fullload,andanyother
any changes that occurred during the reporting period. The specified loading condition. The estimate shall be titled Final
report shall contain the light ship, full load, and any other Preliminary or Final Contract Design Weight Estimate. The
specified loading condition. It also shall reflect the appropriate requirements for the estimate are specified in S3.3.1.1 and
title, such as Preliminary Design Interim Report No. 2. Fig. S3.3.1.3.
S3.6 and Fig. S3.7 provide typical examples. In addition to the S3.3.2 Supplemental Documents—The supplemental docu-
requirements specified in S3.3.1.1, the report shall contain the ments specified in S3.3.2.1 through S3.3.2.10 shall provide
following: additional information and background data required during
(1)Previous design phase group level summary. the preliminary/contract design phases.
(2)Previous report group level summary. S3.3.2.1 Weight and Moment Trade-Off Studies—These
(3)Current group level estimate, and when required, the studies consist of determining the mass properties impact of
element level estimate and longitudinal weight distribution various configuration change proposals and engineering alter-
data. natives that are being considered for inclusion in the design.
(4)Net change, by group and total, between (1) and (3). The studies are delivered on an “as requested” basis and
(5)Net change, by group and total, between (1) and (3). contain detailed mass properties calculations that define the
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FIG. S3.5 Example of Margins Format
impact of the study on ship displacement, KG, list, and trim. S3.3.2.4 Ship Specification Sections—Ship specification
There is no fixed format for the completed study, but the sections shall define the requirements of the weight control
ESWBS classification system shall be used to structure and program and the range of acceptable trim and list limit values
summarize the data. that are to be invoked upon the shipbuilder. Deviations from
S3.3.2.2 Weight Distribution Report—A longitudinal this standard, such as special loading conditions, reporting
units, or margins, shall be defined clearly. The format for the
weight distribution shall be provided in a tabulated format in
accordance with the standard longitudinal station breakdown. specification sections will be provided by NAVSEA.
Weight and longitudinal center of gravity shall be determined S3.3.2.5 Circular of Requirements Sections—These sec-
foreachshipstationforbothlightshipandfull-loadcondition. tions shall provide the weight control requirements when a
Theresultanttotalweightandlongitudinalcenterofgravityfor performance-type contract is used. The content of these sec-
theweightdistributionreportforeachconditionshallequalthe tions shall be similar to S3.3.2.4, with the addition of service-
values reflected in the weight estimate or report for the same life allowance quantities.
condition in that reporting period. S3.3.2.6 Contract Data Requirements List (CDRL)—A
S3.3.2.3 Weight Moment of Inertia—When specifically re- CDRL will be developed that itemizes the data deliverables
that shall be required by the ship acquisition contract. The
quired by the contract, weight moment of inertia dat
...