ISO 19901-5:2016

Petroleum and natural gas industries - Specific requirements for offshore structures - Part 5: Weight control during engineering and construction

ISO 19901:2016 specifies requirements for controlling the weight and centre of gravity (CoG) by means of mass management during the engineering and construction of structures for the offshore environment. The provisions are applicable to offshore projects that include structures of all types (fixed and floating) and materials. These structures can be complete new installations or the modifications to existing installations. Maintaining the weight control of existing installations is not part of the main body of this part of ISO 19901, but some guidance on this is included in the Annex G. ISO 19901:2016: - specifies quality requirements for reporting of weights and centres of gravity; - specifies requirements for weight reporting; - provides a basis for overall project weight reports or management reports for all weight control classes; - specifies requirements for weight and load budgets; - specifies the methods and requirements for the weighing and the determination of weight and CoG of major assemblies; - specifies requirements for weight information from suppliers, including weighing of equipment and bulk materials for offshore installations. It can be used: - as a basis for planning, evaluating and presenting the client's, contractor's or fabricator's weight management and reporting system; - as a means of refining the structural analysis or model; - as a contract reference between client, contractor and suppliers; - as a basis for costing, scheduling or determining suitable fabrication method(s) or location(s).

Industries du pétrole et du gaz naturel — Exigences spécifiques relatives aux structures en mer — Partie 5: Contrôle des poids durant la conception et la fabrication

L'ISO 19901-5:2016 spécifie les exigences relatives au contrôle du poids et du centre de gravité (CdG) par la gestion des masses pendant les phases d'étude et de construction des structures en mer. Les dispositions s'appliquent aux projets de tous types (structures en mer fixes et flottantes) et matériaux. Ces structures peuvent être des installations entièrement nouvelles ou des modifications d'installations existantes. Le corps principal de l'ISO 19901-5:2016 ne traite pas du suivi des poids des installations existantes. Toutefois, l'Annexe G du présent document fournit des lignes directrices. L'ISO 19901-5:2016: - spécifie les exigences de qualité pour l'établissement de rapports de poids et de centres de gravité; - spécifie les exigences relatives aux rapports de poids; - fournit une base commune pour l'établissement de rapports de poids ou de suivi du projet dans son ensemble, quelle que soit la classe de suivi de poids considérée; - spécifie les exigences relatives aux bilans de poids et de charges; - spécifie les méthodes et les exigences relatives au pesage et à la détermination du poids et du centre de gravité des principaux ensembles; - spécifie les exigences relatives aux données de poids provenant des fournisseurs, y compris le pesage des équipements et des matériels courants pour les installations en mer. Elle peut être utilisée: - comme base de planification, d'évaluation et de présentation du système de suivi et de gestion des poids du maître d'ouvrage, du contracteur ou du fabricant; - comme moyen d'amélioration de l'analyse ou du modèle des structures; - comme référence pour l'établissement du contrat entre le maître d'ouvrage, le contracteur et les fournisseurs; - comme base d'établissement des coûts, de programmation ou de détermination de la (des) méthode(s) ou de l'emplacement de fabrication approprié(s).

General Information

• Status: Withdrawn
• Publication Date: 14-Feb-2016
• Withdrawal Date: 14-Feb-2016
• ICS: 75.180.10 - Exploratory, drilling and extraction equipment
• Technical Committee: ISO/TC 67/SC 7 - Offshore structures
• Drafting Committee: ISO/TC 67/SC 7/WG 6 - Weight engineering
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 16-Nov-2021
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 19901-5:2021 - Petroleum and natural gas industries - Specific requirements for offshore structures - Part 5: Weight management
• Effective Date: 14-Jan-2017
• Revises: ISO 19901-5:2003 - Petroleum and natural gas industries - Specific requirements for offshore structures - Part 5: Weight control during engineering and construction
• Effective Date: 16-Feb-2012

Standards Content (Sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 19901-5
ISO/TC 67/SC 7 Secretariat: BSI
Voting begins on: Voting terminates on:
2013-11-14 2014-04-14
Petroleum and natural gas industries — Specific
requirements for offshore structures —
Part 5:
Weight control during engineering and construction
Industries du pétrole et du gaz naturel — Exigences spécifiques relatives aux structures en mer —
Partie 5: Contrôle des poids durant la conception et la fabrication
[Revision of first edition (ISO 19901-5:2003)]
ICS: 75.180.10
ISO/CEN PARALLEL PROCESSING
This draft has been developed within the International Organization for
Standardization (ISO), and processed under the ISO lead mode of collaboration
as defined in the Vienna Agreement.
This draft is hereby submitted to the ISO member bodies and to the CEN member
bodies for a parallel five month enquiry.
Should this draft be accepted, a final draft, established on the basis of comments
received, will be submitted to a parallel two-month approval vote in ISO and
THIS DOCUMENT IS A DRAFT CIRCULATED
formal vote in CEN.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
To expedite distribution, this document is circulated as received from the
IN ADDITION TO THEIR EVALUATION AS
committee secretariat. ISO Central Secretariat work of editing and text
BEING ACCEPTABLE FOR INDUSTRIAL,
composition will be undertaken at publication stage.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 19901-5:2013(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2013

ISO/DIS 19901-5:2013(E)
Copyright notice
This ISO document is a Draft International Standard and is copyright-protected by ISO. Except as
permitted under the applicable laws of the user’s country, neither this ISO draft nor any extract
from it may be reproduced, stored in a retrieval system or transmitted in any form or by any means,
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ii © ISO 2013 – All rights reserved

ISO/DIS 19901-5
ontents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms . 7
5 Weight control classes . 8
5.1 General . 8
5.2 Class A: High definition of weight and CoG . 8
5.3 Class B: Medium definition of weight and CoG . 8
5.4 Class C: Low definition of weight and CoG . 8
5.5 Selection of class of weight control . 9
6 Weight and load budget (WLB) . 10
6.1 General . 10
6.2 Requirements . 11
6.3 Content . 12
6.3.1 General . 12
6.3.2 50/50 weight estimate . 12
6.3.3 Weight reserves . 13
6.3.4 Future weights and loads . 13
6.3.5 Loading conditions and parameters . 14
6.3.6 Formats and levels . 15
6.3.7 CoG envelopes . 16
7 Weight control procedure . 17
8 Weight reporting . 19
8.1 General . 19
8.2 Requirements to the weight report . 20
9 Requirements for weight data and weighing of equipment and bulk . 25
9.1 General . 25
9.2 Provision of weight information . 25
9.3 Requirements for weighing . 25
9.4 Weighing equipment . 26
9.5 Weighing procedure . 26
9.6 Notification and witnessing of weighing . 27
9.7 Calibration of weighing equipment . 27
9.8 Weighing operation . 27
9.9 Temporaries during weighing . 28
9.10 Items excluded during weighing . 28
10 Requirements for weighing of major assemblies . 29
10.1 Weighing procedure . 29
10.2 Environmental conditions . 29
10.2.1 Light . 29
10.2.2 Wind . 29
10.2.3 Temperature and humidity . 30
10.3 Weighing. 30
10.3.1 Number and timing of weighing . 30
10.3.2 Weighing procedure . 31
10.3.3 Notification and witnessing of weighing's . 31
10.3.4 Preparation of the weighing . 32
10.3.5 Weighing equipment . 33
ISO/DIS 19901-5
10.3.6 Calibration of weighing system . 36
10.3.7 Foundation and supports . 36
10.3.8 Structural integrity . 37
10.3.9 Weighing operation . 37
10.3.10 CoG calculations. 38
10.3.11 Weighing certificate . 39
10.3.12 Weighing report . 39
11 Requirements for "as-built" weight documentation . 40
Annex A (informative) Weight data sheets-Tagged equipment . 41
Annex B (informative) Weighing certificates . 43
B.1 Bulk and equipment weighing certificate . 43
B.2 Major Assembly weighing certificate. 45
Annex C (informative) Weight and load budget (WLB) formats and levels . 47
Annex D (informative) Major elements of the weight displacement . 48
Annex E (informative) Supplier weighing procedure . 49
Annex F (informative) Guidelines for displacement measurement of floaters . 51
F.1 General . 51
F.1.1 Procedure for displacement measurement . 51
F.1.2 Displacement measurement subcontractor . 51
F.2 Environmental conditions for displacement measurement . 51
F.3 Displacement measurement . 51
F.3.1 Displacement measurement procedure . 51
F.3.2 Notification . 52
F.3.3 Preparation of the displacement measurement . 52
F.3.4 Equipment for displacement measurement . 53
F.3.5 Displacement measurement operation . 53
F.3.6 Displacement measurement certificate . 53
F.3.7 Displacement measurement report. 54
Annex G (informative) Requirements for weight control during operations . 55
G.1 General . 55
G.2 References to weight control during operations in other ISO standards . 55
G.2.1 References in ISO 19902 for fixed structures . 55
G.2.2 References in ISO 19904 for floating structures . 55
Annex H (informative) Requirements for topside weight estimation. New builds/green field. 56
H.1 Introduction . 56
H.2 Topside weight estimation methodology . 56
H.3 Recommended weight estimation requirements . 57
H.4 Master Equipment List (MEL) . 58
H.5 Weight allowance . 58
H.6 Recommended content for weight estimation report, feasibility and concept phase . 59
H.7 Recommended weight reporting format. 59
Annex I (informative) Executive summary description . 60
I.1 General . 60
I.2 Trend for weight and CoG . 60
I.3 Comparison to budget . 61
I.4 Loading conditions . 61
I.4.1 Management reserve analysis . 61
I.4.2 Changes this report . 61
I.4.3 Potential changes for next report . 61
I.5 Additional summaries (depending on project) . 61
I.5.1 Additional loading conditions . 61
I.5.2 Construction modules weight summaries . 61
I.5.3 Lift weight summaries (including temporaries) . 61
I.5.4 Cost account weight summaries . 61
iv © ISO 2013 – All rights reserved

ISO/DIS 19901-5
I.5.5 Material take-off weight summaries . 61
I.5.6 Summary of the weight and CoG history over the life of the project . 61
I.6 DA weight summary . 61
Annex J (informative) Weighing result uncertainty . 62
Annex K (informative) Weight control database structure . 63

ISO/DIS 19901-5
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 19901-5 was prepared by Technical Committee ISO/TC 67, Materials,equipment and offshore structures
for petroleum, petrochemical and natural gas industries, Subcommittee SC 7, Offshore structures.
This second/third/. edition cancels and replaces the first/second/. edition (), [clause(s) / subclause(s) /
table(s) / figure(s) / annex(es)] of which [has / have] been technically revised.
ISO 19901 consists of the following parts, under the general title Petroleum and natuaral gas industries —
Specific requirements for offshore structures:
 Part 5: Weight control during engineering and construction
 Part [n]:
 Part [n+1]:
vi © ISO 2013 – All rights reserved

ISO/DIS 19901-5
Introduction
The offshore structures International Standards ISO 19900 to ISO 19906 constitute a common basis covering
those aspects that address design requirements and assessments of all offshore structures used by the
petroleum and natural gas industries worldwide. Through their application the intention is to achieve reliability
levels appropriate for manned and unmanned offshore structures, whatever the type of structure and the
nature of the materials used.
It is important to recognize that structural integrity is an overall concept comprising models for describing
actions, structural analyses, design rules, safety elements, workmanship, quality control procedures and
national requirements, all of which are mutually dependent. The modification of one aspect of design in
isolation can disturb the balance of reliability inherent in the overall concept or structural system. The
implications involved in modifications, therefore, need to be considered in relation to the overall reliability of all
offshore structural systems.
The offshore structures International Standards are intended to provide a wide latitude in the choice of
structural configurations, materials and techniques without hindering innovation. Sound engineering
judgement is therefore necessary in the use of these International Standards.
DRAFT INTERNATIONAL STANDARD ISO/DIS 19901-5

Petroleum and natuaral gas industries — Specific requirements
for offshore structures — Part 5: Weight control during
engineering and construction
1 Scope
This part of ISO 19901 specifies requirements for controlling the weight and centre of gravity (CoG) by means
of mass management during the engineering and construction of structures for the offshore environment. The
provisions are applicable to offshore projects that include structures of all types (fixed and floating) and
materials. These structures can be complete new installations or the modifications to existing installations.
Maintaining the weight control of existing installations is not part of the ISO main standards, but some
guidance on this is included in the Annex G.
This part of ISO 19001:
 specifies quality requirements for reporting of weights and centres of gravity;
 specifies requirements for weight reporting;
 provides a basis for overall project weight reports or management reports for all weight control classes;
 specifies requirements for weight and load budgets;
 specifies the methods and requirements for the weighing and the determination of weight and centre of
CoG of major assemblies;
 specifies requirements for weight information from suppliers, including weighing of equipment and bulk
materials for offshore installations;
and may be used
 as a basis for planning, evaluating and presenting the client’s, contractor's or fabricator’s weight
management and reporting system;
 as a means of refining the structural analysis or model;
 as a contract reference between client, contractor and suppliers;
 as a basis for costing, scheduling or determining suitable fabrication method(s) or location(s).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO ab-c:199x, General title of series of parts — Part c: Title of part
ISO xyz (all parts), General title of the series of parts
ISO/DIS 19901-5
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
assembly
designed and fabricated group of bulk and equipment items which form one unit
3.2
budget weight
weight reference figures as defined in the weight and load budget and related to the initial or changed design
concept
3.3
bulk
component or arrangement of components defined as stock materials or of low complexity
Note 1 to entry: Bulk items support the equipment items by providing infrastructure around and between them.
3.4
centre of gravity (CoG)
the average location of the weight of an item. For assemblies, modules or topsides the aggregate CoG is the
mathematical weighted average of the CoG’s of the individual items (comprising the completed assembly,
module or topsides) measured from a common reference point
3.5
client weight reserve
weight addition (usually a lump sum weight) controlled by the client and used to account for any orders for
variation to the contractual design concept
3.6
CoG envelope
defined constraint volume within which the centre of gravity (CoG) of an assembly shall remain
3.7
consumables
variable content that do not remain at a constant level due to consumption during the operation of an offshore
installation
EXAMPLES Potable/service water, diesel fuel, crew provisions, bulk drilling powders for creation of mud and/or
cement.
3.8
contents
fluids or bulk powders held within bulks (piping or structural tanks) or equipment at their normal operating
levels. Typical contents are hydrocarbons, cooling and heating mediums, chemicals, fuels, condensates,
seawater, fresh water, dry powders (drilling cement and mud additives), dry stores for workshops, sack stores,
etc. Fluids that are expected to be continuously installed in an item of equipment (e.g. coolants and lubricating
oils) are not to be considered as contents. See dry weight for further explanation
3.9
contractor weight reserve
additional weight (either a lump sum weight or percentage of a total weight) at a specified CoG, controlled by
the contactor and used to account for any design growth within their control
ISO/DIS 19901-5
3.10
deadweight
total carrying capacity of a floating structure, ref. Annex D
Note 1 to entry: Includes weight of crude oil, deck cargo, temporaries, water, snow and ice accumulations, marine
growth, ballast water, consumables, crew and their effects.
3.11
discipline
a branch of knowledge reflecting a single aspect in the project
EXAMPLES Architectural, drilling, electrical, HVAC, instrumentation, loss control (Safety), piping, structural and
telecommunications.
3.12
discipline check list
a document detailing the weight items that are within the discipline’s control
3.13
displacement
weight of the volume of water displaced by a floating structure
Note 1 to entry: The sum of lightweight and deadweight including mooring system load, appendences and/ or
appurtenances e.g. structures outside the moulded hull. See Annex D.
3.14
dry weight
weight of a component, weight item or an assembly in its dry installed condition including permanent utilities
Note 1 to entry: Examples of permanent utilities are gearbox oil, hydraulic oil, filter sand, etc.
Note 2 to entry: Any content of operating fluid flowing through a component, weight item or an assembly is excluded.
3.15
equipment
component or arrangement of components, built for specific function(s)
Note 1 to entry: The component/assembly normally has unique documentation due to its function and complexity.
3.16
estimated weight
weight determined based on previous experience
3.17
first fill
initial filling of contents in items of equipment or piping prior to start of operation of an offshore facility
Note 1 to entry: First fill typically takes place towards the end of site construction, prior to tow-out and prior to filling for
normal operations.
3.18
float-out
loading condition in which a major assembly is transferred from a dry construction site to become self-floating
3.19
future weight
weight of a component or an assembly to be installed after the start of production
ISO/DIS 19901-5
3.20
grillage
steel structure, secured to the deck of a barge or vessel, designed to support the cargo and distribute the
loads between the cargo and the barge or vessel
3.21
gross weight
sum of the net weight and weight allowances
3.22
hook-up
installation of components or assemblies after the modules have been installed in their final position, to
connect to the existing installation
3.23
hook weight
sum of lifting weight and lifting gear weight
3.24
initial operating (loading condition)
a load condition for an operating offshore facility defined at the start of steady-state production. All bulk and
equipment items are present with contents at nominal operating levels
3.25
lifting gear
equipment needed during a lifting operation
EXAMPLE Slings, spreader bars, lifting frames, shackles, etc.
3.26
lifting weight
weight of a component, an assembly or a module at padeyes, including temporaries and residual fluid content
but excluding lifting gear
3.27
lightship weight
dry and invariable weight of a floating unit (incl. minimum utility content to secure a safe condition, ref Annex
D)
3.28
loading condition
defined event for which a weight and CoG need to be controlled
Note 1 to entry: For each loading condition, all weight items and variable loads that are known or predicted to occur
are identified, quantified and located.
Note 2 to entry: Typical loading conditions are dry installed offshore, float-out at assembly site, future operating
installed offshore, initial operating installed offshore, load-out to offshore transport vessel, transport to offshore field, etc.
3.29
load-out
the transfer - by way of horizontal movement - of an assembly, module or topsides from its land-based
fabrication site onto a floating or grounded transport barge or vessel
Note 1 to entry: The following are typical load-out operations:
 skidded: load-out using a combination of skid-ways, skid-shoes or runners, propelled by towing engines, jacks or
winches;
ISO/DIS 19901-5
 trailer: load-out using multi-axle trailers (SPMT’s – self-propelled modular transporter).
3.30
master equipment list (MEL)
a project specific database for control and management of technical data for tagged equipment
3.31
mating
transfer of a major assembly supported on barge(s) or vessel(s) to a temporary or permanent support
structure
3.32
module
a major assembly of items forming a major building block which need to be controlled with respect to weight
and CoG
3.33
net weight
the calculated or estimated weight of an item excluding allowances
3.34
not-to-exceed weight/NTE weight
maximum acceptable weight for any given loading condition, with an associated limiting CoG envelope
3.35
operating weight
sum of the dry weight and the content weight
3.36
project management
with respect to weight management; management personnel tasked with implementing weight policy,
objectives and procedures
3.37
residual content
content in bulks and equipment remaining after testing or commissioning, and being present during the
subsequent loading conditions up to the start of production
3.38
sea fastening
items used for temporary fastening to keep all items in position during transportation at sea
3.39
tagged equipment
equipment identified and labelled in accordance with the project coding manual and tracked in MEL
3.40
temporary item or temporaries
items temporarily installed during a loading condition and removed afterwards. Temporaries do not form part
of a structure’s permanent dry or operating weight
3.41
test weight
sum of the dry weight plus the content required to test the equipment or assembly
3.42
tow-out
towing of a complete floating structure to the offshore installation site
ISO/DIS 19901-5
3.43
transport (loading condition)
transfer of an assembly or module from one inshore or atshore location to another location, or to the offshore
installation site
3.44
weight allowance
weight additions to account for expected general growth due to immaturity of the current project stage and/or
components which are not estimated in detail at the current project stage
3.45
weight and load budget (WLB)
a document defining the weight and CoG limits for each loading condition, major assembly (and disciplines for
the dry installed offshore load condition). The WLB are to act as a comparison reference for:
a) weight, load and CoG control and reporting for the duration of the project through the engineering,
construction, installation and operation phases;
b) structural capacity requirements for individual sections or modules and for the total topsides or supporting
structure;
c) temporary and permanent bearing capacity and stability of the total facility;
d) overall cost and schedule control
3.46
50/50 weight estimate
value representing the median value in the probability distribution of weight estimates
Note 1 to entry: The actual weight is equally likely to be smaller or larger than the 50/50 weight estimate.
Note 2 to entry: The 50/50 weight estimate is used as the basis for weight budgeting.
3.47
weight installation code
a code which verifies whether a weight item is physically installed or not in an assembly or module
3.48
weight item
item or collection of bulk and/or equipment, content or assembly identified for weight reporting purposes
3.49
weight management
all planned and controlled activities which deal with:
 definition and publication of the project weight procedures, objectives and policies;
 identification of information about and evaluation of alternative design solutions;
 selection and implementation of an optimal design with respect to weight, CoG, volume, functionality, cost
and progress;
 monitoring and reporting weight data throughout the complete life cycle of an installation to assess
present and potential weight status
Note 1 to entry: Project management, engineering disciplines and weight control discipline shall cooperate and
participate to influence the weight management process by means of adequate working methods and tools.
ISO/DIS 19901-5
3.50
weight objective
defined set of engineering goals necessary to fulfil the project contractual weight/CoG requirements and
intentions in order to contribute to the correct design quality as defined by the management
3.51
weight phase code
a code used to identify the loading conditions in which a weight item is present
3.52
weight policy
based on the weight objective, a statement from the project management defining how the weight objective is
to be achieved. As a minimum, the policy shall include:
 the importance of the weight objective to the project aims and results;
 the priority, profile and control of weights at different levels in the project;
 a philosophy for responsibility and authority within and between project groups engaged in weight matters
3.53
weight report
a regularly issued project document that details weight and CoG data determined from specific source
documents
3.54
weight reporting
the adequate and timely publication of weight information in order to fulfil contractual and design requirements
for the project
3.55
weight status code
a code, based on the maturity of the design, used to identify the level of accuracy of the weight of a weight
item. The weight status code is often used to assess the value of the weight allowance applied. As a design
matures, the weight status code will change so that an item’s weight allowance is reduced
4 Abbreviated terms
CoG centre of gravity
MEL master equipment list
NTE not to exceed
WLB weight and load budget
WTO weight take-off
ISO/DIS 19901-5
5 Weight control classes
5.1 General
In order to select the most appropriate level for weight control and reporting according to the degree of weight
and/or CoG sensitivity of the project, three classes of weight control have been defined. These classes may
also be used to determine the level of effort required in the weight management activities for a project.
The tender documents and final contract shall specify the applicable weight control class, so that the
contractor can allocate the required resources.
5.2 Class A: High definition of weight and CoG
Class A shall apply if the project is weight and/or CoG sensitive for any of the anticipated loading cases, or
has many contractor interfaces.
Class A weight projects shall:
a) regardless of the source, have full traceability of all weight and CoG data
b) record weight and CoG data using a relational database from the commencement of detail engineering;
with integration of suppliers', fabricators' and weighing results into the system
c) verify the calculated weight and CoG of assemblies, modules or topsides by means of physical weighings
d) update weight data per weight item produced during the design phases to “as-built” status during the
fabrication
5.3 Class B: Medium definition of weight and CoG
Class B shall apply to projects where the focus on weight and CoG is less critical for any of the anticipated
loading cases than for projects where Class A is applicable.
Class B weight projects shall:
a) based on the complexity of the project, determine whether a relational database or spread sheet software
is required for recording of weight and CoG data
b) verify the calculated weight and CoG of assemblies, modules or topsides by means of physical weighings
c) have less stringent requirements for updating “as-built” status during fabrication
5.4 Class C: Low definition of weight and CoG
Class C shall apply to projects where requirements for updating “as-built” status during fabrication is not
critical.
Class C weight projects shall:
a) as a minimum use a spread sheet software for recording weight and CoG data
b) verify the calculated weight and CoG of assemblies, modules or topsides by means of physical weighings
c) provide supporting weight and CoG documentation consisting of equipment weights and summarized bulk
weights by drawing
d) have no requirements for updating “as-built” status during fabrication
ISO/DIS 19901-5
5.5 Selection of class of weight control
The design basis, NTE weight and CoG criteria, together with WLBs established at the close of the concept
phase, are major factors to be considered when selecting the class of weight control.
Potential weight and CoG problems, specific to the loading condition also need to be assessed before
selecting the class of weight control.
Class selection may be made from examination of Table 1, included as a guide for determining the required
degree of weight and CoG control for a project. The class of weight control selected should be the highest
class meeting any of the Project Parameters in Table 1.
Table 1 — Guidance criteria for weight control class selection
Description Class A Class B Class C
Concept type new partly known well known
Weight sensitivity high medium low
CoG sensitivity impact high medium low
Weight data processing high medium low
requirement
Contract requirement detailed general none
Weight data external interfaces 4 to 6 1 to 3
> 6
(other contractors)
NOTE Weight sensitivity may be a result of constraints established by installation method (i.e. capacity of lifting
device) or capacity of supporting structure (i.e. jacket, GBS, hull, etc.)

ISO/DIS 19901-5
6 Weight and load budget (WLB)
6.1 General
Class A Class B Class C
For all offshore installations, weight and As Class A. As Class A, except that d) is not
CoG information for all loading conditions required.
shall be controlled from the start of
conceptual design. Budget weights and
CoG constraints shall be determined for
the modules, topsides and supporting
substructures (inclusive of temporaries
required for the appropriate loading
conditions). This shall be done in
cooperation with the structural and marine
disciplines as well as the project
management. The budget weights and
CoG constraints shall be presented in the
project WLB as a reference point to be
used during an engineering and
construction project.
The WLB is to be reference point for:
a) weight, load, and CoG control and
reporting during all phase of the
project: engineering, construction,
installation and operation;
b) structural capacity requirements for
assemblies, modules, topsides and
supporting structures;
c) bearing capacity and stability of the
total installation (temporary or
permanent);
d) control of overall cost and schedule;
e) assuring that all loading conditions
are within the anticipated capacities.

ISO/DIS 19901-5
6.2 Requirements
Class A Class B Class C
Each participant in a project (typically the As Class A. The contractor WLBs are established
client, contractor and sub-contractors) either by the client, and are included
shall be allocated a separate WLB. in the project contract, or by the
project contractor. Unless specified
The contractor WLBs shall be established
by the client, the format and
by either the client or the contractor. If
complexity is left to the discretion of
established by the client, the WLBs shall
the contractor.
be included in the project contract
documents.
The project management or client shall
hold overall responsibility for deciding the
variations between the various WLBs.
WLBs for subcontractors and vendors
shall be established by the contractor.
Under normal circumstances, revisions to
WLBs shall not take place unless concept
or major changes to the design - which
impact the weight, load or CoG - are
implemented by the project
management/client.
All participants in the project shall be
responsible for adherence to established
WLB values.
In the event that the project weight
management detects the possibility of a
significant variation from the established
WLBs, corrective actions shall be initiated
by the project management in order that
weight overruns or unfavourable CoGs do
not occur, or their impact is minimized.

ISO/DIS 19901-5
6.3 Content
6.3.1 General
Class A Class B Class C
The WLB consists of different types of As Class A. As Class A.
weights, loads and associated CoGs, as
defined in Figure 1.
Figure 1 - General weight development figure

6.3.2 50/50 weight estimate
Class A Class B Class C
The primary basis for the WLB figures are As Class A. As Class A.
the weight, load and CoG estimates for
the chosen design concept as carried out
either by the client or the contractor.
If it is found necessary, the basis for the
WLBs may be verified by re-estimation at
the commencement of the engineering
phase.
Normally, the weight allowance is included
as a part of the estimated weight to
determine the 50/50 weight estimate of
the facility.
ISO/DIS 19901-5
6.3.3 Weight reserves
Class A Class B Class C
A contractor weight reserve including CoG As Class A. As Class A.
may be added on top of the WLB
estimated weight.
In addition to the contractor weight
reserve, the client may add a weight
reserve including CoG.
The value and location of the weight
reserve will depend upon the concept type
and the proj
...

INTERNATIONAL ISO
STANDARD 19901-5
Second edition
2016-02-15
Petroleum and natural gas
industries — Specific requirements
for offshore structures —
Part 5:
Weight control during engineering
and construction
Industries du pétrole et du gaz naturel — Exigences spécifiques
relatives aux structures en mer —
Partie 5: Contrôle des poids durant la conception et la fabrication
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2016 – All rights reserved

Contents Page
Foreword .v
0 Introduction .vi
1 Scope . 1
2 Normative references . 1
3  Terms and definitions . 2
4 Abbreviated terms . 8
5 Weight control classes . 8
5.1 General . 8
5.2 Class A: High definition of weight and CoG . 8
5.3 Class B: Medium definition of weight and CoG. 8
5.4 Class C: Low definition of weight and CoG . 9
5.5 Selection of class of weight control . 9
6 Weight and load budget (WLB).10
6.1 General .10
6.2 Requirements .11
6.3 Content .11
6.3.1 General.11
6.3.2 Weight reserves .12
6.3.3 Future weights and loads .13
6.3.4 Loading conditions and parameters .13
6.3.5 Formats and levels.14
6.3.6 CoG envelopes .14
7 Weight control procedure .15
8 Weight reporting .16
8.1 General .16
8.2 Weight report requirements .17
9  Requirements for suppliers’ weight data and weighing of equipment and bulks .20
9.1 General .20
9.2 Provision of weight information .20
9.3 Weighing requirements .20
9.4 Weighing equipment .21
9.5 Weighing procedure .21
9.6 Notification and witnessing of weighing .22
9.7 Calibration of weighing equipment .22
9.8 Weighing operation .22
9.9 Temporaries during weighing .23
9.10 Items not installed during weighing .23
10  Requirements for weighing of major assemblies .23
10.1 Weighing procedure .23
10.2 Environmental conditions .23
10.2.1 Light .23
10.2.2 Wind .24
10.2.3 Temperature and humidity .24
10.3 Weighing .25
10.3.1 Number and timing of weighing .25
10.3.2 Weighing procedure .25
10.3.3 Notification and witnessing of weighings .26
10.3.4 Preparation of the weighing.26
10.3.5 Weighing equipment .27
10.3.6 Calibration of weighing system .30
10.3.7 Weighing foundation and supports .30
10.3.8 Structural integrity .31
10.3.9 Weighing operation .31
10.3.10 CoG calculations .32
10.3.11 Weighing certificate.33
10.3.12 Weighing report .33
11  Requirements for “as-built” weight documentation .34
Annex A (informative) Weight data sheets — Tagged equipment .35
Annex B (informative) Weighing certificates .37
Annex C (informative) Weight and load budget (WLB) formats and levels .41
Annex D (informative) Major elements of the weight displacement .42
Annex E (informative) Supplier weighing procedure.43
Annex F (informative) Guidelines for displacement measurement of floaters .45
Annex G (informative) Requirements for weight control during operations .49
Annex H (informative) Requirements for topside weight estimation — New builds/green field .65
Annex I (informative) Executive summary description .70
Annex J (informative) Weighing result uncertainty .72
Annex K (informative) Weight control database structure .73
Bibliography .75
iv © ISO 2016 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 67, Materials,equipment and offshore structures
for petroleum, petrochemical and natural gas industries, Subcommittee SC 7, Offshore structures.
This second edition cancels and replaces the first edition (ISO 19901-5:2003), which has been technically
revised.
ISO 19901 consists of the following parts, under the general title Petroleum and natural gas industries —
Specific requirements for offshore structures:
— Part 1: Metocean design and operating considerations
— Part 2: Seismic design procedures and criteria
— Part 3: Topsides structure
— Part 4: Geotechnical and foundation design considerations
— Part 5: Weight control during engineering and construction
— Part 6: Marine operations
— Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units
— Part 8: Marine soil investigations
The following parts are under preparation:
— Part 9: Structural integrity management
0 Introduction
0.1 General
The International Standards ISO 19900 to ISO 19906 relating to offshore structures constitute a
common basis covering those aspects that address design requirements and assessments of all offshore
structures used by the petroleum and natural gas industries worldwide. Through their application the
intention is to achieve reliability levels appropriate for manned and unmanned offshore structures,
whatever the type of structure and the nature of the materials used.
It is important to recognize that structural integrity is an overall concept comprising models for
describing actions, structural analyses, design rules, safety elements, workmanship, quality control
procedures and national requirements, all of which are mutually dependent. The modification of one
aspect of design in isolation can disturb the balance of reliability inherent in the overall concept or
structural system. The implications involved in modifications, therefore, need to be considered in
relation to the overall reliability of all offshore structural systems.
ISO 19900 to ISO 19906 relating to offshore structures are intended to provide a wide latitude in the
choice of structural configurations, materials and techniques without hindering innovation. Sound
engineering judgement is therefore necessary in the use of these International Standards.
0.2 Preface
It is proposed to canvass the TC 67/SC 7 member countries to widen the scope of this part of ISO 19901
for the third edition. As a consequence, the title might change.
— It is proposed to expand and re-structure this part of ISO 19901 to more comprehensively address
topsides weight engineering principles, roles, responsibilities and objectives for a complete platform
life cycle.
— It is proposed to re-format into a more traditional ISO document layout.
— The use of weight class A, B and C tables will be reviewed.
— There will be an outline of how to control topside weight, and of the aims and expectations of a
Weight Review Panel (or similar).
— A common topside operating philosophy will be included with a matrix of coincident drilling loads,
operating loads, and laydown / storage loads to be included in topside weight databases.
— It is proposed to give guidance on applied design contractor allowances during detailed design, plus
the use of client operational and management reserves.
— The weight and CoG accuracy expected from weighings will be addressed.
— Separate clauses will be added to give clarity to specific requirements of floating structures and
jackets
— The contents and terminology will be coordinated to interface with ISO 19902, Design of offshore
structures, and the forthcoming ISO19901-9, Structural integrity management (due to be published
in 2017).
It is proposed to give more guidance on a range of topics encountered during the phases of a platform
life cycle, typically:
a) Weight control principles
Overview of principles, aims and objectives
Roles and responsibilities
Competency
vi © ISO 2016 – All rights reserved

Software selection
Deliverables for each project phase
Weight report contents
b) Floating structures and jackets
Specific requirements for floating structures
c) Concept and feasibility phase
Use of historical volumetric weight norms
Use of area based weight calculations
Use of footprint ratios
d) Front end engineering design phase
Design parameters to be fixed prior to setting Not-to-Exceed weights
e) Detailed design phase
Control of weight using a Weight Review Panel or similar
Use of contractor allowances
Use of client reserves
Discipline reporting responsibilities
Coincident operating loads
Coincident drilling loads
Coincident laydown and storage loads
Laydown and storage drawings and area signage
Vendor weighing requirements
f) Fabrication phase
Fabricator responsibilities
Reporting of site run materials
Weighing requirements
Preparations for weighing
Expected weight and CoG accuracy from weighings
Predictions and witnessing of weighings
Post-weighing reconciliation and weighing corrections
g) Installation and hook-up phase
Reporting of hook-up weights
h) Operational phase
Control of weight and CoG for topside modifications
Interfaces with ISO 19901-9 and ISO 19902
i) Decommissioning phase
Preparations for decommissioning
Some of the above proposed changes are outlined in Annex G of this document (informative).
It is proposed that preparation of the third edition of this part of ISO 19901 will begin immediately
after the issue of this edition with a target publication date of 2017.
viii © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 19901-5:2016(E)
Petroleum and natural gas industries — Specific
requirements for offshore structures —
Part 5:
Weight control during engineering and construction
1 Scope
This part of ISO 19901 specifies requirements for controlling the weight and centre of gravity
(CoG) by means of mass management during the engineering and construction of structures for the
offshore environment. The provisions are applicable to offshore projects that include structures of all
types (fixed and floating) and materials. These structures can be complete new installations or the
modifications to existing installations. Maintaining the weight control of existing installations is not
part of the main body of this part of ISO 19901, but some guidance on this is included in the Annex G.
This part of ISO 19901:
— specifies quality requirements for reporting of weights and centres of gravity;
— specifies requirements for weight reporting;
— provides a basis for overall project weight reports or management reports for all weight control
classes;
— specifies requirements for weight and load budgets;
— specifies the methods and requirements for the weighing and the determination of weight and CoG
of major assemblies;
— specifies requirements for weight information from suppliers, including weighing of equipment and
bulk materials for offshore installations.
It can be used:
— as a basis for planning, evaluating and presenting the client’s, contractor’s or fabricator’s weight
management and reporting system;
— as a means of refining the structural analysis or model;
— as a contract reference between client, contractor and suppliers;
— as a basis for costing, scheduling or determining suitable fabrication method(s) or location(s).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
assembly
designed and fabricated group of bulk and equipment items which form one unit
3.2
budget weight
weight reference figures as defined in the weight and load budget and related to the initial or changed
design concept
3.3
bulk
component or arrangement of components defined as stock materials or of low complexity
Note 1 to entry: Bulk items support the equipment items by providing infrastructure around and between them.
3.4
centre of gravity
CoG
average location of the weight of an item
Note 1 to entry: For assemblies, modules or topsides, the aggregate CoG is the mathematical weighted average
of the CoGs of the individual items (comprising the completed assembly, module or topsides) measured from a
common reference point.
3.5
client
organisation for which a weight report is prepared
Note 1 to entry: This is the project owner (oil company/operator, fabricator, engineering sub-contractor,
lift/transportation contractor, etc.).
3.6
client weight reserve
weight addition (usually a lump sum weight) controlled by the client and used to account for any orders
for variation to the contractual design concept
3.7
CoG envelope
defined constraint volume within which the centre of gravity (CoG) of an assembly shall remain
3.8
consumables
variable content that does not remain at a constant level due to consumption during the operation of an
offshore installation
EXAMPLE Potable/service water, diesel fuel, crew provisions, bulk drilling powders for creation of mud
and/or cement.
3.9
contents
fluids or bulk powders held within bulks (piping or structural tanks) or equipment at their normal
operating levels
Note 1 to entry: Typical contents are hydrocarbons, cooling and heating mediums, chemicals, fuels, condensates,
seawater, fresh water, dry powders (drilling cement and mud additives), dry stores for workshops, sack stores,
etc. Fluids that are expected to be continuously installed in an item of equipment (e.g. coolants and lubricating
oils) are not to be considered as contents. See dry weight (3.16) for further explanation.
2 © ISO 2016 – All rights reserved

3.10
contractor
organization tasked with constructing a portion of, or an overall project facility
3.11
contractor weight reserve
additional weight (either a lump sum weight or percentage of a total weight) at a specified CoG,
controlled by the contactor and used to account for any design growth within their control
3.12
deadweight
total carrying capacity of a floating structure
Note 1 to entry: Includes weight of crude oil, deck cargo, temporaries, water, snow and ice accumulations, marine
growth, ballast water, consumables, crew and their effects.
Note 2 to entry: See Annex D.
3.13
discipline
discrete branch of engineering reflecting a single aspect in the project
EXAMPLE Architectural, drilling, electrical, HVAC, instrumentation, loss control (safety), piping, structural
and telecommunications.
3.14
discipline check list
document detailing the weight items that are within the discipline’s control
3.15
displacement
weight of the volume of water displaced by a floating structure
Note 1 to entry: The sum of lightweight and deadweight including mooring system load, appendences and/or
appurtenances e.g. structures outside the moulded hull
Note 2 to entry: See Annex D.
3.16
dry weight
weight of a component, weight item or an assembly in its dry installed condition including permanent
utilities
Note 1 to entry: Examples of permanent utilities are gearbox oil, hydraulic oil, filter sand.
Note 2 to entry: Any content of operating fluid flowing through a component, weight item or an assembly is
excluded.
3.17
equipment
component or arrangement of components, built for specific function(s)
Note 1 to entry: The component/assembly normally has unique documentation due to its function and complexity.
Note 2 to entry: Refer to tagged equipment (3.41) for further explanation.
3.18
estimated weight
weight determined based on previous experience
3.19
first fill
initial filling of specific contents in items of equipment or piping prior to start of operation of an offshore
facility
Note 1 to entry: First fill typically takes place towards the end of site construction, prior to tow-out and prior to
filling for normal operations.
3.20
float-out
loading condition in which a major assembly is transferred from a dry construction site to become self-
floating
3.21
future weight
weight of a component or an assembly to be installed after the start of production
3.22
grillage
steel structure, secured to the deck of a barge or vessel, designed to support the cargo and distribute
the loads between the cargo and the barge or vessel
3.23
gross weight
sum of the net weight and weight allowances
3.24
hook-up
installation of components or assemblies after the modules have been installed in their final position, to
connect to the existing installation
3.25
hook weight
sum of component, assembly or module lift weight and lifting gear
3.26
operating
at the start of steady-state production
Note 1 to entry: All bulk and equipment items are present with contents at nominal operating levels.
3.27
lifting gear
equipment needed during a lifting operation
EXAMPLE Slings, spreader bars, lifting frames, shackles.
3.28
lift weight
weight of a component, assembly or a module, including temporaries and residual fluid content but
excluding lifting gear
3.29
lightship weight
dry and invariable weight of a floating unit, including minimum utility content to secure a safe condition
Note 1 to entry: See Annex D.
4 © ISO 2016 – All rights reserved

3.30
loading condition
defined event for which a weight and CoG need to be controlled
Note 1 to entry: For each loading condition, all weight items and variable loads that are known or predicted to
occur are identified, quantified and located.
Note 2 to entry: Typical loading conditions are dry installed offshore, float-out at assembly site, future operating
installed offshore, operating installed offshore, load-out to offshore transport vessel, transport to offshore field, etc.
3.31
load-out
transfer by way of horizontal movement of an assembly, module or topsides from its land-based
fabrication site onto a floating or grounded transport barge or vessel
Note 1 to entry: The following are typical load-out operations:
— skidded: load-out using a combination of skid-ways, skid-shoes or runners, propelled by towing engines,
jacks or winches;
— trailer: load-out using multi-axle trailers [self-propelled modular transporter (SPMT)].
3.32
master equipment list
MEL
project -specific database for control and management of technical data for tagged equipment
3.33
mating
transfer of a major assembly supported on barge(s) or vessel(s) to a temporary or permanent support
structure
3.34
module
major assembly of items forming a major building block which needs to be controlled with respect to
weight and CoG
3.35
net weight
calculated or estimated weight of an item excluding allowances
3.36
not-to-exceed weight
NTE weight
maximum acceptable weight for any given loading condition, with an associated limiting CoG envelope
3.37
operating weight
sum of the dry weight and the content weight
3.38
project management
management personnel tasked with implementing weight policy, objectives and
procedures
3.39
residual content
content in bulks and equipment remaining after testing or commissioning, and being present during
the subsequent loading conditions up to the start of production
3.40
sea fastening
items used for temporary fastening to keep all items in position during transportation at sea
3.41
tagged equipment
equipment identified and labelled in accordance with the project coding manual and tracked in MEL
3.42
temporary items
temporaries
items temporarily installed during a loading condition and removed afterwards
Note 1 to entry: Temporaries do not form part of a structure’s permanent dry or operating weight.
3.43
test weight
sum of the dry weight plus the content required to test the equipment or assembly
3.44
tow-out
towing of a complete floating structure to the offshore installation site
3.45
transport
transfer of an assembly or module from one inshore or at shore location to another
location, or to the offshore installation site
3.47
weight allowance
weight additions to account for expected general growth due to immaturity of the current project stage
and/or components which are not estimated in detail at the current project stage
3.48
weight and load budget
WLB
document defining the weight and CoG limits for each loading condition, major assembly (and disciplines
for the dry installed offshore load condition)
Note 1 to entry: The WLB are to act as a comparison reference for:
a) weight, load and CoG control and reporting for the duration of the project through the engineering,
construction, installation and operation phases;
b) structural capacity requirements for individual sections or modules and for the total topsides or supporting
structure;
c) temporary and permanent bearing capacity and stability of the total facility;
d) overall cost and schedule control.
3.49
weight item
item or collection of bulk and/or equipment, content or assembly identified for weight reporting
purposes
6 © ISO 2016 – All rights reserved

3.50
weight management
all planned and controlled activities which deal with:
— definition and publication of the project weight procedures, objectives and policies;
— identification of information about and evaluation of alternative design solutions;
— selection and implementation of an optimal design with respect to weight, CoG, volume, functionality,
cost and progress;
— monitoring and reporting weight data throughout the complete life cycle of an installation to assess
present and potential weight status
Note 1 to entry: Project management, engineering disciplines and weight control discipline shall cooperate and
participate to influence the weight management process by means of adequate working methods and tools.
3.51
weight objective
defined set of engineering goals necessary to fulfil the project contractual weight/CoG requirements
and intentions in order to contribute to the correct design quality as defined by the management
3.52
weight phase code
code used to identify the loading conditions in which a weight item is present
3.53
weight policy
statement from the project management, based on the weight objective, defining how the weight
objective is to be achieved
Note 1 to entry: As a minimum, the policy should include:
— the importance of the weight objective to the project aims and results;
— the priority, profile and control of weights at different levels in the project;
— a philosophy for responsibility and authority within and between project groups engaged in weight matters
3.54
weight report
regularly issued project document that details the weight and CoG for required assemblies and load
conditions based on best available information
Note 1 to entry: This document provides the basic load case for the project Structural Integrity models.
3.55
weight status code
code, based on the maturity of the design, used to identify the level of accuracy of the weight of a
weight item
Note 1 to entry: The weight status code is often used to assess the value of the weight allowance applied. As a
design matures, the weight status code will change so that an item’s weight allowance is reduced.
4 Abbreviated terms
CoG Centre of Gravity
FEED Front End Engineering Design
MEL Master Equipment List
NTE Not to Exceed
WLB Weight and Load Budget
WTO Weight Take-Off
5 Weight control classes
5.1 General
In order to select the most appropriate level for weight control and reporting according to the degree of
weight and/or CoG sensitivity of the project, three classes of weight control have been defined. These
classes may also be used to determine the level of effort required in the weight management activities
for a project.
The tender documents and final contract shall specify the applicable weight control class, so that the
contractor can allocate the required resources.
5.2  Class A: High definition of weight and CoG
Class A shall apply if the project is weight and/or CoG sensitive for any of the anticipated loading cases,
or has many contractor interfaces.
Class A weight projects shall:
a) regardless of the source, have full traceability of all weight and CoG data;
b) record weight and CoG data using a relational database from the commencement of detail
engineering, with integration of suppliers’, fabricators’ and weighing results into the system;
c) verify the calculated weight and CoG of assemblies, modules or topsides by means of physical
weighings;
d) update weight data per weight item produced during the design phases to “as-built” status during
the fabrication.
5.3  Class B: Medium definition of weight and CoG
Class B shall apply to projects where the focus on weight and CoG is less critical for any of the anticipated
loading cases than for projects where Class A is applicable.
Class B weight projects shall:
a) based on the complexity of the project, determine whether a relational database or spread sheet
software is required for recording of weight and CoG data;
b) verify the calculated weight and CoG of assemblies, modules or topsides by means of physical
weighings;
c) have less stringent requirements for updating “as-built” status during fabrication.
8 © ISO 2016 – All rights reserved

5.4  Class C: Low definition of weight and CoG
Class C shall apply to projects where requirements for updating “as-built” status during fabrication is
not critical.
Class C weight projects shall:
a) as a minimum use a spread sheet software for recording weight and CoG data;
b) verify the calculated weight and CoG of assemblies, modules or topsides by means of physical
weighings;
c) provide supporting weight and CoG documentation consisting of equipment weights and
summarized bulk weights by drawing;
d) have no requirements for updating “as-built” status during fabrication.
5.5 Selection of class of weight control
The design basis, NTE weight and CoG criteria, together with WLBs established at the close of the
concept phase, are major factors to be considered when selecting the class of weight control.
Potential weight and CoG problems, specific to the loading condition, also need to be assessed before
selecting the class of weight control.
Class selection may be made from examination of Table 1, included as a guide for determining the
required degree of weight and CoG control for a project. The class of weight control selected should be
the highest class meeting any of the Project Parameters in Table 1.
Table 1 — Guidance criteria for weight control class selection
Description Class A Class B Class C
Concept type new partly known well known
Weight sensitivity high medium low
CoG sensitivity high medium low
Weight data processing requirement high medium low
Contract requirement detailed general none to minimal
Weight data external interfaces > 6 4 to 6 1 to 3
(other contractors)
NOTE Weight sensitivity may be a result of constraints established by installation method (i.e. capacity of lifting device)
or capacity of supporting structure (i.e. jacket, GBS, hull, etc.)
6 Weight and load budget (WLB)
6.1 General
Class A Class B Class C
For all offshore installations, weight and As Class A. As Class A, except that d) is not
CoG information for all loading condi- required.
tions shall be controlled from the start
of conceptual design. Budget weights and
CoG constraints shall be determined for
the modules, topsides and supporting
substructures (inclusive of temporaries
required for the appropriate loading con-
ditions). This shall be done in cooperation
with the structural and marine disciplines
as well as the project management. The
budget weights and CoG constraints shall
be presented in the project WLB as a ref-
erence point to be used during a project.
The WLB is to be reference point for:
a) weight, load, and CoG control and
reporting during all phases of the project:
engineering, construction, installation
and operation;
b) structural capacity requirements
for assemblies, modules, topsides and
supporting structures;
c) bearing capacity and stability
of the total installation (temporary or
permanent);
d) control of overall cost and sched-
ule;
e) ensuring that all loading condi-
tions are within the anticipated capacities.
10 © ISO 2016 – All rights reserved

6.2  Requirements
Class A Class B Class C
Each participant in a project (typically the As Class A. The contractor WLBs are estab-
client, contractor and sub-contractors) lished either by the client, and are
shall be allocated a separate WLB. included in the project contract, or
by the project contractor. Unless
The contractor WLBs shall be established
specified by the client, the format and
by either the client or the contractor.
complexity is left to the discretion
If established by the client, the WLBs
of the contractor.
shall be included in the project contract
documents.
The project management or client shall
hold overall responsibility for deciding
the variations between the various WLBs.
WLBs for subcontractors and vendors
shall be established by the contractor.
Under normal circumstances, revisions to
WLBs shall not take place unless concept or
major changes to the design - which impact
the weight, load or CoG - are implemented
by the project management/client.
All participants in the project shall be
responsible for adherence to established
WLB values.
In the event that the project weight man-
agement detects the possibility of a sig-
nificant variation from the established
WLBs, corrective actions shall be initiated
by the project management in order that
weight or CoG variations do not occur, or
their impact is minimized.
6.3 Content
6.3.1 General
Class A Class B Class C
The WLB consists of different types of As Class A. As Class A.
weights, loads and associated CoGs, as
defined in Figure 1.
Figure 1 — Weights, loads and associated CoGs
6.3.2 Weight reserves
Class A Class B Class C
A contractor weight reserve including As Class A. As Class A.
CoG may be added on top of the WLB
estimated weight.
In addition to the contractor weight re-
serve, the client may add a weight reserve
including CoG.
The value and location of the weight re-
serve will depend upon the concept type
and the project weight policy.
Any relevant variation orders issued by
the client after the contract has been
issued may affect the weight reserve and
may necessitate a WLB revision.
In special situations, if the chosen design
concept is declared too heavy and thus
subject to weight reductions, the weight
reserve will be negative. This will result
in a WLB weight below the current esti-
mated or reported weight.
12 © ISO 2016 – All rights reserved

6.3.3 Future weights and loads
Class A Class B Class C
Future weights and/or loads are not in- As Class A. As Class A.
cluded in the weight reserve, but shall be
identified separately in the WLBs.
6.3.4 Loading conditions and parameters
6.3.4.1 General
Class A     Class B     Class C
A set of relevant loading conditions and     As Class A.     As Class A.
associated weight/load parameters shall
be defined for weight control and weight
reporting purposes.
Corresponding WLBs shall be provided.          Not required.
This shall be done in cooperation with
the structural and marine disciplines as
well as the project management.
Agreement between the client and the          As Class A.
contractor shall be reached for:
...

NORME ISO
INTERNATIONALE 19901-5
Deuxième édition
2016-02-15
Industries du pétrole et du gaz
naturel — Exigences spécifiques
relatives aux structures en mer —
Partie 5:
Contrôle des poids durant la
conception et la fabrication
Petroleum and natural gas industries — Specific requirements for
offshore structures —
Part 5: Weight control during engineering and construction
Numéro de référence
©
ISO 2016
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2016, Publié en Suisse
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni utilisée
sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie, l’affichage sur
l’internet ou sur un Intranet, sans autorisation écrite préalable. Les demandes d’autorisation peuvent être adressées à l’ISO à
l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
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Tel. [phone]
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www.iso.org
ii © ISO 2016 – Tous droits réservés

Sommaire Page
Avant-propos .v
0 Introduction .vi
1 Domaine d’application . 1
2 Références normatives . 1
3  Termes et définitions . 2
4 Abréviations . 8
5 Classes de suivi des poids . 8
5.1 Généralités . 8
5.2 Classe A: définition précise du poids et du centre de gravité . 8
5.3 Classe B: définition moyenne du poids et du centre de gravité . 9
5.4 Classe C: définition minimale du poids et du centre de gravité . 9
5.5 Choix d’une classe de suivi de poids . 9
6 Bilan des poids et des charges (WLB) .11
6.1 Généralités .11
6.2 Exigences .12
6.3 Contenu .12
6.3.1 Généralités .12
6.3.2 Réserves de poids . . .13
6.3.3 Poids et charges futurs .14
6.3.4 Conditions et paramètres de charge .14
6.3.5 Formats et niveaux .15
6.3.6 Enveloppes de centre de gravité .15
7 Procédure de contrôle des poids .16
8 Rapports de poids .17
8.1 Généralités .17
8.2 Exigences relatives au rapport de poids .18
9 Exigences relatives aux données de poids du fournisseur et au pesage des
équipements et du matériel courant .20
9.1 Généralités .20
9.2 Fourniture des informations relatives au poids .20
9.3 Exigences relatives au pesage .21
9.4 Équipement de pesage .21
9.5 Procédure de pesage .22
9.6 Notification du pesage et présence lors du pesage.22
9.7 Étalonnage de l’équipement de pesage .23
9.8 Opération de pesage .23
9.9 Éléments provisoires pendant le pesage .24
9.10 Éléments non installés pendant le pesage .24
10 Exigences relatives au pesage des principaux ensembles .24
10.1 Procédure de pesage .24
10.2 Conditions environnementales .24
10.2.1 Lumière .24
10.2.2 Vent .25
10.2.3 Température et humidité .25
10.3 Pesage .25
10.3.1 Nombre et calendrier des pesages .25
10.3.2 Procédure de pesage .26
10.3.3 Notification du pesage et présence lors des pesages .26
10.3.4 Préparation en vue du pesage .27
10.3.5 Équipement de pesage .28
10.3.6 Étalonnage du système de pesage .31
10.3.7 Fondations et supports de pesage .31
10.3.8 Intégrité structurale .32
10.3.9 Opération de pesage .32
10.3.10 Calculs de centre de gravité .33
10.3.11 Certificat de pesage .34
10.3.12 Rapport de pesage .35
11  Exigences relatives à la documentation concernant le poids «tel que construit» .36
Annexe A (informative) Feuilles de données de poids — Équipement marqué.37
Annexe B (informative) Certificats de pesage .39
Annexe C (informative) Formats et niveaux de bilan des poids et des charges .43
Annexe D (informative) Principaux éléments du déplacement de poids .44
Annexe E (informative) Procédure de pesage du fournisseur .45
Annexe F (informative) Lignes directrices pour le mesurage du déplacement de
supports flottants .47
Annexe G (informative) Exigences relatives au contrôle du poids pendant les opérations .51
Annexe H (informative) Exigences relatives à l’estimation de poids des superstructures —
Constructions neuves/installations nouvelles .69
Annexe I (informative) Description d’un résumé analytique .74
Annexe J (informative) Incertitude des résultats de pesage .76
Annexe K (informative) Structure de la base de données de contrôle des poids .77
Bibliographie .79
iv © ISO 2016 – Tous droits réservés

Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www.
iso.org/directives).
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www.iso.org/brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la signification des termes et expressions spécifiques de l’ISO liés à
l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion de l’ISO aux principes
de l’OMC concernant les obstacles techniques au commerce (OTC), voir le lien suivant: Avant-propos —
Informations supplémentaires.
Le comité chargé de l’élaboration du présent document est l’ISO/TC 67, Matériel, équipement et structures
en mer pour les industries pétrolière, pétrochimique et du gaz naturel, sous-comité SC 7, Structures en mer.
Cette deuxième édition annule et remplace la première édition (ISO 19901-5:2003), qui fait l’objet d’une
révision technique.
L’ISO 19901 comprend les parties suivantes, présentées sous le titre général Industries du pétrole et du
gaz naturel — Exigences spécifiques relatives aux structures en mer:
— Partie 1: Dispositions océano-météorologiques pour la conception et l’exploitation
— Partie 2: Procédures de conception et critères sismiques
— Partie 3: Superstructures
— Partie 4: Bases conceptuelles des fondations
— Partie 5: Contrôle des poids durant la conception et la fabrication
— Partie 6: Opérations marines
— Partie 7: Systèmes de maintien en position des structures en mer flottantes et des unités mobiles en mer
— Partie 8: Reconnaissance des sols en mer
La partie suivante est en cours d’élaboration:
— Partie 9: Gestion de l’intégrité structurelle
0 Introduction
0.1  Généralités
Les Normes internationales ISO 19900 à ISO 19906 relatives aux structures en mer constituent une
base commune couvrant les aspects liés aux exigences de conception et de l’évaluation de l’ensemble
des structures en mer utilisées par les industries du pétrole et du gaz naturel dans le monde entier.
Leur mise en œuvre a pour finalité d’atteindre des niveaux de fiabilité appropriés pour les structures
en mer habitées ou non, quels que soient le type de structure et la nature des matériaux utilisés.
Il est important de savoir que l’intégrité structurale est un concept global qui comprend la modélisation
des actions, les analyses structurales, les règles de conception, les aspects liés à la sécurité, la qualité
de l’exécution, ainsi que les procédures de contrôle de la qualité et les réglementations nationales,
ces divers éléments étant interdépendants. La modification d’un aspect isolé des bases conceptuelles
peut avoir, en termes de fiabilité, une incidence sur la conception globale ou sur les performances de la
structure dans son ensemble. Par conséquent, les effets de toute modification apportée à une structure
en mer doivent être considérés par rapport à la fiabilité de l’ensemble du système.
Les ISO 19900 à ISO 19906 relatives aux structures en mer ont pour objectif de donner toute latitude
en ce qui concerne le choix des configurations structurelles, des matériaux et des techniques sans
entraver l’innovation. Une solide capacité de jugement en termes d’ingénierie est donc nécessaire pour
l’utilisation de ces Normes internationales.
0.2  Préface
Un sondage des pays membres du TC 67/SC 7 est proposé afin d’élargir le domaine d’application de
la présente partie de l’ISO 19901 pour la troisième édition. Le titre pourra donc être amené à subir
quelques modifications.
— Il est proposé d’étendre et de restructurer la présente partie de l’ISO 19901 de manière à examiner
plus en détail les principes de conception, les rôles, les responsabilités et les objectifs en termes de
poids des superstructures tout au long du cycle de vie d’une plate-forme.
— Une remise en forme est également suggérée afin d’obtenir un document ayant un format ISO plus
traditionnel.
— L’utilisation des tableaux relatifs aux classes de poids A, B et C sera réexaminée.
— Un aperçu de la méthode de contrôle du poids des superstructures sera donné, ainsi que des objectifs
et attentes d’un Comité d’examen des poids (ou d’un groupe similaire).
— Une philosophie d’exploitation commune des superstructures sera exposée avec une matrice des
charges simultanées de forage, de service et de rangement/stockage à inclure dans les bases de
données relatives aux poids des superstructures.
— Il est proposé de donner des lignes directrices concernant les tolérances appliquées aux contracteurs
au cours de la conception détaillée, ainsi que l’utilisation par le maître d’ouvrage des réserves
opérationnelles et des réserves de gestion.
— L’exactitude des poids et des centres de gravité attendus des pesages sera examinée.
— Des paragraphes distincts seront ajoutés afin de clarifier des exigences spécifiques relatives aux
structures flottantes et aux enveloppes.
— Le contenu et la terminologie seront harmonisés par rapport à l’ISO 19902, Structures en mer fixes en
acier, et à la prochaine ISO 19901-9, Gestion de l’intégrité structurelle (publication prévue en 2017).
vi © ISO 2016 – Tous droits réservés

Il est suggéré de fournir des lignes directrices complémentaires sur un éventail de sujets rencontrés au
cours des phases du cycle de vie d’une plate-forme, à savoir:
a) Principes de contrôle des poids
— Vue d’ensemble des principes, buts et objectifs
— Rôles et responsabilités
— Compétence
— Sélection des logiciels
— Produits livrables à chaque phase de projet
— Contenu du rapport de poids
b) Structures flottantes et enveloppes
— Exigences spécifiques relatives aux structures flottantes
c) Phase de conception et d’étude de faisabilité
— Utilisation des normes historiques sur les poids volumiques
— Utilisation des calculs de poids basés sur des surfaces
— Utilisation des rapports d’encombrement
d) Phase d’ingénierie de base
— Paramètres de conception à définir avant les poids à ne pas dépasser
e) Phase de conception détaillée
— Contrôle du poids par un Comité d’examen des poids ou un groupe similaire
— Utilisation des tolérances des contracteurs
— Application de réserves par le maître d’ouvrage
— Responsabilités de chaque discipline en ce qui concerne les rapports à fournir
— Charges de service simultanées
— Charges de forage simultanées
— Charges de rangement et de stockage simultanées
— Plans de rangement et de stockage et signalisation des zones
— Exigences relatives aux pesages à réaliser par les vendeurs
f) Phase de fabrication
— Responsabilités des fabricants
— Déclaration des matériaux utilisés sur site
— Exigences relatives au pesage
— Préparation au pesage
— Exactitude des poids et des centres de gravité attendus des pesages
— Prédictions des poids et présence lors du pesage
— Comparaison post-pesage et corrections de poids
g) Phase d’installation et de raccordement
— Déclaration des poids après raccordement
h) Phase opérationnelle
— Contrôle des poids et des centres de gravité pour les superstructures modifiées
— Interfaces avec les ISO 19901-9 et ISO 19902
i) Phase de démantèlement
— Préparation au démantèlement
Certaines des modifications proposées ci-dessus sont exposées à l’Annexe G du présent document
(informative).
Il est proposé de débuter la préparation de la troisième édition de la présente partie de l’ISO 19901
juste après la publication de la présente édition, en ciblant 2017 comme date de publication.
viii © ISO 2016 – Tous droits réservés

NORME INTERNATIONALE ISO 19901-5:2016(F)
Industries du pétrole et du gaz naturel — Exigences
spécifiques relatives aux structures en mer —
Partie 5:
Contrôle des poids durant la conception et la fabrication
1 Domaine d’application
La présente partie de l’ISO 19901 spécifie les exigences relatives au contrôle du poids et du centre de
gravité (CdG) par la gestion des masses pendant les phases d’étude et de construction des structures
en mer. Les dispositions s’appliquent aux projets de tous types (structures en mer fixes et flottantes)
et matériaux. Ces structures peuvent être des installations entièrement nouvelles ou des modifications
d’installations existantes. Le corps principal de la présente partie de l’ISO 19901 ne traite pas du suivi
des poids des installations existantes. Toutefois, l’Annexe G du présent document fournit des lignes
directrices.
La présente partie de l’ISO 19901:
— spécifie les exigences de qualité pour l’établissement de rapports de poids et de centres de gravité;
— spécifie les exigences relatives aux rapports de poids;
— fournit une base commune pour l’établissement de rapports de poids ou de suivi du projet dans son
ensemble, quelle que soit la classe de suivi de poids considérée;
— spécifie les exigences relatives aux bilans de poids et de charges;
— spécifie les méthodes et les exigences relatives au pesage et à la détermination du poids et du centre
de gravité des principaux ensembles;
— spécifie les exigences relatives aux données de poids provenant des fournisseurs, y compris le
pesage des équipements et des matériels courants pour les installations en mer.
Elle peut être utilisée:
— comme base de planification, d’évaluation et de présentation du système de suivi et de gestion des
poids du maître d’ouvrage, du contracteur ou du fabricant;
— comme moyen d’amélioration de l’analyse ou du modèle des structures;
— comme référence pour l’établissement du contrat entre le maître d’ouvrage, le contracteur et les
fournisseurs;
— comme base d’établissement des coûts, de programmation ou de détermination de la (des) méthode(s)
ou de l’emplacement de fabrication approprié(s).
2 Références normatives
Les documents ci-après, dans leur intégralité ou non, sont des références normatives indispensables à
l’application du présent document. Pour les références datées, seule l’édition citée s’applique. Pour les
références non datées, la dernière édition du document de référence s’applique (y compris les éventuels
amendements).
ISO/IEC Guide 98-3, Incertitude de mesure — Partie 3: Guide pour l’expression de l’incertitude de mesure
(GUM:1995).
3  Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
3.1
ensemble
groupe d’équipements et de matériel courant, conçu et fabriqué pour former une unité
3.2
poids prévisionnel
valeurs de référence de poids définies dans le bilan des poids et des charges et liées au concept théorique
initial ou modifié
3.3
matériel courant
composant ou agencement de composants défini en tant que matériel stocké ou de faible complexité
Note 1 à l’article: Le matériel courant supporte les équipements en fournissant une infrastructure autour et
entre eux.
3.4
centre de gravité
CdG
position moyenne du poids d’un élément
Note 1 à l’article: Pour les ensembles, les modules ou les superstructures, le CdG global est la moyenne
mathématique pondérée des CdG des éléments individuels (comprenant l’ensemble, le module ou la superstructure
terminé) mesuré par rapport à un point de référence commun.
3.5
maître d’ouvrage
organisation pour laquelle un rapport de poids est préparé
Note 1 à l’article: Le maître d’ouvrage peut être une compagnie pétrolière, un exploitant pétrolier, un fabricant,
un sous-traitant d’ingénierie, un sous-traitant de levage/transport, etc.
3.6
réserve de poids du maître d’ouvrage
ajout de poids (généralement un poids global) contrôlé par le maître d’ouvrage et utilisé pour tenir
compte de toute demande de modification par rapport au concept théorique contractuel
3.7
enveloppe du centre de gravité
volume de contrainte défini à l’intérieur duquel le centre de gravité (CdG) d’un ensemble doit demeurer
3.8
consommables
contenu variable qui ne reste pas à un niveau constant en raison de la consommation au cours de
l’exploitation d’une installation en mer
EXEMPLE Eau de service/potable, carburant diesel, réserves, produits pulvérulents en vrac pour la création
de boue et/ou de ciment de forage.
2 © ISO 2016 – Tous droits réservés

3.9
contenu
fluides ou produits pulvérulents stockés dans le matériel courant (tuyauterie ou réservoirs structurels)
ou les équipements à leurs niveaux de service normaux
Note 1 à l’article: Les contenus types sont des hydrocarbures, des fluides de chauffage et de refroidissement, des
produits chimiques, des combustibles, des condensats, de l’eau de mer, de l’eau douce, des poudres sèches (additifs
pour ciment et boue de forage), des stockages secs pour ateliers, des produits en sac, etc. Les fluides destinés à
séjourner en continu dans un équipement (fluides de refroidissement et huiles de lubrification, par exemple) ne
sont pas considérés comme des contenus. Voir poids à sec (3.16) pour obtenir des détails complémentaires.
3.10
contracteur
organisation chargée de la construction d’une partie ou de la totalité d’une installation du projet
3.11
réserve de poids du contracteur
ajout de poids (poids global ou pourcentage du poids total) en un centre de gravité spécifié, contrôlé
par le contracteur et utilisé pour tenir compte de toute augmentation de poids au cours de la conception
et dont le contracteur est responsable
3.12
port en lourd
capacité de charge totale d’une structure flottante
Note 1 à l’article: Il inclut le poids du pétrole brut, du chargement en pontée, des éléments provisoires, des
accumulations d’eau, de neige et de glace, des concrétions marines, de l’eau de ballast, des consommables, de
l’équipage et de leurs effets.
Note 2 à l’article: Voir l’Annexe D.
3.13
discipline
branche d’ingénierie distincte reflétant un aspect spécifique du projet
EXEMPLE Architecture, forage, électricité, climatisation, instrumentation, contrôle des dommages
(sécurité), tuyauterie, structure et télécommunications.
3.14
liste de contrôle par discipline
document détaillant les éléments de poids qui relèvent du contrôle de la discipline
3.15
déplacement
poids du volume d’eau déplacé par une structure flottante
Note 1 à l’article: Le déplacement est la somme du poids lège et du port en lourd incluant la charge du système
d’amarrage, les appendices et/ou accessoires (par exemple les structures à l’extérieur de la coque).
Note 2 à l’article: Voir l’Annexe D.
3.16
poids à sec
poids d’un composant, d’un élément de poids ou d’un ensemble à l’état installé et sec, y compris les
utilités permanentes
Note 1 à l’article: Les utilités permanentes comprennent, par exemple, l’huile de boîte de vitesses, l’huile
hydraulique et le sable de filtration.
Note 2 à l’article: Tout fluide de travail circulant dans un composant, un élément de poids ou un ensemble est exclu.
3.17
équipement
composant ou agencement de composants construit pour une (des) fonction(s) spécifique(s)
Note 1 à l’article: Le composant/l’ensemble a normalement une documentation unique en raison de sa fonction et
de sa complexité.
Note 2 à l’article: Voir équipement marqué (3.41) pour obtenir des détails complémentaires.
3.18
poids estimé
poids déterminé sur la base de l’expérience antérieure
3.19
premier remplissage
remplissage initial du contenu spécifique d’un équipement ou d’une tuyauterie avant le début de
l’exploitation d’une installation en mer
Note 1 à l’article: Le premier remplissage a généralement lieu vers la fin de la construction sur site, avant le
remorquage et avant le remplissage en vue des opérations normales.
3.20
mise à l’eau
condition de charge dans laquelle un ensemble majeur est transféré d’un site de construction à sec pour
flotter par lui-même
3.21
poids futur
poids d’un composant ou d’un ensemble à installer après le lancement de la production
3.22
treillis
structure en acier, fixée sur le pont d’une barge ou d’un navire, conçue pour supporter le chargement et
répartir les charges entre le chargement et la barge ou le navire
3.23
poids brut
somme du poids net et des tolérances de poids
3.24
raccordement
installation de composants ou d’ensembles après avoir installé les modules dans leur position finale,
afin de les raccorder à l’installation existante
3.25
poids au crochet
somme du poids à lever des composants, ensembles ou modules et du poids des apparaux de levage
3.26
exploitation
au lancement de la production en régime stable
Note 1 à l’article: Tout le matériel courant et tous les équipements sont présents avec des contenus à leurs niveaux
de service nominaux.
3.27
apparaux de levage
équipement requis pendant une opération de levage
EXEMPLE Élingues, palonniers, structures de levage, manilles.
4 © ISO 2016 – Tous droits réservés

3.28
poids de levage
poids d’un composant, d’un ensemble ou d’un module, y compris les éléments provisoires et le contenu
fluide résiduel, mais en excluant les apparaux de levage
3.29
poids lège
poids à sec et invariable d’une unité flottante, y compris le contenu utilitaire minimal pour garantir de
bonnes conditions de sécurité
Note 1 à l’article: Voir l’Annexe D.
3.30
condition de charge
événement défini au cours duquel le poids et le centre de gravité doivent être contrôlés
Note 1 à l’article: Pour chaque condition de charge, tous les éléments de poids et charges variables dont la
présence est connue ou prévue sont identifiés, quantifiés et localisés.
Note 2 à l’article: Les conditions de charge classiques sont: installé en mer et à sec, mis à l’eau sur le site de
montage, installé en mer pour une exploitation future, installé en mer pour l’exploitation, chargé sur le navire de
transport en mer, transporté jusqu’au champ en mer, etc.
3.31
chargement
transfert, par un déplacement horizontal, d’un ensemble, d’un module ou d’une superstructure depuis
son site de fabrication à terre sur une barge ou un navire de transport flottant ou en cale sèche
Note 1 à l’article: Les opérations de chargement classiques sont:
— le ripage: chargement utilisant une combinaison de chemins de ripage, de patins ou de roulements, mis en
mouvement par des moteurs de remorquage, des vérins ou des treuils;
— le remorquage: chargement utilisant des remorques à essieux multiples (SPMT, transporteur modulaire
autopropulsé).
3.32
liste des équipements principaux
MEL
base de données spécifique au projet, utilisée pour le contrôle et la gestion des données techniques
relatives aux équipements marqués
3.33
accouplement
transfert d’un ensemble majeur supporté sur une (des) barge(s) ou un (des) navire(s) vers une structure
de support provisoire ou permanente
3.34
module
ensemble majeur constitué d’éléments formant un bloc de construction majeur dont le poids et le centre
de gravité doivent être contrôlés
3.35
poids net
poids calculé ou estimé d’un élément, hors tolérances
3.36
poids à ne pas dépasser
poids NTE
poids maximal acceptable pour toute condition de charge donnée, auquel est associée une enveloppe de
centre de gravité restrictive
3.37
poids d’exploitation
somme du poids à sec et du poids du contenu
3.38
direction de projet
personnel d’encadrement chargé de mettre en œuvre une politique, des objectifs et
des procédures relatives aux poids
3.39
contenu résiduel
contenu du matériel courant et des équipements restant après les essais ou la mise en service, et présent
pendant les conditions de charge ultérieures jusqu’au lancement de la production
3.40
fixation en mer
éléments utilisés pour la fixation provisoire de tous les éléments afin de les maintenir en place pendant
le transport en mer
3.41
équipement marqué
équipement identifié et marqué conformément au manuel de codage du projet et suivi dans la MEL
3.42
éléments provisoires
éléments installés provisoirement pendant une condition de charge et retirés par la suite
Note 1 à l’article: Les éléments provisoires sont exclus du poids à sec permanent ou du poids d’exploitation d’une
structure.
3.43
poids d’essai
somme du poids à sec et du contenu requis pour soumettre l’équipement ou l’ensemble à essai
3.44
remorquage
remorquage d’une structure flottante complète jusqu’au site d’installation en mer
3.45
transport
transfert d’un ensemble ou module d’un lieu situé sur la côte ou le rivage vers un
autre lieu, ou vers le site d’installation en mer
3.47
tolérance de poids
ajouts de poids destinés à tenir compte des développements généraux attendus en raison de l’immaturité
au stade actuel du projet et/ou de composants qui ne sont pas spécifiés en détail au stade actuel du projet
3.48
bilan des poids et des charges
WLB
document définissant les limites de poids et de centre de gravité pour chaque condition de charge
et ensemble majeur (ainsi que pour chaque discipline pour la condition de charge en mer après
installation à sec)
Note 1 à l’article: Le bilan sert de base de comparaison pour:
a) le contrôle et l’établissement de rapports de poids, de charges et de centres de gravité pendant toute la durée
du projet comprenant les phases d’étude, de construction, d’installation et d’exploitation;
b) les exigences de capacité structurale des sections ou modules individuels et l’ensemble des superstructures
ou de la structure de support;
6 © ISO 2016 – Tous droits réservés

c) la capacité portante provisoire et permanente et la stabilité de la totalité de l’installation;
d) le coût global et le contrôle du planning du projet.
3.49
élément de poids
élément ou ensemble du matériel courant et/ou des équipements, contenu ou ensemble, identifié pour
l’établissement des rapports de poids
3.50
gestion des poids
ensemble des activités planifiées et contrôlées se rapportant à:
— la définition et la publication des procédures, objectifs et politiques du projet en matière de poids;
— l’identification d’informations concernant l’évaluation d’autres solutions de conception;
— le choix et la mise en œuvre d’une conception optimale en termes de poids, de centre de gravité, de
volume, de fonctionnalité, de coût et d’évolution;
— la surveillance et l’établissement de rapports sur les données de poids tout au long du cycle de vie
d’une installation afin d’évaluer l’état de poids actuel et potentiel
Note 1 à l’article: La direction de projet, les disciplines techniques et la discipline de suivi de poids doivent
coopérer et participer afin d’influer sur le processus de gestion des poids, en utilisant des méthodes de travail et
des outils adaptés.
3.51
objectif de poids
ensemble défini d’objectifs techniques nécessaire pour satisfaire aux exigences et aux intentions
contractuelles de poids/centre de gravité du projet afin de contribuer à la qualité de conception correcte
telle que définie par la direction
3.52
code de phase de poids
code utilisé pour identifier les conditions de charge dans lesquelles se trouve un élément de poids
3.53
politique de poids
déclaration de la direction de projet, basée sur l’objectif de poids et définissant la manière d’atteindre
ce dernier
Note 1 à l’article: Il convient que la politique de poids inclue au minimum:
— l’importance de l’objectif de poids pour les objectifs et les résultats du projet;
— la priorité, le profil et le contrôle des poids aux différents niveaux du projet;
— les principes de responsabilité et d’autorité dans et entre les groupes de projet concernés par les questions
de poids.
3.54
rapport de poids
document de projet à publication régulière, fournissant des données détaillées sur les poids et centres
de gravité pour les conditions de charge et ensembles requis, sur la base des meilleures informations
disponibles
Note 1 à l’article: Ce document fournit le cas de charge de base pour les modèles d’intégrité structurelle du projet.
3.55
code d’état de poids
code basé sur la maturité de la conception, utilisé pour identifier le niveau d’exactitude du poids d’un
élément de poids
Note 1 à l’article: Le code d’état de poids est souvent utilisé pour évaluer la valeur de la tolérance de poids
appliquée. Au fur et à mesure que la conception arrive à maturité, le code d’état de poids changera de manière à
réduire la tolérance de poids d’un élément.
4 Abréviations
CdG Centre de gravité
FEED Ingénierie de base
MEL Liste des équipements principaux
NTE À ne pas dépasser
WLB Bilan des poids et des charges
WTO Poids établi lors de l’avant-métré
5 Classes de suivi des poids
5.1 Généralités
Pour choisir le niveau le plus approprié de contrôle des poids et d’établissement de rapports de poids
en fonction du degré de sensibilité du projet aux variations de poids et/ou de centre de gravité, trois
classes de suivi de poids ont été définies. Ces classes peuvent également servir à déterminer le niveau
d’effort requis dans les activités de gestion des poids d’un projet.
Les documents d’appel d’offre et le contrat final doivent préciser la classe de suivi de poids applicable de
façon à permettre au contracteur d’allouer les ressources nécessaires.
5.2  Classe A: définition précise du poids et du centre de gravité
La classe A doit s’appliquer si le projet est sensible aux variations de poids et/ou de centre de gravité
pour tous les cas de charge anticipés, ou s’il implique plusieurs contracteurs.
Les projets impliquant des poids de classe A doivent:
a) assurer une traçabilité totale de toutes les données de poids et de centre de gravité, quelle que soit
la source considérée;
b) enregistrer les données de poids et de centre de gravité en utilisant une base de données
relationnelle dès le début de l’ingénierie de détail, en intégrant les données des fournisseurs, des
fabricants et du pesage physique dans le système;
c) vérifier, par des pesages physiques, le poids et le centre de gravité calculés des ensembles, modules
ou superstructures;
d) actualiser les données de poids pour chaque élément de poids produit au cours des phases d’étude,
pour qu’elles soient à l’état «tel que construit» pendant la fabrication.
8 © ISO 2016 – Tous droits réservés

5.3  Classe B: définition moyenne du poids et du centre de gravité
La classe B doit s’appliquer aux projets pour lesquels l’attention portée au poids et au centre de gravité
pour les cas de charge anticipés est moins critique que pour les projets pour lesquels la classe A
s’applique.
Les projets impliquant des poids de classe B doivent:
a) déterminer, sur la base de la complexité du projet, si une base de données relationnelle ou un
tableur est nécessaire pour l’enregistrement des données de poids et de centre de gravité;
b) vérifier, par des pesages physiques, le poids et le centre de gravité calculés des ensembles, modules
ou superstructures;
c) avoir des exigences moins rigoureuses en ce qui concerne la mise à jour de l’état «tel que construit»
pendant la fabrication.
5.4  Classe C: définition minimale du poids et du centre de gravité
La classe C doit s’appliquer aux projets pour lesquels les exigences relatives à la mise à jour de l’état «tel
que construit» pendant la fabrication ne sont pas critiques.
Les projets impliquant des poids de classe C doivent:
a) au minimum utiliser un tableur pour l’enregistrement des données de poids et de centre de gravité;
b) vérifier, par des pesages physiques, le poids et le centre de gravité calculés des ensembles, modules
ou superstructures;
c) fournir une documentation pour référence des poids et des centres de gravité constituée des poids
des équipements et des poids globaux récapitulés sur un plan;
d) n’avoir aucune exigence relative à la mise à jour de l’état «tel que construit» pendant la fabrication.
5.5 Choix d’une classe de suivi de poids
Les critères de base de la conception, de poids à ne pas dépasser (NTE) et de centre de gravité, ainsi que
les bilans des poids et des charges (WLB) établis au terme de la phase de conception, sont les principaux
facteurs à prendre en considération lors du choix de la classe de suivi de poids.
Les problèmes potentiels liés aux poids et à la position du centre de gravité, spécifiques à la condition
de charge, doivent également être évalués avant de choisir la classe de suivi de poids.
La classe peut être choisie en consultant le Tableau 1 qui fait office de guide dans la détermination du
degré de contrôle des poids et des centres de gravité requis pour un projet. Il convient que la classe
de suivi de poids choisie soit la classe la plus élevée correspondant aux paramètres de projet spécifiés
dans le Tableau 1.
T
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