ISO 15402:2000

Ships and marine technology — Bulk carriers — Repair quality of hull structure

This International Standard specifies the quality requirements for the hull structure maintenance and repair of steel bulk carriers. It does not apply to double-skin bulk carriers. Requirements for the construction of steel bulk carriers are given in ISO 15401.

Navires et technologie maritime — Vraquiers — Qualité de réparation de la structure de la coque

General Information

• Status: Published
• Publication Date: 02-Feb-2000
• ICS: 47.020.10 - Hulls and their structure elements
• Technical Committee: ISO/TC 8/SC 8 - Ship design
• Drafting Committee: ISO/TC 8/SC 8 - Ship design
• Current Stage: 9093 - International Standard confirmed
• Start Date: 28-Mar-2022
• Completion Date: 14-Feb-2026

Overview

ISO 15402:2000 - Ships and Marine Technology - Bulk Carriers - Repair Quality of Hull Structure is an international standard developed by ISO under the guidance of Technical Committee ISO/TC 8. This standard specifies the quality requirements for the maintenance and repair of hull structures in steel bulk carriers. It focuses on ensuring safety, durability, and the integrity of single-skin steel bulk carriers during their service life. The requirements laid out exclude double-skin bulk carriers, with construction standards addressed in ISO 15401.

ISO 15402:2000 was designed to harmonize ship-repair procedures internationally, referencing rules of recognized classification societies like the International Association of Classification Societies (IACS). This document provides comprehensive processes for inspection, maintenance, assessment, and repair of hull structures, ensuring continued safe operation and regulatory compliance.

Key Topics

• Scope of Application: Applies specifically to single-skin steel bulk carriers, not double-skin types.
• Inspection and Maintenance: Defines regular inspection intervals and items for various hull components, such as shell plates, decks, superstructures, hatch coamings, cargo holds, tanks, and peaks.
• Assessment Criteria: Provides guidelines for measuring hull structural thickness, evaluating corrosion levels, deformation, fractures, and weld integrity in accordance with classification society standards.
• Repair Methods and Acceptance: Outlines processes for repairing or replacing structural members, welds, and coatings-including criteria for acceptable corrosion, deformation, and fracture repairs.
• Corrosion Protection: Encourages protective measures for hull structures, such as appropriate coatings and electrochemical protection (sacrificial anodes).
• Documentation and Records: Stipulates the need for written inspection and maintenance reports, repair documentation, and compliance tracking.

Applications

ISO 15402:2000 is practically applied in:

• Shipyards and Dry Docks: Standardizes repair quality for hull structures during routine or emergency drydocking, ensuring hull integrity after corrosion, fractures, or deformation.
• Vessel Operators and Crews: Assists in carrying out and documenting regular inspections and maintenance, including periodic assessment of corrosion, coating condition, and mechanical damage.
• Classification Societies: Provides a reference for assessing repairs during statutory surveys and for approving repair procedures.
• Ship Repair Contractors: Ensures repair work meets internationally accepted standards, minimizing variation and improving safety across fleets.
• Fleet Management: Establishes baseline repair and maintenance practices for aging bulk carriers, especially those over 15 years old, to prolong vessel lifespan and comply with regulatory requirements.

Related Standards

• ISO 15401: Ships and marine technology - Bulk carriers - Construction quality of hull structure. This standard provides the construction requirements referenced by ISO 15402.
• IACS Unified Requirements: Rules and recommendations from the International Association of Classification Societies, often incorporated as best practices in ISO standards.
• ISO 9001: Quality management systems - Requirements, relevant for shipyards and repair organizations implementing structured quality controls.

Practical Value

Adhering to ISO 15402:2000 enables shipowners, operators, and repair yards to:

• Ensure the ongoing structural safety and seaworthiness of bulk carriers.
• Comply with international regulations and facilitate port state control inspections.
• Prolong the service life of vessels through consistent, high-quality maintenance and repair.
• Minimize operational downtime and repair costs by adopting standard inspection and preventive maintenance schedules.
• Reduce the risk of accidents or catastrophic failure linked to hull degradation.

By standardizing hull structure repair and inspection processes, ISO 15402:2000 plays a crucial role in global maritime safety and the sustainable operation of bulk carriers.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15402
First edition
2000-02-15
Ships and marine technology — Bulk
carriers — Repair quality of hull structure
Navires et technologie maritime — Vraquiers — Qualité de réparation
de la structure de la coque
Reference number
©
ISO 2000
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ii © ISO 2000 – All rights reserved

Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative reference .1
3 Terms and definitions .1
4 Inspection and maintenance .2
4.1 Inspection.2
4.2 Maintenance of coating system .5
5 Repair of the hull structure.6
5.1 Assessment of the hull structure.6
5.2 Requirements for hull structure repair.12
5.3 Protection of the hull structure from corrosion .15
5.4 Approval and documentation after repair of the hull structure .17
Bibliography.18
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 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 15402 was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 8, Structures.
iv © ISO 2000 – All rights reserved

Introduction
The aim of this International Standard is to provide guidelines for good ship-repair conditions.
Details, where appropriate, given in this International Standard were developed with reference to applicable
International Association of Classification Societies (IACS) rules and requirements.
INTERNATIONAL STANDARD ISO 15402:2000(E)
Ships and marine technology — Bulk carriers — Repair quality of
hull structure
SAFETY PRECAUTIONS — It is the responsibility of the user of this International Standard to establish
appropriate safety and health practices, and determine the applicability of regulatory limitations prior to
use.
1 Scope
This International Standard specifies the quality requirements for the hull structure maintenance and repair of steel
bulk carriers. It does not apply to double-skin bulk carriers.
Requirements for the construction of steel bulk carriers are given in ISO 15401.
2 Normative reference
The following normative document contains provisions which, through reference in this text, constitute provisions of
this International Standard. For a dated reference, subsequent amendments to, or revisions of, the publication do
not apply. However, parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent edition of the normative document indicated below. For an undated
reference, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
1)
ISO 15401:— , Ships and marine technology — Bulk carriers — Construction quality of hull structure.
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
bulk carrier
ship which is generally constructed with a single deck, topside tanks and hopper side tanks in cargo spaces, and is
intended primarily to carry dry cargo in bulk
3.2
length
L
NOTE The definition is taken from the rules of classification societies.
3.3
coating condition
3.3.1
good coating
condition with only minor spot rusting
1) To be published.
3.3.2
fair coating condition
condition with local breakdown at edges of coating of stiffeners and weld connections and/or light rusting over 20 %
or more of areas under consideration, but less than as defined for poor coating conditions
3.3.3
poor coating condition
condition with general breakdown of coating over 20 % or more of areas or hard scale on 10 % or more of areas
under consideration
4 Inspection and maintenance
4.1 Inspection
4.1.1 Inspection purposes
Inspection of the hull structure shall be carried out earnestly by specially hired inspection crews (referred to as
“crew” in the following text). This is in addition to the periodical inspection by the classification society. The purpose
of this inspection is to ensure the safety of a bulk carrier while on a voyage and during loading and/or unloading at
the port, and to be ready for repairs in dock and/or berth. Corrosion, fracture and deformation of the hull structure
and any other circumstance relating to the strength of the hull structure and the safety of the ship shall be
discovered by the crews in time. The inspection should be carried out in accordance with a written established
procedure valid for the characteristics of the vessel.
The loading/unloading sequence condition should be recorded.
2 © ISO 2000 – All rights reserved

4.1.2 Inspection items and periods
The crews' inspection shall be carried out in accordance with the requirements for the items and periods given in
Table 1.
Table 1 — Items and periods of crews’ inspection
Kind of Maximum
No. Area Main points
deterioration period
Corrosion
Deformation
1 Shell plate Corrosion and deformation of side shell 6 months
Weld corrosion
Fracture
a) Fracture at the hatch corner of the deck;
b) Corrosion and fracture at the transition
from cross-deck plating to the strength-deck
plating;
c) Corrosion and deformation of cross-deck
plating between hatches and the underdeck
stiffeners/structure;
Fracture:
d) Fracture at the connections of the hatch-
Corrosion
3 months
end beams and the top-side tank;
Deformation
2 Upper deck e) Corrosion and fracture of the deck plating
Fracture around the foundations of deck fittings;
Corrosion:
f) Fracture of the deck plating at the toes of
Weld corrosion
6 months
end/stay brackets of hatchway coamings;
g) Fracture of the deck at the toes of the
bulwark stay, especially at the expansion
joints;
h) Corrosion at the connections of the upper
deck and air pipe, ventilation duct, filling pipe
and sounding pipe.
Corrosion
Corrosion at the lower ends of the super-
a
3 Superstructure Deformation 6 months
structure and deck-house walls;
Fracture
a) Corrosion and fracture in the form of cut-
outs and notches of the coamings and their
end/stay brackets;
Corrosion
b) Fracture in the fillet-weld connection of the
coamings to the deck, particularly at the
4 Hatch coaming Deformation 3 months
coaming plate at the corner junction of the
Fracture
longitudinal and transverse hatch coamings;
c) Corrosion and fracture at the termination
of the hatch-coaming extension brackets.
Corrosion a) Corrosion of plating and stiffeners;
5 Hatch cover Deformation b) Damaged sealing; Every voyage
Watertight c) Damaged moving mechanism.
a
In the accommodation space, steel surfaces cannot be inspected from the inside because walls and decks are covered
with linings and ceilings. Inspections can be made from the outside of the space.
Table1— (continued)
Kind of Maximum
No. Area Main points
deterioration period
a) Corrosion, fracture and detachment of
side-shell frames on their webs;
b) Corrosion, fracture and detachment at the
toes of the upper and lower brackets of the
side frames;
Corrosion
c) Fracture at the weld connections of the
Side-shell frames
Deformation corrugated bulkhead to the stool;
of vessel above
d) Fracture at the weld connections of
6 Cargo hold Fracture 15 years:
transverse bulkheads or stool structure to
6 months
Weld corrosion
boundary-deck plate, side-shell plate, sloping
Any other case:
plate of topside tanks and hopper tanks, inner-
Detachment of
12 months
bottom plate, etc.;
frames
e) Corrosion at the midheight and bottom of
the transverse bulkheads;
f) Fracture at the transition regions with fore
bulkhead of engine room and collision bulk-
head due to discontinuities of the longitudinal
structures.
Inner bottom
Low part of Damage of inner bottom, lower part of bulk-
Deformation
7 bulkhead heads and side-shell structure due to loading/ Every voyage
Fracture unloading operations.
Side-shell
structure
a) Corrosion of the internal structure of the
topside tank and inlet/outlet seawater valves
due to the heat of upper deck and the
moisture in the tank;
b) Fracture at the corners of transverse webs
in topside tank, hopper tank, and at the
transverse brackets where there is no trans-
verse web;
c) Fracture at the connections of longitu- Coating in good
dinals to transverse webs, i.e., at the cut-out condition:
Topside tank, Corrosion of transverse web in the topside tank and 30 months
hopper tank and hopper tank;
8 Deformation Coating in
other ballast
d) Fracture due to the knuckle between the
fair / poor
tanks
Fracture
inner bottom and hopper tank sloping plating;
condition, or
e) Fracture in the double bottom at the vessel above
connections of longitudinals to floors, i.e., at 15 years:
the cut-out of floors and at the discontinuities 12 months
of the longitudinals;
f) Fracture at the edges of the unreinforced
openings and manholes;
g) Fracture at the connections of the deck
longitudinals to the bulkheads.
h) Corrosion / fracture of plating and internal
stiffening of transverse tanks on top of
bulkheads (if any).
4 © ISO 2000 – All rights reserved

Table1— (continued)
Kind of Maximum
No. Area Main points
deterioration period
Coating in good
condition:
a) Corrosion of the inner-bottom plating in 30 months
the engine room;
Corrosion Coating in
b) Corrosion and fracture at the weld fair / poor
9 Engine room
Deformation
connections of the top/bottom end of side- condition, or
Fracture shell plating to the fore/aft bulkheads of the vessel above
engine room. 15 years:
12 months
a) Corrosion at the bottom of forecastle Coating in good
spaces and Bo’sun store; condition:
30 months
b) Corrosion at the joint of the top of fore
Corrosion
Forecastle peak and the aft wall of forecastle; Coating in
spaces fair / poor
Deformation
c) Corrosion and deformation at side-shell
condition, or
Bo’sun store platings of the forecastle due to rough seas or
Fracture
vessel above
contact with other objects such as quay, buoy
15 years:
or other vessels.
12 months
a) Corrosion at the top of fore/aft peak; Coating in good
condition:
Corrosion b) Fracture of the side shell and damage of
30 months
the internal structure in the fore peak due to
Deformation
collision/or sloshing; Coating in
11 Fore/aft peak
Fracture
fair / poor
c) Fracture of the internal structure of the aft
Weld corrosion
condition, or
peak due to propeller vibration;
vessel above
Detachment of
frames d) Inspection of the anti-corrosion zinc plates 15 years:
12 months
in the fore and aft peak shall be carried out.
4.1.3 Inspection reports
The inspection reports shall be written after the crews' inspection of the hull structure, and be filed on board.
Personnel name, date, location, contents, result of the inspection and suggested follow-on actions shall be included
in the reports. Reports with proposals for remedial actions shall be forwarded to the operator of the vessel. Follow-
up procedures shall be established.
4.2 Maintenance of coating system
4.2.1 Maintenance purposes
Maintenance of the areas which affect the safety of the ship shall be carried out in time by the crew after the
inspection of the hull structure. The maintenance shall be carried out within the limits of the crew's ability and the
crew's safety shall be insured.
4.2.2 Maintenance items and periods
The crews' maintenance of the hull-structure coating shall be carried out in accordance with the requirements for
the items and periods given in Table 2.
Table 2 — Items and periods of crews’ maintenance
No. Area Item Period
Remove corrosion
1 Shell plate above light waterlines 6 months
Patch up coating
Remove corrosion
2 Upper deck, forecastle and poop deck, superstructure 6 months
Patch up coating
Remove corrosion
3Bulwark 6 months
Patch up coating
Remove corrosion
4 Hatch coaming 6 months
Patch up coating
Remove corrosion
5 Hatch cover, pressure pipes of hydraulic hatch cover 6 months
Patch up coating
30 months
Remove corrosion
6 Cargo hold
or 12� 3
Patch up coating
a
months
30 months
Remove corrosion
7 Topside tank
or 12� 3
Patch up coating
a
months
30 months
Remove corrosion
8 Hopper tank, ballast tank in double bottom
or 12� 3
Patch up coating
a
months
30 months
Remove corrosion
9 Fore and aft peak
or 12� 3
Patch up coating
a
months
a
For those bulk carriers having ages of 15 years or more, the maintenance period of 12 � 3 months is required.
4.2.3 Maintenance records
The maintenance records shall be written after the crews' maintenance of the hull structure. Personnel name, date,
location and contents of the maintenance shall be included in the records.
5 Repair of the hull structure
5.1 Assessment of the hull structure
5.1.1 Thickness measurement of the hull structure
5.1.1.1 General
In order to determine the extent to which the longitudinal strength and local strength of a bulk carrier are weakened
due to the structural wastage/corrosion and to adopt necessary repair measures to reinforce the hull structure, it is
required to measure the thickness of the hull structural members during the related survey.
6 © ISO 2000 – All rights reserved

5.1.1.2 Measurement method
5.1.1.2.1 The thickness-measuring equipment shall be calibrated before use.
5.1.1.2.2 Coating and rust at the measuring position shall be cleaned away.
5.1.1.2.3 The thickness measurement shall be carried out by a qualified, certified company or an organization
recognized by the administration or by a qualified technician employed by operator of the vessel. The measurement
report shall be prepared in accordance with the approval format. The surveyor shall verify and countersign the
thickness-measurement reports.
5.1.1.3 Location and amount of thickness measurements
5.1.1.3.1 The location of the thickness-measurement points shall be determined by the classification society
according to a random method. Upon request, thickness measurement can be done at other locations as a function
of theclose-upsurvey.
5.1.1.3.2 The number of thickness measurements shall be increased with the rise in the ship's age as well as
the deteriorated technical conditions.
5.1.1.3.3 The thickness measurements and close-up survey shall be in compliance with the requirements given
in Tables 3 and 4, respectively.
5.1.1.3.4 The thickness measurements may be dispensed, provided the surveyor is satisfied by the close-up
survey, that there is no structural corrosion-wastage and that the coating applied remains effective.
Table 3 — Thickness-measurement requirements
Ages in years
Ageu 5
5 � Ageu 10 10 � Ageu 15 Age � 15
12 3 4
1. Suspect areas 1. Suspect areas 1. Suspect areas 1. Suspect areas
2. Within the cargo length 2. Within the cargo length 2. Within the cargo length
area: area: area:
a) Two transverse sections of a) Each deck plate outside the a) Each deck plate outside
deck plating outside the line of line of cargo-hatch openings. the line of cargo-hatch open-
cargo-hatch openings. ings.
b) Two transverse sections,
one of which should be in the b) Three transverse sections,
amidship area, outside the one of which should be in the
line of cargo-hatch openings. amidship area, outside the
line of cargo-hatch openings.
c) Each bottom plate.
3. Measurement, for general 3. Measurement, for general 3. Points 3 to 7 referred to in
assessment and recording of assessment and recording of column 3.
corrosion pattern, of those corrosion pattern, of those
structural members subject to structural members subject to
a close-up survey in accord- a close-up survey in accord-
ance with Table 4. ance with Table 4.
4. All cargo-hold hatch covers 4. All cargo-hold hatch covers
and coamings (plating and and coamings (plating and
stiffeners). stiffeners)
5. Selected areas of deck plat- 5. All deck plating inside the
ing inside the line of openings line of openings between car-
between cargo-hold hatches. go-hold hatches.
6. All wind and water strakes 6. All wind and water strakes
within the cargo length area. within the cargo length area.
7. Selected wind and water
strakes outside the cargo
length area.
NOTE The requirements of the classification societies should also be considered.
8 © ISO 2000 – All rights reserved

Table 4 — Close-up survey requirements
Ages in years
Ageu 5
5 � Ageu 10 10 � Ageu 15 Age � 15
12 3 4
(A) 25 % of shell frames in the (A) 25 % of shell frames in all (A) All shell frames in the (A) All shell frames in all cargo
forward cargo hold at repre- cargo holds including upper forward cargo hold and 25 % holds including upper and
sentative positions. Selected and lower end attachments of frames in remaining cargo lower end attachments and ad-
frames in remaining cargo and adjacent shell plating. holds, including upper and jacent shell plating.
holds. lower end attachments and
(B) One transverse web with (B) Areas (B) to (E) as for
adjacent shell plating.
(B) One transverse web with associated plating and longi- column 3.
associated plating and longi- tudinals in each water ballast (B) All transverse webs with
tudinals in two representative tank (i.e., topside, hopper side associated plating and longi-
water ballast tanks of each or side tank). tudinals in each water ballast
type (i.e., topside, hopper side tank (i.e., topside, hopper side
(B) Forward and aft trans-
or side tank). or side tank).
verse bulkhead in one side
(C) Two selected cargo hold ballast tank, including stiffen- (B) All transverse bulk-heads
transverse bulkheads, includ- ing system. in ballast tanks, including
ing internal structure of upper stiffening system.
(C) One transverse bulkhead
and lower stools, where fitted.
in each cargo hold, including (C) All cargo-hold transverse
(D) All cargo-hold hatch internal structure of upper and bulkheads including internal
covers and coamings lower stools, where fitted. structure of upper and lower
stools, where fitted
(D) All cargo-hold hatch
covers and coamings. D) All cargo-hold hatch covers
and coamings.
(E) Selected areas of dec
...