ISO 23121-2:2019

INTERNATIONAL ISO
STANDARD 23121-2
First edition
2019-12
Ships and marine technology —
Inflatable buoyancy support systems
against flooding of ships —
Part 2:
Buoyancy chamber
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 2
4.1 General . 2
4.2 Valves . 2
4.2.1 Topping-up inflation valve . 2
4.2.2 Non-return valve . 2
4.2.3 Relief valve . 2
4.3 Indicator . 2
4.4 High pressure hose assembly (if fitted) . 2
5 Materials . 3
5.1 Metallic parts . 3
5.2 Fabrics . 3
5.3 Test methods . 4
5.3.1 General conditions . 4
5.3.2 Test specimens. 4
5.3.3 Tensile strength . 4
5.3.4 Tear test (constant rate of traverse method) . 4
5.3.5 Coating adhesion, ply separation and surface receptiveness test . 4
5.3.6 Low temperature bend test . 4
5.3.7 Porosity test . 4
5.3.8 Ageing test . 5
5.3.9 Hydrolysis test . 5
5.3.10 Resistance to blocking test . 5
5.3.11 Oil resistance test . 5
5.3.12 Seam strength test . 5
6 Inflation tests . 5
6.1 General . 5
6.2 Ambient temperature test . 5
6.3 High temperature test . 6
6.4 Low temperature test . 6
6.5 Pressure test . 6
6.5.1 Test for air pressure conservation . 6
6.5.2 Excess pressure test . 6
Bibliography . 8
Foreword
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This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 8, Ship design.
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iv © ISO 2019 – All rights reserved

Introduction
This document is intended to support the development and technical implementation of various types
of buoyancy support systems.
In case of marine accidents, such as collisions and groundings, excessive damage and flooding can
cause the ship to sink, capsize or impede the use of its essential navigation equipment. As a ship has
watertight bulkheads, doors, hatches and other equipment, the consequences of flooding accidents can
usually be mitigated at the early phases of the accident. Subsequently, the progressive flooding after an
important accident can cause the sinking or capsizing of the ship.
To counter these problems, inflatable buoyancy support systems can be used, which are composed of
a gas supply system and a buoyancy chamber, where the gas supply system provides the medium for
the inflation of the buoyancy chamber. A fixed fire extinguisher can be used as a gas inlet when the
ship is at risk of sinking or overturning. When fire extinguishers are used to supply the media into the
buoyancy chamber, additional means must be available not to impair fire-fighting, following SOLAS,
Chapter II-2A, Regulation 4. Buoyancy chambers have various shapes and capacities to aid a damaged
ship’s buoyancy.
INTERNATIONAL STANDARD ISO 23121-2:2019(E)
Ships and marine technology — Inflatable buoyancy
support systems against flooding of ships —
Part 2:
Buoyancy chamber
1 Scope
This document specifies general requirements, the materials and test methods for the buoyancy
chamber of inflatable buoyancy support systems, which serve residual buoyancy for damaged ships not
to sink or capsize, and which can be installed in machinery spaces and/or cargo holds.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 1402, Rubber and plastics hoses and hose assemblies — Hydrostatic testing
ISO 1419:2019, Rubber- or plastics-coated fabrics — Accelerated-ageing tests
ISO 1421:2016, Rubber- or plastics-coated fabrics — Determination of tensile strength and elongation
at break
ISO 2231:1989, Rubber- or plastics-coated fabrics — Standard atmospheres for conditioning and testing
ISO 2411, Rubber- or plastics-coated fabrics — Determination of coating adhesion
ISO 4674-1:2016, Rubber- or plastics-coated fabrics — Determination of tear resistance — Part 1: Constant
ra
...