ISO 5411:2024

International
Standard
ISO 5411
First edition
Ships and marine technology —
2024-03
Submersibles — Vocabulary
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Types .1
3.2 Performance .2
3.3 Structural system .4
3.4 Mechanical system .6
3.5 Electrical system .7
3.6 Acoustic system .9
3.7 Control system .10
3.8 Surface system .11
3.9 Work mode . 12
3.10 Test and maintenance . 13
3.11 Personnel .14
Bibliography .16
Index . 17

iii
Foreword
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iv
Introduction
Many countries have the technology and ability to design, construct and operate submersibles, together
with the industrial capability and resources to support safe and effective submersible operations. To
enable greater international understanding and collaboration between participating regions, operators and
manufacturers, it is advantageous to use a common set of terms and concept definitions. This will result
in several benefits including facilitating comparison of products, contributing to innovation, reducing
misunderstanding, improving efficiency and enabling international trade. In essence, standardized
terminology is fundamental to a series of standardization activities of submersibles.

v
International Standard ISO 5411:2024(en)
Ships and marine technology — Submersibles — Vocabulary
1 Scope
This document provides basic terminology and concepts related to submersibles. It covers 11 aspects of
terminology related to submersibles: types, performance, structural system, mechanical system, electrical
system, acoustic system, control system, surface system, work pattern, test and maintenance and personnel.
It is not applicable to particular conditions, such as the classification and construction of submersibles.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Types
3.1.1
submersible
type of powered vessel that can travel and manoeuvre underwater
3.1.2
manned submersible
submersible (3.1.1) that encloses one or more persons within its pressure hull (3.3.2), fitted with one or more
available surface accesses, or underwater pressurized or non-pressurized accesses
3.1.3
tethered submersible
submersible (3.1.1) with an umbilical (3.8.1) or tether (3.8.2) attached to the surface, support ship (3.8.4) or
underwater structure
3.1.4
untethered submersible
submersible (3.1.1) without an umbilical (3.8.1) or tether (3.8.2)
3.1.5
transport submersible
manned submersible (3.1.2), designed for the movement of cargo, equipment or passengers (3.11.3) in addition
to crew (3.11.2) underwater, for recreation, scientific expedition, rescue or other purposes
3.1.6
passenger submersible
passenger-carrying mobile vessel, which primarily operates under water and relies on surface support
[SOURCE: IMO MSC/Circ. 981, 1.2.12]

3.1.7
deep submergence rescue vehicle
DSRV
submarine rescue vehicle
SRV
manned submersible (3.1.2) and untethered submersible (3.1.4), specifically designed to evacuate persons
from a disabled or distressed submarine using an underwater mating interface to create one or more dry
personnel transfer structures under normobaric or hyperbaric conditions
3.1.8
lock-out submersible
manned submersible (3.1.2) and untethered submersible (3.1.4), equipped with a lock-in or lock-out chamber
and access hatch for entry, egress and accommodation of a diver or divers (3.11.4) with an adjustable
operating pressure (3.2.8) capability
3.1.9
towed submersible
tethered submersible (3.1.3) towed by a power-driven vessel with depth and attitude adjustment ability
3.1.10
atmospheric diving suit
ADS
anthropomorphic and single-person tethered submersible (3.1.3) with manually operated articulated arms
and/or legs, which can perform related underwater tasks, withstanding external pressure and maintaining
internal pressure at or near one atmosphere
3.1.11
dry diving bell
manned submersible (3.1.2) and tethered submersible (3.1.3), equipped with a hemispherical frame and
specialized apparatus for transferring persons between the underwater site and deck or the deck compression
chamber (3.8.6) of a support ship (3.8.4) for operation, rescue or other purposes
3.1.12
saturation diving system
complex of functionally integrated technical means, devices and facilities in which a diver (3.11.4) is exposed
to hyperbaric pressure for a period until the diver's blood and tissues have absorbed all the gas
Note 1 to entry: The time required for decompression becomes constant at this hyperbaric pressure after the diver's
blood and tissues have absorbed all of the gas.
3.1.13
seabed laboratory
submersible (3.1.1) designed to conduct a field inspection and support a long-term underwater habitat for
persons or other creatures for an in-situ test
3.2 Performance
3.2.1
life expectancy
designed number of dives that a submersible (3.1.1) can complete safely before requiring an appropriate
technical engineering review of its structural integrity to ensure it can again be safely operated underwater
3.2.2
design mission time
time period for a submersible (3.1.1) from launch to recovery, when the designed mission is performed under
operating conditions defined by the manufacturer
3.2.3
working time
time period which consists of design mission time (3.2.2), excluding the processing time of the launch and
recovery system (3.8.5) and the related surfacing and submerging

3.2.4
bottom time
time during which a submersible (3.1.1) is permitted to sit on seabed
3.2.5
light weight
air mass of a complete submersible (3.1.1) including all its permanently installed components, liquids and
gas in machinery and piping (3.4.16) to their working levels as defined by the manufacturer, but excluding
consumables, payload (3.2.6), persons and effect
3.2.6
payload
passengers (3.11.3) from the transport submersible (3.1.5), rescued persons from the deep submergence
rescue vehicle (3.1.7) or other items carried by a submersible (3.1.1) in addition to the crew (3.11.2), pilot
(3.11.1) and permanently fitted equipment, performing the specific mission
3.2.7
operating depth
depth in metres of water (seawater or fresh water) for which a submersible (3.1.1) normally operates
3.2.8
operating pressure
pressure which a submersible (3.1.1) withstands to operate normally
Note 1 to entry: It is expressed in megapascals (MPa).
3.2.9
design depth
maximum operating depth (3.2.7) to which a submersible (3.1.1) is designed to dive safely, as measured from
the surface to its keel
3.2.10
design pressure
maximum pressure which a submersible (3.1.1) can withstand to dive safely
Note 1 to entry: It is expressed in megapascals (MPa).
3.2.11
collapse depth
depth at which a submersible’s pressure-resistant structure (3.3.1) is predicted to fail, causing the pressure
hull (3.3.2) to collapse
3.2.12
collapse pressure
external pressure which is liable to causing the pressure-resistant structure (3.3.1) to collapse
3.2.13
test depth
pre-determined depth used to enable safe pressure testing of the submersible (3.1.1) during manufacture
and through life certification of the vessel
3.2.14
test pressure
pressure withstood by the pressure-resistant structure (3.3.
...