ISO 15370:2021

INTERNATIONAL ISO
STANDARD 15370
Third edition
2021-01
Ships and marine technology — Low-
location lighting (LLL) on passenger
ships — Arrangement
Navires et technologie maritime — Éclairage situé en bas sur les
navires à passagers — Disposition
Reference number
ISO 15370:2021(E)
©
ISO 2021

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ISO 15370:2021(E)

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ISO 15370:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Performance requirements . 3
4.1 General . 3
4.2 Phosphorescent systems . 4
4.3 Electrically powered systems . 5
5 Technical product documentation . 6
6 Installation on board . 6
6.1 General . 6
6.2 Corridors . 7
6.3 Doors . 8
6.4 Stairways . 8
6.5 Signs and escape route signs . 8
7 Approval of the installation. 9
8 Maintenance .10
Annex A (normative) Testing of phosphorescent low-location lighting materials .11
Annex B (normative) Assessment of installations on board .12
Annex C (informative) Measurement record for phosphorescent materials .13
Annex D (normative) Minimum width and required luminance .14
Annex E (normative) Testing of electrically powered low-location lighting systems .15
Annex F (normative) Corridor recess and stairway arrangement diagrams .18
Annex G (informative) LLL installation and arrangement examples .20
Bibliography .30
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ISO 15370:2021(E)

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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 1, Maritime safety.
This third edition cancels and replaces the second edition (ISO 15370:2010), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the Introduction has been clarified to better explain the purpose of the system;
— in Clause 2, the normative references have been updated;
— in Clause 3, definitions have been added, and some of the existing ones have been clarified;
— in Clause 4, performance requirements for LLL system components have been reviewed and
updated;
— in Clause 6, clarification on how and where escape routes shall be marked by the LLL system has
been made;
— in 6.5, further details have been provided for the LLL signage system for both arrangement and
characteristics;
— in Clause 8 and in Annexes A, B, and E, maintenance and testing procedures have been clarified;
— in Annexes F and G, the examples of installation have been reviewed; and
— in the Bibliography, the informative references have been updated.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 15370:2021(E)

Introduction
This document is intended to supplement International Maritime Organization (IMO) requirements for
low-location lighting used on passenger ships complying with the 1974 Safety of Life at Sea Convention
(SOLAS 74), as amended.
The LLL system was made mandatory on passenger ships by IMO Resolution MSC.24(60), adopted on
10 April 1992, and by Resolution MSC.27(61), adopted on 11 December 1992, following the fire that
occurred on the passenger ship Scandinavian Star, in 1990. Both resolutions require that the means
of escape relevant to passenger and crew accommodation areas – including stairways and exits – be
marked by lighting or phosphorescent strip indicators placed not more than 0,3 m above the deck.
Following IMO Res. A.752(18), adopted on 4 November 1993, provided for relevant guidelines for its
application.
The purpose of such a system is given by IMO resolutions A.752(18) and SOLAS regulation II-2/13.3.2.5:
i.e. it shall enable passengers and crew to clearly identify the routes of escape and the relevant exits
when the normal emergency lighting is less effective due to smoke.
This extensive revision of the standard has been prepared in order to provide more details and
clarifications on the arrangement and performance of the LLL system so to better assist designers and
manufacturers, as well as the representatives of the competent authority who are requested to verify
the compliance of the on board system with this document.
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INTERNATIONAL STANDARD ISO 15370:2021(E)
Ships and marine technology — Low-location lighting (LLL)
on passenger ships — Arrangement
1 Scope
This document specifies the requirements for the approval, installation and maintenance of low-
location lighting systems as defined in Chapter II-2, Regulation 13.3.2.5.1 of the International Convention
for the Safety of Life at Sea, 1974 (SOLAS 74), as amended in 2000, and detailed in Chapter 11 of the
International Code for Fire Safety Systems (FSS Code).
2 Normative references
The following referenced 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 2919:2012, Radiological protection — Sealed radioactive sources — General requirements and
classification
ISO 3795, Road vehicles, and tractors and machinery for agriculture and forestry — Determination of
burning behaviour of interior materials
ISO 16069:2017, Graphical symbols — Safety signs — Safety way guidance systems (SWGS)
ISO 24409-1, Ships and marine technology — Design, location and use of shipboard safety signs, fire control
plan signs, safety notices and safety markings — Part 1: Design principles
ISO 24409-2, Ships and marine technology — Design, location, and use of shipboard safety signs, fire
control plan signs, safety notices and safety markings — Part 2: Catalogue of shipboard safety signs and fire
control plan signs
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60598-2-22, Luminaires — Part 2-22: Particular requirements — Luminaires for emergency lighting
IEC 60945, Marine navigation and radiocommunication equipment and systems — General requirements —
Methods of testing and required test results
IMO, International Convention for the Safety of Life at Sea, 1974 (SOLAS 74), as amended
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
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ISO 15370:2021(E)

3.1
accommodation spaces
passenger and crew spaces used for public spaces, cabins, offices, hospitals, cinemas, lounges, barber
shop, pantries containing no cooking appliances, corridors, toilets and similar spaces
Note 1 to entry: This definition is consistent with the one given by IMO SOLAS II-2/3.1.
3.2
approval
formal acceptance of the product and arrangement issued by the competent authority (3.4)
3.3
assembly station
distinct and designated internal or external space for mustering and marshalling passengers and crew
arranged in the vicinity of, and permitting ready access for the passengers and crew to, the embarkation
stations
Note 1 to entry: The assembly station can also be the embarkation station.
3.4
competent authority
administration whose flag the ship is entitled to fly, or an organization authorized by that administration
to perform functions required by this document
3.5
dead-end corridor
corridor, or part of a corridor, whose depth is greater than its width, and from which there is only one
escape route (3.7)
3.6
EP system
electrically powered system
LLL system (3.12) that requires electrical power for its operation, such as systems using incandescent
bulbs, light-emitting diodes, electroluminescent strips or lamps, electrofluorescent lamps, or other
electrically powered light-emitting material
3.7
escape route
designated route, principally along corridors, stairways and through exits, by which people can be
directed to an assembly station (3.3) and/or to a lifesaving appliances embarkation station
Note 1 to entry: The escape routes are shown on the approved escape plan.
3.8
excitation
effect of UV and visible light in the absorption spectrum that allows the materials to be activated and
store energy
3.9
exit
egress along the escape route (3.7) that can lead into a safe space, or to another escape route, not
affected by smoke
3.10
fire-fighting equipment
fixed or portable manually operated equipment that can be used to suppress fire
Note 1 to entry: Smoke detectors and fire-fighters’ outfit are not part of the fire-fighting equipment for the
purposes of this document.
EXAMPLE Fire hydrants and hoses, portable fire extinguishers.
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ISO 15370:2021(E)

3.11
installation plan
plan consisting of a ship’s general arrangement showing the layout of the LLL system (3.12) using
different kinds of lines, colours, and various symbols
3.12
LLL system
low-location lighting system
electrically powered lighting or phosphorescent guidance lines or indicators and relevant signs (3.17)
placed as continuous as practicable along the escape routes (3.7) relevant to passenger and crew
accommodation spaces (3.1) to readily identify such routes when the normal or the emergency light is
less effective due to smoke
3.13
luminance
luminous intensity per unit area of phosphorescent materials
Note 1 to entry: The luminance is measured in millicandelas per square metre.
3.14
maintenance
measures for the preservation and/or restoration of the original conditions of the technical elements of
a system as well as all measures for the determination and evaluation of the actual conditions
3.15
PL system
phosphorescent lighting system
LLL system (3.12) based on material incorporating phosphors that, if excited by UV or visible radiation,
store energy that is emitted as light over a period of time
3.16
phosphorescent
PL
photoluminescent delayed by storage of energy in an intermediate energy level
Note 1 to entry: SOLAS 74 (as amended), Chapter II-2, Regulation 13.3.2.5.1, uses the word “photoluminescent”.
In this document, the word phosphorescent is used in place of photoluminescent and should be considered
synonymous for the purpose of applying this standard to SOLAS 74, as amended.
3.17
sign
safety sign used in conjunction with LLL systems (3.12), indicating the escape routes (3.7) to the assembly
stations (3.3) and/or to embarkation stations, and the location of the fire-fighting equipment (3.10)
Note 1 to entry: These safety signs are defined in ISO 24409-1 and ISO 24409-2.
3.18
visible delineation
identification of the boundaries of the escape route (3.7) by a series of conspicuous, continuous
lighting lines
4 Performance requirements
4.1 General
4.1.1 The competent authority shall ensure that LLL systems and their components meet the
requirements set out in this document, as verified through the presentation of relevant documents issued
by laboratories recognized by the competent authority.
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ISO 15370:2021(E)

4.1.2 The supplementary emergency lighting for ro-ro passenger ships required by Chapter II-1,
Regulation 42-1 of SOLAS 74, as amended, may be accepted to form partly or wholly the LLL system,
provided that such a system complies with the requirements of this document.
4.1.3 The LLL system consists of the following components: the guidance lines at low-location, the
marking of exit doors, and the signs at low-location relevant to escape routes and fire-fighting equipment.
4.1.4 For EP systems, the colour of the line sources or point sources of light shall be green, white
or yellow.
4.1.5 Escape route signs shall be placed adjacent to, or integrated in, the low-location guidance lines.
4.1.6 LLL guidance lines shall be as continuous as practicable in order to provide a visible delineation
of the escape routes. Interruption of the LLL system due to constructional practicalities such as corridors,
doors, small protrusions, as well as to the ship’s plants and systems (ducts, cables, pipes, etc.), fixed
furniture or artworks shall be permitted provided that they neither exceed 2 m in length nor impair the
visible delineation of the escape route.
4.1.7 The LLL system shall function continuously for at least 60 min after its activation.
4.1.8 LLL products shall not contain radioactive materials unless such materials are designated “sealed
radioactive materials” and are tested in accordance with ISO 2919. Materials containing radionuclides as
given in ISO 2919:2012, Annex A, are considered sealed radioactive materials that should be tested in
accordance with ISO 2919.
4.2 Phosphorescent systems
2
4.2.1 Phosphorescent (PL) materials shall provide a luminance of at least 15 mcd/m measured
10 min after the removal of all external illuminating sources. The system shall continue to provide
2
luminance values greater than 2 mcd/m for 60 min. The luminance shall be measured at the surface of
the materials.
4.2.2 For excitation from an 8 W tubular fluorescent lamp of standard F2 cool white with a colour
temperature of 4 100 °K, Annex A specifies the method of test for determining the minimum illuminance,
measured at the surface of the phosphorescent material, which would enable the phosphorescent
material to meet the minimum luminance requirements at 10 min and 60 min. For a different excitation
lamp and luminaire, the test procedure of Annex A can be used to determine the minimum illuminance
for the particular lamp and luminaire.
4.2.3 PL guidance lines shall have a width of 75 mm or greater. PL guidance lines having a width less
than 75 mm shall only be used if the luminance is increased to compensate for the reduced width in
accordance with Annex D.
4.2.4 Escape route signs shall have minimum height of 50 mm or the width of guidance line if greater,
and be made of phosphorescent material, and use graphical symbols in accordance with ISO 24409-1
and ISO 24409-2.
A supplementary direction arrow graphical symbol cannot be used on its own; it shall be in combination
with a safety sign (e.g. exit, lifeboat, assembly station, as given in ISO 24409-2).
4.2.5 PL materials shall be flame-retardant in accordance with ISO 3795 with the contact of 38 mm
flame for 15 s and classified as F1.
4.2.6 Annex A specifies testing methods on phosphorescent low-location lighting materials.
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ISO 15370:2021(E)

4.3 Electrically powered systems
4.3.1 Electrically powered systems shall be connected to the emergency switchboard as required by
Regulation II-1/42 of SOLAS 74, as amended, so as to be powered by the main source of electrical power
under normal circumstances and also by the emergency source(s) of electrical power (as identified by
Regulation II-1/42.3) when the latter is in operation. Alternatively, for passenger ships carrying more
than 36 passengers and built before 1994-10-01, EP systems may be connected to the main lighting
system so that independent batteries provide a backup of at least 60 min and are charged from the main
lighting system.
4.3.2 The components of EP LLL systems can consist of planar light sources or point light sources or a
combination of both.
2
4.3.3 The minimum luminance of planar line sources used for LLL guidance lines shall be 20 cd/m .
The minimum width of the line source shall be 10 mm. The ratio of the maximum luminance to the
minimum luminance along a line source shall not be greater than 2:1.
The 10 mm line width may be realized by two lines of 5 mm with a separation no greater than 1 mm.
Where the line source is horizontal bulkhead mounted, the perceived width of the line may be increased
by sloping the horizontal line slightly out at its base so that it faces upwards and inwards towards the
line of sight of an escapee. The minimum width of the line source shall remain 10 mm.
4.3.4 The luminance performance of the components of the LLL system, as described in 4.1.3, shall be
the same as that of the guidance line.
4.3.5 Escape route signs made of electrically powered planar light sources shall use graphical symbols
in accordance with Figure 1 of ISO 16069:2017 or with modified geometry if on the floor; see Figure 2 of
ISO 16069:2017. The minimum height of the escape route sign shall be 30 mm. The minimum luminance
2
of the green colour shall be 20 cd/m . The contrast colour shall be either white with a luminance at least
five times greater than the luminance of the green colour, or be black.
4.3.6 The luminous intensity of point sources used for-LLL guidance lines shall be not less than 30 mcd.
The spacing between the point sources shall be no greater than 200 mm. The luminous intensity of a
point source can be produced by a cluster of point sources. Where the line source is horizontal bulkhead
mounted, the direction of peak intensity of the point light sources shall be pointing upwards and inwards
towards the line of sight of an escapee.
4.3.7 Escape door frame marking shall be formed by continuation of the point source line. The luminous
intensity of point sources used for door frame marking shall be 100 mcd or greater, the direction of peak
intensity pointing normally into the corridor. The spacing between the point sources shall be no greater
than 200 mm.
4.3.8 Escape route signs made of point sources can be used to outline the graphical symbol of the
escape route signs in accordance with Figure 1 of ISO 16069:2017, or with a modified geometry if on
the floor; see Figure 2 of ISO 16069:2017. The colour of the outlining point sources shall be green. The
height of the graphical symbols shall be in accordance with 6.5.2. The maximum spacing between the
point sources shall be 5 mm. The luminous intensity of every single point source used for the escape
route sign shall be ⩾ 100 mcd.
4.3.9 The power-supply arrangements to the EP system shall be arranged so that a single break in the
cabling does not result in the system becoming ineffective. This can be achieved by using at least two
battery power supplies in each single main vertical fire zone.
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ISO 15370:2021(E)

4.3.10 Entire systems, including those that are automatically activated, shall be capable of being
manually activated by a single action either from the continuously manned central control station or
from the safety centre.
4.3.11 EP systems shall meet the relevant requirements for emergency luminaires in accordance with
IEC 60598-2-22 when tested at a reference temperature of 40 °C.
4.3.12 EP systems shall meet the requirements for vibration and electromagnetic interference in
accordance with IEC 60945.
4.3.13 EP systems shall provide a minimum degree of ingress protection of at least IP 55 in accordance
with IEC 60529.
4.3.14 EP materials shall be flame-retardant in accordance with IEC 60092-101.
4.3.15 The luminance of the EP materials shall be tested in accordance with Annex E.
5 Technical product documentation
5.1 The technical product documentation for LLL systems shall comprise the following documents:
— installation plan, or plans, which should include the wiring layout and a general arrangement;
— list of items depicted in the legend on the installation plan;
— description of installation;
— material certificates;
— measurement reports of the installed system in accordance with Annex C;
— measurement record; and
— maintenance requirements.
5.2 Approval documentation for PL materials shall include test data showing the type and minimum
level of incident light that, when illuminated for 24 h, is required to charge the PL material to meet the
required luminance specified in 4.2 or to meet the requirements for narrower width specified in Annex D.
6 Installation on board
6.1 General
6.1.1 The LLL system shall be installed along the escape routes in accommodation spaces as described
in the approved escape plan for movement to leave individual zones to exits, assembly stations and/or
embarkation stations. Other accommodation spaces, unless forming part of the escape route described
by the approved escape plan, are not considered as part of the escape routes.
6.1.2 To enhance the effectiveness of the LLL system to guide people to any exit, the arrangement
shall be made such that people do not cross over LLL guidance lines. This applies particularly to door
thresholds or across stairway landings. In order to provide for a continuous and visible delineation of
the escape route along corridors, LLL guidance lines can be fitted on the deck at, or in way of, cabin door
thresholds.
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ISO 15370:2021(E)

6.1.3 LLL arrangements are normally fitted along escape routes as in 6.1.1. Risk assessment shall be
used to justify extension of the system for smaller isolated accommodation spaces normally occupied by
less than 4 persons, such as toilets, pantries, small offices arranged in provision or in galley areas, or in
similar working or occupied areas; see Figure G.1 for an example of such smaller isolated spaces. Small
lobbies such as the ones used to separate accommodation spaces from stairways, or public spaces from
open decks, or the ones between accommodation spaces are considered not to need LLL provisions; see
Figure G.3 for an example.
6.1.4 The arrangement of LLL systems shall be such that the fire boundary of divisions, i.e. of bulkheads
and decks, is not impaired.
6.1.5 LLL arrangements shall be fitted in accordance with the manufacturer's or installers specification.
When the LLL arrangement is installed on decks, it shall be arranged in such a way that the LLL guidance
lines are not directly on the main walk surface. Generally, LLL guidance lines should be installed on or
close to bulkheads or when necessary as flush with the walking surface as possible.
6.1.6 Combinations of PL and EP systems may be used throughout decks or stairway enclosures.
However, the two systems shall be separated, e.g. by normally closed doors or by doors that can be closed,
locally or remotely, in case of emergency; see Figure G.2 for an example. Signs made of PL materials are
used with both PL and EP systems as described in 6.5.
6.1.7 For each main vertical zone (MVZ) and water-tight zone (WTZ), only escape routes relevant to
accommodation spaces shall be marked by an LLL system; e.g. when two MVZ or WTZ are adjacent to
each other, but only one of the two contains accommodation spaces, the escape routes of the other zone
need not be marked by the LLL system even if they are part of the means of escap
...