ISO/PRF 24681

Ships and marine technology — Fibre-reinforced plastic gratings

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General Information

• Status: Not Published
• ICS: 47.020.50 - Deck equipment and installations
• Technical Committee: ISO/TC 8/SC 8 - Ship design
• Drafting Committee: ISO/TC 8/SC 8 - Ship design
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Completion Date: 13-Mar-2023

Standards Content (Sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 24681
ISO/TC 8/SC 8 Secretariat: KATS
Voting begins on: Voting terminates on:
2022-04-29 2022-07-22
Ships and marine technology — Fibre-reinforced plastic
gratings
ICS: 47.020.50
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
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 24681:2022(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 2022
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ISO/DIS 24681:2022(E)
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© ISO 2022

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© ISO 2022 – All rights reserved
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ISO/DIS 24681:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Classification ............................................................................................................................................................................................................ 2

4.1 Types ............................................................................................................................................................................................................... 2

4.1.1 Molded grating ..................................................................................................................................................................... 2

4.1.2 Pultruded grating .............................................................................................................................................................. 3

4.1.3 Other type gratings .......................................................................................................................................................... 3

5 Technical requirements ............................................................................................................................................................................... 3

5.1 Appearance ................................................................................................................................................................................................ 3

5.2 Load-bearing capacity ..................................................................................................................................................................... 4

5.3 Corrosion resistance ......................................................................................................................................................................... 4

5.4 Skid resistance ....................................................................................................................................................................................... 4

5.5 Flame spread characteristics .................................................................................................................................................... 4

5.6 Smoke and toxicity .............................................................................................................................................................................. 4

5.7 Anti-electrostatic property ......................................................................................................................................................... 4

5.8 Fire integrity ............................................................................................................................................................................................ 5

5.9 UV resistance ........................................................................................................................................................................................... 5

5.10 Asbestos-free requirement ........................................................................................................................................... ............... 5

6 Inspection and test methods ...................................................................................................................................................................5

6.1 Appearance ................................................................................................................................................................................................ 5

6.2 Load-bearing capacity test .......................................................................................................................................................... 5

6.3 Corrosion resistance ......................................................................................................................................................................... 5

6.4 Skid resistance ....................................................................................................................................................................................... 5

6.5 Flame spread characteristics .................................................................................................................................................... 6

6.6 Smoke and toxicity .............................................................................................................................................................................. 6

6.7 Anti-electrostatic property ......................................................................................................................................................... 6

6.8 Fire integrity ............................................................................................................................................................................................ 6

6.9 UV resistance ........................................................................................................................................................................................... 6

7 Marking, packing and transportation .......................................................................................................................................... 6

7.1 Marking ......................................................................................................................................................................................................... 6

7.2 Packing .......................................................................................................................................................................................................... 6

7.3 Transportation ....................................................................................................................................................................................... 6

Annex A (normative) Load-bearing capacity test (Three point bending method) .............................................7

Annex B (normative) FRP grating fire integrity test .......................................................................................................................10

Annex C (informative) FRP grating application guideline.........................................................................................................12

Bibliography .............................................................................................................................................................................................................................14

iii
© ISO 2022 – All rights reserved
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ISO/DIS 24681:2022(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 8, Ship design.

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.
© ISO 2022 – All rights reserved
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DRAFT INTERNATIONAL STANDARD ISO/DIS 24681:2022(E)
Ships and marine technology — Fibre-reinforced plastic
gratings
1 Scope

This document specifies the terms and definitions, structure, technical requirements and test methods

of gratings for fiber reinforced plastics (FRP) in the marine.

This document is applicable to the design, manufacture and inspection of self-support FRP gratings

used for pedestrian pathways and platforms on ships or offshore platforms.
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 834-1:1999, Fire-resistance tests — Elements of building construction — Part 1: General requirements

ISO 4892-3:2013, Plastics – Methods of exposure to laboratory light sources – Part 3: Fluorescent UV lamps

ISO 9227:2017, Corrosion tests in artificial atmospheres — Salt spray tests

ISO 14125:1998, Fibre-reinforced plastic composites — Determination of flexural properties

IEC 61892-7:2007, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas

IMO International Code for Application of Fire Test Procedures, 2010(FTP Code)
IMO International convention for the safety of life at sea, 1974(SOLAS)

ASTM D2047, Test method for static coefficient of friction of polish-coated flooring surfaces as measured by

the James machine.

ASTM E84, Standard test method for surface burning characteristics of building materials

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 https:// www .electropedia .org/
3.1
FRP

fiber reinforced plastic, a composite material made of resin reinforced with fiber.

Note 1 to entry: Glass fibers are widely used as reinforced fiber.
3.2
skid resistance

property of the trafficked surface which limits the relative movement between the contact patch of

pedestrian footwear or a vehicle tyre and the surface
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ISO/DIS 24681:2022(E)
4 Classification
4.1 Types

FRP grating is a kind of composite panel material with a certain aperture ratio, which is based on

thermosetting resin and reinforced with fiberglass roving, and is processed by special technology. The

raw materials shall meet recognized standards and be specified in the technical specification, so as to

ensure its continuous and stable performance.

FRP gratings are generally divided into two types, molded or pultruded FRP gratings. For typical

examples, see Figure 1 and Figure 2.
Figure 1 — Molded grating
Figure 2 — Pultruded grating
4.1.1 Molded grating

Molded FRP gratings are produced by the open mold process in which thermosetting resin and dry

glass fiber are placed in the mold in cross directions. After filling the mold with the designated amount

of material, the resin is allowed to cure in the open mold. Molded grating is usually manufactured

in square mesh or rectangular mesh configurations. Square mesh molded grating has nearly equal

strength in longitudinal and transverse directions. Rectangular mesh has better strength along

longitudinal direction. For the common mesh configuration, see Table 1.
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ISO/DIS 24681:2022(E)
Table 1 — Common molded FRP grating configuration.
Dimensions in millimetres
Mesh size Height Web thickness
Bottom thickness / top thickness
25,4×25,4 50 6/8
38,1×38,1 25 5/6,35
38,1×38,1 30 5/6,6
38,1×38,1 38 5/7
38,1×38,1 50 5,8/8,5
38,1×38,1 50 9/11,5
38,1×38,1 63 5,8/9
38,1×38,1 63 9/12
50,7×50,7 50 5/8,3
25,4×50,8 50 9/11,5
25,4×152,4 38 5/7
38,1×101,6 38 5/7
38,1×152,4 50 7/9

NOTE Molded FRP gratings are in general with inverted trapezoidal web section. The bottom thickness is smallest

decided by the mold, and top thickness would be larger depending on the height .
4.1.2 Pultruded grating

Pultruded grating consists of longitudinal bearing bars secured in position by transverse bars. The

reinforced fiber is impregnated by thermosetting resin and pultruded to make shaped bearing bar

under compression and heat. The bearing bar profile is generally “I” or “T” shaped. The product has

high strength along bearing bars direction and is suitable for large span use. Common specifications

are shown in Table 2 below:
Table 2 — Common Pultruded FRP grating configuration
Dimensions in millimetres
Bering bar Width Space Height
I 15 10/15/23 25/30/38
T 25,4 12,7/25,4 50,8
NOTE The common transverse securing bar is arranged in 152,4 mm interval.
4.1.3 Other type gratings

Other type gratings of occupied areas for workers or machinery must be confirmed by authorities.

5 Technical requirements
5.1 Appearance

5.1.1 FRP grating shall be smooth and flat, no obvious stratification, burr, crack, fiber exposure and

impurities.

5.1.2 No pores larger than 3 mm in diameter are allowed. The number of pores between 1 mm and

3 mm in any 300 mm × 300 mm area shall not exceed 10.
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ISO/DIS 24681:2022(E)

5.1.3 The warpage shall be not more than 2,5 mm/m along bearing bar direction and not more than

5 mm/m in other directions.
5.2 Load-bearing capacity
5.2.1 The flexural strength of FRP grating panel shall be not less than 345 MPa.

5.2.2 No crack, stratification or other destructive damage shall be observed when the FRP grating is

subject to 1,5 times design load.

5.2.3 The design load of FRP grating used in pedestrian pathways and platform of ship shall be 4 kN/

m uniform load or equivalent. The design load may be other specified if they are dedicated for certain

load condition. The grating deflection in the middle point of span shall not be greater than 1/120 of the

span under design load, and the maximum deflection shall not exceed 9 mm.

5.2.4 For FRP grating used as steps of stair ladders, 2 kN concentrated load applied at the middle of

step shall also be considered. The deflection of the middle point of the tread shall not be greater than

1/200 of its span, and the maximum deflection shall not exceed 6 mm.
5.3 Corrosion resistance

FRP grating should have good corrosion resistance. Gratings used for exposed area or ballast tanks

shall be designed with good resistance to sea water and high salt fog conditions. After the salt spray

test, the load-bearing capacity shall meet the requirements of 5.2.1 above.
5.4 Skid resistance
FRP gratings should have good skid resistance. T
...