ISO 24061:2021

INTERNATIONAL ISO
STANDARD 24061
First edition
Ships and marine technology — High
holding power balance anchors
PROOF/ÉPREUVE
Reference number
ISO 24061:2021(E)
©
ISO 2021

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ISO 24061:2021(E)

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© ISO 2021
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Published in Switzerland
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ISO 24061:2021(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Design . 1
4.1 Structure . 1
4.2 Basic specifications and dimensions . 1
4.3 Material . 2
5 Production . 2
5.1 Visual appearance . 2
5.2 Dimensional tolerance and geometrical tolerance . 3
5.3 Welding and welding repair . 4
5.4 Heat treatment . 4
5.5 Non-destructive test . 4
5.6 Painting . 4
5.7 Mass . 5
5.8 Balance . 5
6 Test methods . 5
6.1 Drop test . 5
6.2 Proof test . 6
6.3 Holding power test . 7
7 Marking . 7
8 Certificate . 7
Annex A (informative) Anchor structure and dimensions . 8
Annex B (normative) Anchor proof test method .11
Annex C (normative) Anchor holding power test method at sea .13
Bibliography .16
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ISO 24061:2021(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
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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
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Attention is drawn to the possibility that some of the elements of this document may be the subject of
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 4, Outfitting and deck machinery.
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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INTERNATIONAL STANDARD ISO 24061:2021(E)
Ships and marine technology — High holding power
balance anchors
1 Scope
This document specifies the design and production requirements, test methods, marking and inspection
certificate for high holding power balance anchors (hereinafter referred to as anchors).
It is applicable to the design, selection, production and acceptance of high holding power balance
anchors.
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 3828, Shipbuilding and marine structures — Deck machinery — Vocabulary and symbols
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3828 and the following 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
high holding power balance anchor
HHBP anchor
anchor with a rotatory fluke that can be restored back to upright position by gravity once the anchor
is hoisted from the sea bed, and with a holding power of at least twice that of an ordinary stockless
anchor of the same mass
4 Design
4.1 Structure
An anchor is generally composed of a shank, a fluke, a head pin, a lateral pin, a shackle and an anchor
shackle. The typical structure is shown in Annex A.
4.2 Basic specifications and dimensions
Anchors shall be designed as per the quantity required by outfitting. They shall be classified into
different specifications based on the anchor theoretical mass. The corresponding basic dimensions are
shown in Table A.1.
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ISO 24061:2021(E)

4.3 Material
4.3.1 The chemical composition of the anchor components shall be as specified in Table 1.
Table 1 — Chemical composition of anchor components
Values in percent (%)
a)
Chemical element content
b)
Component Residual element
c)
C Si Mn S P
Ni Cr Cu Mo total
shackle body, 1,10 to
0,29 0,35 0,035 0,035 - - - - -
shank 1,60
0,50 to
shank, fluke 0,23 0,60 0,04 0,04 0,40 0,30 0,30 0,15 0,80
1,60
head pin, lateral 0,30 to
0,23 0,45 0,035 0,035 0,25 0,25 0,25 0,15 0,80
pin, shackle pin 1,50
a)
All figures are maximum values, in %, except the ranges.
b)
Unless required by the purchaser, the residual elements do not need to be analyzed.
c)
0,04 % Mn may be added to the upper limit for each 0,01 % carbon reduction .
4.3.2 The mechanical properties of anchor components shall be as specified in Table 2.
Table 2 — Mechanical properties of anchor components
a)
Mechanical property
Percentage of
Extension
Tensile strength Yield strength breaking area Impact energy
Component
percentage
reduction
2 2
N/mm N/mm J
%
%
shackle body
490 295 22 - 27
shank
shank, fluke,
450 230 22 35 25
shank
head pin, lateral
410 245 25 35 27
pin, shackle pin
a)
All figures are minimum values.
4.3.3 The surface and the inside of cast and forged components of anchors should be free from cracks,
airholes, cratering, cold shuts, scabs and any other defects that may affect the strength.
4.3.4 A Charpy V-notch impact test below 0 °C should be carried out regarding ice zone navigation
requirements. The impact absorbing energy should not be less than 27 J.
4.3.5 The welding material used during the fabrication of the anchor should be compatible with the
parent material.
5 Production
5.1 Visual appearance
Anchor rotary parts should be ground to Ra 25 μm and be able to flexibly rotate around the centre of
gravity. The surface roughness of non-processed parts should be not more than Ra 100 μm.
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ISO 24061:2021(E)

5.2 Dimensional tolerance and geometrical tolerance
5.2.1 The permissible dimensional tolerance on each component of the anchor should be ±4 %, and its
maximum value shall not exceed ±20 mm.
5.2.2 The permissible tolerance between the swing angles of the anchor flukes should be ±1°
respectively.
5.2.3 The straightness deviation of the anchor shank should not be more than 3 mm for a length within
1 m.
5.2.4 The anchor assembling tolerances should meet the following provisions.
a) Any side clearance between the shackle and the shank should be as specified in Table 3.
Table 3 — Clearance between shackle and shank
Nominal mass of the anchor Clearance value
t mm
≤ 3 ≤ 3
>3 to ≤5 ≤ 4
>5 to ≤7 ≤ 6
> 7 ≤ 12
b) When the diameter of the shackle pin is less than or equal to 57 mm, the diameter difference
between the shackle pin and the shackle pin hole shall not be more than 0,5 mm. When the diameter
of the shackle pin is more than 57 mm, the diameter difference between the shackle pin and the
shackle pin hole should not be more than 1,0 mm.
c) The clearance difference between the pin, the shackle pin and the anchor shank hole should not be
more than 1,0 mm.
d) The length of the head pin shall be able to prevent the longitudinal movement of the anchor. Its
clearance shall be no more than 1 % of the pin slot length.
e) The lateral inclination of the anchor shank shall not exceed 3°. See Figure 1.
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ISO 24061:2021(E)

Figure 1 — Lateral inclination of the anchor
5.3 Welding and welding repair
Allowable defects should be repaired only after being evaluated through a qualified technical process.
Stress relieving should be implemented.
5.4 Heat treatment
The anchor shank, fluke and shackle should be treated with a normalizing and tempering process, with
a tempering temperature of not less than 600 °C.
5.5 Non-destructive test
The surface of cast and forged parts after machining shall be subject to a non-destructive test (NDT).
The test for anchor cast components should be conducted in accordance with IACS REC. 69; the test for
anchor forged parts should be conducted in accordance with IACS REC. 68.
5.6 Painting
Anchors should be painted with 2 coats, of asphalt and black paint; other paints can be used if mutually
agreed.
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ISO 24061:2021(E)

5.7 Mass
The permissible deviation of the weighted mass relative to the nominal mass should be within 7 % to
-3 %.
5.8 Balance
The fluke should be able to be restored back to its upright position automatically when the anchor is
fully hanged. The alignment of the two fluke bills should not exceed any lateral plane of the anchor
shank.
6 Test methods
6.1 Drop test
Anchors should be subject to a drop inspection, where the anchor is dropped from a height of 4,0 m; the
anchor should be free from crack defects. The detailed procedures are as follows.
a) Being hung horizontally and vertically (head-down) respectively (see Figure 2), the shank and
anchor fluke are dropped from a height of 4,0 m onto a steel lining (with a thickness of not less than
50 mm) fixed onto a solid foundation.
b) After the drop inspection, the anchor flukes and shank should be lifted off the ground with a non-
metal rope and subject to a hammering test with a hammer weighing 3 kg to 7 kg.
c) Check whether the sound is clear or not. If there is a
...